UC-NRLF 


THE  PROPERTY  OF 


yovw 


vvi 

\ 
«  \ 


MEDICAL 


t<tt<. 


>. 

L 


I  >  <  1     Jfr:  > 

€ 


\ 


HUMAN 


PHYSIOLOGY 


BY 


ROBLEY  DJJNGLISON,  M.  D., 

PROFESSOR  OF   THE  INSTITUTES  OF  MEDICINE  IN  JEFFERSON  MEDICAL  COLLEGE,  PHILADELPHIA: 

VICE-PRESIDENT  OF  THE  SYDENHAM  SOCIETY  OF  LONDON; 
SECRETARY  TO  THE  AMERICAN  PHILOSOPHICAL  SOCIETY,  ETC.  ETC. 


;  Vastissimi  studii  primas  quasi  lineas  circumscripsi."— HALLER. 


WITH 


NEARLY  FIVE   HUNDRED  ILLUSTRATIONS. 


SEVENTH  EDITION, 

THOROUGHLY  REVISED,  AND  EXTENSIVELY  MODIFIED  AND  ENLARGED. 

IN    TWO    VOLUMES. 

VOL.  I. 


PHILADELPHIA: 
LEA    AND    BLANCHARD 

1850. 


Entered  according  to  the  Act  of  Congress,  in  the  year  1841, 

By  ROB  LET  DuifGLisoK, 
In  the  Clerk's  Office  of  the  District  Court  for  the  Eastern  District  of  Pennsylvania. 


T.  K.  AND  P.  G.  COLLINS,  PRINTERS. 


V3I 

Y-l 

1850- 


JDebkati0tt  ta  tlje  ,f  irst  arib  Qetorib  (£bition0. 


TO 
JAMES    MADISON, 

EX-PRESIDENT  OF  THE  UNITED  STATES,  ETC.,  ETC., 

ALIKE   DISTINGUISHED   AS   AN   ILLUSTRIOUS   BENEFACTOR   OF   HIS   COUNTRY, 

A  ZEALOUS  PROMOTER  OF  SCIENCE  AND  LITERATURE, 

AND  THE  FRIEND  OF  MANKIND, 

SI)  10  iDork, 

INTENDED  TO  ILLUSTRATE  THE  FUNCTIONS  EXECUTED  BY  THAT  BEING, 
WHOSE    MORAL   AND   POLITICAL    CONDITION    HAS  BEEN   WITH   HIM   AN    OBJECT   OF 

ARDENT  AND  SUCCESSFUL  STUDY, 
IS,    WITH  HIS  PERMISSION,   INSCRIBED, 

IN  TESTIMONY  OP  UNFEIGNED  RESPECT  FOR  HIS  TALENTS  AND  PHILANTHROPY, 

AND  OF  GRATITUDE  FOR  NUMEROUS  EVIDENCES  OF  FRIENDSHIP, 

BY  HIS   OBEDIENT  AND  OBLIGED  SERVANT, 

THE    AUTHOR. 


13488 


DIRECTION  TO  THE  BINDER. 

THE  Plates  of  the  System  of  Respiratory  Nerves,  and  of  the  Regular  or  Symmetrical 
Nerves  between  pages  88  and  89. 


PREFACE  TO  THE  SEVENTH  EDITION. 


ON  no  previous  revision  of  this  work  has  the  author  bestowed  more 
care  than  on  the  present.  In  the  successive  editions,  it  was,  of  course, 
necessary  to  incorporate  the  different  facts  and  principles,  which  had 
been  added  from  time  to  time,  to  the  science ;  and  this  rendered  it 
difficult  to  preserve  throughout  the  evenness  of  style,  which  is  so  desir- 
able in  every  treatise,  and  more  especially  in  one  that  is  placed  in  the 
hands  of  so  many  of  the  younger  portion  of  scientific  inquirers.  To 
accomplish  this  object,  the  present  edition  has  been  subjected  to  an 
entire  scrutiny,  not  only  as  regards  the  important  matters  of  which  it 
treats,  but  the  language  in  which  they  are  conveyed. 

Perhaps,  at  no  time  in  the  history  of  the  science  have  observers 
been  more  numerous,  energetic,  and  discriminating  than  in  the  last 
few  years.  Many  modifications  of  fact  and  inference  have  consequently 
taken  place,  which  it  has  been  necessary  for  the  author  to  record,  and 
to  express  his  views  in  relation  thereto.  Especially  has  he  endeavoured 
to  note  the  phenomena  that  have  presented  themselves  to  the  most 
accurate  observers,  and  to  deduce  from  them  laws  which  may  tend  to 
enlarge  the  boundaries  of  the  science  :  he  has  not,  however,  felt  himself 
at  liberty  to  discard  the  results  of  the  observations  of  all  former  anthro- 
pologists, or  the  opinions  they  had  embraced  in  regard  to  the  various 
functions.  It  not  unfrequently,  indeed,  happens,  that  in  ignorance  of 
the  history  of  the  science,  views  are  esteemed  new,  which  had  been  pro- 
mulged  by  earlier  investigators.  He  has,  therefore,  in  an  encyclopsediac 
work  like  the  present,  retained  many  of  those  opinions,  whilst  he  has 
laboured  to  do  especial  justice  to  such  as  have  emanated  from  more 
recent  inquirers.  In  this  respect,  his  work  differs  from  valuable  phy- 
siological treatises  that  are  before  the  public.  Whilst,  too,  he  has 
inserted  the  main  results  of  the  labours  of  recent  histologists,  espe- 
cially such  as  are  directly  applicable  to  physiology,  he  has  not  considered 
it  advisable  to  pursue  the  subject  to  such  an  extent  as  if  the  work  were 
on  general  anatomy,  to  which  histology  properly  belongs. 


VI  4  PREFACE. 

On  the  whole  subject  of  physiology  proper,  as  it  applies  to  the  func- 
tions executed  by  the  different  organs,  the  present  edition,  the  author 
natters  himself,  will  be  found  to  contain  the  views  of  the  most  distin- 
guished physiologists  of  all  periods.  The  contributions  to  the  science 
of  life  have,  of  late  years,  been  rich  and  varied  ;  and  to  collate  and 
weigh  them,  and  to  separate  the  most  trustworthy  and  valued,  has  been 
a  work  of  no  little  discriminating  labour, — but  to  the  author  a  labour 
of  Jove,  inasmuch  as  they  are  subjects  which  he  has  been  long  accus- 
tomed to  investigate  :  and  on  which  he  has  annually  to  treat  before  the 
class  of  Institutes  of  Medicine  of  the  Jefferson  Medical  College.  The 
Bibliography,  prefixed  to  the  first  volume,  will  exhibit  the  number 
and  variety  of  sources  of  information  at  home  and  abroad,  which  he 
has  had  to  consult,  and  will  afford  a  coup  d'oeil  of  the  chief  biological 
investigations,  undertaken  since  the  appearance  of  the  last  edition  more 
especially,  which  have  so  changed  the  face  of  the  science  in  regard  to 
certain  subjects  as  to  require  that  they  should  be  re-written. 

The  rich  collection  of  materials  in  the  possession  of  his  publishers 
has  enabled  him  to  increase  greatly  the  list  of  illustrations,  and  to 
substitute  in  'many  cases  better;  whilst  new  cuts  have  been  added  so 
as  to  make  the  whole  number  four  hundred  and  seventy-four,  in  place 
of  three  hundred  and  sixty-eight,  as  in  the  last  edition.  It  has  been 
difficult  in  all  cases  to  assign  these  to  the  original  projectors ;  but  an 
effort  has  been  made  so  to  do. 

On  no  former  occasion  has  the  author  felt  as  satisfied  with  his  endea- 
vours to  have  the  work  on  a  level  with  the  existing  state  of  the  science  ; 
and,  for  the  seventh  time,  he  ventures  to  place  it  before  a  profession, 
which  has  already  done  too  much  honor  to  his  efforts  to  be  useful. 
His  crowning  desire,  in  all  his  literary  undertakings,  has  been  to  faci- 
litate the  onward  course  of  those  who  are  pressing  forward  to  distinction 
in  a  truly  learned  and  difficult  profession,  and  the  reception  these  un- 
dertakings have  met  with  has  satisfied  him,  that  his  labours  have  been 
far  from  fruitless. 

EOBLEY  DUNGLISON. 

18  GIBARD  STREET, 

August,  1850. 


AUTHORS  REFERRED  TO  IN  THE  PREPARATION  OF  THIS 

EDITION. 


Abercrombie,  J.,  Pathological  and  Practical  Researches  on  Diseases  of  the  Brain 
and  the  Spinal  Cord,  Amer.  edit.,  Philada.,  1843. 

Agassiz,  L.,  Geographical  Distribution  of  Animals,  in  Christian  Examiner,  March, 
1850. 

Lake  Superior ;  its  Physical  Characters,  Vegetation,  and  Animals,  com- 
pared with  those  of  other  and  similar  regions,  Boston,  1850. 

The  Diversity  of  Origin  of  the  Human  Races,  in  Christian  Examiner, 

July,  1850. 

Agassiz  &  Gould,  Principles  of  Zoology,  &c.,  pt.  i.,  Comparative  Physiology,  Bos- 
ton, 1848. 

Albert,  On  the  Colour  of  the  Vagina  in  Pregnancy,  cited  in  British  and  Foreign 
Medico-Chirurg'ical  Review,  July,  1848. 

Amringe.  (See  Van  Amringe.) 

Ashwell,  S.,  A  Practical  Treatise  on  the  Diseases  peculiar  to  Women,  third  edit. 
Lond.,  1848. 

Baly,  W.,  On  the  Glands  of  Peyer,  in  London  Medical  Gazette  for  March,  1847. 
and  Kirkes,  William  Senhouse,  Recent  Advances  in  the  Physiology  of 

Motion,  the  Senses,  Generation,  and  Development,  London,  1848. 
Barrow,  Sir  John,  An  Autobiographical  Memoir,  Lond.,  1847. 
Barry,  W.  J.,  Case  of  Doubtful  Sex,  in  New  York  Journal  of  Medicine,  January, 

1847. 

Beck,  Mr.,  Nerves  of  the  Uterus,  in  Philosophical  Transactions,  pt.  ii.  for  1846. 
Be"clard,  M.,  Blood  of  the  Portal  Vein,  in  Annales  de  Chimie  et  de  Physique, 

Paris,  1847. 
Bendz,  Haandbog  i  den  Almindenige  Anatomic,   Kiobenhavn,   1847,  cited  by 

Kirkes  &  Paget. 
Berard,  P.,  On  Gelatin  as  a  Nutriment;  Archives  Generates  de  MMecine,  Fevrier, 

1850. 
Cours  de  Physiologic  fait  a  la  Faculte"  de  MMecine  de  Paris,  Paris, 

1848-9. 

P.  H.,  Art.  Olfaction,  Dictionnaire  de  Medecine,  2de  e"dit.,  Paris,  1840. 


Bernard,  C.,  On  the  Communication  of  Veins  and  Lymphatics,  in  Union  Medicale, 
No.  116,  and  Brit,  and  For.  Medico-Chir.  Rev.,  Jan.,  1850. 

On  the  Formation  of  Sugar  by  the  Liver,  in  Archives  Generates  de 

Medecine,  Nov.,  1848. 

On  Insalivation  of  Food,  in  Archives  Gene'rales  de  Medecine,  4e  s6rie, 


torn.  xiii. 

—  Action  of  Pancreatic  Fluid  on  Oil,  in  Archives  Ge~nerales  de  Medecine, 
vol.  xix.  p.  60. 

On  the  Pancreatic  Juice,  in  Archives  G6n&rales  de  M6decine,  vol.  xiv., 


and  in  Provincial  Med.  and  Surgical  Journal,  March,  1849,  and  in  Gazette  Me"- 
dicale,  No.  9,  Paris,  1849. 

,  On  the  Transformation  of  Starch  into  Sugar,  in  Canstatt  und  Eisen- 

niann's  Jahresbericht  uber  die  Fortschritte  in  der  Biologic  im  Jahre  1847. 


Vlll  AUTHORS  REFERRED  TO. 

Berthold,  Cause  of  Parturition,  Comptes  Rendus,  Paris,  1844 ;  and  Archives  G6n. 
de  Medecine,  Juin,  1844. 

,  A.  A.,  Lehrbuch  der  Physiologie,  3te  Auflage,  Getting.,  1848. 

Bertholet,  P.  G.,  Weight  of  Twins,  Medical  Examiner,  Aug.,  1848. 

Bidder,  Prof.  F.,  Versuche  zur  Bestimmung  der  Chylusmenge,  in  Muller's  Archiv. 
fur  Anatomie,  Jahrgang  1845. 

,  Art.  Schmecken,  in  "Wagner's  Handwbrterbuch  der  Physiologie,  13te 

Lieferung,  Braunschweig,  1846. 

Bischoff,  T.  L.  W.,  On  the  Amount  of  Chyle  Formed,  in  Muller's  Archiv.,  Jahr- 
gang 1846. 

,  Art.  Entwickelungsgeschichte  mitbesondererBeriicksichtigung 

der  Missbildungen,  in  Wagner's  Handwb'rterbuch  der  Physiologie,  6te  Lieferung, 
Braunschweig,  1843. 

-,  Theorie  der  Befruchtung  und  tiber  die  Rolle  welchedie  Sper- 


matozo'iden  dabei  spielen,  in  Muller's  Archiv.  der  Anatomie,  u.  s.  w.,  Jahrgang 
1847. 

-,  Ueber  die  Glandulae  Utriculares  des  Uterus  des  Menschen,  und 


Ihren  Antheil  an  der  Bildung  der  Decidua,  in  Muller's  Archiv.  fur  Anatomie, 
Jahrgang  1846. 

Bishop,  J.,  On  the  Voice,  in  Proceedings  of  the  Royal  Society,  No.  65,  1847. 

Blake,  J.,  On  the  Quantity  of  Blood  in  the  Body,  in  Medical  Examiner,  Aug.,  1849. 

,  Velocity  of  the  Circulation  in  Edinb.  Medical  and  Surgical  Journal,  Oct., 

1841 ;  St.  Louis  Medical  and  Surgical  Journal,  Nov.  and  Dec.,  1848 ;  and  Ameri- 
can Journal  of  Medical  Sciences,  July,  1849. 

Blondlot,  Essai  sur  les  Fonctions  du  Foie,  Paris,  1846. 

Bouchardat,  A.,  Annuaire  de  Therapeutique,  de  Matiere  Medicale,  de  Pharmacie 
et  de  Toxicologie,  pour  1848. 

Bouchut,  M.,  Signs  of  Death,  in  Abeille  Me"dicale,  No.  6,  Juin,  1848. 

Boudin,  M.,  Comparative  Pathology  of  the  Different  Races  of  Men,  in  Annales 
d'Hygiene,  vol.  xlii ;  and  in  British  and  Foreign  Medico-ChirurgicalReview,  Oct., 
1849. 

Bourgery,  M.,  On  the  Capillary  System  of  Vessels,  in  Comptes  Rendus,  1848,  and 
Gazette  Medicale,  No.  37,  1848. 

Boussingault,  Schlossberger,  and  Kemp,  On  the  Proportion  of  Nitrogen  in  Ali- 
ments, in  Annal.  der  Chemie  und  Pharmacie,  B.  Ivi ;  and  in  Philosophical  Maga- 
zine, Nov.,  1845. 

Bowman,  W.,  Art.  Pacinian  Bodies,  in  Todd's  Cyclopaedia  of  Anatomy  and  Phy- 
siology, Pt.  xxvi.  8vo.,  Lond.,  1846. 

Braid,  Mr.,  On  Nervous  Sleep,  Edinb.  Medical  and  Surgical  Journal,  Oct.  1846. 

Brillat-Savarin,  Physiologie  du  Gout,  Paris,  1843. 

Brinton,  Wm.,  Art.  Serous  and  Synovial  Membranes,  in  Todd's  Cyclopaedia  of 
Anatomy  and  Physiology,  Pt.  xxxiv.,  Lond.,  Jan.,  1849. 

Browne,  P.  A.,  The  Classification  of  Mankind  by  the  Hair  and  Wool  of  their  Heads, 
with  an  answer  to  Dr.  Prichard's  assertion,  "  that  the  covering  of  the  head  of 
the  Negro  is  hair  properly  so  termed,  and  not  wool/'  Philad.,  1850. 

Buckingham,  J.  S.,  Travels  in  France,  Piedmont,  &c.,Lond.,  1849. 

Budge,  J.,  Art.  Sympathischer  Nerv  mit  besonderer  Rucksicht  auf  die  Herzbewe- 
^ung,  in  Wagner's  Handwb'rterbuch,  u.  s.  w.  17te  Lieferung,  Braunschweig, 


Burrows,  G.  M.,  On  Disorders  of  the  Cerebral  Circulation,  Amer.  edit.,  Philad., 

1848. 

Cammann,  Dr.,  On  the  Capillaries  of  the  Lungs,  in  New  York  Journal  of  Medicine, 

Jan.,  1848. 
Campbell,  Lord,  The  Lives  of  the  Lord  Chancellors  and  Keepers  of  the  Great  Seal 

of  England,  Amer.  edit.,  Philad.,  1847. 
Carpenter,  W.  B.,  Principles  of  Human  Physiology,  with  their  chief  applications 

to  Pathology,  Hygiene  and  Forensic  Medicine,  4th  Amer.  edit.,  Philad.,  1850. 
,  Art.  Sensation,  in  Todd's  Cyclopaedia  of  Anatomy  and  Physiology,  Pt. 

xxxiv.,  Lond.,  Jan.,  1849. 

-,  Art.  Sleep,  in  Cyclopaedia  of  Anatomy  and  Physiology,  Pt.  xxxv.,  Mar., 


1849. 


AUTHORS  REFERRED  TO.  IX 

Carpenter,  Art.  Smell,  Cyclopaedia  of  Anatomy  and  Physiology,  Pt.  xxxvi.,  London, 

June,  1849. 

Carter,  R.,  Case  of  Superfcetation,  Medical  Examiner,  Sept.,  1849. 
Cazeaux,  M.,  Hydrosemia  in  Pregnancy,  in  Archives  Generates  de  Me"decine,  Mars, 

1850. 

— ,  Traite  Theorique  et  Pratique  de  PArt  des  Accouchements,  Paris,  1840. 
Chelius,  J.  M.,  System  of  Surgery,  translated  by  Mr.  South,  Amer.  edit.,  Philad., 

1847. 
Churchill,  F.,  On  the  Theory  and  Practice  of  Midwifery,  3d  Amer.  edit.,  by  Dr. 

Huston,  Philad.,  1848. 

Clendinning,  Dr.,  in  Medico-Chirurgical  Transactions,  vol.  xix. 
Clutterbuck,  H.,  Art.  Apoplexy,  in  Cyclopaedia  of  Practical  Medicine,  Amer.  edit., 

by  the  Author,  Philad.,  1844. 

Cooper,  B.  B.,  Life  of  Sir  Astley  Cooper,  Bart.,  8vo.,  London,  1843. 
Coste,  M.,  Histoire  G6nerale  et  Particuliere  du  De"veloppement  des  Corps  organises, 

publie"e  sous  les  Auspices  de  M.  Villemain,  Ministre  de  PInstruction  publique, 

Tom.  ler.,  ler  et  2de  Fascicule,  Paris,  1847—1849.  ^ 
Courtz,  M.,  Archives  d'Anatomie  Generale  et  de  Physiologie,  Sept.,  1846. 
Craigie,  D.,  on  Obliteration  of  the  Vena  Portae,  in  Edinb.  Medical  and  Surgical 

Journal,  April,  1850. 
Curling,  T.  B.,  Descent  of  the  Testicle,  in  Lancet,  April  10,  1841. 

,  Practical  Treatise  on  the  Diseases  of  the  Testis,  London,  1843. 

,  on  Spermatozoids  in  Hydrocele,  in  Edinb.  Monthly  Journal  of  Medi- 
cal Science,  May,  1843. 

-,  Art.  Testicle,  Cyclopaedia  of  Anatomy  and  Physiology,  Pt.  xxxviii., 


Feb.  7,  1850. 

Darwin,  Charles,  Journal  of  Researches  into  the  Natural  History  and  Geology  of 
the  countries  visited  during  the  voyage  of  H.  M.  S.  Beagle  round  the  World, 
Amer.  edit.,  New  York,  1846. 

De  Lamartine.     (See  Lamartine.) 

De  Serres,  Marcel,  On  the  Ethiopian  as  the  original  type  of  man,  in  L'Institut, 
13  F6vr.  1850. 

De  Strzelecki,  P.  E.,  Physical  Description  of  New  South  Wales  and  Van  Diemen's 
Land,  Lond.,  1845. 

Donn6,  A.,  Cours  de  Microscopie,  Paris,  1845. 

Dowler,  B.,  Contributions  to  Physiology,  No.  3,  Experiments,  &c.,  on  decapitated 
alligators,  New  Orleans,  1849,  from  New  Orleans  Journal  of  Medicine. 

Experimental  Researches  on  the  post  mortem  contractility  of  the 

Muscles,  with  observations  on  the  reflex  theory,  reprinted  from  New  York  Jour- 
nal of  Medicine,  May,  1846. 

Researches,  Clinical  and  Experimental,  on  the  Capillary  Circulation; 


reprinted  from  New  Orleans  Medical  and  Surgical  Journal,  Jan.,  1849. 

on  the  Heart's  Action,  in  Contributions  to  Physiology,  New  Orleans, 


1849. 
Draper,  J.  W.,  A  Text  Book  on  Chemistry,  New  York,  1846. 

on  the  Forces  which  produce  the  Organization  of  Plants. 

Dujardin,  M.,  on  Spermatozoids,  in  Annales  des  Sciences  Natur.,  Zoologie,  viii.  291, 

and  in  Manuel  de  1'Observateur  au  Microscope,  Paris,  1843. 

Ecker,  A.,  Art.  Blutgefassdrlisen  in  Wagner's  Handworterbuch  der  Physiologie, 
23te  Lieferung,  Braunschweig,  1849. 

,  On  the  Spleen,  in  Schmidt's  Jahrbucher,  u.  s.  w.,  No.  5,  Jahrgang 

1848. 

Emerson,  G.,  The  Effect  of  Depressing  Influences  on  the  Number  of  Male  Concep- 
tions, in  American  Journal  of  the  Medical  Sciences,  July,  1848. 

Erman,  A.,  Travels  in  Siberia,  translated  from  the  German  by  W.  D.  Cooley,  Lond., 
1848 ;  Philad.,  1850. 

Flint,  T.  M.,  Case  in  which  the  Stomach  had  Separated  from  the   (Esophagus, 

in  Medical  Examiner,  for  Decem.,  1848. 
Frerichs,  F.  F.,  Art.  Synovia,  in  Wagner's  Handworterbuch  der  Physiologie,  18te 

Lieferung,  Braunschweig,  1848. 


X  AUTHORS  REFEREED  TO. 

Frerichs,  F.  F.,  Art.  Thranensecretion,  in  Wagner's  Handworterbuch  der  Physio- 

logie,  19te  Lieferung,  Braunschweig,  1848. 
,  Art.  Verdauung,  in  Wagner's  Handworterbuch  der  Physiologic, 

19te  Lieferung,  Braunschweig,  1848. 
Frick,  Chas.,  On  the   Organic   Constituents  of  the  Blood,  in  American  Journal 

of  the  Medical  Sciences,  Jan.,  1848. 

Gerlach,  J.,  Handbuch  der  Allgemeinen  und  Speciellen  Gewebelehre  des  Mensch- 

lichen  Korpers,  Mainz.,  1849. 
,  On  the  Kidney,  in  Mliller's  Archiv.  flir  Anatomie  u.  s.  w.,  Jahrgane 

^848. 
Gibbs,  J.,  Wound  of  Abdomen,  in  American  Journal  of  the  Medical  Sciences,  Oct., 

1846. 

Girou  de  Buzareingues,  Precis  Elementaire  de  Physiologie  Agricole,  Paris,  1849. 
Goodsir,  J.,  Anatomical  and  Pathological  Observations,  Edinb.,  1845. 

,  Development  of  the  Teeth,  Edinb.  Med.  and  Surg.  Journal,  vol.  i. 

Gorup-Besanez.  (See  Von  Gorup-Besanez.) 

Gould,  A.  A.  (See  Agassiz  and  Gould.) 

Giinther,  A.  F.,  Lehrbuch  der  Physiologie  des  Menschen,  Leipz.,  1848. 

Gulliver.  (See  Hewson.) 

Guy,  W.  A.,  Art.  Pulse,  Cyclopaedia  of  Anatomy  and  Physiology,  Pt.  xxxi.,  Lond., 

May,  1848. 

Hamernjk,  Prager  Vierteljahrschrift,  1847,  cited  in  Schmidt's  Jahrblicher,  Jahr- 

gahg.  1848  and  1849,  and  in  Edinburgh  Monthly  Journal,  Jan.,  1849. 
Harless,  E.,  Experimente  zur  Lehre  von  der  Muskelirritabilitat,  Miiller's  Archiv., 

H.  ii.  Jahrgang  1847. 
Harris,  S.  H.,  Case  of  Doubtful  Sex,  in  American  Journal  of  the  Medical  Sciences, 

July,  1847. 
Harrison,  J.,  Coagulation  of  the  Blood,  in  New  Orleans  Medical  and  Surgical 

Journal,  July,  1847. 

Harvey,  A.,  On  Hybridity,  in  Monthly  Journal  of  the  Medical  Sciences,  Oct.,  1849. 
Hassall,  A.,  The  Microscopic  Anatomy  of  the  Human  Body  in  Health  and  Dis- 
ease, Pt.  xii.,  London,  1848. 
Helmholtz,  H.,  Ueber  die  Warmentwickelung  bei  der  Muskelaction,  in  Miiller's 

Archiv,  Jahrgang  1848. 

Henle,  J.,  Handbuch  der  rationellen  Pathologic,  Braunschweig,  1849 — 50. 
Hewson,  W.,  Works  of,  Sydenham  Society's  edition,  by  Gulliver,  London,  1846. 
Horlbeck,  E.,  Case  of  Superfoetation,  Charleston  Medical  Journal,  and  Review, 

Jan.,  1848. 

Hornor,  C.  W.,  Secretion  of  milk  in  a  male,  in  Medical  Examiner,  August,  1850. 
Horsford,  E.  N.,  On   the   Proportion  of  Nitrogen   in   Aliments,  in   Philosophical 

Magazine  for  Nov.,  1845. 
Humboldt,  Baron  von,  Ansichten   der  Natur,  or  Aspects  of  Nature,  translated  by 

Mrs.  Sabine,  Amer.  edit.,  Philad.,  1849. 
Hutchinson,  J.,  On  Respiration,   in  Medico-Chirurgical  Transactions,  vol.  xxix., 

Lond.,  1846. 
,  On  the  Spirometer,  in  Medico-Chirurgical  Review,  vol.  xxix.,  Lond., 

1846. 
Ilyrtl,  Jos.,  M.D.,  Lehrbuch  der  Anatomie  des  Menschen,  Prag.,  1846. 

Jackson,  J.  B.  S.,  A  Descriptive  Catalogue  of  the  Anatomical  Museum  of  the  Bos- 
ton Society  for  Medical  Improvement,  Boston,  1847. 

Jacubowitsch,  De  Saliva,  dissert,  inaugural.  Med.  Univers.  Dorpat.  cited  by  Scherer, 
in  Constatt  und  Eisenmaun's  Jahresbericht,  u.  s.  w.  im  Jahre  1848. 

Jobert,  M.,  Nerves  of  the  Uterus,  in  Comptes  Rendus,  Paris,  1841. 

Johnson,  Geo.,  Art.  Ren.,  Cyclopaedia  of  Anatomy  and  Physiology,  Pt.  xxxii.,  Lond., 
Aug.,  1848. 

Joly,  M.,  On  the  Nutritive  Contents  of  the  Ovum,  in  Comptes  Rendus,  No.  20, 
12  Nov.,  1848. 

Jones,  H.  B.,  On  the  Acidity  of  the  Urine,  in  Philosophical  Transactions  for  1849, 
Pt.  2. 


AUTHORS  REFERRED  TO.  XI 

Jones,  T.  W.,  The  Principles  and  Practice  of  Ophthalmic  Medicine  and  Surgery, 
American  edition,  edited  by  Isaac  Hays,  M.  D.,  12mo.,  Philad.,  1847. 

Kellie,  Dr.,  Circulation  in  the  Brain,  in  Medico-Chirurgical  Transactions,  Edin- 
burgh, vol.  i. 

Kemp.  (See  Boussingault.) 

Kesteven,  Mr.,  On  Ovulation  and  Menstruation,  Lond.  Med.  Gaz.,  Nov.,  1849. 
Kirby,  Wm.,  and  Spence,  Win.,  Introduction  to  Entomology,  Amer.  edit,  from  the 

sixth  London,  Philad.,  1846. 
Kirkes,  W.  S.,  and  Paget,  J.,  Manual  of  Physiology,  Amer.  edit.,  12mo.,  Philad., 

1849. 
Klencke,  Ph.  F.  H.,  Ueber  das  physiologische  und  pathologische  Leben  der  Mikro- 

pischen  Zellen,  Jena,  1844. 
Kolliker,  A.,  Mittheilungen  der  Zliricher  Natiirforschenden  Gesellschaft,  von  Jahre 

1847 ,  and  art.  Spleen,  Cyclop,  of  Anat.  and  Physiol.,  pts.  xxxvi.  and  xxxvii., 

June  and  Oct.,  1849. 
Koss,  M.,  On  the  Conversion  of  Amylaceous  and  Saccharine  Matters  into  Oil,  in 

London  Medical  Gazette  for  October,  1846. 
Krause,  Prof.,  Art.  Haut  in  Wagner's  Handworterbuch  der  Physiologic,  7te  Liefer- 

ung,  Braunschweig,  1844. 

Lamartine,  A.,  Histoire  des  Girondins,  Paris,  1847. 

Lassaigne,  M.,  On  the  Insalivation  of  Food,  in  Journal  de  Chiniie  Medicale,  Paris, 

1845. 

Lebert,  H.,  J?hysiologie  Pathologique,  Paris,  1845. 
Lebby,  R.,  Spleen  wanting,  in  Southern  Journal  of  Medicine  and  Pharmacy,  Sept., 

1846. 
Leconte,  J.,  Experiments  illustrating  the  seat  of  volition  in  the  Alligator,  in  New 

York  Journal  of  Medicine  for  Nov.,  1845. 

Lee,  Robt.,  Ganglia  of  the  Heart,  Philosophical  Transactions,  1849. 
,  Lectures  on  the  Theory  and  Practice  of  Midwifery,  Amer.  edit., 

Philad.,  1844. 
Lehmann,  On  the  Chlorohydric  Acid  of  the  Gastric  Juice,  in  Archiv.  der  Pharma- 

cie;  cited  in  British  and  Foreign  Medico-Chirurgical  Review  for  Jan.,  1849. 

,  Schmidt's  Jahrbiicher  der  Gesammten  Medicin,  No.  6,  Leipzig,  1846. 

Leidy,  Jos.,  On  the  Air-Ceils,  in  Amer.  edit,  of  Quain's  Human  Anatomy,  vol.  ii., 

Philad.,  1849. 
,  On  several  important  points  in  the  Anatomy  of  the  Human  Larynx, 

in  American  Journal  of  the  Medical  Sciences  for  July,  1846. 

,  Histology  of  the  Liver,  in  Amer.  Journal  of  the  Medical  Sciences,  Jan., 


1848. 

on  the  Sheaths  of  Muscles,  in  Proceedings  of  the  Academy  of  Natural 


Sciences  of  Philadelphia,  vol.  iv.,  Philad.,  1848. 
Leray,  M.,  Cause  of  Parturition,  cited  in  Lancet,  Jan.  15,  1848. 
Lewis,  Judge  Ellis,  Duration  of  Pregnancy,  Amer.  Journ.  of  the  Medical  Sciences, 

Oct.,  1846. 

Lewy,  on  the  Composition  of  the  Air,  in  Comptes  Rendus  for  1842. 
Liebig,  Justus,  Chemistry  and  Physics  in  relation  to  Physiology  and  Pathology, 

Lond.,  1846. 

,  Chemistry  of  Food,  Lond.,  1847. 

,  Researches  on  the  Motion  of  the  Juices  in  the  Animal  Body,  by  W. 

Gregory,  M.  D.,  Lond.,  1848. 
Litzmann,  Prof.,  Art.  Schwangerschaft,  Wagner's  Handworterbuch  der  Physiolo- 

gie,  13te  Lieferung,  Braunschweig,  1846. 

Longet,  F.  A.,  M.  D.,  Traite  de  Physiologic,  Tome  2,  Paris,  1850._ 
Ludwig,  G.,  Beitrage  zur  Kenntniss  des  Einflusses  der  Respirationsbewegungen- 

auf  den  Blutlauf  in  Aortensysteme,  in  Mliller's  Archiv.,  H.  iv.,  Jahrgang  1847. 

Macdonnell,  P.  L.,  on  Spermatozoids  in  Hydrocele,  in  British  American  Journal 

of  Medicine,  Montreal,  1849. 
M'llvain,  R.  H.,  Duration  of  Pregnancy,  in  Amer.  Journal  of  the  Medical  Sciences, 

July,  1848. 


Xll  AUTHORS  REFERRED  TO. 

Maclaurin,  Mr.,  on  the  Instinct  of  Bees,  Philosophical  Transactions,  vol.  ix. 
M'William,  J.  0.,  Report  of  the  Niger  Expedition,  in  Lond.  Med.  Gazette,  Jan.,  1847. 
Madden,  Dr.,  Effect  of  Narcotics  on  Nervous  Conduction,  in  British  and  Foreign 

Medico-Chirurgical  Review,  July,  1848. 
Magendie,  M.,  On  the  formation  of  Sugar  in  the  Economy,  in  Union  Medicale,  Nos. 

72,  75,  and  79;  and  in  Brit,  and  For.  Medico-Chirurg.  Rev.,  Oct.,  1849. 

,  On  the  Transformation  of  Starch  into  Sugar,  in  Comptes  Rendus,  1847. 

Marotte,  M.,  Case  of  Supernumerary  Mammae,  in  Archiv.  Generales  de  Medecine, 

Janvier,  1850. 
Mathews,  Mrs.,  A  Continuation  of  the  Memoirs  of  Charles  Mathews,  Comedian, 

Arner.  edit.  Philad.,  1839. 
Matteucci,  C.,  Lectures  on  the  Physical  Phenomena  of  Living  Beings  :  translated 

under  the  superintendence  of  Jonathan  Pereira,  M.D.,  Amer.  edit.  Philad.,  1848. 
Meckel,  H.,  On  the  Conversion  of  Sugar  by  Bile  into  Fatty  Matter  :  in  Henle  and 

Pfeufer's,  Zeitschrift  fur  rationelle  Medicin ;  and  in  British  and  Foreign  Med. 

Rev.,  July,  1846. 

Meigs,  C.  D.,  Cases  of  Double  Vagina,  in  Medical  Examiner,  Dec.,  1846. 
,  On  the  Corpus  Luteum,  in  Transactions  of  the  American  Philosophical  So- 
ciety, Philad.,  1847. 

,  Obstetrics,  the  Science  and  the  Art,  Philad.,  1849. 

Mendelssohn,  Der  Mechanismus  der  Respiration  und  Circulation,  Berlin,  1845, 

cited  by  Dr.  John  Reid. 
Metcalf,  J.  G.,  On  the  Weight  of  the  New  Born,  in  Amer.  Journal  of  the  Medical 

Sciences,  Oct.  1847. 

Michel,  Myddelton,  Early  Human  Ovum,  American  Journal  of  the  Ittedical  Sci- 
ences for  Oct.,  1847. 

Millon,  M.  E.,  in  Comptes  Rendus,  Paris,  1848. 
Mitchell,  T.  D.,  Case  of  Delivery  at  an  Advanced  Age,  in  Western  Lancet,  Nov., 

1846. 
,  On  the  Chyle  and  Lymph,  in  Archives  Generales  de  Medecine,  Fev., 

1850. 

Monro,  secundus,  Observations  on  the  Structure  and  Functions  of  the  Nervous  Sys- 
tem, Edinb.,  1783. 
Morren,  On  the  Composition  of  the  Air,  in  Annales  de  Chimie  et  de  Physique,  vol. 

xii.,  Paris,  1844. 
Morton,    S.  G.,    Catalogue  of  Skulls  of  Man  and  the   Inferior  Animals,  in   the 

Collection  of  Samuel  Geo.  Morton,  M.D.,  3d  edit.,  Philad.,  1849. 
,  Hybridity  in  Animals  and  Plants,  considered  in  reference  to 

the  question  of  the  Unity  of  the  Human  Species,  New  Haven,  1847. 
Miiller,  J.,  Principles  of  Physics   and  Meteorology,   first  American   edit.,  Phi- 

lada.,  1848. 
'Mulder,  G.  J.,  The  Chemistry  of  Vegetable  and  Animal  Physiology,  translated  by 

Dr.  P.  F.  H.  Fromberg,  with  Introduction  and  Notes  by  James  F.  W.  Johnson, 

&c.,  Edinb.  and  Lond.,  1849. 

Nasmyth,  A.,  On  the  Teeth,  in  Medico-Chirurgical  Transactions,  vol.  xxii. 
Researches  on  the  Development,  Structure,  &c.,  of  the  Teeth,  London, 

1849. 
Nasse,  H.,  Art  Lymph,  in  Wagner's  Handwb'rterbuch  der  Physiologie,  9te  Liefe- 

rung,  Braunschweig,  1845. 

Art  Thierishe  Warme,  Ibid.,  23te  Lieferung,  Braunschweig,  1849. 

Neill,  John,  Observations  on  the  Occipital  and  Superior  Maxillary  Bones  of  the 

African  Cranium,  in  4-mer.  Journal  of  the  Medical  Sciences,  Jan.,  1850. 
Norris,  W.,  Case  of  Satyriasis,  in  Transactions  of  the  Medical  Society  of  London, 

vol.  i.,  p.  176,  Lond.,  1810. 
Nott,  J.  C.,  On  the  Mulatto,  in  the  American  Journal  of  the  Medical  Sciences, 

July,  1843. 
Nuhn,  A.,  Ueber  die  Verbindung  der  Saugadern  mit  den  Venen,  in  Muller's  Archiv. 

fur  Anatomie,  s.  173,  Jahrgang,  1848. 

Oesterlen,  F.,  On  the  Absorption  of  Insoluble  Substances,'  in  Heller's  Archiv. 
Band  iv. ;  and  in  Lond.  Med.  Gaz.,  July,  1847. 


AUTHORS  REFERRED  TO.  Xlll 

Oesterlen,  F.,  Beitrage  zur  Physiologie  des  Gesunden  und  Kranken  Organismus, 
Jena,  1843. 

Ollivier,  P.,  Art  Ut6rus  (Anatomie),  Dictionnaire  de  Me"decine,  vol.  xxx.,  Paris, 
1846. 

Owen,  R.,  Lectures  on  the  Comparative  Anatomy  and  Physiology  of  the  Inverte- 
brate Animals,  Lond.,  1843. 

— ,  Lectures  on  the  Comparative  Anatomy  and  Physiology  of  the 
Vertebrate  Animals,  Lond.,  1846. 

Paget,  J.    (See  Kirkes  and  Paget.) 


Re 


sport  on  the  Progress  of  Human  Anatomy  and  Physiology,  in  1844-5, 
in  British  and  Foreign  Medical  Review,  July,  1846. 

Parrish,  Isaac,  On  the  effects  of  Confinement  in  Prisons,  and  on  the  health  of  their 
inmates,  in  Transactions  of  the  American  Medical  Association,  vol.  ii.,  Philad., 
1849. 

Pennock,  C.  W.,  On  the  Pulse  of  the  Aged,  in  American  Journal  of  the  Medical 
Sciences,  July,  1847. 

Pepys,  Saml.,  Diary  and  Correspondence  of  Samuel  Pepys,  F.  R.  S.,  by  Lord  Bray- 
brooke,  3d  edit.,  Lond.,  1848. 

Pickering,  Charles,  United  States  Exploring  Expedition,  during  the  years  1838, 
1839,  1840,  1841,  1842,  under  the  command  of  Charles  Wilkes,  U.  S.  N.,  Vol. 
IX.  The  Races  of  Man  and  their  Geographical  Distribution,  Boston  and  Lon- 
don, 1848. 

Plateau,  M.,  Annales  de  Chimie,  vol.  Iviii. 

Porta,  J.  B.,  Magise  Naturalis  libri  viginti,  Lugd.  Bat.,  1644. 

Prichard,  J.  C.,  Natural  History  of  Man,  London,  1843. 

Pouchet,  F.  A.,  Theorie  positive  de  1'Ovulation  spontanee  et  de  la  FScondation, 
Paris,  1847. 

Purkinje,  J.,  Mailer's  Archiv.  fur  Anatomie,  u.  s.  w.,  Berlin,  1845. 
/ 

Quain,  J.,  M.  D.,  Human  Anatomy,  edited  by  R.  Quain  and  W.  Sharpey,  M.  D., 
Amer.  edit,  by  J.  Leidy,  M.  D.,  Philad.,  1849. 

Quetelet,  M.  A.  A.,  Treatise  on  Man,  and  the  Developement  of  his  Faculties,  trans- 
lated by  R.  Knox,  M.  D.,  Edinb.,  1842. 

Raikem,  M.,  Obliteration  of  the  Vena  Portse,  in  Me"moires  de  1'Acad.  Royale  de 
Medecine  de  Belgique,  torn,  i.,  Bruxelles,  1848. 

Rainey,  Mr.,  On  the  Bronchia  in  Medico-Chirurgical  Transactions,  vol.  xxviii.,  Lon- 
don, 1845. 

On  the  Sudoriparous  Glands,  in  Proceedings  of  the  Royal  Medical  and 

Chirurgical  Society,  June,  1849,  and  Lond.  Med.  Gazette,  July,  1849. 

On  the  Synovial  Membrane,  in  Proceedings  of  the  Royal  Society  of 


London,  No.  65,  1847. 
Rawitz,  Ueber  die  Einfachen  Nahrungsmittel,  Breslau,  1846,  cited  by  Kirkes  and 

•Paget. 
Rees,  G.  0.,  Art.  Sweat,  in  Cyclopaedia  of  Anat.and  Physiology,  pt.  xxxvii.,  Lond., 

Oct.,  1849. 

—  Theory  of  Respiration,  in  Proceedings  of  the  Royal  Society  of  London, 

June,  1847 ;  and  in'  Lond.,  Edinb.  and  Dublin  Philosophical  Magazine,  July, 

1848. 
Regnault  and  Reiset,  On  the  Changes  of  the  Air  in  Respiration,  in  Comptes  Rendus, 

Paris,  1848. 

Reichenbach.  (See  Von  Reichenbach.) 
Reichert,  Prof.,  On  the  Intestinal  Mucous  Membrane  during  digestion,  in  M  tiller's 

Archiv.  fur  Anatomie,  u.  s.  w.,  Jahrgang  1844. 
Reid,  John,  London  and  Edinburgh  Monthly  Journal  of  Medical  Sciences,  for 

April,  1843. 
Art.  Par  Vagum,  in  Cyclopaedia  of  Anatomy  and  Physiology,  Pt.  xxviii., 

Lond.,  April,  1847. 

Art.  Respiration,  Ibid.,  Pt.  xxxii.,  Lond.,  Aug.,  1848. 


Retzius,  A.,  Beurtheilung  der  Phrenologie  vom  Standpunkte  der  Anatomie  aus,  in 
Miiller's  Archiv.  H.  3,  Berlin,  1848. 


XIV  AUTHORS  REFERRED  TO. 

Rippault,  M.,  On  the  Signs  of  Death,  in  London  Medical  Gazette,  May,  1846. 
Robinson,  Geo.,  Contents  of  the  Foetal  Stomach,  Lond.  and  Edinb.  Monthly  Journal 

of  Medical  Science,  Jan.,  1847. 

Rouchoux,  M.,  On  the  Air-Cells  of  the  Lungs,  in  Gazette  M6dicale,  Jan.,  1845. 
Rodrigue,   A.,  Duration  of  Pregnancy,   in  American  Journal  of   the  Medical 

Sciences,  Oct.,  1845. 

Rognetta,  M.  F.,  Traite"  Philosophique  et  Clinique  d'Ophthalmologie,  Paris,  1844. 
Ruete,  C.  G.  T.,  Art.  Die  Physiologic  in  ihrer  Anwendung  anf  Augenheilkunde,  in 

Wagner's  Handworterbuch  der  Physiologic,  16te  Lieferung,  Braunschweig,  1847. 

Sanders,  W.  R.,  On  the  Spleen,  in  Goodsir's  Annals  of  Anatomy  and  Physiology, 

Feb.,  1850. 

— ,  On  the  Spleen,  Medical  Times,  April,  1849. 
Scherer,  Analysis  of  Blood,  in  Canstatt  und  Eisenmann's  Jahresbericht  uber  die 

Fortschritte  in  der  Biologie  im  Jahr  1848.  Erlang,  1849. 

,  Analysis  of  Bile,  Ibid. 

,  Ibid.,  Jahrgang  1847  ;  Erlangen,  1848. 

,  Art.  Milch,  in  Wagner's  Handworterbuch,  Physiologie,  lOte  Lieferung, 

Braunschweig,  1840. 
,  On  the  Saliva,  in  Canstatt  und  Eisenmann's  Jahresbericht,  u.  s.  w.,  im 

Jahre  1848. 

,  On  the  Chemistry  of  the  Urine,  Ibid.,  Jahrgang  1848. 

Schleiden,  M.  J.,  Principles  of  Scientific  Botany,  by  Dr.  Lancaster,  London,  1849. 

Schlossberger.  (See  Boussingault.) 

Schwann,  Th.,  Microscopical  Researches  into  the  Accordance  in  the  Structure  and 

Growth  of  Animals  and  Plants,  Translated  by  Henry  Smith,  Sydenham  Society 

edition,  London,  1847. 
Serres.  (See  De  Serres.) 
Sharpey,  W.,  On  the  Decidua,  in  Miiller's  Elements  of  Physiology,  by  Baly,  Lond., 

J838. 

.   (See  Quain.) 

Sibson,  F.,  On  the  Movements  of  the  Chest,  in  Provincial  Medical  and  Surgical 

Journal,  Sept.,  1849. 
Simon,  J.  F.,  Animal  Chemistry,  Sydenham  Society  edition,  Lond.,  1845,  1846 ; 

Amer.  edit.,  Philad.,  1846. 

,  J.,  A  Physiological  Essay  on  the  Thymus  Gland,  Lond.,  1845. 

Simpson,  J.  Y.,  Duration  of  Labour,  in  Monthly  Journal  and  Retrospect  of  the 

Medical  Sciences,  Nov.,  1848. 

on  the  Motions  of  the  Foetus  in  Utero,  ibid.,  July,  1849. 

Position  of  the  Foetus  in  Utero,  ibid.,  July,  1849. 

Ratio  of  Twins,  ibid.,  Nov.,  1848. 

Signs  of  Pregnancy,  ibid.,  July,  1848. 

Weight  of  the  New  Born,  ibid.,  Nov.,  1848. 

,  Sir  Geo.,  An  Overland  Journey  round  the  World,  Amer.  edit.,  Philad., 

1847. 
Smith,  John,  Case  of  Early  Menstruation,  Lond.  Med.  Gazette,  Nov.,  1848. 

,  Rev.  Sydney,  Elementary  Sketches  of  Moral  Philosophy,  Lond.,  1850. 

,  W.  Tyler,  Parturition  and  the  Principles  and  Practice  of  Obstetrics,  Amer. 

edit.,  Philad.,  1849. 
Solly,  Samuel,  The  Human  Brain ;  its  structure,  physiology,  and  diseases,  Amer. 

edit.,  from  the  second  London,  1848. 
Southey,  Robert,  The  Doctor,  Lond.,  1837. 

Statistique  de  la  Belgique,  etc.  pendant  1'Annee  1844,  Bruxelles,  1845. 
Stilling,  B.,  and  Wallach,  J.,  Untersuchungen  liber  die  Textur  des  Riickenmarks, 

Leipz.,  1842. 
Strzelecki.     (See  De  Strzelecki.) 

Taylor,  A.,  Medical  Jurisprudence,  2d  Amer.  edit,  from  3d  London,  Philad.,  1850. 

',  Thos.  B.,  Case  of  Superfcetation,  New  Orleans  Journal  of  Medicine,  &c., 

Nov.,  1848. 

Theile,  Prof.,  Art.  Leber,  in  Wagner's  Handworterbuch  der  Physiologie,  9te  Liefe- 
rung, Braunschweig,  1845. 


AUTHOKS  REFERRED  TO.  XV 

Thomson,  Allen,  Outlines  of  Physiology,  for  the  use  of  Students,  Edinb.,  1848. 
,  Robert  Dundas,  Experimental  Researches  on  the   Food  of  Animals, 

Amer.  edit.,  New  York,  1846. 
Tiedemann,  F.,  Versuche  liber  die  Bewegung  des  Herzens  unter  dem  Recipienten 

der  Luftpumpe,  in  Mliller's  Archiv.  fur  Anatomie,  Jahrgang  1847. 
Todd,  R.  B.,  and  Bowman,  Wm.,  The  Physiological  Anatomy  and  Physiology  of 

Man,  Lond.,  1845,  Amer.  edit.,  Philad.,  1850. 

Tomes,  J.,  A  Course  of  Lectures  on  Dental  Physiology  and  Surgery,  Lond.,  1848. 
Tschudi,  J.  von,  Travels  in  Peru  during  the  years  1838-1842,  from  the  German, 

by  Thomasine  Ross,  Amer.  edit.,  New  York,  1847. 

Valentin,  G.,  Art.  Flimmerbewegung,  in  Wagner's  Handworterbuch  der  Physiolo- 
gic, 3te  Lieferung,  Braunschweig,  1842. 

,  Grundriss  der  Physiologie  fur  das  erste  Studium  und  zur  Selbstbe- 

lehrung,  Braunschweig,  1846. 

— ,  Handbuch  der  Entwickelungsgeschichte,  cited  by  "Wagner. 

-,  Lehrbuch  der  Physiologie  des  Mensehen  fur  Aerzte  und  Studirende, 


8vo.,  Braunschweig,  1844. 
Vallee,  M.,  Theorie  de  1'CEil,  Paris,  1843. 
Van  Amringe,  Wm.  Frederick,  An  Investigation  of  the  Theories  of  the  Natural 

History  of  Man,  by  Lawrence,  Prichard,  and  others,  New  York,  1848. 
Vierordt,  K.,  Art.  Respiration,  in  Wagner's  Handworterbuch  der  Physiologie,  12te 

Lieferung,  Braunschweig,  1845. 
,  Art.  Trassudation   und  Endosmose,  in  Wagner's  Handworterbuch 

der  Physiologie,  19te  Lieferung,  Braunschweig,  1848. 
Vogel,  Julius,  The  Pathological  Anatomy  of  the  Human  Body,  translated  by  Dr. 

Day,  Lond.,  1847,  Amer.  edit.,  Philad.,  1847. 

Volkmann,  A.  W.,  On  Lymph  Hearts,  in  Mliller's  Archiv.  flir  Anatomie,  Jahr- 
gang 1844.      ' 

,   Art.   Nervenphysiologie,  in  Wagner's   Handworterbuoh  der 

Physiologie,  lOte  Lieferung,  Braunschweig,  1845. 

-,  Art.  Sehen,   in  Wagner's  Handworterbuch  der  Physiologie, 


14te  Lieferung,  Braunschweig,  1846. 
Von  Gorup-Besanez,  Untersuchungen  liber  Galle,  Erlangen,  1846. 
Von  Reichenbach,  Baron,  Physico-Physiological  Researches  on  the  Dynamics  of 

Magnetism,  &c.,  in  their  Relations  to  Vital  Force,  Eng.  edit.,  by  Dr.  Ashburner, 

Lond.,  1850. 

Von  Tschudi.  (See  Tschudi.) 
Vrolik,  W.,  Art.  Teratology,  in  Cyclopaedia  of  Anatomy   and  Physiology,   Pt. 

xxxviii.;  Feb.,  1850. 

Wagner,  R.,  Elements  of  Physiology,  by  Robert  Willis,  Lond.,  1844. 

,    Art.  Lympathische   Ganglien   des   Herzens,    in   his   Handworterbuch, 

u.  s.  w.,  17te  Lieferung,  Braunschweig,  1847. 

,  and  Leuckardt,  Art.  Semen,  Cyclopaedia  of  Anat.  and  Physiol.,  Pt.  xxxiv., 


Jan.,  1849. 

Wallace,  Wm.  Clay,  M.  D.,  A  Treatise  on  the  Eye,  3d  edit.,  New  York,  1841. 
,  The  Accommodation  of  the  Eye  to  Distances,  New 

York,  1850. 
Wanner,  Mr.,  On  the  Proportion  of  Blood  to  the  Body,  Edinb.  Med.  and  Surg. 

Journ.,  July,  1845. 
Waters,  Wm.,  Case  of  Cancerous  Communication  between  the  Stomach  and  Colon, 

in  Medical  Examiner,  April,  1845. 
Weber,  E.,  Art.  Muskelbewegung,  in  Wagner's  Handworterbuch  der  Physiologie, 

15te  Lieferung,  Braunschweig,  1846, 
,  E.  H.,  Uber  den  Descensus  testiculorum  bei  den  Mensehen  und  einigen 

S'augethieren,  in  Mliller's  Archiv.,  Jahrgang  1847. 

,  Uber  den  Mechanismus  der  Einsaugung  des  Speisesaftes,  in  Mul- 


ler's  Archiv.  flir  Anatomie,  u.  s.  w.,  Jahrgang  1847. 

-,  Art.  Tastsinn  und  das  Gemeingeflihl,  in  Wagner's  Handworterbuch 


der  Physiologie,  u.  s.  w.,  22ste  Lieferung,  Braunschweig,  1849. 


XVI  AUTHORS  REFERRED  TO. 

Weber,  E.  H.,  Zusatze  zur  Lehre  von  Baue  und  von  den  Verrichtungen  der  Ge- 
schlechtsorgane,  in  Mailer's  Archiv.  fur  Anatomie,  Jahrgang  1846. 

,  E.  and  E.  H.,Ueber  die  Wirkungen,  welche  die  magneto-elektrische  Reizung 

der  Blutgefasse  bei  lebenden  Thieren  hemorbringt,  in  Muller's  Archiv.  fur  Ana- 
tomie, Jahrgang  1847. 

Whitehead,  Jas.,  On  the  Causes  and  Treatment  of  Abortion  and  Sterility,  Amer. 
edit,  Philad.,  1848.  > 

Williams,  C.  J.  B.,  Principles  of  Medicine,  comprising  general  Pathology  and  The- 
rapeutics, &c.,  3d  Amer.  edit.,  by  Dr.  Clymer,  Philad.,  1848. 

Wilson,  E.,  On  Diseases  of  the  Skin,  2d  Amer.  edit.,  Philad.,  1847. 

Wyman,  Jeffries,  A  Description  of  two  additional  Crania  of  the  Enge"-ana,  in 
American  Journal  of  Science  and  Arts,  second  series,  vol.  ix. 

Zimmermann,  on  Kyeetein,  cited  in  London  Medical  Gazette,  Sept.,  1846. 


CONTENTS  OF  VOL.  I. 


PRELIMINARY  OBSERVATIONS. 

PAGE 

PROLEGOMENA. 

I.  Of  Natural  Bodies      .            .            .            .            .  .             .            .  .33 

1.  Difference  between  Inorganic  and  Organized  Bodies               ...  34 

2.  Difference  between  Animals  and  Vegetables         .  .             .             .  .39 

GENERAL  PHYSIOLOGY  OF  MAN. 

I.  Material  Composition  of  Man        .  .  .  .  .  .  .  43 

a.  Organic  Elements  that  contain  Nitrogen  .  .  .  .  .47 

b.  Organic  Elements  that  do  not  contain  Nitrogen        .  .  .  53 

c.  Solid  parts  of  the  Human  Body  .  .  .  .  .  .56 

d.  Fluids  of  the  Human  Body  .  ......  61 

e.  Physical  Properties  of  the  Tissues          .  .  .  .  .  .63 

II.  Functions  of  Man  .  .  .  .  .  .  .  .  69 

BOOK  I. 

ANIMAL  FUNCTIONS,  OR  FUNCTIONS  OF  RELATION. 

CHAP.  I.  Sensibility        .........       72 

1.  Nervous  System  .......  72 

2.  Physiology  of  Sensibility   .  .  .  .  .  .  .110 

a.  Sensations    .  .  .  .  .  .  .110 

a.  External  Sensations        .  .  .  .  .  .  .119 

Sense  of  Tact  or  Touch — Palpation          .  .             .             .             .           121 

1.  Anatomy  of  the  Skin,  Hair,  Nails,  &c.  ....     122 

2.  Physiology  of  Tact  and  Touch  .             .            .            .133 
Sense  of  Taste  or  Gustation    .             .             .  .             .             .             .144 

1.  Anatomy  of  the  Organs  of  Taste  ....  144 

2.  Savours         ........     147 

3.  Physiology  of  Taste        .  .  .  .  .  .150 

Sense  of  Smell  or  Olfaction    .  .  .  .  ...  .157 

1.  Anatomy  of  the  Organ  of  Smell  .  .  .  .  157 

2.  Odours         ........     161 

3.  Physiology  of  Olfaction  .  .  .  .  .  167 
Sense  of  Hearing  or  Audition             .             .             .             ...             .174 

1.  Anatomy  of  the  Organ  of  Hearing         .  .  .  .  174 

2.  Sound  ........     184 

VOL.  I.— 2 


XY111  CONTENTS. 

PAGE 

3.  Physiology  of  Audition  .  .  .  .  .189 

Sense  of  Sight  or  Vision          .......     205 

1.  Light      ........  206 

2.  Anatomy  of  the  Organ  of  Vision     .  .  .  .  .214 

3.  Accessory  Organs  .  .  .  .  .  .  229 

4.  Physiology  of  Vision  ......     234 

5.  Phenomena  of  Vision     .  .  .  .  .  .253 

Additional  Senses        .  .  .  .  .  .  .  .296 

b.  Internal  Sensations           .             .             .             .             .             .  299 

Mental  Faculties,  &c.               .             .             .             .             .             .  .301 

1.  Physiology  of  the  Intellectual  and  Moral  Faculties         .             .  321 

CHAP.  II.  Of  Muscular  Motion,  especially  of  Locomotility  or  Voluntary  Motion  .     362 

1.  Anatomy  of  the  Motory  Apparatus     .             .             .             .             .  362 

2.  Muscles -.362 

3.  Bones  .........  376 

4.  Physiology  of  Muscular  Motion     ......     383 

5.  Attitudes           ........  437 

6.  Movements  .....  ...     443 

7.  Locomotive  Movements           ......  445 

a.  Walking            .             .             .             .             .             .             .  .445 

fe.  Leaping      .              .......  447 

c.  Running  ........  448 

d.  Swimming  .......  449 

e.  Flying  .........  452 

/.   Other  varieties  of  Muscular  Action  ....  452 

8.  Function  of  Expression  or  of  Language    •  454 

a.  Of  the  Voice  .......  454 

1.  Anatomy  of  the  Vocal  Apparatus  .  .  .     454 

2.  Physiology  of  the  Voice  .  .  .  .  .459 

1.  Intensity  or  Strength  of  Voice  .             .             .             .  .463 

2.  Tone  of  Voice           ......  463 

3.  Timbre  or  Quality  of  Voice        .             .             .             .  .471 

3.  Natural  or  Inarticulate  Language           ....  478 

4.  Artificial  or  Articulate  Language    .             .             .             .  .480 

5.  Singing               .             .                          .             .  491 

b.  Gestures  ........     493 

Ciliary  Motion         .......  509 


BOOK  II. 

NUTRITIVE  FUNCTIONS. 

CHAP.  I.  Digestion 

1.  Anatomy  of  the  Digestive  Organs        .  512 

2.  Food  of  Man          .  .540 

3.  Physiology  of  Digestion  .  .  553 

4.  Digestion  of  Solid  Food      . 

a.  Hunger         ... 

b.  Prehension  of  Food       .  .  .  .561 

c.  Oral  or  Buccal  Digestion 

d.  Deglutition         ......  .     568 


CONTENTS.  XIX 

PAGE 

e.  Chymification    '.......  572 

/.  Action  of  the  Small  Intestine    ......     607 

g.  Action  of  the  Large  Intestine  .  .  .  .  .  615 

5.  Digestion  of  Liquids  .  .  .     623 

6.  Of  Eructation,  Regurgitation,  and  Rumination  .  .  .  626 
CHAP.  II.  Absorption .                          .635 

I.  Digestive  Absorption     .  ...  636 

a.  Absorption  of  Chyle  or  Chylosis  .....     636 

1.  Anatomy  of  the  Chyliferous  Apparatus  ....  636 

2.  Chyle  .  .  .  .  .  .  .  .643 

3.  Physiology  of  Chylosis     .....  647 
6.  Absorption  of  Drinks     .......     656 

II.  Absorption  of  Lymph  or  Lymphosis    .....  662 

1.  Anatomy  of  the  Lymphatic  Apparatus  ....     663 

2.  Lymph          ....  669 

3.  Physiology  of  Lynaphosis  .  .  .  .  .672 

III.  Venous  Absorption         .....  677 
1.  Physiology  of  Venous  Absorption           .             .             .             .             .678 

IV.  Internal  Absorption        .......  684 

V.  Accidental  Absorption          .....  .     686 

a.  Cutaneous  Absorption  ......  687 

b.  Other  Accidental  Absorptions     .  .  .  .  .  .691 


LIST  OF  ILLUSTKATIONS  IN  VOL.  I. 


FIG.                                                                                                       ,  PAGE 

1.  Endosmometer,                 .......  67 

2.  Anterior  view  of  the  brain  and  spinal  marrow,  .  .  .73 

3.  Front  view  of  the  skull,                ......  75 

4.  Falx  cerebri  and  sinuses  of  upper  and  back  part  of  skull,         .            .  76 

5.  Lateral  view  of  the  spinal  column,          .  .  ,    .  .77 

6.  Longitudinal  section  of  the  brain  on  the  mesial  line,                 .            .  78 

7.  The  convolutions  of  one  side  of  the  cerebrum,  as  seen  from  above,      .  78 

8.  Superior  part  of  the  lateral  ventricles,  corpora  striata,  septum  lucidum, 

fornix,  &c.,  as  given  by  a  transverse  section  of  the  cerebrum,            .  79 

9.  Section  of  the  cerebrum,  displaying  the  surfaces  of  the  corpora  striata, 

and  optic  thalami,  the  cavity  of  the  third  ventricle,  and  the  upper 

surface  of  the  cerebellum,          ......  80 

10.  An  under  view  of  the  cerebellum,  seen  from  behind,     .  .  .81 

11.  Posterior  superior  view  of  the  pons  Varolii,  cerebellum,  and  medulla 

oblongata  and  M.  spinalis,         ......  81 

12.  Analytical  diagram  of  the  encephalon — in  a  vertical  section,  after  Mayo,  82 

13.  Anterior  view  of  the  medulla  oblongata,  showing  the  decussation  of  the 

pyramids,  and  of  the  upper  part  of  the  spinal  cord,  after  Mayo,        .  83 

14.  Transverse  sections  of  the  spinal  cord,  Todd  and  Bowman,      .            .  84 

15.  Shows  the  under  surface  or  base  of  the  encephalon  freed  from  its 

membranes,         .  .  .  .  .  .  .  .85 

16.  Terminal  nerves,  on  the  sac  of  the  second  molar  tooth  of  the  lower  jaw, 

in  the  sheep ;  showing  the  arrangement  in  loops,  after  Valentin,       .  86 

17.  18.  Pacinian  corpuscles,  after  Todd  and  Bowman,          .  .  .87 

19.  Represents  a  nerve  consisting  of  many  smaller  cords  or  funiculi  wrapped 

up  in  a  common  cellular  sheath,  .  .  .  .  .88 

20.  A  portion  of  the  spinal  marrow,  showing  the  origin  of  some  of  the 

spinal  nerves,                  .......  88 

21.  Plans  in  outline,  showing  the  front  A,  and  the  sides  B,  of  the  spinal 

cord,  with  the  fissures  upon  it ;  also  sections  of  the  gray  and  white 

matter,  and  the  roots  of  the  spinal  nerves,       ....  88 

22.  Roots  of  a  dorsal  spinal  nerve,  and  its  union  with  sympathetic,  Todd 

and  Bowman,      ........  91 

23.  Great  sympathetic  nerve,              ......  92 

24.  Structure  of  the  spinal  cord,  according  to  Stilling,         .            .            .  100 

25.  Transverse  section  of  the  medulla,  after  Stilling,           .            .            .  101 

26.  Tubular  nerve-fibres,        .            .           .            .            .                       .  103 

2* 


XX11  LIST  OF  ILLUSTRATIONS. 

FIG-  PAGE 

27.  Gelatinous  nerve-fibres,                ......  103 

28.  Ganglion  corpuscles,  after  Valentin,       .....  104 

29.  Stellate  or  caudate  nerve-corpuscles,  after  Hannover,                .            .  104 

30.  Circle  of  Willis,  /  .  .  .  .  "         .  .106 

31.  Sinuses  of  the  base  of  the  skull,              .....  108 

32.  Capillary  net-work  of  nervous  centres,  after  Berres,                  .            .  108 

33.  Distribution  of  capillaries  at  the  surface  of  the  skin  of  the  finger,  after 

Berres,                ........  113 

34.  Brain  of  squirrel,  laid  open,  after  Solly,  .  .  .  .115 

35.  Brain  of  turtle,  after  Solly,          .  .  .  .  .  .115 

36.  37.  Brains  of  fishes,  after  Leuret,  .  .  .  .  .115 

38.  Vertical  section  of  epidermis,  from  the  palm  of  the  hand,  after  Wilson,  123 

39.  Surface  of  the  skin  of  the  palm,  showing  the  ridges,  furrows,  cross- 

grooves,  and  orifices  of  the  sweat-ducts,  Todd  and  Bowman,              .  123 

40.  Vertical  section  of  the  cuticle  from  the  scrotum  of  a  negro,  Todd  and 

Bowman,             ........  124 

41.  Section  of  the  skin,          .  .  .  .  .  .  .124 

42.  Papillae  of  the  palm,  the  cuticle  being  detached,  magnified  35  diameters,  125 

43.  Sections  of  hair,                .......  126 

44.  Thin  layer  from  the  scalp,            ......  127 

45.  Magnified  view  of  the  root  of  the  hair,  Kohlrausch,      .            .            .  127 

46.  Section  of  the  skin  on  the  end  of  the  finger,  Todd  and  Bowman,         .  130 

47.  A.  Separated  epithelium  cells  from  mucous  membrane  of  the  mouth. 

B.  Pavement-epithelium  of  the  mucous  membrane  of  the  smaller  bron- 
chial tubes,         ........  131 

48.  Tesselated  epithelium,      .......  132 

49.  Scales  of  tesselated  epithelium,  after  Henle,      ....  132 

50.  Diagram  of  the  structure  of  an  involuted  mucous  membrane,  showing 

the  continuation  of  its  elements  in  the  follicles  and  villi,  Todd,         .  133 

51.  Cylinders  of  intestinal  epithelium,  after  Henle,             .            .            .  133 

52.  Capillary  net-work  at  margin  of  lips,  after  Berres,        .            .            .  139 

53.  Front  view  of  the  upper  surface  of  the  tongue,  as  well  as  of  the  pala- 

tine arch,  Wilson,           .            .            .            .            .            .            -  145 

54.  View  of  a  papilla  of  the  smallest  class,  magnified  25  diameters,  Todd 

and  Bowman,      ........  145 

55.  Vertical  section  of  one  of  the  gustatory  papillae  of  the  largest  class, 

showing  its  conical  form,  its  sides,  and  the  fissure  between  the  dif- 
ferent papillae,  Todd  and  Bowman,       .....  146 

56.  The  hypoglossal;  lingual  branch  of  fifth  pair;  glosso-pharyngeal  and 

deep-seated  nerves  of  the  neck,             .....  146 

57.  Papillae  of  the  tongue,  Todd  and  Bowman,        ....  147 

58.  Vertical  section  of  the  middle  part  of  the  nasal  fossse,  giving  a  poste- 

rior view  of  the  arrangement  of  the  ethmoidal  cells,  &c.,       .             .  158 

59.  View  of  the  olfactory  nerve,  with  its  distribution  on  the  septum  nasi ; 

the  nares  divided  by  a  longitudinal  section  made  immediately  to  the 

left  of  the  septum,  the  right  nares  being  preserved  entire,        .            .  159 

60.  A  portion  of  the  pituitary  membrane  of  the  nasal  septum,  magnified  9 

times,  showing  the  number,  size,  and  arrangement  of  the  mucous 

crypts,                  .             .             .             .            .            .             .            .  160 


LIST  OF  ILLUSTRATIONS.  XX111 

FIG.  PAGE 

61.  A  portion  of  the  pituitary  membrane,  with  its  arteries  and  veins  inject- 

ed, magnified  15  diameters,       .            .            .            .            ...  160 

62.  Olfactory  filaments  of  the  dog,  Todd  and  Bowman,       .            .            .  160 

63.  View  of  the  left  ear  in  its  natural  state,  .  .  .  .175 

64.  General  view  of  the  external,  middle,  and  internal  ear,  as  seen  in  a 

prepared  section,  from  Scarpa,              .....  175 

65.  Anterior  view  of  the  external  ear,  as  well  as  of  the  meatus  auditorius, 

labyrinth,  &c.,  .  .  .  .  .  •.  .176 

66.  Membrana  tympani  from  the  outer  (A)  and  from  the  inner  (B)  sides,  177 

67.  Ossicles  of  the  left  ear  articulated,  and  seen  from  the  outside  and  below,  178 

68.  Labyrinth  separated  from  the  solid  bone  in  which  it  lies  embedded,    .  180 

69.  Cochlea  divided  parallel  with  its  axis,  through  the  centre  of  the  mo- 

diolus,  Breschet,                          ^            .....  180 

70.  Osseous  labyrinth  laid  open  to    show   especially  the  membranous 

labyrinth,             ........  181 

71.  Auditory  nerve,     ........  182 

72.  Ampulla  of  the  external  semicircular  membranous  canal,  showing  the 

mode  of  termination  of  its  nerve,          .....  182 

73.  Auditory  nerve  taken  out  of  the  cochlea,            .            .            .            .  183 

74.  Papillae  of  the  auditory  nerve,  on  a  segment  of  the  spiral  lamina  of  the 

cochlea  of  a  young  mouse,         ......  183 

75.  Reflection  of  sound,          .......  186 

76.  Vertical  section  of  the  head  and  neck,  through  the  mesial  line,  to 

show  the  opening  of  the  Eustachian  tube  and  its  relations  to  the 

pharynx,               ........  194 

77.  Reflection  and  refraction  of  light,           .....  208 

78.  Prism,        .........  210 

79.  Double  convex  lens,          .......  211 

80.  Double  concave  lens,         .......  211 

81.  Prismatic  spectrum,           .......  212 

82.  Aberration  of  sphericity,              ......  213 

83.  Aberration  of  refrangibility,        ......  214 

84.  Front  view  of  the  left  eye — moderately  opened,             .            .            .  214 

85.  Side  view  of  the  same  eye,  as  in  fig.  84,  showing  that  the  cilia  of  the 

upper  lid  are  concave  upwards,  and  those  of  the  lower  lid  concave 

downwards.    The  general  convexity  of  the  eyeball  is  seen,    .            .  215 

86.  Choroid  coat  of  the  eye,  .......  215 

87.  Pigmentum  nigrum,  after  Todd  and  Bowman,  ....  216 

88.  Retina,      .  .  .  .  .  .  .  .  .216 

89.  A.  An  enlarged  plan  of  the  retina,  in  section.    B.  The  outer  surface  of 

Jacob's  membrane,  from  Hannover,      .            .            .            .            .  217 

90.  Part  of  the  retina  of  a  frog  seen  from  the  outer  surface,            .            .  218 

91.  Vertical  section  of  the  human  retina  and  hyaloid  membrane,  after  Todd 

and  Bowman,     ........  218 

92.  Papillae  of  the  retina  of  the  frog,  seen  from  the  side  turned  towards  the 

vitreous  humour,            .             ......  219 

93.  Plan  of  the  structures  in  the  fore  part  of  the  eye,  seen  in  section,         .  219 

94.  Posterior  segment  of  transverse  section  of  the  globe  of  the  eye  seen 

from  within,        ........  220 


XXIV  LIST  OF  ILLUSTRATIONS.  , 

FIG.  PAGE 

95.  Vertical  section  of  the  sclerotic  and  cornea,  showing  the  continuity  of 

their  ^tissue  between  the  dotted  lines,  after  Todd  and  Bowman,          .      220 

96.  Longitudinal  section  of  the  globe  of  the  eye,     ....      221 

97.  Lens,  hardened  in  spirit  and  partially  divided  along  the  three  interior 

planes,  as  well  as  into  lamellae. — Magnified  three  and  a  quarter 

diameters,  after  Arnold,  ......  222 

98.  Front  view  of  the  crystalline  humour  or  lens,  in  the  adult,       .  .  222 

99.  Side  viewvof  the  adult  lens,  ......  222 

100.  Internal  view  of  the  iris,  ......      223 

101.  External  view  of  the  iris,  .  .  .  .  .  .      223 

102.  A  representation  of  some  of  the  nerves  of  the  orbit,  especially  to  show 

the  lenticular  ganglion,  after  Arnold,  .....      224 

103.  Segment  of  the  anterior  face  of  the  iris  with  its  vessels  injected.    Mag- 

nified twenty-five  diameters,  after  Todd  and  Bowman,  .  .      224 

104.  An  enlarged  view  of  the  arteries  of  the  iris,  from  Arnold,        .  .      224 

105.  Anterior  segment  of  a  transverse  section  of  the  globe  of  the  eye  seen 

from  within,        ........  225 

106.  Choroid  and  iris,  exposed  by  turning  aside  the  sclerotica,         .  .  225 

107.  Optic  nerves,  with  the  origin  of  seven  other  pairs  of  nerves,     .  .  227 

108.  Muscles  of  the  eyeball,     .  .  .  .  .  231 

109.  Meibomian  glands  seen  from  the  inner  or  ocular  surface  of  the  eyelids, 

with  the  lachrymal  gland — the  right  side,        .  .  .  .231 

110.  View  of  tlie  third,  fourth,  and  sixth  pairs  of  nerves,     .            .            .  232 

111.  Posterior  view  of  the  eyelids  and  lachrymal  gland,        .            .            .  233 

112.  Lachrymal  canals,         .  .            .            .            .            .            .            .  233 

113.  Progress  of  luminous  rays  through  the  eye,       ....  235 

114.  Camera  obscura,   .            .            ...            .            .            .            .  238 

115.  Experiment  of  Mariotte,  .......  253 

116.  Muscse  volitantes,  after  T.  W.  Jones,      .  .  .  .  .256 

117.  Lines  of  visible  direction,            ......  259 

118.  Accidental  colours,           .......  261 

119.  Myopic  vision,      ...            .            .            .            .            .            .  271 

120.  Presbyopic  vision,             .......  271 

121.  Binocular  vision. — Professor  Wheatstone's  experiments,           .            .  275 

122.  123.  Binocular  vision,       .......  275 

124.  Do.  do 276 

125.  Multiple  vision  with  one  eye,       ......      279 

126.  Do.  do.  ......      280 

127.  Visual  angle,         .  .         . 284 

128.  Foreshortening,     ........      275 

129.  Perspective,  ....  .285 

130.  Concave  mirror,    ........      294 

131.  Convex  mirror,     ........      294 

132.  133.  Thaumatrope,  ....  .295 

134.  Facial  line  and  angle  of  man,  after  Sir  C.  Bell,  .  .332 

135.  Facial  line  and  angle  of  orang-outang,  .....      333 

136.  Old  phrenological  head,    .  .  .  .  .  .  .341 

137.  Phrenological  head  by  Dolci,  A.  D.  1562,  .  .  .  .341 

138.  139,  140.  Phrenological  organs  according  to  Gall,         .  .  .345 


LIST  OF  ILLUSTRATIONS.  XXV 

PIG.  PAGE 

141,  142,  143.  Phrenological  organs  according  to  Spurzheim,          .            .  348 

144,  145.  Non-striated  muscular  fibre,  after  Bowman  and  Wilson,              .  363 

146,  147.  Striated  muscular  fibres,     .......  365 

148.  Fragments  of  an  elementary  fibre  of  the  skate,  held  together  by  the 

untorn  but  twisted  sarcolemma,  after  Todd  and  Bowman,     .            .  366 

149.  Transverse  section  of  fibres  from  the  pectoral  muscle  of  a  teal,  after 

Bowman,                      *            ......  366 

150.  Transverse  section  of  ultimate  fibres  of  biceps,  after  Bowman,           .  366 

151.  Fragment  of  muscular  fibre  from  macerated  heart  of  ox,  showing  for- 

mation of  strise  by  aggregation  of  beaded  fibrillae,  after  Bowman,    .  367 

152.  Portion  of  human  muscular  fibre,  separating  into  disks,  by  cleavage  in 

direction  of  transverse  strise,  after  Bowman,              .            .            .  367 

153.  Fragments  of  striated  elementary  fibres,  showing  a  cleavage  in  oppo- 

site directions. — Magnified  300  diameters,      ....  367 

154.  Mass  of  ultimate  fibres  from  the  pectoralis  major  of  the  human  foetus, 

at  nine  months,  after  "Wilson,              .            .            .            .            .  369 

155.  Muscular  fibrils  of  the  pig,  after  Sharpey,       .  .  .  .369 

156.  Attachment  of  tendon  to  muscular  fibre,  in  skate,  after  Bowman,       .  370 

157.  Capillary  net-work  of  muscle,  after  Berres,      ....  371 

158.  Loop-like  termination  of  the  nerves  in  voluntary  muscle,  after  Burdach,  372 

159.  Compound  ventriform  muscle,   ......  373 

160.  Penniform  muscle,          ........  373 

161.  Double  penniform  muscle,          ......  373 

162.  Sections  of  a  bone,         .......  379 

163.  Haversian  canals,  seen  on  a  longitudinal  section  of  the  compact  tissue 

of  the  shaft  of  one  of  the  long  bones,  after  Todd  and  Bowman,       .  381 

164.  Transverse  section  of  compact  tissue  of  humerus  magnified  about  150 

diameters,         ..*....•  381 

165.  Direction  of  encephalic  impulses,           .....  393 

166.  Muscular  fibre  of  dytiscus  in  contraction,  after  Bowman,       .            .  398 

167.  Muscular  fibre  of  skate,  .  .  .  .  .  .399 

168.  Centre  of  gravity,           .......  419 

169.  Do.          do. 420 

170.  Condition  of  equilibrium,           ......  420 

171.  172.  Composition  of  forces,        ......  421 

173.  Do.                 do 422 

174.  Lever  of  the  first  kind,  .  .  .  .  .  .422 

175.  Lever  of  the  second  kind,          ......  422 

176.  Lever  of  the  third  kind, 423 

177.  178.  Action  of  the  deltoid,          .            .            .            .            .            .  425 

179.  Action  of  the  biceps,      .......  426 

180.  Insertion  of  fibres  into  tendon,              .....  426 

181.  Tendon  of  the  great  toe,             ......  428 

182.  183.  Action  of  intercostal  muscles,        .....  428 
184,  185.  Action  of  intercostals         ....'..  429 

186.  Do.          do 430 

187.  Action  of  biceps,            .......  430 

188.  Combined  muscular  movements  in  rising,         ....  431 

189.  Ligamentum  nuchae,       .......  438 


XXVI  LIST  OF  ILLUSTRATIONS. 

FIG.  PAGE 

190.  Lateral  view  of  a  dorsal  vertebra,          .....  438 

191.  Lateral  view  of  a  lumbar  vertebra,        .....  439 

192.  Upper  portion  of  thigh-bone,  % .  .  .  .  .  440 

193.  Movement  of  the  foot  in  walking,         .....  445 

194.  Lateral  view  of  the  larynx,        ......  455 

195.  View  of  the  interior  of  the  left  half  of  the  larynx,  to  show  the  ventricle 

and  laryngeal  pouch,  after  Hilton,      .  .  .  .  .456 

196.  Larynx  from  above,  after  Willis,  .....        456 

197.  Scheme  of  the  larynx,    .......        457 

198.  Origin  and  distribution  of  the  eighth  pair  of  nerves,  .  .        458 

199.  Scheme  of  a  bird-call,    .......        468 

200.  Do.  do.          .......        469 

201.  Muscles  of  the  head  and  face,    ......        494 

202.  Distribution  of  the  facial  nerve,  .....        496 

203.  Plan  of  the  branches  of  the  fifth  nerve,  modified  from  a  sketch  by  Sir 

C.  Bell,  . 497 

204.%>aralysis  of  the  facial  nerve,  after  Marshall  Hall,       .  .  .        498 

205.  Broad  laughter,  after  Sir  Charles  Bell,  .  .  .  .500 

206.  Faun  weeping,  after  Sir  Charles  Bell,    .  .  .  .  .500 

207.  Physiognomy  of  melancholy,  after  Sir  Charles  Bell,    .  .  .        505 

208.  Cilia,        .  .  .  .  .  .  .  .510 

209.  Vibratile  or  ciliated  epithelium,.  .....        510 

210.  Diagram  of  the  stomach  and  intestines  to  show  their  course,  .        513 

211.  Skull  of  the  Polar  bear,  ......        514 

212.  Skull  of  the  cow, -515 

213.  Salivary  glands  in  situ,  .  .  '          .  .  .  .517 

214.  Cavity  of  the  mouth,  as  shown  by  dividing  the  angles  and  turning  off 

the  lips,  ........        518 

215.  Pharynx  seen  from  behind,        .  .  .  .  .  .518 

216.  Longitudinal  section  of  oesophagus,  near  the  pharynx,  seen  on  its  inside,      518 

217.  Section  of  the  oesophagus,          ......        518 

218.  Stomach  seen  externally,  ......        520 

219.  Vertical  and  longitudinal  section  of  stomach  and  duodenum,  .        521 

220.  Section  of  a  piece  of  stomach  not  far  from  pylorus,     .  .  .        521 

221.  Tubular  follicle  of  pig's  stomach,  after  Wasmann,      .  .  .522 

222.  Vertical  section  of  a  stomach  cell  with  its  tubes,  after  Todd  and  Bow- 

man,     .........        522 

223.  Mucous  membrane  of  the  stomach,  Todd  and  Bowman,  .  .        522 

224.  Front  view  of  stomach,  distended  by  flatus,  with  peritoneal  coat  turned 

off,  523 

225.  Distribution  of  the  glosso-pharyngeal,  pneumogastric  and  spinal  acces- 

sory nerves,  or  the  eighth  pair,  .....  524 

226.  Stomach  of  the  ox,          .....  .  525 

227.  Section  of  the  stomach  of  the  ruminant  animal,          .  .  .  525 

228.  Gastric  apparatus  of  the  turkey,  .....  526 

229.  Interior  of  the  gastric  apparatus  of  the  turkey,  .  .  .  527 

230.  Portion  of  the  stomach  and  duodenum  laid  open  to  show  their  interior,  529 

231.  Longitudinal  section  of  the  upper  part  of  the  jejunum  extended  under 

water,   .......••        529 


LIST  OF  ILLUSTRATIONS.  XXV11 

FIG.  PAGE 

232.  Muscular  coat  of  the  ileum,       ......  530 

233.  Distribution  of  capillaries  in  the  villi  of  the  intestine,  after  Berres,   .  530 

234.  Distribution  of  capillaries  around  follicles  of  mucous  membrane,  after 

Berres, 530 

235.  Bloodvessels  of  villi  of  the  hare,  after  Dollinger,          .            .            .  531 

236.  Longitudinal  section  of  the  jejunum,  showing  the  villi  as  seen  under 

the  microscope,             .......  531 

237.  One  of  the  glandulae  majores  simplices  of  the  large  intestine,  as  seen 

from  above,  and  also  in  a  section,  after  Boehm,          .            .            .  531 

238.  Follicles  of  Lieberkiihn  filled  with  tenacious  white  secretion  in  fever, 

after  Boehm,     ........  532 

239.  Conglomerate  gland  of  Brunner,  magnified  100  times,  after  Boehm,  .  532 

240.  Portion  of  one  of  the  patches  of  Peyer's  glands  from  the  end  of  the 

ileum:  highly  magnified.     The  villi  are  also  shown,  after  Boehm,  .  533 

241.  Section  of  small  intestine,  containing  some  of  the  glands  of  Peyer,  as 

shown  under  the  microscope,               .             .            .            .            .  533 

242.  Side  view  of  intestinal  mucous  membrane  of  a  cat,  after  Bendz,         .  533 

243.  Muscular  coat  of  the  colon,  as  seen  after  the  removal  of  the  peritoneum,  535 

244.  Longitudinal  section  of  the  end  ef  the  ileum,  and  of  the  beginning  of 

the  large  intestine,       .......  535 

245.  View  of  external  parietes  of  abdomen,  with  the  position  of  the  lines 

drawn  to  mark  off  its  regions,             .....  537 

246.  Reflections  of  the  peritoneum,  as  shown  in  a  vertical  section  of  the 

body, 539 

247.  Action  of  the  lower  jaw  in  prehension,             ....  562 

248.  Gastric  glands  of  the  oesophagus  magnified  fifteen  times,  after  Sir  E. 

Home, 591 

249.  Chyliferous  vessels,        .......  637 

250.  Chyliferous  apparatus,    .            .            .            .            .                     '   .  638 

251.  Section  of  intestinal  villus,  after  Gerlach,        .  '                      .            .  639 

252.  Intestinal  villus  with  the  commencement  of  a  lacteal,  after  Krause,  639 

253.  Thoracic  duct,  after  Wilson,       ......  641 

254.  Diagram  of  a  lymphatic  gland,  showing  the  intra-glandular  net-work, 

and  the  transition  from  the  scale-like  epithelia  of  the  extra-glandular 
lymphatics,  to  the  nucleated  cells  of  the  intra-glandular,  after  Good- 
sir,  .  642 

255.  Portion  of  the  intra-glandular  lymphatic,  showing  along  the  lower  edge 

the  thickness  of  the  germinal  membrane,  and  upon  it,  the  thick  layer 

of  glandular  epithelial  cells,  after  Goodsir,     ....  642 

256.  Vessels  and  lymphatic  glands  of  axilla,                                     „  663 

257.  Lymphatic  vessels  and  glands  of  the  groin  of  the  right  side,              .  664 

258.  Lymphatics,        ........  666 

259.  Bloodvessels  and  lymphatics  from  the  tail  of  the  tadpole,       .            .  667 

260.  Termination  of  thoracic  duct,    ......  673 

261.  Lymph  heart  of  python  bivittatus,  after  "Weber,          .            .            .  675 


HUMAN  PHYSIOLOGY, 


PROLEGOMENA. 

I.  NATURAL  BODIES. 

THE  extensive  domain  of  Nature  is  divisible  into  three  great  classes : 
— Minerals,  Vegetables,  and  Animals.  This  division  was  universally 
adopted  by  the  ancients,  and  still  prevails,  especially  amongst  the  un- 
scientific. When,  however,  we  carefully  examine  their  respective  cha- 
racteristics, we  discover,  that  the  animal  and  the  vegetable  resemble 
each  other  in  many  essential  particulars.  This  resemblance  has  given 
occasion  to  the  partition  of  all  bodies  into  two  classes :  the  Inorganic, 
or  those  not  possessing  organs  or  instruments  adapted  for  the  perform- 
ance of  special  actions  or  functions,  and  the  Organized,  or  such  as 
possess  this  arrangement. 

In  all  ages,  philosophers  have  attempted  to  point  out  a 

"Vast  chain  of  being,  which  from  GOD  began, 
Nature's  ethereal,  human,  angel,  man, 
Beast,  bird,  fish,  insect,  what  no  eye  can  see, 
No  glass  can  reach — " 

the  links  of  which  chain  they  have  considered  to  be  constituted  of  all 
natural  bodies ;  passing  by  insensible  gradations  through  the  inorganic 
and  the  organized,  and  forming  a  rigid  and  unbroken  series ;  and  in 
which,  they  have  conceived, 

" Each  moss, 

Each  shell,  each  crawling  insect,  holds  a  rank, 
Important  in  the  plan  of  Him  who  framed 
This  scale  of  beings — holds  a  rank  which,  lost, 
Would  break  the  chain,  and  leave  behind  a  gap 
Which  Nature's  self  would  rue." 

Crystallization  has  been  esteemed  by  them  as  the  highest  link  of 
the  inorganic  kingdom;  the  lichen,  which  encrusts  the  stone,  as  but 
one  link  higher  than  the  stone  itself;  the  mushroom  and  the  coral  as 
the  connecting  links  between  the  vegetable  and  the  animal ;  and  the 
immense  space,  which  separates  man — the  highest  of  the  mammalia — 
from  his  Maker,  they  have  conceived  to  be  occupied  in  succession  by 
beings  of  gradually  increasing  intelligence.  If,  however,  we  investi- 
gate the  matter  minutely,  we  discover  that  many  links  of  the  chain 
appear  widely  separated  from  each  other;  and  that,  in  the  existing 

VOL.  I. — 3 


34  NATURAL  BODIES. 

state  of  our  knowledge,  the  catenation  cannot  be  esteemed  rigidly 
maintained.1  Let  us  inquire  into  the  great  characteristics  of  the  dif- 
ferent kingdoms,  and  endeavour  to  describe  the  chief  points  in  which 
living  bodies  differ  from  those  that  have  never  possessed  vitality,  and 
into  the  distinctions  between  organized  bodies  themselves. 

1.    DIFFERENCE  BETWEEN  INORGANIC  AND  ORGANIZED  BODIES. 

Inorganic  bodies  possess  the  common  properties  of  matter.  Their 
elements  are  fixed  under  ordinary  circumstances.  Their  study  con- 
stitutes Physics,  in  its  enlarged  sense,  or  Natural  Science.  Organized 
bodies  have  properties  in  common  with  inorganic,  but  they  have  like- 
wise others  superadded,  which  control  the  first  in  a  singular  manner. 
They  are  beings,  whose  elements  are  undergoing  constant  mutation, 
and  the  sciences  treating  of  their  structure  and  functions  are  Anatomy 
and  Physiology. 

They  differ  from  each  other  in — 

1.  Origin. — Inorganic  bodies  are  not  born:  they  do  not  arise  from 
a  parent :  they  spring  from  the  general  forces  of  matter, — the  parti- 
cles being  merely  in  a  state  of  aggregation,  and  their  motions  regulated 
by  certain  fixed  and  invariable  laws.     The  animal  and  the  vegetable, 
on  the  other  hand,  are  products  of  generation ;  they  must  spring  from 
beings    similar  to  themselves ;    and   they  possess   the  force    of  life, 
which  controls  the  ordinary  forces  of  matter.     Yet  it  has  been  sup- 
posed, that  they  are  capable  of  creating  life ;  in  other  words,  that  a 
particular  organization  presupposes  life.     This  is  not  the  place  for 
entering  into  the  question  of  generation.    It  will  be  sufficient  at  present 
to  remark,  that  in  the  upper  classes  of  animals,  the  necessity  of  a  pa- 
rent cannot  be  contested ;  the  only  difficulty  that  can  possibly  arise 
regards  the  very  lowest  classes ;  and  analogy  warrants  the  conclusion, 
that  every  living  being  must  spring  from  an  egg  or  a  seed. 

2.  Shape. — The  shape  of  inorganic  bodies  is  not  fixed  in  a  deter- 
minate manner.     It  is  true,  that  by  proper  management  every  mineral 
can  be  reduced  to  a  primitive  nucleus,  which  is  the  same  in  all  minerals 
of  like  composition ;  still,  the  shape  of  the  mineral,  as  it  presents  itself 
to  us,  differs.     Carbonate  of  lime,  for  example,  although  it  may  always 
be  reduced  to  the  same  primitive  nucleus,  assumes  various  appearances ; 
— being  sometimes  rhomboidal;  at  others,  in  regular  hexahedral  prisms; 
— in  solids,  terminated  by  twelve  scalene  triangles,  or  in  dodecahedrons, 
whose  surfaces  are  pentagons.     In  organized  bodies,  on  the  contrary, 
the  shape  is  constant.     Each  animal  and  vegetable  has  the  one  that 
characterizes  its  species,  so  that  no  possible  mistake  can  be  indulged ; 
and  this  applies  not  only  to  the  whole  body,  but  to  every  one  of  its 
parts,  numerous  as  they  are. 

3.  Size. — The  size  of  an  inorganic  body  is  by  no  means  fixed.     It 
may  be  great,  or  small,  according  to  the  quantity  present  of  the  parti- 
cles that  have  to  form  it.     A  crystal,  for  example,  may  be  minute,  or 
the  contrary,  according  to  the  number  of  saline  particles  in  the  solu- 
tion.    On  the  other  hand,  organized  bodies  attain  a  certain  size, — at 

1  Fleming's  Philosophy  of  Zoology,  i.  4.     Edinburgh,  1822. 


INORGANIC  AND  ORGANIZED.  35 

times  by  a  slow,  at  others  by  a  more  rapid  growth, — but  in  all  cases 
the  due  proportion  is  preserved  between  the  various  parts, — between 
the  stem  and  the  root,  the  limb  and  the  trunk.  Each  vegetable  and 
each  animal  has  its  own  size,  by  which  it  is  known ;  and  although  we 
occasionally  meet  with  dwarf  or  gigantic  varieties,  these  are  unfrequent, 
and  mere  exceptions  establishing  the  position. 

4.  Chemical  character. — Great  difference  exists  between  inorganic 
and  organized  bodies  in  this  respect.  In  the  mineral  kingdom  are 
found  all  the  elementary  substances,  or  those  which  chemistry,  at  pre- 
sent, considers  simple;  amounting  to  at  least  sixty-three.  They  are  as 
follows : — Non-metallic  bodies.  Oxygen,  hydrogen,  nitrogen,  sulphur, 
selenium,  phosphorus,  chlorine,  iodine,  bromine,  fluorine,  carbon,  boron, 
silicon.  Metals.  Potassium,  sodium,  lithium,  calcium,  magnesium, 
barium,  strontium,  aluminium,  glucinium,  zirconium,  yttrium,  thorium, 
ironr  manganese,  zinc,  cadmium,  lead,  tin,  copper,  bismuth,  mercury, 
silver,  gold,  platinum,  rhodium,  palladium,  osmium,  iridium,  nickel, 
cobalt,  uranium,  cerium,  antimony,  arsenic,  chromium,  molybdenum, 
tungsten,  columbium,  tellurium,  titanium,  vanadium,  lantanium,  didy- 
mium,  erbium,  terbium,  pelopium,  niobium,  ruthenium,  norium,  and 
ilmenium.  In  the  organized,  a  few  only  of  these  elements  of  matter 
are  met  with,  viz.,  oxygen,  hydrogen,  azote,  carbon,  sulphur,  phosphorus, 
chlorine,  fluorine,  potassium,  sodium,  calcium,  silicium,  aluminium,  iron, 
manganese,  titanium,  and  arsenic. 

The  composition  of  inorganic  bodies  is  more  simple ;  several  consist 
of  but  one  element;  and,  when  composed  of  more,  the  combination  is 
rarely  higher  than  ternary.  Organized  bodies,  on  the  other  hand,  are 
never  simple,  nor  even  binary.  They  are  always  at  least  ternary  or 
quaternary.  The  simplest  vegetable  consists  of  a  union  of  oxygen, 
carbon,  and  hydrogen ;  the  simplest  animal,  of  oxygen,  hydrogen, 
carbon,  and  nitrogen. 

The  composition  of  the  mineral,  again,  is  constant.  Its  elements 
have  entirely  satisfied  their  affinities ;  and  all  remains  at  rest.  In  the 
organized  kingdom,  the  affinities  are  not  satisfied;  compounds  are  formed 
to  be  again  decomposed ;  and  this  happens  from  the  earliest  period  of 
foetal  formation  till  the  cessation  of  life :  all  is  in  commotion,  and  the 
chemical  character  of  the  corporeal  fabric  incessantly  undergoing 
modification.  This  applies  to  every  organized  body ;  and,  accordingly, 
change  of  some  kind  is  essential  to  our  idea  of  active  life.  In  the  case 
of  the  seed,  which  has  remained  unaltered  for  centuries,  and  subse- 
quently vegetates  under  favourable  circumstances,  life  may  be  considered 
to  be  dormant  or  suspended.  It  possesses  vitality,  or  the  power  of 
being  excited  to  active  life  under  favouring  influences. 

In  chemical  nomenclature,  the  term  element  has  a  different  accepta- 
tion, according  as  it  is  applied  to  inorganic  or  organic  chemistry.  In 
the  former,  it  means  a  substance,  which,  in  the  present  state  of  science, 
does  not  admit  of  decomposition.  We  say,  "jn  the  present  state  of 
the  science,"  for  several  bodies,  now  esteemed  compound,  were,  not 
many  years  ago,  classed  amongst  the  simple  or  elementary.  It  is  not 
much  more  than  thirty  years  since  the  alkalies  were  found  to  be  com- 
posed of  two  elements.  Previously,  they  were  considered  simple.  In 


36  NATURAL  BODIES. 

the  animal  and  the  vegetable,  we  find  substances,  also  called  elements, 
but  with  the  epithet  organic  prefixed,  because  they  are  only  found  in 
organized  bodies;  and  are  therefore  the  exclusive  products  of  organi- 
zation and  life.  For  example,  in  both  animals  and  vegetables  we  meet 
with  oxygen,  hydrogen,  carbon,  nitrogen,  and  different  metallic  sub- 
stances :  these  are  chemical  or  inorganic  elements.  We  further  meet 
with  albumen,  gelatin,  fibrin,  osmazome,  &c.,  substances  which  consti- 
tute the  various  organs,  and  have,  therefore,  been  termed  organic  ele- 
ments or  compounds  of  organization;  yet  they  are  capable  of  decom- 
position ;  and  in  one  sense,  therefore,  not  elementary. 

In  the  inorganic  body,  all  the  elements,  that  constitute  it,  are  formed 
by  the  agency  of  general  chemical  affinities ;  but,  in  the  organized, 
the  formation  is  produced  by  the  force  that  presides  over  the  formation 
of  the  organic  elements  themselves, — the  force  of  life.  Hence,  the 
chemist  is  able  to  recompose  many  inorganic  bodies;  whilst  the  products 
of  organization  and  life  set  his  art  at  defiance. 

The  different  parts  of  an  inorganic  body  enjoy  an  existence  inde- 
pendent of  each  other ;  whilst  those  of  the  organized  are  materially 
dependent.  No  part  can,  indeed,  be  injured  without  the  mass  and  the 
separated  portion  being  more  or  less  affected.  If  we  take  a  piece  of 
marble,  which  is  composed  of  carbonic  acid  and  lime,  and  break  it 
into  a  thousand  fragments,  each  portion  will  be  found  to  consist  of 
carbonic  acid  and  lime.  The  mass  will  be  destroyed ;  but  the  pieces 
will  not  suffer  from  the  disjunction.  They  will  continue  as  fixed  and 
unmodified  as  at  first.  Not  so  with  an  organized  body.  If  we  tear 
the  branch  from  a  tree,  the  stem  itself  participates  more  or  less  in  the 
injury;  the  detached  branch  speedily  undergoes  striking  changes;  it 
withers ;  becomes  shrivelled ;  and,  in  the  case  of  the  succulent  vege- 
table, undergoes  decomposition ;  certain  of  its  constituents,  no  longer 
held  in  control  by  vital  agency,  enter  into  new  combinations,  are  given 
off  in  the  form  of  gas,  and  the  remainder  sinks  to  earth. 

Changes,  no  less  impressive,  occur  in  the  animal  when  a  limb  is 
separated  from  the  body.  The  parent  trunk  suffers  ;  the  system  recoils 
at  the  first  infliction  of  the  injury,  but  subsequently  arouses  itself  to  a 
reparatory  effort, — at  times  with  such  energy  as  to  destroy  its  own 
vitality.  The  separated  limb,  like  the  branch,  is  given  up,  uncontrolled, 
to  new  affinities ;  and  putrefaction  soon  reduces  the  mass  to  a  state 
in  which  its  previously  admirable  organization  is  no  longer  perceptible. 
Some  of  the  lower  classes  of  animals  may,  indeed,  be  divided  with  im- 
punity; and  with  no  other  effect  than  that  of  multiplying  the  animal 
in  proportion  to  the  number  of  sections  ;  but  these  cases  are  exceptions; 
and  we  may  regard  the  destructive  process, — set  up  when  parts  of 
organized  bodies  are  separated, — as  one  of  the  best  modes  of  distinction 
between  the  inorganic  and  organized  classes. 

5.  Texture. — In  this  respect  the  inorganic  and  organized  differ  con- 
siderably,— a  difference  which  has  given  rise  to  their  respective  appel- 
lations. To  the  structure  of  the  latter  class  only  can  the  term  texture 
be  with  propriety  applied.  If  we  examine  a  vegetable  or  animal  sub- 
stance with  attention,  we  find,  that  it  has  a  regular  and  determinate 
arrangement  or  structure ;  and  readily  discover,  that  it  consists  of  va- 


INORGANIC  AND  ORGANIZED.  37 

rious  parts ; — in  the  vegetable,  of  wood,  bark,  leaves,  roots,  flowers, 
&c. ;  and  in  the  animal,  of  muscles,  nerves,  vessels,  &c. ;  all  of  which 
appear  to  be  instruments  or  organs  for  special  purposes  in  the  economy. 
Hence,  the  body  is  said  to  be  organized,  and  the  result,  as  well  as  the 
process,  is  often  called  organization.  Properly,  organization  means 
the  process  by  which  an  organized  being  is  formed;  organism,  the  result 
of  such  process,  or  organic  structure. 

The  particles  of  matter  in  an  organized  body,  in  many  instances, 
constitute  fibres,  which  interlace  and  intersect  each  other  in  all  direc- 
tions, and  form  a  spongy  areolar  texture  or  tissue,  of  which  the  various 
organs  of  the  body  are  composed.  These  fibres,  and  indeed  every  or- 
ganized structure,  are  considered  by  modern  histologists  to  be  formed 
originally  from  cellgerms  or  cytoblasts :  the  resulting  cells  assuming 
an  arrangement  appropriate  to  the  particular  tissue.  "  A  texture,"  says 
Mr.  Goodsir,1  "  maybe  considered  either  by  itself,  or  in  connexion  with 
the  parts  which  usually  accompany  it.  These  subsidiary  parts  may  be 
entirely  removed  without  interfering  with  the  anatomical  constitution 
of  the  texture.  It  is  essentially  non-vascular ; — neither  vessels  nor 
nerves  entering  into  its  intimate  structure.  It  possesses  in  itself  those 
powers  by  which  it  is  nourished,  produces  its  kind,  and  performs  the 
actions  for  which  it  is  destined,  the  subsidiary  or  superadded  parts  sup- 
plying it  with  materials,  which  it  appropriates  by  its  own  inherent 
powers,  or  connecting  it  in  sympathetic  and  harmonious  action  with 
other  parts  of  the  organism  to  which  it  belongs.  In  none  of  the  tex- 
tures are  these  characters  more  distinctly  seen  than  in  the  osseous.  A 
well-macerated  bone  is  one  of  the  most  easily  made,  and  at  the  same 
time  one  of  the  most  curious  of  anatomical  preparations.  It  is  a  per- 
fect example  of  a  texture  completely  isolated ;  the  vessels,  nerves,  mem- 
branes, and  fat,  are  all  separated ;  and  nothing  is  left  but  the  non- 
vascular  osseous  substance." 

In  the  inorganic  substance  the  mass  is  homogeneous ;  the  smallest 
particle  of  marble  consists  of  carbonic  acid  and  lime ;  and  all  the  par- 
ticles concur  alike  in  its  formation  and  preservation. 

Lastly,  while  an  inorganic  body,  of  a  determinate  species,  has  always 
a  fixed  composition,  the  living  being,  although  constituting  a  particular 
species,  may  present  individual  differences,  which  give  rise  in  the  animal, 
to  various  temperaments,  constitutions,  go. 

6.  Mode  of  preservation. — Preservation  of  the  species  is,  in  organ- 
ized bodies,  the  effect  of  reproduction.  As  regards  individual  preser- 
vation, that  of  the  mineral  is  dependent  upon  the  same  actions  that 
effected  its  formation ;  on  the  persistence  of  the  affinities  of  cohesion 
and  combination  that  united  its  various  particles.  The  animal  and  the 
vegetable,  on  the  other  hand,  are  maintained  by  a  mechanism  peculiar 
to  themselves.  From  the  bodies  surrounding  them  they  lay  hold  of 
nutritious  matter,  which,  by  a  process  of  elaboration,  they  assimilate  to 
their  own  composition ;  at  the  same  time,  they  are  constantly  absorbing 

.  *  Anatomical  and  Pathological  Observations,  p.  64,  Edinburgh,  1845.  See  also  Schwann, 
Microscopical  Researches  into  the  Accordance  in  the  Structure  and  Growth  of  Animals  and 
Plants;  translated  by  Henry  Smith.  Sydenham  Society  edit.  Lond.  1847. 


38  NATURAL  BODIES. 

or  taking  up  particles  of  their  own  structure,  and  throwing  them  off. 
The  actions  of  composition  and  decomposition  are  constant  whilst  life 
persists ;  although  subject  to  particular  modifications  at  different  pe- 
riods of  existence,  and  under  different  circumstances. 

Again : — the  inorganic  and  organized  are  alike  subject  to  changes 
during  their  existence ;  but  the  character  of  these  changes,  in  the  two 
classes,  differs  essentially.  The  mineral  retains  its  form,  unless  acted 
upon  by  some  mechanical  or  chemical  force.  Within,  all  the  particles 
are  at  rest,  and  no  internal  force  exists,  which  can  subject  them  to 
modification.  There  is  no  succession  of  conditions  that  can  be  termed 
ages.  How  different  is  the  case  with  organized  bodies !  Internally, 
there  is  no  rest ;  from  birth  to  death  all  is  in  a  state  of  activity.  The 
plant  and  the  animal  are  subject  to  incessant  changes.  Each  runs 
through  a  succession  of  conditions  or  ages.  We  see  it  successively  de- 
velope  its  structure  and  functions,  attain  maturity,  and  finally  decay. 

Characteristic  differences  likewise  exist  in  the  external  conformation 
of  the  beings  of  the  two  divisions,  as  well  as  in  their  mode  of  increase. 
Inorganic  bodies  have  no  covering  to  defend  them ;  no  exterior  enve- 
lope to  preserve  their  form ;  a  stone  is  the  same  at  its  centre  as  at 
its  circumference;  whilst  organized  bodies  are  protected  by  an  elastic 
and  extensible  covering,  differing  from  the  parts  beneath,  and  inservient 
to  valuable  purposes  in  the  economy. 

Every  change  to  which  an  inorganic  body  is  liable  must  occur  at  its 
surface.  It  is  there  that  the  particles  are  added  or  abstracted  when 
it  experiences  increase  or  diminution.  Increase — for  growth  it  can 
scarcely  be  termed — takes  place  by  accretion  or  juxtaposition,  that  is, 
by  the  successive  application  of  fresh  particles  upon  those  that  form 
the  nucleus  ;  and  diminution  in  bulk  is  produced  by  the  removal  of 
the  external  layers  or  particles.  In  organized  substances,  increase  or 
growth  is  caused  by  particles  deposited  internally,  and  diminution  by 
particles  subtracted  from  within.  We  see  them,  likewise,  under  two 
conditions,  to  which  there  is  nothing  similar  in  the  mineral  kingdom — 
health,  and  disease.  In  the  former,  the  functions  are  executed  with 
freedom  and  energy ;  in  the  latter,  with  oppression  and  restraint. 

7.  Termination. — Every  body,  inorganic  or  organized,  may  cease  to 
exist,  but  the  mode  of  cessation  varies  greatly  in  the  two  classes.  The 
mineral  is  broken  down  by  mechanical  violence ;  or  it  ceases  to  exist 
in  consequence  of  modifications  in  the  affinities,  which  held  it  concrete. 
It  has  no  fixed  duration ;  and  its  existence  may  be  terminated  at  any 
moment,  when  the  circumstances,  that  retained  it  in  aggregation,  are 
destroyed.  The  vegetable  and  the  animal,  on  the  other  hand,  carry 
on  their  functions  for  a  period  only  which  is  fixed  and  determinate  for 
each  species.  For  a  time,  new  particles  are  deposited  internally.  The 
bulk  is  augmented,  and  the  external  envelope  distended,  until  maturity 
or  full  developement  is  attained  ;  but,  after  this,  decay  commences ;  the 
functions  are  exerted  with  gradually  diminishing  energy;  the  fluids 
decrease  in  quantity ;  and  the  solids  become  more  rigid, — circumstances 
premonitory  of  the  cessation  of  vitality.  This  term  of  duration  is 
different  in  different  species.  Whilst  many  of  the  lower  classes  of  ani- 


ANIMALS  AND  VEGETABLES.  69 

mals  and  vegetables  have  but  an  ephemeral  existence,  some  of  the 
more  elevated  individuals  of  the  two  kingdoms  outlive  a  century. 

8.  Motive  forces i — Lastly,  observation  has  satisfactorily  proved,  that 
there  are  certain  forces,  which  affect  matter  in  general,  inorganic  as 
well  as  organized ;  and  that,  in  addition  to  these,  organized  bodies 
possess  a  peculiar  force  or  forces,  which  modify  them  in  a  remarkable 
manner.  Hence,  we  have  general  forces;  and  special  or  vital;  the  first 
acting  upon  all  matter,  the  dead  and  the  living,  and  including  the  forces 
of  gravitation,  cohesion,  chemical  affinity,  &c. ;  the  latter  appertaining 
exclusively  to  living  beings. 

Such  are  the  chief  distinctions  to  be  drawn  between  the  two  great 
divisions  of  natural  bodies ;  the  inorganic  and  the  organized.  By  the 
comparison  which  has  been  instituted,  the  objects  of  physiology  have 
been  indicated.  To  inquire  into  the  mode  in  which  a  living  being  is 
born,  nourished,  reproduced,  and  dies,  is  the  legitimate  object  of  the 
science.  We  have,  however,  entered  only  into  a  comparison  between 
the  inorganic  and  the  organized.  The  two  divisions  constituting  the 
latter  class  differ  also  materially  from  each  other.  Into  these  differ- 
ences we  shall  now  inquire. 

2.    DIFFERENCE  BETWEEN  ANIMALS  AND  VEGETABLES. 

The  distinctions  between  the  divisions  of  organized  bodies  are  not  so 
rigidly  fixed,  or  so  readily  appreciated,  as  those  between  the  inorganic 
and  the  organized.  There  are  certain  functions  possessed  by  both ; 
hence  called  vegetative,  plastic,  or  organic, — nutrition  and  reproduction, 
for  example  ;  but  vegetables  are  endowed  with  these  only.  All  organ- 
ized bodies  must  have  the  power  of  assimilating  foreign  matters  to  their 
own  substance,  and  of  producing  a  living  being  similar  to  themselves ; 
otherwise,  the  species,  having  a  limited  duration,  would  perish.  In 
addition  to  these  common  functions,  animals  have  sensation  and  volun- 
tary motion ;  by  the  possession  of  which  they  are  said  to  be  animated. 
Hence,  they  are  termed  animals,  and  the  condition  is  called  animality. 
This  division  of  the  functions  into  animal  and  organic  has  been  adopted, 
with  more  or  less  modification,  by  most  physiologists. 

Between  animals  and  vegetables,  situate  high  in  their  respective 
scales,  no  confusion  can  exist.  The  characters  are  obvious  at  sight. 
No  one  can  confound  the  horse  with  the  oak ;  the  butterfly  with  the 
potato.  It  is  on  the  lower  confines  of  the  two  kingdoms,  that  we  are 
liable  to  be  deceived.  Many  of  the  zoophytes  have  alternately  been 
considered  vegetable  and  animal ;  but  we  are  generally  able  to  classify 
any  doubtful  substance  with  accuracy;  and  the  following  are  the  prin- 
cipal points  of  difference. 

1.  Composition. — It  was  long  supposed,  that  the  essential  difference 
between  animal  and  vegetable  substances  consists  in  the  former  con- 
taining nitrogen ;  whilst  the  latter  do  not.  Modern  researches  have, 
however,  satisfactorily  shown,  that  the  organized  portions  of  animals 
and  vegetables  are  essentially  alike ;  and  consist  of  the  four  elements, 
— carbon,  oxygen,  hydrogen,  and  nitrogen ;  whilst  the  unorganized — 
as  the  fat  of  the  animal,  and  the  starch  of  the  vegetable — are  composed 
of  three  elements  only — carbon,  oxygen,  and  hydrogen.  Still,  their 


40  NATURAL  BODIES. 

intimate  composition  must  vary  greatly;  for,  when  burning,  the  animal 
substance  is  readily  known  from  the  vegetable ; — a  fact,  which,  as  Dr. 
Fleming1  has  remarked,  is  interesting  to  the  young  naturalist,  if  un- 
certain to  which  kingdom  to  refer  any  substance  met  with  in  his  re- 
searches. The  smell  of  a  burnt  sponge,  of  coral,  or  other  zoophytic 
animal,  is  so  peculiar,  that  it  can  scarcely  be  mistaken  for  that  of  a 
vegetable  body  in  combustion.  According  to  Mulder,2  there  is  this  real 
difference  between  plants  and  animals  in  composition,  that  cellulose 
(C24H21021)  forms  the  principal  part  of  the  cellular  mass  in  plants ; 
whilst  in  animals  the  primary  material  is  gelatin  (C13H10N205) ;  and  to 
this  rule,  he  says,  no  exception  has  yet  been  discovered  either  among 
animals  or  plants. 

2.  Texture. — In  this  respect,  important  differences  are  observable. 
Both  animals  and  vegetables  consist  of  solid  and  fluid  parts.     In  the 
former,  however,  the  fluids  bear  a  large  proportion :  in  the  latter,  the 
solids.     This  is  the  cause,  why  decomposition  occurs  so  much  more 
rapidly  in  the  animal  than  in  the  vegetable ;  and  in  the  succulent  more 
than  in  the  dry  vegetable.     If  we  analyze  the  structure  of  the  vege- 
table, we  cannot  succeed  in  detecting  more  than  one  elementary  tissue, 
which  is  vesicular  or  areolar,  or  arranged  in  vesicles  or  areolse,  and 
appears  to  form  every  organ  of  the  body;  whilst,  in  the  animal,  we 
discover  at  least  three  of  these  anatomical  elements,  the  areolar — 
analogous  to  that  of  the  vegetable ; — the  muscular,  and  the  nervous. 
The  vegetable  again  has  no  great  splanchnic  cavities  containing  the 
chief  organs   of  the  body.     It  has  a  smaller  number  of  organs,  and 
none  that  are  destined  for  sensation  or  volition ;  in  other  words,  no 
brain,  no  nerves,  no  muscular  system ;  and  the  organs  of  which  it  con- 
sists are  simple,  and  readily  convertible  into  each  other. 

But  these  differences  in  organization,  striking  as  they  may  appear, 
are  not  sufficient  for  rigid  discrimination,  as  they  are  applicable  only 
to  the  upper  classes  of  each  kingdom.  In  many  vegetables,  the  fluids 
appear  to  preponderate  over  the  solids ;  numerous  animals  are  devoid 
of  muscular  and  nervous  tissues,  and  apparently  of  vessels  and  distinct 
organs;  whilst  MM.  Dutrochet,3  Brachet,4  and  others,5  admit  the 
existence  of  a  rudimental  nervous  system  even  in  vegetables. 

3.  Sensation  and  voluntary  motion. — There  is  one  manifest  distinc- 
tion between  animals  and  vegetables.     Whilst  the  latter  receive  their 
nutrition  from  the  objects  around  them — irresistibly  and  without  voli- 
tion, or  the  participation  of  mind;  and  whilst  the  function  of  repro- 
duction is  effected  without  the  union  of  the  sexes,  both  volition  and  sen- 
sation are  necessary  for  the  nutrition  of  the  former,  and  for  acts  that 
are  requisite  for  the  reproduction  of  the  species.     Hence,  the  necessity 

1  Philosophy  of  Zoology,  i.  41.     Edinburgh,  1822. 

Q  The  Chemistry  of  Animal  and  Vegetable  Physiology;  translated  by  Fromberg,  p.  91. 
Edinburgh  and  London,  1849. 

3  Recherches  Anatomiques  et  Physiologiques  sur  la  Structure  Intime  des  Animaux,  et  des 
Vegetaux,  et  sur  leur  Motilite.     Paris,  1824. 

4  Recherches  Experimental  sur  les  Fonctions  du  Systeme  Nerveux  Ganglionnaire,  &c. 
2d  edit.     Paris  et  Lyons,  1837. 

6  Sir  J.  E.  Smith,  Introduction  to  Botany,  7th  edit.,  by  Sir  W.  J.  Hooker,  p.  40.  Lond. 
1833. 


ANIMALS  AND  VEGETABLES.  41 

of  two  faculties  or  functions  in  the  animal,  that  are  wanting  in  the 
vegetable, — sensibility ',  or  the  faculty  of  consciousness  and  feeling ;  and 
motility,  or  the  power  of  moving  at  will  the  whole  body  or  any  of  its 
parts.  Vegetables  are  possessed  of  spontaneous,  but  not  of  voluntary 
motion.  Of  the  former  we  have  numerous  examples  in  the  direction 
of  the  branches  and  upper  surfaces  9f  the  leaves,  although  repeatedly 
disturbed,  to  the  light ;  and  in  the  unfolding  and  closing  of  flowers  at 
stated  periods  of  the  day.  This,  however,  is  distinct  from  the  sensi- 
bility and  motility  that  characterize  the  animal.  By  sensibility  man 
feels  his  own  existence, — becomes  acquainted  with  the  universe, — ap- 
preciates the  bodies  that  compose  it;  and  experiences  all  the  desires 
and  inward  feelings  that  solicit  him  to  the  performance  of  those  ex- 
ternal actions,  which  are  requisite  for  his  preservation  as  an  individual, 
and  as  a  species ;  and  by  motility  he  executes  those  external  actions 
which  his  sensibility  may  suggest  to  him. 

By  some  naturalists  it  has  been  maintained,  that  those  plants,  which 
are  borne  about  on  the  waves,  and  fructify  in  that  situation,  exhibit 
examples  of  the  locomotility,  which  is  described  as  characteristic  of 
the  animal.  One  of  the  most  interesting  novelties  in  the  monotonous 
occurrences  of  a  voyage  across  the  Atlantic  towards  the  Gulf  of  Flo- 
rida is  the  almost  interminable  quantity  of  Fucus  natans,  Florida 
weed  or  Grulf  weed,  with  which  the  surface  of  the  ocean  is  covered. 
But  how  different  is  this  from  the  locomotion  of  animals !  It  is  a 
subtlety  to  conceive  them  identical.  The  weed  is  passively  and  uncon- 
sciously borne  whithersoever  the  winds  and  the  waves  may  urge  it ; 
whilst  animal  locomotion  requires  the  direct  agency  of  volition,  of  a 
nervous  system  that  can  excite,  and  of  muscles  that  can  act  under  such 
excitement. 

The  spontaneity  and  perceptivity  of  plants  must  also  be  explained  in 
a  different  manner  from  the  elevated  function  of  sensibility  on  which 
we  shall  have  to  dwell.  These  properties  must  be  referred  to  the  fact 
of  certain  vegetables  being  possessed  of  the  faculty  of  contracting  on 
the  application  of  a  stimulus,  independently  of  sensation  or  conscious- 
ness. If  we  touch  the  leaf  of  the  sensitive  plant,  Mimosa  pudica,  the 
various  leaflets  collapse  in  rapid  succession.  In  the  barberry  bush, 
Berberis  vulgaris,  we  have  another  example  of  the  possession  of  this 
faculty.  In  the  flower,  the  six  stamens,  spreading  moderately,  are  shel- 
tered under  the  concave  tips  of  the  petals,  till  some  extraneous  body, 
as  the  feet  or  trunk  of  an  insect  in  search  of  honey,  touches  the  inner 
part  of  each  filament,  near  the  bottom.  The  susceptibility  of  this  part 
is  such,  that  the  filament  immediately  contracts,  and  strikes  its  anther, 
full  of  pollen,  against  the  stigma.  Any  other  part  of  the  filament  may 
be  touched  without  this  result,  provided  no  concussion  be  given  to  the 
whole.  After  a  while,  the  filament  retires  gradually,  and  may  be  again 
stimulated ;  and  when  each  petal,  with  its  annexed  filament,  has  fallen 
to  the  ground,  the  latter,  on  being  touched,  shows  as  much  sensibility 
as  ever.1 

These  singular  effects  are  produced  by  the  power  of  contractility  or 

1  Sir  J.  E.  Smith's  Introduction  to  Botany,  p.  325. 


42  NATURAL  BODIES. 

irritability,  the  nature  of  which  will  fall  under  consideration  here- 
after. It  is  possessed  equally  by  animals  and  vegetables,  and  is  essen- 
tially organic  and  vital.  This  power,  we  shall  see,  needs  not  the 
intervention  of  volition:  it  is  constantly  exerted  in  the  animal  without 
consciousness,  and  therefore  necessarily  without  volition.  Its  existence 
in  vegetables  does  not,  consequently,  demonstrate  that  they  are  pos- 
sessed of  consciousness. 

4.  Nutrition. — A  great  difference  exists  between  plants  and  animals 
in  ^this  respect.     The  plant,  being  fixed  to  the  soil,  cannot  search  after 
food.     It  must  be  passive  ;  and  obtain  its  supplies  from  the  materials 
around,  and  in  contact  with  it ;  and  the  absorbing  vessels  of  nutrition 
must  necessarily  open  on  its  exterior.     In  the  animal,  on  the  other 
hand,  the  aliment  is  scarcely  ever  found  in  a  state  fit  for  absorption  : 
it  is  crude,  and  in  general — Ehrenberg1  thinks  always — requires  to  be 
received  into  a  central  organ   or  stomach,  for  the  purpose  of  under- 
going changes,  by  a  process  termed  digestion,  which  adapts  it  for  the 
nutrition  of  the  individual.     The  absorbing  vessels  of  nutrition  arise, 
in  this  case,  from  the  internal  or  lining  membrane  of  the  alimentary 
tube.     The  analogy  that  exists  between  these  two  kinds  of  absorption 
is  great,  and  had  not  escaped  the  attention  of  the  ancients* — Quem- 
admodum  terra  arboribus,  ita  animalibus  ventriculus  sicut  humus," 
was    an  aphoristic   expression  of  universal  reception.     With  similar 
feelings,  Boerhaave  asserts,  that  animals  have  their  roots  of  nutrition 
in  their  intestines ;  and  Dr.  Alston2  has  fancifully  termed  a  plant  an 
inverted  animal. 

After  all,  however,  the  most  essential  difference  consists  in  the  steps 
that  are  preliminary  to  the  reception  of  food.  These,  in  the  animal, 
are  voluntary, — requiring  prehension ;  often  locomotion ;  and  always 
consciousness. 

5.  Reproduction. — In  this  function  we  find  a  striking  analogy  be- 
tween animals  and  vegetables ;  but  differences  exist,  which  must  be 
referred  to  the   same   cause  that  produced  many  of  the  distinctions 
already  pointed  out, — the  possession,  by  the  animal,  of  sensibility  and 
locomotility.     For  example,  every  part  of  the  generative  act,  as  before 
remarked,  is,  in  the  vegetable,  without  the  perception  or  volition  of  the 
being: — the  union  of  the  sexes,  fecundation,  and  the  birth  of  the  new 
individual  are  alike  automatic.     In  the  animal,  on  the  other  hand,  the 
approximation  of  the  sexes  is  always  voluntary  and  effected  consciously : 
— the  birth  of  the  new  individual  being  not  only  perceived,  but  some- 
what aided  by  volition.     Fecundation  alone  is  involuntary  and  irre- 
sistible. 

Again,  in  the  vegetable  the  sexual  organs  do  not  exist  at  an  early 
period ;  and  are  not  developed  until  reproduction  is  practicable.  They 
are  capable  of  acting  for  once  only,  and  perish  after  fecundation ;  and 
if  the  plant  be  vivacious,  they  fall  off  after  each  reproduction,  and  are 
annually  renewed.  In  the  animal,  on  the  contrary,  they  exist  from  the 
earliest  period  of  foetal  development,  survive  repeated  fecundations, 
and  continue  during  the  life  of  the  individual. 

1  Edinb.  New  Philosophical  Journal,  for  Sept.  1831 ;  and  Jan.  1838,  p.  232. 
a  Tirocinium  Botanicum  Edinburgense,  8vo.,  Edinb.  1753. 


MATERIAL  COMPOSITION  OF  MAN.  43 

Lastly,  the  possession  of  sensibility  and  locomotility  leads  to  other 
characteristics  of  animated  beings.  These  functions  are  incapable  of 
constant,  unremitting  exertion.  Sleep,  therefore,  becomes  necessary. 
The  animal  is  also  capable  of  expression,  or  of  language,  in  a  degree 
proportionate  to  the  extent  of  his  sensibility,  and  of  his  power  over  the 
beings  that  surround  him. 

But  these  differences  in  function  are  not  so  discriminate  as  they  may 
appear  at  first.  There  are  many  animals,  that  are  as  irresistibly  at- 
tached to  the  soil  as  the  vegetables  themselves.  Like  the  latter,  they 
must,  of  necessity,  be  compelled  to  absorb  their  food  in  the  state  in 
which  it  is  presented  to  them.  Sensibility  and  locomotility  appear,  in 
the  zoophyte,  to  be  no  more  necessary  than  in  the  vegetable.  No 
nervous,  no  muscular  system  is  required;  and,  accordingly,  none  can 
be  traced  in  them ;  whilst  many  of  those  spontaneous  motions  of  the 
vegetable,  to  which  allusion  has  been  made,  have  been  considered  by 
some  to  indicate  the  first  rudiments  of  sensibility  and  locomotility;  and 
Linnaeus1  has  regarded  the  closure  of  the  flowers  towards  night  as  the 
sleep,  and  the  movements  of  vegetables,  for  the  approximation  of  the 
sexual  organs,  as  the  marriage,  of  plants. 

«  II.  GENERAL  PHYSIOLOGY  OF  MAN. 

The  observations  made  on  the  differences  between  animals  and  vege- 
tables have  anticipated  many  topics,  that  would  require  consideration 
under  this  head.  These  general  properties,  which  man  possesses  along 
with  other  animals,  have  been  referred  to  in  a  cursory  manner.  They 
will  now  demand  a  more  special  investigation. 

1.    MATERIAL  COMPOSITION  OF  MAN. 

The  detailed  study  of  human  organization  is  the  province  of  the 
anatomist, — of  its  intimate  composition,  that  of  the  chemist.  In  ex- 
plaining the  functions  executed  by  the  various  organs,  the  physiologist 
will  frequently  have  occasion  to  trench  upon  both. 

The  bones,  in  the  aggregate,  form  the  skeleton.  The  base  of  the 
skeleton  is  a  series  of  vertebrse,  with  the  skull  as  a  capital, — itself  re- 
garded as  a  vertebra.  This  base  is  situate  on  the  median  line  through 
the  whole  trunk,  and  contains  a  cavity,  in  which  are  lodged  the  brain 
and  spinal  marrow.  On  each  side  of  this,  other  bones,  which  by  some 
have  been  called  appendices,  are  arranged  in  pairs.  Upon  the  skeleton 
are  placed  muscles,  for  moving  the  different  parts  of  the  body ;  and  for 
changing  its  situation  with  regard  to  the  soil.  The  body  is  divided 
into  trunk  and  limbs.  The  trunk,  which  is  the  principal  portion,  is 
composed  of  three  splanchnic  cavities,  the  abdomen,  thorax,  and  head, 
situate  one  above  the  other.  They  contain  the  most  important  organs 
of  the  body, — those  that  effect  the  functions  of  sensibility,  digestion, 
respiration,  circulation,  &c.  The  head  comprises  the  face,  in  which  are 
the  organs  of  four  of  the  senses — sight,  hearing,  smell,  and  taste, — 
and  the  cranium,  which  lodges  the  brain — the  organ  of  the  mental 
manifestations,  and  the  most  elevated  part  of  the  nervous  system.  The 

1  Amcenit.  Academ.,  torn.  iv. 


44  MATERIAL  COMPOSITION  OF  MAN. 

thorax  or  chest  contains  the  lungs — organs  of  respiration — and  the 
heart,  the  central  organ  of  the  circulation.  The  abdomen  contains  the 
principal  organs  of  digestion,  and  (if  we  include  in  it  the  pelvis),  those 
of  the  urinary  secretion  and  of  generation.  Of  the  limbs,  the  upper, 
suspended  on  each  side  of  the  thorax,  are  instruments  of  prehension; 
and  are  terminated  by  the  hand,  the  great  organ  of  touch.  The  lower 
are  beneath  the  trunk ;  and  are  agents  for  supporting  the  body,  and 
for  locomotion.  Vessels,  emanating  from  the  heart,  are  distributed  to 
every  part, — conveying  to  them  the  blood  necessary  for  their  life  and 
nutrition:  these  are  the  arteries.  Other  vessels  communicate  with 
them,  and  convey  the  blood  back  to  the  heart — the  veins;  whilst  a  third 
set  arise  in  the  tissues,  and  convey  into  the  circulation,  by  a  particular 
channel,  a  fluid  called  lymph — whence  they  derive  the  name  lymphatics. 
Nerves,  communicating  with  the  great  central  masses  of  the  nervous 
system,  are  distributed  to  every  part ;  and  lastly,  a  membrane  or  layer, 
possessed  of  acute  sensibility — the  skin — serves  as  an  outer  envelope 
to  the  whole  body. 

It  was  before  observed,  that  two  kinds  of  elements  enter  into  the 
composition  of  the  body — the  chemical  or  inorganic;  and  the  organic, 
which  are  compound,  and  formed  only  under  the  force  of  life. 

The  chief  CHEMICAL  or  INORGANIC  ELEMENTS,  met  with,  are — oxygen, 
hydrogen,  carbon,  nitrogen,  phosphorus,  calcium ;  and,  in  smaller  quan- 
tity, sulphur,  iron,  manganese,  calcium,  silicium,  aluminium,  chlorine; 
also,  sodium,  magnesium,  &c.  &c. 

1.  Oxygen. — This  is  widely  distributed  in  the  solids  and  fluids ;  and 
a  constant  supply  of  it  from  the  atmosphere  is  indispensable  to  animal 
life.     It  is  almost  always  found  combined  with  other  bodies ;  often  in 
the  form  of  carbonic  acid, — that  is,  united  with  carbon.    In  a  separate 
state  it  is  met  with  in  the  air-bag  of  fishes,  in  which  it  is  found  varying 
in  quantity,  according  to  the  species,  and  the  depth  at  which  the  fish 
has  been  caught. 

2.  Hydrogen. — This  gas  occurs  universally  in  the  animal  kingdom. 
It  is  a  constituent  of  all  the  fluids,  and  of  many  of  the  solids;  and  is 
generally  in  a  state  of  combination  with  carbon.     In  the  human  intes- 
tines it  has  been  found  pure,  as  well  as  combined  with  carbon  and  sul- 
phur. 

3.  Carbon. — This  substance  is  met  with  under  various  forms,  in  both 
fluids  and  solids.     It  is  most  frequently  found  under  that  of  carbonic 
acid.     Carbonic  acid  has  been  detected  in  an  uncombined  state  in  urine 
by  Front ;  and  in  the  blood  by  Vogel.1     It  exists  in  the  intestines  of 
animals ;  but  is  chiefly  met  with  in  animal  bodies,  in  combination  with 
the  alkalies  or  earths ;  and  is  emitted  by  all  animals  in  the  act  of  re- 
spiration. 

4.  Nitrogen. — This  gas  is  likewise  widely  distributed  as  a  component 
of  animal  substances,  and  especially  of  the  tissues.     It  occurs  in  an 
uncombined  state,  in  the  swimming-bladder  of  certain  fishes. 

5.  Phosphorus  is  an  essential  constituent  of  neurine ;  and  is  found 
united  with  oxygen,  in  the  state  of  phosphoric  acid,  in  many  of  the 

1  Annals  of  Philosophy,  vii.  56. 


MATERIAL  COMPOSITION  OF  MAN.  45 

solids  and  fluids.  It  is  this  acid  that  is  combined  with  the  earthy  mat- 
ter of  bones ;  and  with  potassa,  soda,  ammonia,  and  magnesia,  in  other 
parts.  It  is  supposed  to  give  rise  to  the  luminousness  of  certain  ani- 
mals— as  of  the  firefly,  Pyrosoma  Atlanticum,  &c. — but  nothing  pre- 
cise is  known  on  this  subject. 

6.  Calcium. — This  metal  is  found  in  the  animal  economy  only  in  the 
state  of  oxide — lime  ;  and  it  is  generally  united  with  phosphoric  or  car- 
bonic acid.     It  is  the  earth,  of  which  the  hard  parts  of  animals  are 
constituted. 

7.  Sulphur  is  not  met  with  extensively  in  animal  solids  or  fluids;  nor 
is  it  often  found  free,  but  usually  in  combination  with  oxygen  united  to 
soda,  potassa,  or  lime.     It  seems  to  be  an  invariable  concomitant  of 
albumen ;  and  is  found  in  the  intestines,  in  the  form  of  sulphuretted 
hydrogen;  and  as  an  emanation  from  fetid  ulcers. 

8.  Iron. — This  metal  has  been  detected  in  the  colouring  matter  of 
the  blood ;  in  bile,  and  in  milk.     In  the  first  of  these  fluids  it  was,  for 
a  long  time,  considered  to  be  in  the  state  of  phosphate  or  sub-phosphate. 
Berzelius1  showed,  that  this  was  not  the  case ;  that  the  ashes  of  the 
colouring  matter  always  yielded  oxide  of  iron  in  the   proportion  of 
l-200th  of  the  original  mass.     That  distinguished  chemist  was,  how- 
ever, unable  to  detect  the  condition  in  which  the  metal  exists  in  the 
blood ;  and  could  not  discover  its  presence  by  any  of  the  liquid  tests. 
Subsequently,  Engelhart  showed,  that  the  fibrin  and  albumen  of  the 
blood,  when  carefully  separated  from  colouring  particles,  do  not  contain 
a  trace  of  iron ;  whilst  he  could  procure  it  from  the  red  corpuscles  by 
incineration.     He  also  succeeded  in  proving  its  existence  in  the  red 
corpuscles  by  liquid  tests ;  and  his  experiments  were  repeated,  with  the 
same  results,  by  Rose  of  Berlin.2    In  milk,  iron  seems  to  be  in  the  state 
of  phosphate. 

9.  Manganesium  has  been  found  in  the  state  of  oxide,  along  with 
iron,  in  the  ashes  of  the  hair ;  in  bones,  and  blood,  and  also  in  gall- 
stones, and  in  the  blood. 

10.  Copper  and  lead. — It  was  conceived  by  M.  Devergie,  that  copper 
and  lead  may  exist  naturally  in  the  tissues  ;3  but  MM.  Flandin  and 
Danger,  and  a  commission  of  the  Acaddmie  Royale  de  Me'decine  of 
Paris,  were  unable  to  confirm  the  existence  of  copper ;  and  the  results 
of  the  investigations  of  Professor  F.  de  Cattanei  di  Momo,4  of  Pavia, 
seem  to  prove  the  non-existence  of  lead  also.     M.  Barse,  however,  in 
a  paper  read  before  the  Royal  Academy  of  Sciences  of  Paris,  in  August, 
1843,  states,  that  he  found  both  metals  in  the  bodies  of  two  persons, 
to  whom  they  could  not  have  been  given  for  poisons.     The  researches 
of  Signer  Cattanei  di  Momo  appeared  to  prove  that  these  metals  do 
not  exist  in  the  bodies  of  new-born  children  or  infants ;  and  M.  J. 
Rossignon  has  offered  a  solution  as  to  the  probable  source  of  the  copper, 
as  he  found  it  not  only  in  the  blood  and  muscles  of  the  dog,  but  in 

1  Medico- Chirurgical  Transact.,  vol.  iii. 

3  Turner's  Chemistry,  fifth  ed.,  p.  963.     London,  1834. 

3  Bullet,  de  1'Academ.  Royale  de  Medecine,  19  Fevr.,  1839. 

4  Annali  Universal!  di  Medicina,  Aprile,  1840;  cited  in  British  and  Foreign  Medical  Re- 
view, Jan.,  1841,  p.  226. 


46  MATERIAL  COMPOSITION  OF  MAN. 

many  articles  of  vegetable  and  animal  food ;  in  gelatin  from  bones,  for 
example,  in  sorrel,  chocolate,  bread,  coffee,  succory,  madder,  and  sugar. 
The  ashes  obtained  from  starch  sugar  yielded  4  per  cent,  of  copper ; 
those  of  gelatin,  0'03  per  cent.;  and  those  of  bread,  0*005  to  0*008 
per  cent.1  It  is  now  generally  considered  to  be  present  in  the  human 
liver,2  and  M.  E.  Millon3  asserts,  that  human  blood  invariably  contains 
lead,  copper,  silica,  and  manganese. 

11.  Silicium. — Silica  is  found  in  the  hair,  bones,  blood,  urine,  and 
in  urinary  calculi. 

12.  Chlorine. — In  combination  with  hydrogen,  and  forming  chloro- 
Jiydric  acid,  chlorine  is  met  with  in  most  of  the  animal  fluids.     It  is 
generally  united  with  soda.    Free  chlorohydric  acid  has  also  been  found 
by  Dr.  Prout4  in  the  stomach  of  the  rabbit,  hare,  horse,  calf,  and  dog ; 
and  he  has  discovered  the  same  acid  in  the  sour  matter  ejected  from 
the  stomachs  of  those  labouring  under  indigestion.    Mr.  Children,  and 
Messrs.  Tiedemann  and  Gmelin,5  made  similar  observations ;  and  Pro- 
fessor Emmet  and  the  author6  found  it  in  considerable  quantity  in  the 
healthy  gastric  secretions  of  man. 

13.  fluorine. — This  simple  substance  has  been  found  combined  with 
calcium — -fluoride  of  calcium — in  the  enamel  of  the  teeth,  bones,  and 
urine. 

14.  Sodium. — Oxide  of  sodium,  soda,  forms  part  of  all  the  fluids. 
It  has  never  been  discovered  in  a  free  state  ;  but  is  united  (without  an 
acid),  to  albumen.     Most  frequently,  it  is  combined  with  chlorine,  and 
phosphoric  acid;  less  frequently,  with  lactic,  carbonic,  and  sulphuric 
acids.     Chloride  of  sodium  is  contained  in  most  of  the  animal  secre- 
tions ;  and  from  its  decomposition  may  result  the  chlorohydric  acid  of 
the  gastric  juice,  and  a  part  the  soda  of  the  bile  and  other  fluids. 

15.  Potassium. — The  oxide,  potassa,  is  found  in  many  animal  fluids, 
but  always  united  with  acids — sulphuric,  chlorohydric,  phosphoric,  &c. 
It  is  much  more  common  in  the  vegetable  kingdom  ;  and  hence  one  of 
its  names — vegetable  alkali. 

16.  Magnesium. — The  oxide,  magnesia,  exists  sparingly  in  bones, 
and  in  some  other  parts ;  but  always  in  combination  with  phosphoric 
acid,  and  appears  to  be  always  associated  with  calcium. 

17.  Aluminium. — Alumina  is  said  by  Morichini  to  exist  in  the  ena- 
mel of  the  teeth.     Fourcroy  and  Vauquelin  found  it  in  the  bones ;  and 
John,  in  white  hairs.     According  to  Schlossberger,  it  is  in  the  flesh  of 
fishes.7 

18.  Titanium. — Dr.  Eees  affirms,  that  he  detected  it  in  salts  ob- 
tained from  the  supra-renal  capsules. 

1  Lond.  Med.  Gaz.,  Dec.  1,  1843,  from  Gazette  Medicale  de  Paris,  and  Mr.  Paget,Rep.  on 
Anatomy  and  Physiology,  1843-4,  in  Brit,  and  For.  Med.  Rev.,  Jan.,  1845,  p.  249. 

2  Kirkes  and  Paget,  Manual  of  Physiology,  Amer.  edit.,  p.  29,  Philad.,  1849. 

3  Comptes  Rend  us,  Paris,  1848. 

<  Philosoph.  Transact,  for  1824,  p.  45. 

5  Recherches  Experimental,  &c.,  sur  la  Digestion,  trad,  par  A.  G.  L.  Jourdan.  Art.  4,  p. 
94,  Paris,  1827. 

6  See  under  the  head  of  "  Digestion,"  and  the  author's  Human  Health,  p.  19*1,  Philadelphia, 
1844. 

7  Henle,  Allgemeine  Anatomic,  s.  4.     Leipz.,  1841,  or  Jourdan's  translation,  i.  2,  Paris, 
1843. 


ORGANIC  ELEMENTS.  47 

19.  Arsenic. — It  was  asserted  by  M.  Orfila,  that  arsenic  exists  natu- 
rally in  the  human  body;  and  that  it  is  a  normal  constituent  of  human 
bones.  Subsequent  experiments,  however,  performed  by  M.  Orfila 
himself,  have  shown  that  there  was  fallacy  in  his  first  observations.1 

ORGANIC  ELEMENTS,  proximate  principles  or  compounds  of  organ- 
ization, are  combinations  of  two  or  more  of  the  elementary  substances, 
in  definite  proportions.  Formerly,  four  only  were  admitted — gelatin, 
fibrin,  albumen,  and  oil.  Of  late,  however,  organic  chemistry  has 
pointed  out  others,  which  are  divided  into  two  classes, — first,  those  that 
contain  nitrogen,  as  albumen,  gelatin,  fibrin,  osmazome,  mucus,  casein, 
urea,  uric  acid,  red  colouring  principle  of  the  blood,  yellow  colouring 
principle  of  the  bile,  &c.;  and  secondly,  those  that  do  not  contain  azote, ' 
— as  olein,  stearin,  the  fatty  matter  of  the  brain  and  nerves,  acetic, 
oxalic,  benzoic,  and  lactic  acids,  sugar  of  milk,  sugar  of  diabetes,  pi- 
cromel,  colouring  principle  of  the  bile,  and  that  of  other  solids  and 
liquids,  &c. 

a.   Organic  JElements  that  contain  Nitrogen. 

1.  Protein. — Modern  researches  appear  to  have  shown,  that  tlie 
chief  proximate  principles  of  animal  tissues,  and  those  that  have  been 
regarded  as  highly  nutritious  among  vegetables,  have  almost  identically 
the  same  composition ;  and  are  modifications  of  a  principle  to  which 
Mulder — its  discoverer — gave  the  name  Protein.  If  animal  albumen, 
fibrin,  or  casein,  be  dissolved  in  a  moderately  strong  solution  of  caustic 
potassa,  and  the  solution  be  exposed  for  some  time  to  a  high  tempera- 
ture, these  substances  are  decomposed.  The  addition  of  acetic  acid 
to  the  solution  causes,  in  all  three,  the  separation  of  a  gelatinous  trans- 
lucent precipitate,  which  has  exactly  the  same  character  and  composi- 
tion, from  whichsoever  of  the  solutions  it  is  obtained.  It  may  be  pro- 
cured, too,  from  globulin  of  blood,  and  from  vegetable  albumen.2 

The  chemical  relations  of  protein,  especially  in  regard  to  oxygen, 
are  full  of  interest.  The  products  of-  its  oxidation,  binoxide  and  trit- 
oxide  of  protein,  occur  constantly  in  the  blood.  They  are  formed  in 
the  lungs  from  fibrin ;  which,  in  a  moist  state,  possesses  the  property 
of  absorbing  oxygen.  Fibrin,  oxidized  in  the  lungs,  is,  according  to 
Mulder,  the  principal — if  not  the  only — carrier  of  the  oxygen  of  the 
air  in  the  blood  to  the  tissues ;  and  it  is  from  this  substance  especially, 
that  the  secretions  are  formed.  In  inflammatory  conditions,  a  much 
larger  quantity  of  protein  in  an  oxidized  state  is  contained  in  the  blood 
than  in  health ;  and  this,  according  to  Mulder,  gives  occasion  to  the 
bufly  coat.3 

The  following  substances  may  be  regarded  as  modifications  or  com- 
binations of  protein.  They  are  composed  of  it  and  of  a  small  quantity 
of  phosphorus,  or  of  sulphur,  or  both.4 

1  Rapport  de  1'Academie  Royale  de  M6decine,  Juillet,  1841;  Taylor's  Medical  Jurispru- 
dence, by  Dr.  Griffith,  p.  133,  Philad.,  1845;  and  Simon,  Animal  Chemistry,  Sydenham  Soc. 
edit.,  p.  4,  Lond.,  1845,  or  Amer.  edit.,  Philad.,  1845. 

9  Liebig,  Animal  Chemistry,  Gregory's  and  Webster's  edit,  p.  100.     Cambridge,  1842. 

3  Simon's  Animal  Chemistry,  Sydenham  Soc.  edit.,  p.  12,  London,  1845;  or  American  edit., 
Philadelphia,  1845.  -»  Henle,  op.  cit.,  p.  31. 


48  MATERIAL  COMPOSITION  OF  MAN. 

a.  Albumen. — This  is  one  of  the  most  common  organic  constituents; 
and  appears  under  two  forms — liquid  and  concrete.    In  its  purest  state, 
the  former  is  met  with  in  white  of  egg — whence  its  name ;  in  the  serum 
of  the  blood;   the  lymph  of  the  absorbents;  the  serous  fluid  of  the 
great  splanchnic  cavities  and  of  the  areolar  membrane;  and  in  the 
synovial  secretion.     It  is  colourless  and  transparent;  without  smell  or 
taste ;  and  is  coagulated  by  acids,  alcohol,  ether,  metallic  solutions, 
infusion  of  galls,  and  by  a  temperature  of  158°  Fahrenheit.     A  very 
dilute  solution,  however,  does  not  become  turbid  until  it  is  boiled.     It 
is  excreted  by  the  kidneys  in  large  quantities,  in  the  disease,  which, 
owing  to  its  presence  in  the  urine,  has  been  called  Albuminuria. 

Concrete,  coagulated,  or  solid  albumen,  is  white;  tasteless;  and  elastic; 
insoluble  in  water,  alcohol,  or  oil ;  but  readily  soluble  in  alkalies. 

Albumen  is  always  combined  with  soda.  It  exists,  in  abundance — 
both  the  liquid  and  concrete — in  different  parts  of  the  animal  body. 
Hair,  nails,  and  horn  consist  of  it ;  and  it  is,  in  some  form  or  other,  a 
constituent  of  many  tumours. 

In  the  advanced  chyliferous  vessels  albumen  is  found  in  quantity; 
and  it  is  probable,  that  every  proteinaceous  aliment,  and  perhaps  those 
that  are  not  proteinaceous,  is  reduced  to  the  form  of  albumen  in  the 
process  of  digestion,  so  that  it  becomes  the  nutritious  constituent  of 
whatever  fluid  is  absorbed  for  the  formation  of  tissue.  It  is  not,  of 
itself,  organizable ;  requiring  first  to  be  converted  into  fibrin. 

b.  Fibrin. — This  proximate  principle  exists  in  the  chyle  ;  enters  into 
the  composition  of  the  blood ;  forms  the  chief  part  of  muscular  flesh ; 
and  may  be  looked  upon  as  one  of  the  most  abundant  animal  substances. 
It  is  obtained  by  beating  the  blood  with  a  rod,  as  it  issues  from  a  vein. 
The  fibrin  attaches  itself  to  each  twig  in  the  form  of  red  filaments, 
which  may  be  deprived  of  their  colour  by  repeated  washing  with  cold 
water.     Fibrin  is  solid  ;  white  ;  flexible  ;  slightly  elastic  ;  insipid ;  in- 
odorous ;  and  heavier  than  water.     It  is  neither  soluble  in  water,  alco- 
hol, nor  acids ;  dissolves  in  liquid  potassa  or  soda,  in  the  cold,  without 
much  change ;  and  when  warm,  becomes  decomposed. 

Fibrin  constitutes  the  buffy  coat  of  blood;  it  is  thrown  out  from  the 
blood-vessels,  as  a  secretion,  in  many  cases  of  inflammation;  and  be- 
comes subsequently  organized. 

There  iswo  mode  of  distinguishing  liquid  fibrin  from  liquid  albumen, 
except  by  the  spontaneous  coagulation  of  the  former.  Consequently, 
according  to  Henle,1  if  a  liquid  does  not  coagulate  of  itself,  it  does  not 
contain  fibrin.  A  very  small  quantity,  however,  of  fibrin  may  be  so 
dissolved  in  serous  fluid,  that  it  will  not  coagulate.2  The  change  of 
albumen  to  fibrin  has  been  regarded  as  the  first  important  step  in  the 
process  of  assimilation,  fibrin  being  endowed  with  much  higher  organ- 
izable properties  than  albumen.  This  has  been  attributed  to  some 
influence  exerted  upon  albuminous  fluids  by  the  living  surfaces  over 
which  they  pass. 

The  correspondence  of  fibrin  with  albumen  is  shown  by  the  circum- 

1  Op.  cit.,  p.  38. 

3  Dr.  Buchanan,  Lond.  Med.  Gaz.  for  1836,  pp.  52  and  90,  and  ibid,  for  1845,  p.  617. 


ORGANIC  ELEMENTS.  49 

stance,  that  it  may  be  wholly  dissolved  in  a  solution  of  nitrate  of  po- 
tassa,  and  that  this  solution  greatly  resembles  a  solution  of  albumen, 
and  is  coagulated  by  heat.  This  happens,  however,  only  to  the  ordi- 
nary fibrin  of  venous  blood.  That  which  is  obtained  from  arterial  blood 
or  from  the  buffy  coat ;  or  which  has  been  exposed  for  some  time  to  the 
air,  is  not  thus  soluble,  the  difference  appearing  to  depend  upon  the 
larger  quantity  of  oxygen  contained  in  the  latter ;  for  a  solution  of 
venous  fibrin  in  nitre,  contained  in  a  deep  cylindrical  jar,  allows  a  pre- 
cipitate in  fine  flocks  to  fall  gradually,  provided  the  air  has  access  to 
the  surface ;  but  not  if  its  access  be  prevented.  This  precipitate  is 
insoluble  in  the  solution  of  nitre,  and  possesses  the  properties  of  arterial 
fibrin.1  Hence,  as  Dr.  Carpenter2  has  remarked,  it  may  be  inferred, 
that  the  fibrin  of  venous  blood  most  nearly  resembles  albumen ;  whilst 
that  of  arterial  blood,  and  of  the  buffy  coat,  contains  more  oxygen,  and 
is  more  highly  animalized ;  and  that  the  matter  of  the  red  corpuscles 
is  not  the  only  constituent  of  the  blood,  which  undergoes  a  change  in 
the  respiratory  process. 

c.  Casein,  Caseum,  Caseous  matter. — This  substance  exists  in  great- 
est abundance  in  milk ;  and  is  the  basis  of  cheese.  It  is  found  also  in 
blood,  saliva,  bile,  pancreatic  juice  ;  in  pus,  tubercular  matter,  &c.  To 
obtain  it,  milk  must  be  left  at  rest,  at  the  ordinary  temperature,  until 
it  is  coagulated :  the  cream  that  collects  on  the  surface  must  be  taken 
off;  the  clot  well  washed  with  water,  drained  upon  a  filter,  and  dried. 
The  residuum  is  pure  casein.  It  is  a  white,  insipid,  inodorous  sub- 
stance, insoluble  in  water,  but  readily  soluble  in  the  alkalies,  especially 
in  ammonia.  It  possesses  considerable  analogy  with  albumen.  Prout 
ascribes  the  characteristic  flavour  of  cheese  to  the  presence  of  caseate 
of  ammonia. 

Until  recently,  it  was  believed  that  vegetable  albumen  and  fibrin 
differ  from  animal  albumen  and  fibrin ;  but  Mulder  showed  that  this  is 
not  the  case ;  and  casein,  which  agrees  with  the  others  in  composi- 
tion, has  been  found  by  Liebig  in  the  vegetable.  Legumin  is  vegetable 
casein.  Of  late,  the  views  of  Mulder  as  to  the  very  existence  of  pro- 
tein have  been  combated  by  Liebig  and  Th.  Fleitmann  ;3  but  still — as 
Messrs.  Kirkes  and  Paget4  have  remarked — there  seems  sufficient  proba- 
bility in  those  views  to  justify  the  received  use  of  the  term  "protein 
compounds"  in  speaking  of  the  class,  including  fibrin,  Jfeumen,  and 
others,  to  which  the  name  of  "albuminous  compounds"  was  formerly 
applied. 

2.  Globulin. — The  globulin  of  Berzelius  consists  of  the  envelopes  of 
the  blood  corpuscles,  and  of  the  part  of  their  contents  that  remains 
after  the  extraction  of  the  hsematosin.  The  two  constitute  hsemato- 
globulin.  M.  Lecanu  regards  globulin  as  identical  with  albumen ;  accord- 
ing to  Mulder,  it  belongs  to  the  combinations  of  protein.  Simon  terms 

1  Scherer,  Chemisch-physiologische  Untersuchungen,  Annalen  der  Chemie,  &c.,  Oct.  1841, 
cited  in  Graham's  Chemistry,  Amer.  edit.,  p.  692,  Phi  lad.,  1843. 
a  Principles  of  Human  Physiology,  2cl  edit.,  p.  479,  Philad.,  1845. 

3  Scherer,  in  Canstatt  und  Eisenmann's  Jahresbericht  fiber  die  Fortschritte  in  der  Biologic 
im  Jahre,  1847,  s.  82.     Erlangen,  1848. 

4  Manual  of  Physiology,  Amer.  edit.,  p.  24,  Philad ,  1849. 

VOL.  I. — 4 


50  MATERIAL  COMPOSITION  OF  MAN. 

it  blood  casein,  and  Henle1  thinks  it  probable,  that  it  is  in  reality  only 
albumen  with  the  membranes  of  the  blood  corpuscles.  Berzelius  con- 
siders the  crystalline  lens  to  be  composed  of  the  same  substance. 

3.  Pepsin. — This  substance,  to  which  Eberle  gave  the  name,  was  dis- 
covered by  Schwann.    It  seems  to  be  a  modification  of  protein,  but  has 
not  been  much  examined.     It  is  contained  in  the  gastric  juice  ;  and  its 
physiological  properties  will  be  described  under  the  head  of  DIGESTION. 
It  greatly  resembles  albumen  ;  coagulates  by  heat  and  alcohol;  and  loses 
its  solvent  virtues.     It  is   best  procured  by  digesting  portions  of  the 
mucous  membrane  of  the  stomach  in  cold  water,  after  they  have  been 
macerated  for  some  time  in  water  at  a  temperature  between  80°  and 
100°  of  Fahrenheit.     The  warm  water  dissolves  various  substances  as 
well  as  some  of  the  pepsin  ;  but  the  cold  water  takes  up  little  more  than 
the  pepsin,  which  is  obtained  by  evaporating  the  cold  solution  in  the  form 
of  a  grayish-brown  viscid  fluid.     The  addition  of  alcohol  throws  down 
the  pepsin  in  grayish-white  flocculi;  and  one  part  of  the  principle  thus 
prepared,  when   dissolved  in  even  60,000  parts  of  water,  will  digest 
meat  and  other  alimentary  substances.     Liebig  doubts  the  existence  of 
pepsin  as  a  distinct  compound.     According  to  him — as  explained  here- 
after— the  solvent  power  of  the  gastric  juice  is  owing  to  the  gradual 
decomposition  of  a  matter  dissolved  from  the  lining  membrane  of  the 
stomach,  aided  by  oxygen  introduced  into  the  saliva. 

4.  G-elatin. — This  is  the  chief  constituent  of  cellular  tissue,  skin, 
tendons,  ligaments,  and  cartilages.     The  membranes  and  bones  also 
contain  a  large  quantity  of  it.     It  is  obtained  by  boiling  these  sub- 
stances for  some  time  in  water ;  clarifying  the  concentrated  solution ; 
allowing  it  to  cool,  and  drying  the  substance,  thus  obtained,  in  the  air. 
In  this  state  it  is  called  glue;  in  a  more  liquid  form,  jelly.     Gelatin 
dissolves  readily  in  hot  water ;  is  soluble  in  acids  and  alkalies ;  insolu- 
ble in  alcohol,  ether,  and  in  fixed  and  volatile  oils.     Alcohol  precipi- 
tates it  from  its  solution  in  water.     It  is  not  a  compound  of  protein : 
hence  it  has  been  concluded,  that  it  cannot  yield  albumen,  fibrin,  or 
casein;  and,  therefore,  that  blood  cannot  be  formed  of  it.    -The  animal 
system,  it  has  been  maintained,  can  convert  one  form  of  protein  into 
another,  but  cannot  form  protein  from  compounds  that  do  not  contain 
it.     This  deduction — as  stated  hereafter — is  probably  too  hasty.     It  is 
admitted,  that  gelatin  may  be  produced  from  fibrin  and  albumen  ;  since, 
in  animals  that  are  fed  on  these  alone,  the  nutrition  of  the  gelatinous 
tissues  does  not  seem  to  be  impaired ;  and  it  is  as  easy  to  conceive  that 
gelatin  may  go  to  the  formation  of  the  proteinaceous  tissues. 

Gelatin,  nearly  in  a  pure  state,  forms  the  air-bag  of  different  fishes, 
and  is  well  known  under  the  name  of  isinglass.  It  is  used  extensively 
in  the  arts,  on  account  of  its  adhesive  quality,  under  the  forms  of  glue 
and  size.  What  is  called  portable  soup  is  dried  jelly,  seasoned  with 
various  spices. 

5.  Ohondrin. — This  was  first  discovered  by  J.  Miiller.    It  is  obtained 
by  boiling  the  cornea,  the  permanent  cartilages,  and  the  bones  before 
ossification.     It  is  a  variety  of  gelatin. 

1  Op.  cit.,  p.  53. 


ORGANIC  ELEMENTS.  51 

6.  Osmazome. — This  is  the  matiere  extractive  du  bouillon,  extractive, 
and  saponaceous  extract  of  meat. — When  flesh,  cut  into  small  frag- 
ments, is  macerated  in  successive  portions  of  cold  water,  the  albumen, 
osmazome,  and  salts  are   dissolved;  and,  on  boiling  the  solution,  the 
albumen  is  coagulated.     From  the  liquid  remaining,  the  osmazome  may 
be  procured  in  a  separate  state,  by  evaporating  to  the  consistence  of 
an   extract,  and  treating  with  cold  alcohol.     This  substance   is  of  a 
reddish-brown  colour;  and  is  distinguished  from  the  other  animal  prin- 
ciples by  solubility  in  water  and  alcohol — whether  cold  or  at  the  boil- 
ing point — and  by  not  forming  a  jelly  when  its  solution  is  concentrated 
by  evaporation. 

Osmazome  exists  in  the  muscles  of  animals,  the  blood,  and  the  brain. 
It  gives  the  peculiar  flavour  of  meat  to  soups ;  and,  according  to  Four- 
croy,  the  brown  crust  of  roast  meat  consists  of  it. 

Kreatin  and  Kreatinin  are  two  principles  which  were  formerly  in- 
cluded among  the  extractive  or  ill-defined  matters  of  muscular  tissue. 
They  have  been  investigated  by  Liebig,1  who  discovered  them  also  in 
urine.  They  appear  to  be  like  urea,  mere  products  of  the  decomposition 
of  muscle. 

7.  Mucus. — This  term  has  been  applied  to  various  substances;  and 
hence  the  discordant  characters  ascribed  to  it.    Applying  it  to  the  fluid 
secreted  by  mucous  surfaces,  it  varies  somewhat  according  to  the  source 
whence  it  is  derived.    Its  leading  characters  may  be  exemplified  in  that 
derived  from  the  nostrils,  which  has  the  following  properties.    It  is 
insoluble  in  alcohol  and  water,  but  imbibes  a  little  of  the  latter,  and 
becomes  transparent;  it  is  neither  coagulated  by  heat,  nor  rendered 
horny;  but  is  coagulated  by  tannic  acid. 

Mucus,  in  a  liquid  state,  serves  as  a  protecting  covering  to  different 
parts.  Hence  it  varies  somewhat  in  its  characters,  according  to  the 
office  it  has  to  fulfil.  When  inspissated,  it  forms,  according  to  some, 
the  minute  scales  that  are  detached  from  the  surface  of  the  body  by 
friction,  corns,  and  the  thick  layers  of  the  soles  of  the  feet,  nails,  and 
horny  parts;  and  it  is  contained  in  considerable  quantity  in  hair,  wool, 
feathers,  scales  of  fishes,  &c. 

8.  Urea.-* This  proximate  principle  exists  in  the  urine  of  the  mam- 
malia when  they  are  in  a  state  of  health.     In  human  urine  it  is  less 
abundant  after  a  meal,  and  it  may  nearly  disappear  in  diabetes,  and 
affections  of  the  liver.     It  is  obtained  by  evaporating  urine  to  the  con- 
sistence of  syrup.     The  syrup  is  then  treated  with  four  parts  of  alco- 
hol, which  are  afterwards  volatilized  by  heating  the  alcoholic  extract. 
The  mass  that  remains  is  dissolved  in  water,  or  rather  in  alcohol,  and 
crystallized. 

The  purest  urea  that  has  been  obtained  assumes  the  shape  of  acicu- 
lar  prisms  similar  to  those  of  the  muriate  of  strontian.  It  is  colourless, 
devoid  of  smell,  or  of  action  on  blue  vegetable  colours,  transparent,  and 
somewhat  hard.  Its  taste  is  cool,  slightly  sharp,  and  its  specific  gra- 
vity is  greater  than  that  of  water. 

Urea  is  supposed  by  Dr.  Prout  to  be  chiefly  derived  from  the  de- 

1  Chemistry  of  Food,  London,  1847. 


52  MATERIAL  COMPOSITION  OF  MAN. 

composition  of  the  gelatinous  tissues ;  but,  as  Dr.  Carpenter  has  re- 
marked,1 there  seems  to  be  no  valid  reason  thus  to  limit  the  mode-  of  its 
production. 

9.  Uric  or  litMc  acid. — This  acid  is  found  in  the  urine  of  man,  birds, 
serpents,  tortoises,  crocodiles,  lizards;  in  the  excrements  of  the  silk- 
worm, and  very  frequently  in  urinary  calculi.     It  is  obtained  by  dis- 
solving any  urinary  calculus  which  contains  it,  or  the  sediment  of  hu- 
man urine,  in  warm  liquid  potassa,  and  precipitating  the  uric  acid  by 
the  chlorohydric.    Pure  uric  acid  is  white,  tasteless,  and  inodorous.    It 
is  insoluble  in  alcohol,  and  is  dissolved  very  sparingly  by  cold  or  hot 
water,  requiring  about  10,000  times  its  weight  of  that  fluid,  at  60°  of 
Fahrenheit,  for  solution.    According  to  Dr.  Prout,  this  acid  is  not  free, 
but  is   commonly  combined  with  ammonia;  the  reddening  of  litmus 
paper  being  not  altogether  owing  to  it,  but  to  the  super-phosphate  of 
ammonia,  which  is  likewise  present  in  urine. 

In  the  herbivora,  this  acid  is  replaced  by  the  hippuric.  Xqnthic 
acid,  found  by*  Marcet  in  urinary  calculi,  seems  to  have  been  uric 
acid. 

10.  Red  colouring  principles  of  the  blood. — It  has  been  already  ob- 
served that  Engelhart  and  Rose,  German  chemists,  had  detected  iron 
in  the  red  corpuscles  of  the  blood,  but  had  not  found  it  in  the  other 
principles  of  that  fluid.     It  has  been  considered  probable,  therefore, 
that  it  has  something  to  do  with  the  colour.     Engelhart's  experiments 
did  not,  however,  determine  the  manner  in  which  it  acts,  nor  in  what  state 
it  exists  in  the  blood.     The  sulphocyanic  acid  which  is  found  in  the 
saliva,  forms,  with  peroxide  of  iron,  a  colour  exactly  like  that  of  venous 
blood;  and  it  is  possible,  that  the  colouring  matter  may  be  a  sulpho- 
cyanate  of  iron. 

To  obtain  the  red  colouring  matter,  hsematin  or  hsematosin,  allow 
the  crassamentum  or  clot,  cut  into  thin  pieces,  to  drain  as  much  as 
possible  on  bibulous  paper,  triturating  it  with  water,  and  then  evapo- 
rating the  solution  at  a  temperature  not  exceeding  122°  of  Fahren- 
heit. When  thus  prepared,  the  colouring  particles  are  no  longer  of 
a  bright  red  colour,  and  their  nature  is  somewhat  modified,  in  conse- 
quence of  which  they  are  insoluble  in  water.  When  half  dried,  they 
form  a  brownish-red,  granular,  friable  mass;  and,  when  completely 
dried  at  a  temperature  between  167°  and  190°,  the  mass  is  tough, 
hard,  and  brilliant.  The  mode  in  which  the  hsematosin  is  concerned 
in  the  coloration  of  the  blood,  will  be  inquired  into  under  the  head  of 
RESPIRATION. 

A  brown  colouring  matter,  hvemaphsein,  and  a  blue  colouring  matter, 
hsemacyanin,  have  been  described.  The  former,  however,  it  has  been 
suggested,  is  nothing  more  than  haematin  modified  by  an  alkali ;  and 
Simon2  never  succeeded  in  detecting  the  latter. 

11.  Yellow  colouring  principle  of  the  bile; — cholepyrrhin  of  Berze- 
lius,  biliphsein  of  Simon. — This  substance  is  present  in  the  bile  of 
nearly  all  animals.     It  enters  into  the  composition  of  almost  all  gall- 
stones, and  is  deposited  in  the  gall-bladder  under  the  form  of  magma. 

1  Human  Physiology,  §  673,  Lond.  1842.  a  Op.  cit,  p.  42. 


ORGANIC  ELEMENTS.  53 

It  is  solid;  pulverulent;  when  dry,  insipid,  inodorous,  and  heavier  than 
water.  When  decomposed  by  heat,  it  yields  carbonate  of  ammonia, 
charcoal,  &c.  It  is  insoluble  in  water,  alcohol,  and  the  oils;  but  solu- 
ble in  alkalies.  On  the  gradual  addition  of  nitric  acid  to  a  fluid,  which 
contains  this  substance  in  solution,  a  very  characteristic  series  of  tints 
is  evolved.  The  fluid  becomes  first  blue,  then  green,  afterwards  vio- 
let and  red,  and  ultimately  assumes  a  yellow  or  yellowish-brown  colour. 

On  adding  an  acid  to  a  solution  of  biliphsein,  a  precipitation  of  green 
flocculi  takes  place :  these  possess  all  the  properties  of  chlorophyll,  or 
the  green  colouring  matter  of  leaves.  In  this  state  it  is  termed  bili- 
verdin  by  Berzelius ;  and  is  a  product  of  the  metamorphosis  of  bili- 
phsein.1 

These  are  the  chief  nitrogenized  organic  elements. 

b.   Organic  Elements  that  do  not  contain  Nitrogen. 

1.  Olein  and  Stearin. — Fixed  oils  and  fats  are  not  pure  proximate 
principles,  as  was  at  one  time  supposed.     They  were  Jong  presumed 
to  consist  of  two  substances,  one  of  which  is  solid  at  the  ordinary  tem- 
perature of  the  atmosphere,  and  the  other  fluid :  the  former  of  these 
was  called  Stearin,  from  of  tap,  suet ;  the  latter  Ela'in  or   Olein,  from 
jT-atov,  oil.     Stearin  is  the   chief  ingredient  of  vegetable  and  animal 
suet ;  of  fat  and  butter ;  and  is  found,  although  in  small  quantity,  in 
fixed  oils.     In  suety  bodies,  it  is  the  cause  of  their  solidity.     Elain 
and  stearin  may  be  separated  from  each  other  by  exposing  fixed  oil  to 
a  low  temperature ;  and  pressing  it,  when  congealed,  between  folds  of 
bibulous  paper.     The  stearin  is  thus  obtained  in  a  separate  form  ;  and 
by  pressing  the  bibulous  paper  under  water,  an  oily  matter  is  procured, 
which  is  elain  in  a  state  of  purity.     Modern  chemistry  has  shown, 
however,  that  fat  contained  in  the  cells  of  adipose  tissue  is  composed 
of  a  base  termed  glycerin — itself  hydrated  oxide  of  glyceryl — with 
stearic  and  margaric  acids.     Stearin  is  a  bi-stearate  of  glycerin: — 
olein,  or  elain,  an  oleate  of  glycerin. 

2.  Fatty  matter  of  the  Brain  and  Nerves.—  Yauquelin2  found  two 
varieties  of  fatty  matter  in  the  brain, — the  one  white,  the  other  red, 
the  properties  of  which  have  not  been  fully  investigated.     Both  give 
rise  to  phosphoric  acid  by  calcination,  without  there  being  any  evidence 
of  an  acid,  or  phosphate  in  their  composition.     They  may  be  obtained 
by  repeatedly  boiling  the  cerebral  substance  in  alcohol ;  filtering  each 
time;  mixing  the  various  liquors,  and  suffering  them  to  cool: — a  lamel- 
lated  substance  is  deposited,  which  is  the  white  fatty  matter.     By  eva- 
porating the  alcohol,  which  still  contains  red  fatty  matter  and  osmazome, 
to  the  consistence  of  bouillie;  and  exposing  this,  when  cold,  to  the 
action  of  alcohol,  the  osmazome  is  entirely  dissolved,  whilst  the  alcohol 
takes  up  scarcely  any  red  fatty  matter. 

3.  Acetic  acid. — This  acid  exists  in  a  very  sensible  manner  in  sweat, 
urine,  and  milk — even  when  entirely  sweet.     It,  or  lactic  acid,  is  formed 
in  the  stomach  in  indigestion ;  was  found  by  the  author  and  his  late 
friend,  Professor  Emmet,  contained  in  the  gastric  secretions  in  health, 

1  Simon,  op.  cit.,  p.  44.  a  Annales  de  Chim.,  Ixxxi.  37. 


54  MATERIAL  COMPOSITION  OF  MAN. 

and  is  one  of  the  constant  products  of  the  putrid  fermentation  of  ani- 
mal or  vegetable  substances.  It  is  the  most  prevalent  of  the  vegetable 
acids,  and  most  easily  formed  artificially. 

4.  Oxalic  acid. — This  acid, — which  exists  extensively  in  the  vege- 
table kingdom,  but  always  united  with  lime,  potassa,  soda,  or  oxide  of 
iron, — is  only  found,  combined  with  lime,  as  an  animal  constituent  in 
certain  urinary  calculi. 

5.  Benzoic  acid. — This  acid,  found  in  many  individuals  of  the  vege- 
table kingdom,  is  likewise  met  with  in  the  urine  of  the  horse,  cow, 
camel,  and  rhinoceros ;  and  sometimes  in  that  of  man,  especially  of 
children.     When  benzoic  acid  is  swallowed,  hippuric  acid  is  observed 
in  the  urine ;  and  it  was  supposed  by  Mr.  A.  Ure  and  others,  that  this 
was  owing  to  the  conversion  of  uric  acid  into  hippuric ;  and  as  the 
hippurates  are  more  soluble,  it  was  suggested  by  him,  that  benzoic  acid 
might  be  advantageously  exhibited  in  lithuria,  and  in  cases  of  gouty 
depositions  of  lithate  of  soda.     It  has  been  found,  however,  by  Drs. 
Keller  and  Garrod,1  and  by  Professor  Booth,  and  Mr.  Boyd,  of  Phila- 
delphia,2 that  the  administration  of  benzoic  acid  exerts  no  influence  on 
the  amount  of  uric  acid  in  the  urine. 

6.  Lactic  acid. — Acid  of  milk  is  met  with  in  blood,  gastric  juice, 
urine,  milk,  marrow,  and  also  in  muscular  flesh.     At  times  it  is  in  a 
free  state,  but  is  usually  united  with  alkalies.     However  much  it  may 
be  concentrated,  it  does  not  crystallize,  but  remains  under  the  form  of 
syrup  or  extract.     When  cold  it  is  tasteless,  but  when  heated  has  a 
sharp  acid  taste.     According  to  Dr.  Prout,  this  acid,  like  urea,  results 
from  the  decomposition  of  the  gelatinous  parts  of  the  system ;  accord- 
ing to  Berzelius,  however,  it  is  a  general  product  of  the  spontaneous 
decomposition  of  animal  matters  within  the  body.     Liebig3  formerly 
denied,  that  any  lactic  acid  is  formed  in  the  stomach  in  health ;  and 
affirmed,  that  the  property  possessed  by  many  substances,  such  as  starch, 
and  the  varieties  of  sugar,  by  contact  with  animal  matters  in  a  state 
of  decomposition,  of  passing  into  lactic  acid,  had  induced  physiologists 
too  hastily  to  assume  the  fact  of  the  production  of  lactic  acid  during 
healthy  digestion : — yet  he  now  admits  its  presence. 

7.  Sugar  of  milk. — This  substance,  which  is  so  called  because  it  has 
a  saccharine  taste,  and  exists  chiefly,  if  not  solely,  in  milk,  differs  from 
ordinary  sugar  in  not  fermenting.     It  is  obtained  by  evaporating  whey, 
formed  during  the  making  of  cheese,  to  the  consistence  of  honey;  al- 
lowing the  mass  to  cool ;  dissolving ;  clarifying  and  crystallizing.     It 
commonly  crystallizes  in  regular  parallelopipedons,  terminated  by  pyra- 
mids with  four  faces.     It  is  white ;  semitransparent ;  hard,  and  of  a 
slightly  saccharine  taste. 

8.  Sugar  of  diabetes. — In  diabetes  meltitus,  the  urine,  which  is  often 
passed  in  enormous  quantity,  contains,  at  the  expense  of  the  economy, 
a  large  amount  of  peculiar  saccharine  matter,  which,  when  properly 
purified,  appears  identical  in  properties  and  composition  with  vegetable 

1  Liebig's  Animal  Chemistry,  p.  316. 

a  Proceedings  of  the  American  Philosophical  Society  at  the  Centennial  Celebration  in  Phila., 
May,  1843,  and  Transactions  of  the  A.  P.  Society,  vol.  ix.  pt.  2,  Philad.,  1845. 
3  Op.  cit.,  p.  107. 


ORGANIC  ELEMENTS.  55 

sugar,  and  approaches  nearer  to  the  sugar  of  grapes — glucose — than 
to  that  of  the  cane.  It  is  obtained  in  an  irregularly  crystalline  mass, 
by  evaporating  diabetic  urine  to  the  consistence  of  syrup,  and  keeping 
it  in  a  warm  place  for  several  days.  It  is  purified  by  washing  in  cold, 
or — at  the  most — gently  heated  alcohol,  till  the  liquor  comes  off  colour- 
less ;  and  then  dissolving  it  in  hot  alcohol.  By  repeated  crystallization 
it  is  thus  rendered  pure.1  In  the  notes  of  two  cases  of  diabetes  mel- 
litus  now  before  the  author,  it  appears,  that  sixteen  ounces  of  the  urine 
of  one  patient,  of  the  specific  gravity  of  1-034,  afforded  a  straw-co- 
loured extract,  which,  when  cold  and  consolidated,  weighed  one  ounce 
and  five  drachms.  The  same  quantity  of  the  urine  of  the  other  patient, 
specific  gravity  1'040,  yielded  one  ounce  and  seven  drachms.  Neither 
extract  appeared  to  contain  urea  when  nitric  acid  was  added ;  but  when 
a  portion  was  dissolved  in  water,  and  subjected  to  a  temperature  of 
212°,  traces  of  ammonia  were  manifested  on  the  vapour  being  presented 
to  the  fumes  of  chlorohydric  acid.  From  this  a  conclusion  was  drawn, 
that  urea  was  present,  as  it  is  the  only  known  animal  matter  decom- 
posed by  the  heat  of  boiling  water.  In  a  little  more  than  a  month, 
the  subject«  of  the  latter  case  passed  about  four  hundred  and  eighty 
pints  of  urine,  or  about  seventy-five  pounds  troy  of  diabetic  sugar ! 

9.  Bilin  or  Picromel. — M.  Thenard2  discovered  this  principle  in  the 
bile  of  the  ox,  sheep,  dog,  cat,  and  several  birds ;   Chevalier,  in  that  of 
man.     To  obtain  it,  the  acetate  of  lead  of  commerce  must  be  added  to 
bile  until  there  is  no  longer  any  precipitate.    By  this  means,  the  yellow 
matter  of  the  bile  and  the  whole  of  the  fatty  matter  are  thrown  down, 
united  with  the  oxide  of  lead ;  the  phosphoric  acid  of  the  phosphate  of 
soda,  and  the  sulphuric  acid  of  the  sulphate  of  soda,  are  likewise  precipi- 
tated.    The  picromel  may  then  be  thrown  down  from  the  filtered  liquor 
by  the  subacetate  of  lead.     The  precipitate,  which  is  a  combination  of 
picromel  with  oxide  of  lead,  must  now  be  washed  and  dissolved  in  acetic 
acid.     Through  this  solution,  sulphuretted  hydrogen  is  passed  to  sepa- 
rate the  lead ;  the  solution  is  then  filtered,  and  the  acetic  acid  driven 
off  by  evaporation. 

Pure  picromel  is  devoid  of  colour,  and  has  the  same  appearance  and 
consistence  as  thick  turpentine.  Its  taste  is  at  first  acrid  and  bitter, 
but  afterwards  sweet.  Its  smell, is  nauseous,  and  specific  gravity  greater 
than  that  of  water.  When  digested  with  resin  of  bile,  a  portion  of 
the  latter  is  dissolved,  and  a  solution  obtained,  which  has  a  bitter  and 
a  sweet  taste,  and  yields  a  precipitate  with  the  subacetate  of  lead  and 
the  stronger  acids.  This  is  the  compound  that  causes  the  peculiar  taste 
of  the  bile. 

10.  Cholesterin. — This  is  a  constituent  principle  of  the  blood,  bile, 
medullary  neurine,  and  vernix  caseosa.     It  is  often  precipitated  from 
bile  in  a  crystalline  state;  and  forms  of  itself  concretions  which  have 
an  evidently  laminated  texture.     It  has  been  very  frequently  met  with 
in  morbid  secretions  and  tissues ;  in  the  fluid  of  dropsies ;  in  that  of 
cysts  and  hydatids ;  and  in  medullary  fungus  and  other  tumours.     At 

1  Prout,  Medico  Chirurg.  Transact.,  viii.  538. 

3  Memoir.  d'Arcueil,  i.  23,  and  Traite  de  Chimie,  torn.  iii. 


56  MATERIAL  COMPOSITION  OF  MAN. 

times,  it  is  dissolved ;  at  others,  swims  upon  the  fluid  in  brilliant  plates, 
or  forms  solid  masses.  It  is  obtained  from  biliary  calculi  by  boiling  in 
water,  and  dissolving  them  afterwards  in  boiling  alcohol.  On  cooling, 
crystals  of  cholesterin  separate. 

These  inorganic  and  organic  elements — with  others  of  less  moment 
discovered  by  modern  chemists — variously  combined  and  modified  by 
the  vital  force,  constitute  the  different  parts  of  the  animal  fabric. 
Chemistry,  in  its  present  improved  condition,  enables  us  to  separate 
them,  and  to  investigate  their  properties ;  but  all  the  information  we 
derive  from  this  source  relates  to  bodies,  that  have  been  influenced  by 
the  vital  force,  but  are  no  longer  so;  and  in  the  constant  muta- 
tions that  occur  in  the  system  whilst  life  exists,  and  under  its  control- 
ling agency,  the  same  textures  might  exhibit  very  different  chemical 
characteristics,  could  our  researches  be  directed  to  them  under  those 
circumstances.  Whenever,  therefore,  the  physiologist  has  to  apply 
chemical  elucidations  to  operations  of  the  living  machine,  he  must  re- 
collect, that  all  his  analogies  are  drawn  from  dead  matter,  which  dif- 
fers so  widely  from  the  living  as  to  suggest  the  necessity  of  a  wise  and 
discriminating  caution. 

The  components  of  the  animal  body  are  invariably  found  under  two 
forms — solids  and  fluids.  Both  are  met  with  in  every  animal,  the  for- 
mer being  derived  from  the  latter;  for,  from  the  blood  every  part  of 
the  body  is  separated;  yet  they  are  mutually  dependent,  for  every 
liquid  is  contained  in  a  solid.  The  blood  itself  circulates  in  solid 
vessels.  Both,  too,  possess  an  analogous  composition  ;  are  in  constant 
motion,  and  incessantly  converted  from  one  into  the  other.  Every 
animal  consists  of  a  union  of  the  two  ;  and  this  union  is  indispensable 
to  life.  Yet  certain  vague  notions  with  regard  to  their  relative  pre- 
ponderance in  the  economy,  and  to  their  agency  in  the  production  of 
disease,  have  led  to  discordant  doctrines  of  pathology, — the  solidists 
believing,  that  the  cause  of  most  affections  is  resident  in  the  solids ; 
the  humorists,  that  we  are  to  look  for  it  in  the  fluids.  In  this,  as  in 
similar  cases,  the  mean  will  lead  to  the  most  satisfactory  result.  The 
causes  of  disease  ought  not  to  be  sought  in  the  one  or  the  other  exclu- 
sively. 

c.   Of  the  Solid  Parts  of  the  Human  Body. 

A  solid  is  a  body  whose  particles  adhere  to  each  other,  so  that  they 
do  not  separate  by  their  own  weight ;  but  require  the  agency  of  some 
extraneous  force  to  effect  the  disjunction.  Anatomists  reduce  all  the 
solids  of  the  human  body  to  twelve  varieties  ; — bone,  cartilage,  muscle, 
ligament,  vessel,  nerve,  ganglion,  follicle,  gland,  membrane,  areolar 
membrane,  and  viscus. 

1.  Bone  is  the  hardest  of  the  solids.     It  forms  the  skeleton ;  the 
levers  for  the  various  muscles  to  act  upon ;  and  serves  for  the  protec- 
tion of  important  organs. 

2.  Cartilage  is  of  a   white  colour,  formed  of  very  elastic  tissue; 
covering  the  articular  extremities  of  bone  to  facilitate  their  movements ; 
sometimes  added  to  bones  to  prolong  them,  as  in  the  case  of  the  ribs; 


SOLID  PARTS.  57 

at  others,  placed  within  the  articulations  to  act  as  elastic  cushions ;  and, 
in  the  foetus,  forming  a  substitute  for  bone.  Hence,  cartilages  are  di- 
vided into  articular  or  incrusting,  cartilages  of  prolongation,  interarti- 
cular  cartilages,  and  cartilages  of  ossification. 

3.  Muscles  constitute  the  flesh  of  animals.     They  consist  of  fasci- 
culi of  red  and  contractile  fibres,  extending  generally  from  one  bone  to 
another ;  and  are  the  agents  of  all  movements. 

4.  Ligaments  are  tough;  difficult  to  tear;  and,  under  the  form  of 
cords  or  membranes,  serve  to  connect  different  parts  with  each  other, 
particularly  bones  and  muscles ;  hence  their  division,  by  some  anato- 
mists, into  ligaments  of  bones — as  the  ligaments  of  the  joints;  and 
ligaments  of  muscles, — as  the  tendons  and  aponeuroses. 

5.  Vessels  are  solids,  having  the  form  of  canals,  in  which  the  fluids 
circulate.     They  are  called — according  to  the  fluid  they  convey — san- 
guineous (arterial  and  venous),  cliyliferous,  lymphatic,  &c. 

6.  Nerves  are  cords,  consisting  of  numerous  tubular  fasciculi.    These 
are   connected  with  the  brain,  spinal  marrow,  or  great  sympathetic. 
They  are  the  organs  by  which  impressions  are  conveyed  to  the  nervous 
centres,  and  by  wThich  each  part  is  endowed  with  vitality.     There  are 
three  great  divisions  of  the  nerves, — the  cerebro- spinal,  true  spinal, 
and  organic. 

7.  Ganglions  are  solid  knots  in  the  course  of  a  nerve  which  seem  to 
be  formed  of  an  inextricable  interlacing  of  nervous  filaments.     The 
term  is  likewise  applied,  by  many  modern  anatomists,  to  similar  inter- 
lacings   of  the  ramifications  of  lymphatic  vessels.      G-anglions  may, 
consequently,  either  be  nervous  or  vascular ;  and  the  latter,  again,  may 
be  divided  into  cJiyliferous  or  lymphatic,  according  to  the  kind  of  ves- 
sel on  which  they  appear.     Chaussier,  a  distinguished  anatomist  and 
physiologist,  has  given  the  name  glandiform  ganglions  to  certain  organs 
whose  nature  and  functions  are  unknown,  but  which  appear  to  be  con- 
cerned in  lymphosis, — as  the  thymus  gland,  the  thyroid  gland,  &c. 

8.  Follicles  or  crypts  are  secretory  organs,  shaped — when  simple — like 
membranous  ampullae  or  vesicles,  formed  by  an  inversion  of  the  outer 
membranes  of  the  body — the  skin  and  mucous  surfaces — and  secreting 
a  fluid  intended  to  lubricate  them.     They  are   often  divided  into  the 
simple  or  isolated;  the  conglomerate;  and  the   compound,  according 
to  their  size,  or  the  manner  in  which  they  are  grouped  and  united  to- 
gether. 

9.  Glands  are  secretory  organs  not  differing  essentially  from  the  last. 
Their  organization  is  more  complex ;  and  the  fluid,  after  secretion,  is 
poured  out  by  means  of  one  or  more  excretory  ducts. 

10.  Membrane. — This  is  one  of  the  most  extensive  and  important  of 
the  substances  formed  by  the  areolar  tissue.     It  is  spread  out  in  the 
shape  of  a  web;  and,  in  man,  serves  to  line  cavities  and  reservoirs;  and 
to  form,  support,  and  envelope  organs. 

Bichat  divides  membranes  into  two  kinds,  simple  and  compound,  ac- 
cording as  they  are  formed  of  one  or  more  layers. 

Simple  membranes  are  of  three  kinds,  serous,  mucous,  and  fibrous. 

1st.  Serous  membranes  constitute  all  the  sacs  or  shut  cavities  of  the 
body, — those  of  the  chest  and  abdomen,  for  example. 


58  MATERIAL  COMPOSITION  OF  MAN. 

2dly.  Mucous  membranes  line  all  the  outlets  of  the  body, — the  air- 
passages,  alimentary  canal,  urinary  and  genital  organs,  &c. 

3dly.  Fibrous  membranes  form  tendon,  aponeurosis,  ligament,  &c. 

Compound  membranes  are  formed  by  the  union  of  the  simple,  and 
are  divided  into  fibro-serous,  as  the  pericardium ;  sero-mucous,  as  the 
gall-bladder,  at  its  lower  part;  and fibro-mucous,  as  the  ureter. 

11.  Areolar,  cellular  or  laminated  tissue — to  be  described  presently 
— is  a  sort  of  spongy  or  areolar  structure,  which  forms  the  framework 
of  the  solids;  fills  up  the  spaces  between  them,  and  serves  at  once  as  a 
bond  of  union  and  separation. 

12.  A  viscus  is  the  most  complex  solid  of  the  body ;  not  only  as  re- 
gards intimate  organization,  but  use.    This  name  is  given  to  organs  con- 
tained in  the  splanchnic  cavities, — brain,  thorax,  and  abdomen, — and 
hence  the  viscera  are  termed  cerebral,  thoracic,  and  abdominal. 

Every  animal  solid  is  either  amorphous  or  fibrous;  that  is,  it  is  either 
without  apparent  arrangement,  like  jelly ;  or  is  disposed  in  minute 
threads,  called  fibres.  The  disposition  of  these  threads,  in  different 
structures,  is  various.  Sometimes,  they  retain  the  form  of  threads ;  at 
others,  they  have  that  of  laminae,  lamellae,  or  plates.  Accordingly, 
when  we  examine  any  animal  solid,  where  the  organization  is  percep- 
tible, it  is  found  to  be  either  amorphous,  or  fibrous  and  laminated. 

This  circumstance  led  the  ancients  to  endeavour  to  discover  an  ele- 
mentary fibre  or  filament,  from  which  the  various  organs  might  be  formed. 
Haller1  embraced  the  idea,  and  endeavoured  to  unravel  every  texture 
to  this  ultimate  element, — which,  he  conceived,  is  to  the  physiologist 
what  the  line  is  to  the  geometer;  and,  as  all  figures  can  be  constructed 
from  the  line,  so  every  tissue  and  organ  of  the  body  may  be  built  up 
from  the  filament.  Haller,  however,  admitted  that  this  elementary 
fibre  is  not  capable  of  demonstration,  and  that  it  is  visible  only  to  the 
"  mind's  eye," — "  invisibilis  ea  fibra,  quam  sold  mentis  acie  adtingi- 
mus."  It  must  be  regarded,  indeed,  as  a  pure  abstraction;  for,  as 
different  animal  substances  in  the  mass  have  different  proportions  of 
carbon,  hydrogen,  oxygen,  and  nitrogen,  it  is  fair  to  conclude  that  the 
elementary  fibre  must  equally  differ  in  the  different  substances. 

The  ancients  believed  that  the  first  product  of  the  elementary  fibre 
was  areolar  tissue ;  and  that  this  tissue  forms  every  organ  of  the 
body, — the  difference  in  the  appearance  of  the  organs  arising  from 
the  different  degrees,  of  condensation  of  its  laminae.  Anatomists, 
however,  have  been  unable  to  reduce  all  animal  solids  to  areolar  tissue 
only. 

In  the  upper  classes  of  animals,  three  primary  fibres  or  tissues  or 
anatomical  elements  are  usually  admitted, — the  areolar,  cellular  or 
laminated;  the  muscular;  and  the  nervous,  pulpy  or  medullary. 

1.  The  areolar,  cellular,  mucous,  filamentous  or  laminated  fibre  or 
tissue  is  the  most  simple  and  abundant  of  animal  solids.  It  exists  in 
every  organized  being ;  and  is  an  element  of  every  solid.  In  the  ena- 
mel of  the  teeth  only  it  has  not  been  detected.  It  is  formed  of  an 
assemblage  of  thin  laminae,  of  delicate,  whitish,  extensible  filaments, 

1  Elementa  Physiologic,  vol.  i.  lib.  i.  sect.  i.  p.  7,  Lausan.,  1757. 


PRIMARY  AND  COMPOUND  TISSUES.  59 

interlacing  and  leaving  between  each  other  areolse  or  cells.  These 
filaments — although  possessed,  like  every  other  living  tissue,  of  con- 
tractility or  the  power  of  feeling  an  appropriate  irritant  and  of  moving 
responsive  to  such  irritant — do  not  move  perceptibly  under  the  influence 
of  mechanical  or  chemical  stimuli.  They  are  mainly  composed  of 
concrete  gelatin. — The  great  bulk  of  animal  solids  consists  of  areolar 
tissue,  arranged  as  membrane. 

2.  Muscular  fibre  or  tissue  is  a  substance  of  peculiar  nature ;  ar- 
ranged in  fibres  of  extreme  delicacy.     The  fibres  are  linear,  soft,  gray- 
ish or  reddish,  and  manifestly  possessed  of  contractility  or  irritability ; 
that  is,  they  move  very  perceptibly  under  the  influence  of  mechanical 
or  chemical  stimuli.     They  are  composed,  essentially,  of  fibrin.     Their 
histology  will  be  described  hereafter. 

Muscular  fibres,  which  are  arranged  in  the  form  of  membranous 
expansions  or  muscular  coats,  differ  from  proper  muscles  chiefly  in  the 
mechanical  disposition  of  the  fibres.  The  physical  and  chemical 
characters  of  both  are  identical.  The  fibres,  instead  of  being  collected 
into  fasciculi,  are  in  layers,  and,  instead  of  being  parallel,  interlace. 
This  tissue  does  not  exist  in  the  zoophyte. 

3.  Nervous,  pulpy,  or  medullary  fibre  or  tissue,  which  will  be  referred 
to  hereafter,  is  much  less  distributed  than  the  preceding.     It  is  of  a 
pulpy  consistence ;  is   composed   essentially  of  albumen  united   to   a 
phosphuretted  fatty  matter ;  and  is  the  organ  for  receiving  and  trans- 
mitting impressions  to  and  from  the   nervous   centres.     Of  it,  brain, 
cerebellum,  medulla  spinalis,  nerves  and  their  ganglia  are  composed. 

Professor  Chaussier1  added  another  primary  fibre  or  tissue, — the 
albugineous.  It  is  white ;  satiny;  resisting;  of  a  gelatinous  nature; 
and  constitutes  tendons  and  tendinous  structures.  Chaussier  is,  per- 
haps, the  only  anatomist  that  admits  this  tissue.  Others  properly  re- 
gard it  as  a  condensed  variety  of  the  areolar. 

These  various  fibres  or  tissues,  by  uniting  differently,  constitute  the 
first  order  of  solids ;  and  these,  again,  by  union,  give  rise  to  compound 
solids,  from  which  the  different  organs  are  formed.  A  bone,  for  ex- 
ample, is  a  compound  of  various  tissues ;  osseous  in  its  body;  medullary 
in  its  interior ;  and  cartilaginous  at  its  extremities. 

Bichat2  was  the  first  anatomist  who  possessed  clear  views  regarding 
the  constituent  tissues  of  the  animal  frame ;  and  whatever  merit  may 
accrue  to  after  anatomists  and  physiologists,  he  is7  entitled  to  the  credit 
of  having  pointed  out  the  path,  and  facilitated  the  labours  of  the  ana- 
tomical analyst. 

The  term  texture  can  only  apply  to  solids ;  but  inasmuch  as  there 
are  in  suspension  in  certain  fluids,  as  the  blood,  chyle  and  lymph,  solid 
corpuscles  of  determinate  form  and  organic  properties,  and  which  are 
not  mere  products  or  secretions  of  a  particular  organ,  or  confined  to  a 
particular  part,  such  corpuscles  have  been  looked  upon  as  organized 
constituents  of  the  body,  and  therefore  considered  along  with  the  solid 
tissues ;  and,  accordingly,  the  textures  and  other  organized  constituents 
have  been  enumerated  as  follows  :3 

1  Table  Synoptique  des  Solides  Organiques.  a  Anatomie  G£n.,  Paris,  1801,  torn.  i. 

3  Quain  and  Sharpey,  Human  Anatomy,  Amer.  edit.,  by  Dr.  Leidy,  i.  39,  Philad.,  1849. 


60  MATERIAL  COMPOSITION  OF  MAN. 

The  blood,  chyle  and  lymph.  Bone  or  osseous  tissue. 

Epidermic  tissue,  including  epi-     Muscular  tissue. 

thelium,    cuticle,    nails,  and     Nervous  tissue. 

hairs.  Bloodvessels. 

Pigment.  Absorbent  vessels  and  glands. 

Adipose  tissue.  Serous  and  synovial  membranes. 

Cellular  (areolar)  tissue.  Mucous  membranes. 

Fibrous  tissue.  Skin. 

Elastic  tissue.  Secreting  glands. 
Cartilage  and  its  varieties. 

Under  the  idea,  now  entertained,  that  all  organized  tissues  are  essen- 
tially composed  of  cells  having  plastic  or  formative  powers,  with  an 
intercellular  substance  or  blastema,  the  tissues  have  been  thus  arranged 
by  Schwann,1  the  great  author  of  the  cell  doctrine. 

1.  Isolated,  independent  cells.     To  this  class  the  cells  in  fluids  pre- 
eminently belong  : — lymph  globules  ;  blood  corpuscles. 

2.  Independent  cells  united  into  continuous  tissues;  such  as  the  horny 
tissues  and  the  crystalline  lens. 

3.  Cells  in  which  only  the  cell  walls  have  coalesced, — cartilage,  bone, 
and  the  substantia  propria  (ivory)  of  the  teeth. 

4.  Fibre  cells, — cellular  (areolar),  fibrous  and  elastic  tissue. 

5.  Cells  in  which  both  the  cell  walls  and  cell  cavities  have  coalesced, 
— muscle,  nerve  and  capillary  vessels. 

Dr.  Allen  Thomson2  has  proposed  the  following  tabular  view,  which 
— he  remarks — may  be  adopted  in  preference  to  the  foregoing  as  com- 
bining similar  theoretical  considerations,  with  a  more  immediate  refer- 
ence to  the  actual  form  of  the  prevailing  structural  elements  in  the 
different  tissues.  He  properly  adds,  however,  that  this  classification  is 
open — as  he  might  have  said  every  arrangement  must  be — to  several 
objections ;  inasmuch  as  it  brings  together,  under  the  same  head,  some 
parts  endowed  with  different  functions ;  and  separates  some  tef tures 
whose  functions  are  closely  related ;  and  it  does  not  point  out  suf- 
ficiently the  usual  degree  of  complexity  of  the  several  textures. 

Some  part  of  it,  moreover,  is  founded  on  theoretical  considerations 
not  yet  fully  established ;  and  the*  distinctions  on  which  it  rests  are 
based  on  a  structural  analysis  of  various  extent  in  the  different  textures. 
On  the  whole,  however,  it  is  a  sufficient  exponent  of  the  existing  state 
of  belief  on  the  subject. 

I.  Organized  textures  in  which  the  cellular  form  of  the  constituent 
elements  is  apparent;  not  unfrequently  also  presenting  granules  of 
molecular  deposition. 

1.  Rounded  simple  cells,  floating  loose  in  fluid,  Blood,  Lymph,  Chyle 
and  Milk  corpuscles,  $c. 

2.  Simple  cells  massed  together,  either  preserving  their  cellular  form, 
and  without  other  parts  intervening,  or  altered  in  form  and  mixed  with 

1  Microscopical  Researches  into  the  Accordance  in  the  Structure  and  Growth  of  Animals 
and  Plants.     Sydenham  Society's  edit.,  by  Henry  Smith,  p.  66,  London,  1847. 
3  Outlines  of  Physiology  for  the  Use  of  Students,  pt.  i.  p.  68,  Edinb.,  1848. 


FLUIDS.  61 

other  solid  elements : — Pigment,  Fat,  Cuticle,  Horny  textures,  Epithe- 
lium, Crystalline  lens,  Cartilage. 

3.  Simple  cells,  or  their  contents,  altered  in  form  : — Ciliated  texture, 
Spermatozoa. 

4.  Compound  cells,  separate  or  mixed  with  other  textures: — Ovum, 
Cranglionic  corpuscles. 

II.  Textures  exhibiting  a  simply  fibrous  structure. 

1.  Filamentous  (areolar)  texture ;  formerly  Cellular  texture. 

2.  Fibrous  textures: — Tendon,  Ligament,  Fibrous  membranes,  Fi- 
brous plates. 

3.  Elastic  fibrous  texture. 

III.  Textures  exhibiting  a  tubular  structure. 

1.  Containing  moving  fluids : — Bloodvessels  and  Absorbent  vessels. 

2.  Containing  muscular  substance : — Striated  and  non-striated  mus- 
cular fibre. 

3.  Containing  nervous  matter : — Primitive  nerve  tubes. 

IV.  Textures  exhibiting  a  membranous  structure. 

1.  Principally  filamentous  : — Serous  and  Synovial  membranes. 

2.  Filamentous  and  vascular: — Mucous  membranes;  True  skin. 

3.  Membrane  and  cells  : — G-lands. 

4.  Membrane  and  Bloodvessels,  &c. : — Lungs. 

In  combining  to  form  the  different  structures,  the  solids  are  arranged 
in  various  ways.  Of  these,  the  chief  are  in  filaments  or  elementary 
fibres,  tissues,  organs,  apparatuses,  and  systems.  A  filament  is  the 
elementary  solid.  A  fibre  consists  of  a'  number  of  filaments  united 
together.  Occasionally,  this  is  called  a  tissue : — the  term  tissue  usually, 
however,  means  a  particular  arrangement  of  fibres.  An  organ  is  a 
compound  of  several  tissues.  An  apparatus  is  an  assemblage  of  organs, 
concurring  to  the  same  end : — the  digestive  apparatus  consists  of  the 
organs  of  mastication,  insalivation,  and  deglutition,  the  stomach,  duo- 
denu]$r,'  pancreas,  liver,  &c.  These  may  be,  and  are,  of  very  dissimilar 
character,  both  as  regards  their  structure  and  functions ;  but,  if  they 
concur  in  the  same  object,  they  form  an  apparatus.  A  system,  on  the 
other  hand,  is  an  assemblage  of  organs,  all  of  which  possess  the  same 
or  an  analogous  structure.  Thus,  all  the  muscles  of  the  body  have  a 
common  structure  and  function ;  and  form,  in  the  aggregate,  the 
muscular  system.  All  the  vessels  of  the  body,  and  all  the  nerves,  for 
like  reasons,  constitute,  respectively,  the  vascular,  and  nervous  sys- 
tems. 

d.   Of  the  Fluids  of  the  Human  Body. 

The  positive  quantity  or  proportion  of  the  fluids  in  the  human  body 
does  not  admit  of  appreciation,  as  it  must  vary  at  different  periods, 
and  under  different  circumstances.  The  younger  the  animal,  the  greater 
is  its  preponderance.  When  we  first  see  the  embryo,  it  appears  to  be 
almost  wholly  fluid.  As  it  becomes  gradually  developed,  the  proportion 
of  solid  parts  increases,  until  the  adult  age ;  after  which  it  becomes  less 
and  less  in  the  progress  of  life.  During  the  whole  of  existence,  too, 
the  quantity  of  fluids  in  the  body  fluctuates.  At  times,  there  is  plethora 


62  MATERIAL  COMPOSITION  OF  MAN. 

or  unusual  fulness  of  blood-vessels;  at  others,  the  blood  is  less  in 
quantity. 

Experiments  have  been  made  for  the  purpose  of  ascertaining  the 
relative  proportion  of  fluids  to  solids.  M.  Richerand  says,  that  they  are 
in  the  ratio  of  six  to  one ;  M.  Chaussier,  of  nine  to  one.  The  latter  pro- 
fessor put  a  dead  body,  weighing  one  hundred  and  twenty  pounds,  into 
a  heated  oven,  and  dried  it.  After  desiccation,  it  was  found  to  be 
reduced  to  twelve  pounds.  It  is  probable,  however,  that  some  of  the 
more  solid  portions  were  driven  off  by  the  heat  employed ;  and  hence, 
that  the  estimated  proportion  of  fluids  was  too  high.  On  this  account, 
M.  BeVard1  thinks,  that  instead  of  estimating  the  proportion  of  liquids 
at  nine-tenths,  it  would  be  better  to  take  the  mean  result  of  experi- 
ments by  M.  Chevreul,  who  performed  the  desiccation  in  vacuo  and 
with  a  very  moderate  heat.  This  would  give  the  proportion  of  water 
in  the  human  body  about  6*667  parts  in  the  10*000. 

In  the  Egyptian  mummies,  which  are  completely  deprived  of  fluid, 
the  solids  are  extremely  light,  not  weighing  more  than  seven  pounds ; 
but  as  we  are  ignorant  of  the  original  weight  of  the  body,  we  cannot 
arrive  at  any  approximation.  The  dead  bodies  found  in  the  arid  sands 
of  Arabia,  as  well  as  the  dried  preparations  of  the  anatomical  theatre, 
afford  additional  instances  of  reduction  by  desiccation.  To  a  less  extent, 
we  have  the  same  thing  exhibited  in  the  excessive  diminution  in  weight 
that  occurs  in  disease,  and  occasionally  in  those  who  are  apparently  in 
health.  Not  many  years  ago,  an  Anatomie  vivante  was  exhibited  in 
London  to  the  gaze  of  the  curious  and  scientific,  whose  weight  was  not 
more  than  eighty  pounds.  Yet  the  ordinary  functions  were  carried  on, 
apparently  unmodified.  In  the  year  1830,  a  still  more  wonderful 
phenomenon  was  shown.  A  man,  named  Calvin  Edson,  forty-two  years 
old,  five  feet  two  inches  high,  weighed  but  sixty  pounds.  His  weight 
had  formerly  been  one  hundred  and  thirty-five  pounds.  For  sixteen 
years  previously,  he  had  been  gradually  losing  flesh,  without  any  ap- 
parent disease,  having  enjoyed  perfect  health  and  appetite,  and  eating, 
drinking,  and  sleeping  as  well  as  any  one.  He  was  properly  called  the 
"living  skeleton.''  It  was  stated  in  the  public  journals2  that  Dr.  Edson, 
a  brother  of  Calvin,  was  to  all  appearance  entirely  destitute  of  flesh. 
He  was,  in  1847,  forty-two  years  old ;  of  ordinary  height — five  feet  six 
inches,  and  yet  weighed  only  forty-nine  pounds.  He  retained  all  his 
faculties  apparently  in  full  vigour.  We  have  it  also,  on  the  authority 
of  Captain  Riley,3  that  after  protracted  sufferings  in  Africa,  he  was 
reduced  from  two  hundred  and  forty  pounds  to  below  ninety  [?]. 

The  fluids  are  variously  contained;  sometimes  in  vessels — as  the 
blood  and  lymph ;  at  others,  in  cavities — as  the  fluids  secreted  by  the 
pleura,  peritoneum,  arachnoid  coat  of  the  brain,  &c.:  others  are  in 
minute  areolse — as  the  fluid  of  the  areolar  membrane ;  whilst  others, 
again,  are  intimately  combined  with  the  solids.  They  differ  likewise 
in  density, — some  existing  in  the  state  of  halitus  or  vapour ;  others 

1  Cours  de  Physiologic,  p.  200,  Paris,  1848. 

a  Philadelphia  Public  Ledger,  Feb.  2,  1847. 

3  Narrative  of  the  Loss  of  tli£  American  Brig  Commerce,  &c.,  p.  302.     New  York,  1817. 


PHYSICAL  PROPERTIES  OF  TISSUES.  63 

being  very  thin  and  aqueous — as  the  fluid  of  the  serous  membranes  ; 
and  others  of  more  consistence — as  the  secretion  of  the  mucous  mem- 
branes, animal  oils,  &c. 

The  physical  and  chemical  properties  of  the  fluids  will  engage  atten- 
tion when  they  fall  individually  under  consideration  ;  and  we  shall  find 
that  one  of  them  at  least — the  blood — exhibits  certain  phenomena 
analogous  to  those  of  the  living  solid. 

The  fluids  have  been  differently  classed,  according  to  the  particular 
views  that  have,  from  time  to  time,  prevailed  in  the  schools.  The  an- 
cients referred  them  all  to  four, — blood,  bile,  phlegm  or  pituita,  and 
atrabilis ;  each  of  which  was  conceived  to  abound  in  one  of  the  four 
ages,  seasons,  climates,  or  temperaments.  Blood  predominated  in 
youth,  in  the  spring,  in  cold  mountainous  regions,  and  in  the  sanguine 
or  inflammatory  temperament.  Pituita  or  phlegm  had  the  mastery  in 
old  age,  in  winter,  in  low  and  moist  countries,  and  in  the  lymphatic 
temperament.  Bile  predominated  in  mature  age,  in  summer,  in  hot 
climates,  and  in  the  bilious  temperament;  and  atrabilis  was  the  cha- 
racteristic of  middle  age,  of  autumn,  of  equatorial  climes,  and  of  the 
melancholic  temperament.  This  was  their  grand  humoral  system, 
which  has  vanished  before  a  better  observation  of  facts,  and  more  im- 
proved methods  of  physical  and  metaphysical  investigation.  The 
atrabilis  was  a  creature  of  the  imagination ;  the  pituitous  condition  is 
unintelligible  to  us ;  and  the  doctrine  of  the  influence  of  the  humours 
on  the  ages,  temperaments,  &c.,  irrational. 

Subsequently,  the  humours  were  classed  according  to  their  physical 
and  chemical  properties :  they  were  divided,  for  instance,  into  liquids, 
vapours,  and  gases ;  into  acid,  alkaline,  and  neutral ;  into  thick  and 
thin;  into  aqueous,  mucilaginous,  gelatinous,  and  oily;  into  saline,  oily, 
saponaceous,  mucous,  albuminous,  and  fibrinous,  &c.  In  more  modern 
times,  endeavours  have  been  made  to  arrange  them  according  to  their 
uses  in  the  economy  into — 1,  recrementitial  fluids,  or  those  intended 
to  be  again  absorbed ;  2,  excrementitial,  those  that  have  to  be  expelled 
from  the  body;  and  3,  those  which  participate  in  both  purposes,  and 
are  hence  termed  excremento-recrementitial.  Blumenbach1  divided  them 
into  crude  humours,  blood,  and  secreted  humours,  a  division  which  has 
been  partly  adopted  by  M.  Adelon  ;2  and  Chaussier,  whose  anatomical 
arrangements  and  nomenclature  have  rendered  him  justly  celebrated, 
reckoned  five  classes: — 1,  those  produced  by  the  act  of  digestion, — 
chyme  and  chyle;  2,  the  circulating  fluids, — lymph  and  blood;  3,  the 
perspired  fluids  ;  4,  the  follicular ;  and  5,  the  glandular.  This  arrange- 
ment has  been  adopted  by  M.  Magendie,3  and,  with  slight  modification, 
is  perhaps  as  satisfactory  as  any  that  has  been  proposed.  All  these 
will  have  to  engage  attention  under  SECRETION. 

e.  Physical  Properties  of  the  Tissues. 
The  tissues  of  the  body  possess  the  physical  properties  of  matter  in 

1  Institutiones  Physiologies,  Sect,  ii.,  §  4.  Getting.,  1798. 
9  Physiologic  de  THomme,  2de  edit.,  i.  124.  Paris,  1829. 
3  Precis  Elementaire  de  Physiol.,  2de  edit.,  i.  20.  Paris,  1825. 


64  MATERIAL  COMPOSITION  OF  MAN. 

general.  They  are  found  to  vary  in  consistence, — some  being  hard, 
and  others  soft ;  as  well  as  in  colour,  transparency,  &c.  They  have, 
also,  physical  properties,  analogous,  indeed,  to  what  are  met  with  in 
certain  inorganic  substances,  but  generally  superior  in  degree.  These 
are  flexibility,  extensibility,  and  elasticity,  which  are  variously  com- 
bined and  modified  in  the  different  forms  of  animal  matter,  but  exist  to 
a  greater  or  less  extent  in  every  tissue.  Elasticity  is  only  exerted 
under  particular  circumstances:  when  the  part,  for  example,  is  put 
upon  the  stretch  or  compressed,  the  force  of  elasticity  restores  it  to  its 
primitive  state,  as  soon  as  the  distending  or  compressing  cause  is  with- 
drawn. The  tissues,  in  which  elasticity  is  inherent,  are  so  disposed 
through  the  body,  as  to  be  kept  in  a  state  of  distension  by  the  mechani- 
cal circumstances  of  situation;  but,  as  soon  as  these  circumstances  are 
modified,  elasticity  comes  into  play,  and  produces  shrinking  of  the  sub- 
stance. It  is  easy  to  see,  that  these  circumstances,  owing  to  the  con- 
stant alteration  in  the  relative  situation  of  parts,  must  be  ever  varying. 
Elasticity  is,  therefore,  constantly  called  into  operation,  and  in  many 
cases  acts  upon  the  tissues  as  a  new  power.  The  cartilages  of  the  ribs, 
joints,  &c.,  are  in  this  manner  valuable  agents  in  particular  functions. 

We  have  other  examples  of  the  mode  in  which  elasticity  exhibits 
itself,  when  the  contents  of  hollow  parts  are  withdrawn,  and  whenever 
muscles  are  divided  transversely.  The  gaping  wound,  produced  by  a 
cut  across  a  shoulder  of  mutton,  is  familiar  to  all.  Previous  to  the 
division,  the  force  of  elasticity  is  kept  neutralized  by  the  mechanical 
circumstances  of  situation, — or  by  the  continuity  of  the  parts;  but  as 
soon  as  this  continuity  is  disturbed,  in  other  words,  as  soon  as  the  me- 
chanical circumstances  are  altered,  the  force  of  elasticity  is  exerted, 
and  produces  recession  of  the  edges.  This  property  has  been  described 
under  various  names,  tone  or  tonicity,  contractilite  de  tissu,  contractilite 
par  defaut  d1  extension,  &c. 

The  other  properties,  flexibility  and  extensibility,  vary  greatly  ac- 
cording to  the  structure  of  parts.  The  tendons,  which  are  composed 
of  areolar  tissue,  exhibit  very  little  extensibility ;  and  this  for  wise 
purposes.  They  are  the  conductors  of  force  developed  by  muscle,  and 
were  they  to  yield,  it  would  be  at  the  expense  of  the  muscular  efforts; 
but  they  possess  great  flexibility.  The  articular  ligaments  are  very 
flexible,  and  somewhat  more  extensible.  On  the  other  hand,  the  fibrous 
or  ligamentous  structures,  which  are  employed  to  support  weights,  or 
are  antagonists  to  muscular  action, — as  the  ligamentum  nuchse,  which 
passes  from  the  spine  to  the  head  of  the  quadruped, — are  very  extensible 
and  elastic. 

Another  physical  property,  possessed  by  animal  substances,  is  a  kind 
of  contractility,  accompanied  with  sudden  corrugation  and  curling. 
This  effect,  which  Bichat  terms  racornissement,  is  produced  by  heat, 
and  by  chemical  agents,  especially  the  strong  mineral  acids.  The 
property  is  exhibited  by  leather  when  thrown  into  the  fire. 

An  effect,  in  some  measure  resembling  this,  is  caused  by  the  evapo- 
ration of  the  water  that  is  united  to  animal  substances.  This  consti- 
tutes what  has  been  called  the  Jiygrometric  property  of  animal  mem- 


PHYSICAL  PROPERTIES  OF  TISSUES.  65 

branes.1  It  is  characteristic  of  dry,  membranous  structures;  all  of 
which  are  found  to  contract,  more  or  less,  by  the  evaporation  of  moist- 
ure, and  to  expand  again  by  its  re-absorption;  hence  the  employment  of 
such  substances  as  hygrometers.  According  to  M.  Chevreul,2  many  of 
the  tissues  are  indebted  for  their  physical  properties  to  the  water  they 
contain,  or  with  which  they  are  imbibed.  When  deprived  of  this  fluid, 
they  become  unfit  for  the  purposes  for  which  they  are  destined  in  life, 
and  resume  them  as  soon  as  they  have  recovered  it. 

A  most  important  property  possessed  by  the  tissues  of  organized 
bodies  is  imbibition;  a  property  to  which  attention  has  been  chiefly  di- 
rected of  late  years.  If  a  liquid  be  put  in  contact  with  any  organ  or 
tissue,  in  process  of  time  the  liquid  will  be  found  to  have  passed  into 
the  areolse  of  the  organ  or  tissue,  as  it  would  enter  the  cells  of  a  sponge. 
The  length  of  time  occupied  in  this  imbibition  will  depend  upon  the 
nature  of  the  liquid  and  the  kind  of  tissue.  Some  parts  of  the  body, 
as  the  serous  membranes  and  small  vessels,  act  as  true  sponges,  ab- 
sorbing with  great  promptitude;  others  resist  imbibition  for  a  considera- 
ble time, — as  the  epidermis. 

Liquids  penetrate  equally  from  within  to  without :  the  process  is  then 
called  transudation. 

Some  singular  facts  have  been  observed  regarding  the  imbibition  of 
fluids  and  gases.  On  filling  membranous  expansions,  as  the  intestine 
of  a  chicken,  with  milk  or  some  dense  fluid,  and  immersing  it  in  water, 
M.  Dutrochet3  observed,  that  the  milk  left  the  intestine,  and  the  water 
entered  it;  hence  he  concluded,  that  whenever  an  organized  cavity, 
containing  a  fluid,  is  immersed  in  another  fluid,  less  dense  than  that 
which  is  in  the  cavity,  there  is  a  tendency  in  the  cavity  to  expel  the 
denser  and  absorb  the  rarer  fluid.  This  M.  Dutrochet  termed  endos- 
mose, or  "inward  impulsion;"  and  he  conceived  it  to  be  a  new  power, 
a  "physico-organic  or  vital  action."  Subsequent  experiments  showed, 
that  a  reverse  operation  could  take  place.  If  the  internal  fluid  was 
rarer  than  the  external,  the  transmission  occurred  in  the  opposite  di- 
rection. To  this  reverse  process,  he  gave  the  name  exosmose,  or  "  out- 
ward impulsion."  At  times,  the  term  endosmose  is  applied  to  the 
mutual  action  of  two  liquids  when  separated  by  a  membrane;4  at  others, 
to  the  passage  of  the  liquid,  that  permeates  the  membrane  in  greatest 
quantity.5 

Soon  after  the  appearance  of  M.  Dutrochet's  essay,  the  experiments 
were  repeated,  with  some  modifications,  by  Dr.  Faust,6  and  by  Dr. 

1  Roget,  art.  Physiology,  in  Supplement  to  Encyclopaedia  Britannica ;  and  Outlines  of  Phy- 
siology, with  an  Appendix  on  Phrenology.     First  American  edition,  with  notes  by  the  author 
of  this  work,  p.  73,  Philad.,  1839. 

2  Magendie,  Precis  Elementaire  de  Physiologie,  2de  edit.,  1825,  i.  13. 

3  Mem.  pour  servir  a  1'Histoire  Anatom.  et  Physiol.  des  Animaux  et  des  Vegetaux,  Paris, 
1837;  art.  Endosmosis,  in  Cyclopaedia  of  Anatomy  and  Physiology,  part  x.  p.  98,  June,  1837. 
See,  also,  Vierordt,  art.  Transudation  und  Endosmose,  in  Wagner's  Handworterbuch  der 
Physiologie,  s.  631,  Braunschweig,  1848. 

4  Matteucci,  Lectures  on  the  Physical  Phenomena  of  Living  Beings;  translated  by  Pereira, 
p.  45,  Amer.  edit.,  Philad.,  1848. 

6  Poiseuille,  Comptes  Rendus,  xix.  944.  Paris,  1844. 
6  Amer.  Journal  of  the  Mod.  Sciences,  vii.  23,  Philad.,  1830. 
VOL.  I. — 5 


DO  MATERIAL  COMPOSITION  OF  MAN. 

Togno,1  of  Philadelphia;  and  with  like  results.  The  fact  of  this  imbi- 
bition and  transudation  was  singular  and  impressive;  and,  with  so 
enthusiastic  an  individual  as  M.  Dutrochet,  could  not  fail  to  give  birth 
to  numerous  and  novel  conceptions.  The  energy  of  the  action  of  both 
endosmose  and  exosmose  is  in  proportion,  he  asserted,  to  the  difference 
between  the  specific  gravities  of  the  two  fluids;  and,  independently  of 
their  gravity,  their  chemical  nature  affects  their  power  of  transmission. 
These  effects — he  at  once  decided — must  be  owing  to  electricity.  The 
cavities,  in  which  the  changes  take  place,  he  conceived  to  be  like  Ley- 
den  jars  having  their  two  surfaces  charged  with  opposite  electricities, — 
the  ultimate  effect  or  direction  of  the  current  being  determined  by  the 
excess  of  the  one  over  the  other. 

In  an  inferesting  and  valuable  communication  by  Dr.  J.  K.  Mitchell,2 
of  Philadelphia,  "on  the  penetrativeness  of  fluids,"  many  of  the  vision- 
ary speculations  of  M.  Dutrochet  are  sensibly  animadverted  upon. 
It  is  there  shown,  that  he  had  asserted,  in  the  teeth  of  some  of  his 
most  striking  facts,  that  the  current  was  from  a  less  dense  to  a  more 
dense  fluid;  and  that  it  was  from  positive  to  negative,  dependent  not 
on  an  inherent  power  of  filtration, — a  power  always  the  same  when  the 
same  membrane  is  concerned, — but  modified  at  pleasure  by  supposed 
electrical  agencies.  This  view  was  subsequently  abandoned  by  M. 
Dutrochet,  in  favour  of  the  following  principle.  It  is  well  known  that 
porous  bodies,  as  sugar,  wood,  or  sponge,  are  capable  of  imbibing 
liquids,  with  which  they  are  in  contact.  In  such  case  the  liquid  is  not 
merely  introduced  into  the  pores  of  the  solid,  as  it  would  be  into  an 
empty  space;  but  is  forcibly  absorbed,  so  that  it  will  rise  to  a  height 
considerably  above  its  former  level.  This  force  is  molecular,  and  is 
the  same  that  we  witness  in  the  phenomena  presented  by  the  capillary 
tube,  which  affords  us  the  simplest  case  of  the  insinuation  of  a  liquid 
into  a  porous  body.  It  cannot  alone,  however,  cause  the  liquid  to  pass 
entirely  through  the  body.  If  a  capillary  tube,  capable  of  raising 
water  to  the  height  of  six  inches,  be  depressed,  so  that  one  inch  only 
be  above  the  surface,  the  water  will  rise  to  the  top  of  the  tube;  but  no 
part  of  it  will  escape.  Even  if  the  tube  be  inserted  horizontally  into 
the  side  of  the  vessel  containing  water,  the  water  will  only  pass  to  the 
end  of  the  tube.  The  same  thing  occurs  when  a  liquid  is  placed  in 
contact  with  one  side  of  a  porous  membrane:  it  enters  the  pores;  passes 
to  the  opposite  side,  and  is  there  arrested.  But  if  this  membrane  com- 
municates with  a  second  vessel  containing  a  different  liquid — as  a  saline 
solution,  capable  of  mixing  with  the  first,  and  affected  to  a  different 
degree  by  capillary  attraction — a  new  phenomenon  will  be  presented. 
It  will  be  found,  that  both  liquids  enter  the  pores,  and  pass  through  to 
the  opposite  side.  They  will  not,  however,  be  carriqd  through  with  the 
same  force:  that  which  has  the  greatest  power  of  capillary  ascension, 
has  the  greatest  affinity  for  the  membrane,  or  will  wet  it  more  readily, 
— in  other  words,  that  which  will  rise  the  highest  in  a  capillary  tube, 
will  pass  through  in  greater  quantity,  and  cause  an  accumulation  of 
liquid  on  the  opposite  side.  The  action  is  well  shown  by  the  simple 

1  Amer.  Journal  of  the  Med.  Sciences,  iv.  73,  Philad.,  1829. 
9  Ibid.,  vii.  23,  Philad.,  1830. 


PHYSICAL  PROPERTIES  OF  TISSUES. 


67 


instrument  figured  in  the  margin.     It  consists  of  a  glass 
tube,  the  lower  extremity  of  which,  covered  by  bladder,  is 
funnel-shaped.  ThisM.  Dutrochet  termed  an  endosmometer. 
If  an  aqueous  solution  of  either  gum  or  sugar  be  poured 
into  it,  and  the  closed  extremity  be  immersed  in  pure  water, 
the  water  is  found  to  pass  continually  into  the  tube  by 
filtration  through   the  membrane,  so  that  the  liquid  will 
rise  in  the  tube,  and  may  even  flow  out  at  the  upper  aper- 
ture.    At  the  same  time,  a  portion  of  the  mucilaginous  or 
saccharine  solution  will  escape  from  the  tube  through  the 
bladder,  and  become  mixed  with  the  water,  but  the  quan- 
tity will  be  much  less  than  that  of  the  water  which  entered. 
The   facts    and    arguments   adduced    by   Dr.    Mitchell 
clearly   exhibit,  that  imbibition   and  transudation  are  de- 
pendent upon  the  penetrativeness  of  the  liquid,  and  the 
penetrability  of  the  membrane ;  that  if  two  liquids,  of  dif- 
ferent rates  of  penetrativeness,  be  placed  on  opposite  sides 
of  an  animal  membrane,   "  they  will  in  time  present  the 
greater  accumulation  on  the  side  of  the  less  penetrant 
liquid,  whether  more  or  less  dense;  but  will,  finally,  tho- 
roughly, and  uniformly  mix  on  both  sides ;  and  at  length, 
if  any  pressure  exist  on  either  side,  yield  to  that,  and  pass 
to  the  other  side."1     In  all  such  cases,  there  are  both  endosmose  and 
exosmose — or  double  imbibition;  in  other  words,  a  certain  quantity  of 
one  fluid  passes  in,  and  a  certain  quantity  of  the  other  passes  out.2 
As    a   general   rule,  imbibition   takes    place   from    the    rarer  to  the 
denser  medium ;  from  pure  water  or  dilute  solutions  towards  those  that 
are  more  concentrated.     It  would  appear,  again,  that  the  stronger  cur- 
rent is  always  from  the  medium  which  has  the  strongest  affinity  for  the 
substance  of  the  septum.     It  is  well  known,  that  in  the  case  of  a  mix- 
ture of  dilute  alcohol  covered  over  by  a  piece  of  bladder,  the  alcohol 
becomes  concentrated,   owing  to  the  water — a   denser  fluid — passing 
more  rapidly  through  the  septum  or  bladder  than  the  alcohol ;  but  if 
the  same  mixture  be  tied  over  with  elastic  gum,  the  contrary  effect  will 
be  produced — the  alcohol  escaping  in  greater  quantity.3     The  general 
conditions  of  the  phenomena  of  endosmose   are : — first,  that  the  two 
liquids  shall  have  an  affinity  for  the  septum  or  interposed  membrane ; 
and,  secondly,  that  they  shall  have  an  affinity  for,  and  be  miscible  with, 
each  other. 

A  portion  of  the  communication  of  Dr.  Mitchell  relates  to  an  ana- 
logous subject,  to  which,  as  M.  Magendie4  has  observed,  little  or  no 
attention  had  been  paid  by  physiologists, — the  permeability  of  mem- 
branes by  gases.  "  The  laminae,"  M.  Magendie  remarks,  "  of  which 
membranes  are  constituted,  are  so  arranged  that  gases  can  penetrate 

1  Amer.  Journal  of  the  Medical  Sciences  for  November,  1833,  p.  100. 
3  Magendie,  Le$ons  sur    les    Phenomenes    Physiques  de    la    Vie,  torn.  i.  p.  99,  Paris, 
1836-38. 

3  Henle,  Allgem.  Anat.,  or  Jourdan's  French  translat.,  p.  210,  Paris,  1843;  and  Wagner, 
Elements  of  Physiology,  by  Willis,  p.  438,  Lond.,  1842. 

4  Precis  Elementaire  de  Physiologie,  2de  edit.,  1825,  i.  13;  and  Leeons,  &c.,  torn.  i.  p. 
132. 


68  MATERIAL  COMPOSITION  OF  MAN. 

them,  as  it  were,  without  obstacle.  If  we  take  a  bladder,  and  fill  it 
with  pure  hydrogen,  and  afterwards  leave  it  in  contact  with  atmospheric 
air,  in  a  very  short  time  the  hydrogen  will  have  lost  its  purity,  and 
be  mixed  with  the  atmospheric  air,  which  has  penetrated  the  bladder. 
This  phenomenon  is  more  rapid  in  proportion  as  the  membrane  is  thin- 
ner and  less  dense.  It  presides  over  one  of  the  most  important  acts  of 
life — respiration  ;  and  continues  after  death." 

Dr.  Mitchell  is  the  first  individual,  who  directed  his  observation  to 
the  relative  penetrativeness  of  different  gases.  This  he  was  enabled 
to  discriminate  by  the  following  satisfactory  experiment,  which  we 
give  in  his  own  words:  "  Having  constructed  a  syphon  of  glass,  with 
one  limb  three  inches  long,  and  the  other  ten  or  twelve  inches,  the 
open  end  of  the  short  leg  was  enlarged  and  formed  into  the  shape  of 
a  funnel,  over  which,  finally,  was  firmly  tied  a  piece  of  thin  gum 
elastic.  By  inverting  this  syphon,  and  pouring  into  its  longer  limb 
some  clear  mercury,  a  portion  of  common  air  was  shut  up  in  the  short 
leg,  and  was  in  communication  with  the  membrane.  Over  this  end,  in 
the  mercurial  trough,  was  placed  the  vessel  containing  the  gas  to  be 
tried,  and  its  velocity  of  penetration  measured  by  the  time  occupied  in 
elevating  to  a  given  degree  the  mercurial  column  in  the  other  limb. 
Having  thus  compared  the  gases  with  common  air,  and  subsequently 
by  the  same  instrument,  and  in  bottles  with  each  other,  I  was  able 
to  arrange  the  following  gases  according  to  their  relative  facility  of 
transmission,  beginning  with  the  most  powerful: — ammonia,  sulphu- 
retted hydrogen,  cyanogen,  carbonic  acid,  nitrous  oxide,  arseniuretted 
hydrogen,  olefiant  gas,  hydrogen,  oxygen,  carbonic  oxide,  and  nitro- 
gen." 

He  found  that  ammonia  transmitted  in  one  minute  as  much  in  volume 
as  sulphuretted  hydrogen  did  in  two  minutes  and  a  half;  cyanogen, 
in  three  minutes  and  a  quarter;  carbonic  acid,  in  five  minutes  and  a 
half ;  nitrous  oxide,  in  six  minutes  and  a  half ;  arseniuretted  hydrogen, 
in  twenty-seven  minutes  and  a  half ;  olefiant  gas,  in  twenty-eight 
minutes;  hydrogen,  in  thirty-seven  minutes  and  a  half;  oxygen,  in  one 
hour  and  fifty-three  minutes ;  and  carbonic  oxide,  in  two  hours  and 
forty  minutes.  It  was  found,  too,  that  up  to  a  pressure  of  sixty-three 
inches  of  mercury,  equal  to  more  than  the  weight  of  two  atmospheres, 
the  penetrative  action  was  capable  of  conveying  the  gases — the  sub- 
jects of  the  experiment — into  the  short  leg  through  the  gum  elastic 
membrane.  Hence,  the  degree  of  force  exerted  in  the  penetration  is 
considerable. 

The  experiments  were  all  repeated  with  animal  membranes,  such  as 
dried  bladder  and  gold-beater's  skin,  moistened  so  as  to  resemble  the 
natural  state.  The  same  results,  and  in  the  same  order,  followed  as 
with  the  gum  elastic.  The  more  fresh  the  membrane,  the  more  speedy 
and  extensive  was  the  effect;  and  in  living  animals  the  transmission 
was  very  rapid. 

To  these  experiments  there  will  be  frequent  occasion  to  refer  in  the 
course  of  this  work.1 

1  See,  connected  with  this  subject,  the  ingenious  papers  by  Dr.  Robert  E.  Rogers,  and  Dr. 
Draper, — the  former  in  the  American  Journal  of  the  Medical  Sciences ,  May,  183(3,  p.  13; 


FUNCTIONS  OF  MAN.  69 

All  these  different  properties  of  animal  solids  are  independent  of  the 
vital  properties.  They  continue  for  some  time  after  the  total  extinc- 
tion of  life  in  all  its  phenomena,  and<  appear  to  be  connected  either 
with  the  physical  arrangement  of  the  molecules,  the  chemical  compo- 
sition of  the  substance  in  which  they  reside,  or  with  peculiar  properties 
in  the  body  that  is  made  to  act  on  the  tissue.  They  do  not,  indeed, 
seem  to  be  affected,  until  the  progress  of  decomposition  has  become 
sensible.  Hence,  many  of  them  have  been  termed  collectively,  by 
Haller,  vis  mortua. 

2.    FUNCTIONS  OF  MAN. 

Having  described  the  intimate  structure  of  the  tissues,  we  pass  to 
the  consideration  of  the  functions ;  the  character  of  each  of  which  is, 
—that  it  fulfils  a  special  and  distinct  office  in  the  economy,  for  which 
it  has  in  general  an  organ  or  instrument,  or  evident  apparatus  of  organs. 
Physiologists  have  not,  however,  agreed  on  the  number  of  distinct 
offices ;  and  hence  the  difference,  in  regard  to  the  number  and  classi- 
fication of  the  functions,  that  prevails  amongst  them.  The  oldest 
division  is  into  the  vital,  natural,  and  animal;  the  vital  functions  in- 
cluding those  of  such  importance  as  not  to  admit  of  interruption, — cir- 
culation, respiration,  and  innervation;  the  natural  functions  those  that 
effect  nutrition,  digestio.n,  absorption,  and  secretion;  and  the  animal, 
those  possessed  exclusively  by  animals, — sensation,  locomotion,  and  voice. 
This  classification,  with  more  or  less  modification,  prevails  at  the  pre- 
sent day. 

The  character  of  this  work  will  not  admit  of  a  detail  of  every  classi- 
fication which  has  been  proposed;  that  of  Bichat,  however,  has  occu- 
pied so  large  a  space  in  the  public  eye,  that  it  cannot  well  be  passed 
over.  It  is  followed  by  M.  Richerand,1  and  many  modern  writers. 
Bichat  includes  all  the  functions  under  two  heads. — functions  of  nutri- 
tion, which  concern  the  life  of  the  individual,  and  functions  of  reproduc- 
tion, which  concern  the  life  of  the  species.  Nutrition  requires,  that  the 
being  shall  establish  relations  around  him  to  obtain  the  materials  of 
which  he  may  stand  in  need ;  and,  in  animals,  the  functions  that  esta- 
blish such  relations,  are  under  the  volition  and  perception  of  the  being. 
Hence  they  are  divided  into  two  sets ;  those  that  commence  or  precede 
nutrition ;  have  external  relations ;  are  dependent  upon  the  will,  and 
executed  with  consciousness;  and  those  that  are  carried  on  within  the 
body  spontaneously,  and  without  consciousness.  Bichat  adopted  this 
basis;  and,  to  the  first  aggregate  of  functions,  he  applied  the  term 
animal  life,  because  it  comprised  those  that  characterize  animality;  the 
latter  he  termed  organic  life,  because  the  functions  comprised  under  it 
are  common  to  every  organized  body.  Animal  life  included  sensation, 
motion,  and  expression ;  organic  life,  digestion,  absorption,  respiration, 
circulation,  nutrition,  secretion,  &c.  In  animal  life,  Bichat  recognized 

and  the  latter  in  the  same  Journal  for  August,  1836.  p.  276  ;  Nov.   1837,  p.  122  :  and  Aue. 
1838,  p.  302. 

1  Nouveaux  Elemens  de  Physiologic,  13eme  edit.,  par  M.  Berard,  aine,  edit.  Beige,  p.  42, 
Bruxelles,  1837:  or  Amer.  reprint  of  Copland's  edit,  of  De  Lys's  translation,  New  York, 
1836. 


70 


FUNCTIONS  OF  MAN. 


two  series  of  actions,  antagonistic  to  each  other ;  the  one  proceeding 
from  without  and  terminating  in  the  brain,  or  passing  from  circum- 
ference to  centre,  and  comprising  the  external  senses;  the  other,  com- 
mencing in  the  brain,  and  acting  on  external  bodies,  or  proceeding 
from  centre  to  circumference,  and  including  the  internal  senses,  loco- 
motion, and  voice.  The  brain,  in  which  one  series  of  actions  terminates 
and  the  other  begins,  he  considered  the  centre  of  animal  life.  In 
organic  life,  he  likewise  recognized  two  series  of  actions :  the  one,  pro- 
ceeding from  without  to  within,  and  effecting  composition ;  the  other 
passing  from  within  to  without,  and  effecting  decomposition.  In  the 
former,  he  included  digestion ;  absorption ;  respiration,  by  which  the 
blood  is  formed ;  circulation,  by  which  the  blood  is  conveyed  to  different 
parts  ;  and  the  functions  of  nutrition,  and  calorification.  In  the  latter, 
that  absorption  by  which  parts  are  taken  up  from  the  body ;  the  cir- 
culation, which  conducts  those  parts  or  materials  to  the  secretory  or 
depuratory  organs ;  and  the  secretions,  which  separate  them  from  the 
economy.  In  this  kind  of  life,  the  circulation  is  common  to  the  two 
movements  of  composition  and  decomposition;  and,  as  the  heart  is  the 
great  organ  of  the  circulation,  he  considered  it  the  centre  of  organic 
life.  Lastly,  as  the  lungs  are  united  with  animal  life  in  the  reception 
of  air,  and  with  organic  life  as  the  organs  of  sanguification,  Bichat 
regarded  them  as  the  bond  of  union  between  the  two  lives.  Genera- 
tion constituted  the  life  of  the  species. 

The  classification,  adopted  in  this  work,  is  essentially  that  embraced 
by  M.  Magendie  ;*  and,  after  him,  by  M.  Adelon,2  who  has  written  one 
of  the  best  systems  of  human  physiology  that  we  possess.  The  FIRST 
CLASS,  or  functions  of  relation  or  animal  functions,  includes  those  that 
establish  our  connexion  with  the  bodies  that  surround  us ;  the  sensations, 
voluntary  motions,  and  expressions.  The  SECOND  CLASS,  or  functions 
of  nutrition,  comprises  digestion,  absorption,  respiration,  circulation, 
nutrition,  calorification,  and  secretion  ;  and  the  THIRD  CLASS,  the  func- 
tions of  reproduction, — generation. 

TABLE  OF  FUNCTIONS. 


I.  Functions  that  relate  to 
the  preservation  of  the  indi- 
vidual. 


I.  Animal  or  of  Relation. 


II.  Nutritive. 


III.  Reproductive. 


1 .  Sensation. 

2.  Muscular  Motion. 

3.  Expression  or  Language. 

4.  Digestion. 

5.  Absorption. 

6.  Respiration. 

7.  Circulation. 

8.  Nutrition. 

9.  Calorification. 
^  10.  Secretion. 

II.  Functions  that  relate  to 
the  preservation  of  the  species. 

In  studying  each  of  these  functions,  we  shall  first  of  all  describe  the 
organ  or  apparatus  concerned  in  its  production, — but  so  far  only  as  is 
necessary  in  a  physiological  point  of  view;  and  shall  next  detail  what 
has  been  called  the  mechanism  of  the  function,  or  the  mode  in  which 
it  is  effected.  In  many  cases,  it  will  happen,  that  some  external  agent 


11.  Generation. 


1  Precis,  &c.,  i.  32. 


9  Physiologie  de  1'Homme,  2de  edit.,  i.  116.     Paris,  1829. 


FUNCTIONS  OF  MAN.  71 

is  concerned, — as  light  in  vision ;  sound  in  audition  ;  odours  in  olfaction  ; 
tastes  in  gustation.  The  properties  of  these  agents  will,  in  all  instances, 
be  detailed  in  a  brief  manner. 

The  difficulty  of  observing  actions,  that  are  carried  on  by  the  very 
molecules  of  which  the  organs  are  composed,  has  given  rise  to  many 
hypothetical  speculations,  some  of  which  are  sufficiently  ingenious; 
others  too  fanciful  to  be  indulged  for  a  moment;  and,  as  might  be 
expected,  the  number  of  these  fantasies  generally  bears  a  direct  pro- 
portion to  the  difficulty  and  obscurity  of  the  subject.  It  will  not  be 
proper  to  pass  over  the  most  prominent  of  these,  but  they  will  not  be 
dwelt  upon ;  whilst  the  results  of  direct  observation  and  experiment 
will  be  fully  detailed;  and  where  differences  exist  amongst  observers, 
such  differences  will  be  reconciled,  where  practicable. 

The  functions,  executed  by  different  organs  of  the  body,  can  be  de- 
duced by  direct  observation;  although  the  minute  and  molecular  action, 
by  which  they  are  accomplished  in  the  very  tissue  of  the  organ,  may 
not  admit  of  detection.  We  see  blood  proceeding  to  the  liver,  and  the 
vessels  that  convey  it  ramifying  in  the  texture  of  that  viscus,  and 
becoming  so  minute  as  to  escape  detection  even  when  the  eye  is  aided 
by  a  powerful  microscope.  We  find,  again,  other  canals  in  the  organ 
becoming  perceptible,  gradually  augmenting  in  size,  and  ultimately 
terminating  in  a  larger  duct,  which  opens  into  the  small  intestine.  If 
we  examine  each  of  these  orders  of  vessels  in  their  most  minute  appre- 
ciable ramifications,  we  discover,  in  the  one,  always  blood ;  and,  in  the 
other,  always  a  very  different  fluid, — bile.  We  are  hence  led  to  the 
conclusion,  that  in  the  intimate  tissue  of  the  liver,  and  in  some  part 
communicating  directly  or  indirectly  with  both  these  orders  of  vessels, 
bile  is  separated  from  the  blood ;  or  that  the  liver  is  the  organ  of  the 
biliary  secretion.  On  the  other  hand,  functions  exist,  which  cannot 
be  so  demonstratively  referred  to  a  special  organ.  We  have  every 
reason  for  believing,  that  the  brain  is  the  exclusive  organ  of  the  mental 
and  moral  manifestations ;  but,  as  few  opportunities  occur  for  seeing  it 
in  action;  and  as  the  operation  is  too  molecular  to  admit  of  direct 
observation  when  we  do  see  it,  we  are  compelled  to  connect  the  organ 
and  function  by  a  process  of  reasoning  only ;  yet,  we  shall  find,  that 
the  results  at  which  we  arrive  in  this  manner  are  often  by  no  means 
the  least  satisfactory. 

The  forces  which  preside  over  the  various  functions  are  either  gene- 
ral,— that  is,  physical  or  chemical ;  or  special, — that  is,  organic  or  vital. 
Some  of  the  organs  afford  us  examples  of  purely  physical  instruments. 
We  have  in  the  eye,  an  eye-glass  of  admirable  construction;  in  the 
organ  of  voice,  an  instrument  of  music ;  in  the  ear,  one  of  acoustics : 
the  circulation  is  carried  on  through  an  ingenious  hydraulic  apparatus  ; 
and  station  and  progression  involve  various  laws  of  mechanics.  In 
many  of  the  functions,  again,  we  have  examples  of  chemical  agency, 
whilst  all  in  which  innervation  is  concerned  are  incapable  of  being 
explained  on  any  physical  or  chemical  principle;  and  we  are  constrained 
to  esteem  them  vital. 


72  NERVOUS  SYSTEM. 


BOOK    I. 

ANIMAL  FUNCTIONS  OR  FUNCTIONS  OF  RELATION. 

THE  functions  of  relation  consist,  first,  of  sensibility,  and,  secondly, 
of  muscular  motion,  including  expression  or  language.  They  are  all 
subject  to  intermission,  constituting  sleep;  a  condition  which  has,  con- 
sequently, by  many  physiologists,  been  investigated  under  this  class ; 
but  as  the  functions  of  reproduction  are  influenced  by  the  same  condi- 
tion, the  consideration  of  sleep  will  be  deferred  until  the  third  class  of 
functions  has  received  attention. 

CHAPTER  I. 

SENSIBILITY. 

SENSIBILITY  is  the  function  by  which  an  animal  experiences  feeling,  or 
has  the  perception  of  an  impression.  In  its  general  acceptation,  it 
means  the  property  possessed  by  living  parts  of  receiving  impressions, 
whether  the  being  exercising  the  property  has  consciousness  of  it  or 
not.  To  the  first  of  these  cases — in  which  there  is  consciousness — 
Bichat  gave  the  epithet  animal;  to  the  second,  organic;  the  latter 
being  common  to  animals  and  vegetables,  and  presiding  over  the  organic 
functions  of  nutrition,  absorption,  exhalation,  secretion,  &c. ;  the  former 
existing  only  in  animals,  and  presiding  over  the  sensations,  internal  as 
well  as  external.  Animal  sensibility  will  be  considered  here.  It 
would  be  well,  indeed,  to  restrict  the  term  sensibility  to  cases  involving 
consciousness. 

Pursuing  the  plan  already  laid  down,  the  study  of  this  interesting 
and  elevated  function  will  be  commenced,  by  pointing  out,  as  far  as 
may  be  necessary,  the  apparatus  that  effects  it,  the  nervous  system. 

1.    NERVOUS  SYSTEM. 

Under  the  name  nervous  system,  anatomists  include  all  those  organs 
that  are  composed  of  nervous  or  pulpy  tissue — neurine.  In  man,  it  is 
constituted  of  three  portions:  first,  of  what  has  been  called  the  cerebro- 
spinal  axis,  a  central  part  having  the  form  of  a  long  cord,  expanded  at 
its  superior  extremity,  and  contained  within  the  cavities  of  the  cranium 
and  spine ;  secondly,  of  cords,  called  nerves,  in  number  thirty-nine  pairs, 
according  to  some, — forty-two,  according  to  others, — passing  laterally 
between  the  cerebro-spinal  axis  and  every  part  of  the  body;  and,  lastly, 
of  a  nervous  cord,  situate  on  each  side  of  the  spine,  from  the  head  to 
the  pelvis,  forming  ganglia  opposite  each  vertebral  foramen,  and  called 
the  great  sympathetic. 


ENCEPHALON. 


Fig.  2. 


1.  Encephalon. — Under  this  term  are  included  the  contents  of  the 
cranium,  namely,  the  cerebrum  or  brain  proper,  the  cerebellum  or  little 
brain,  and  the  medulla  oblongata.  These  parts  collectively  have  been 
by  some  called  brain. 

When  we  look  at  a  section  of  the  encephalon, 
in  its  natural  position,  we  find  many  distinct  parts, 
and  the  appearances  of  numerous  and  separate 
organs.  So  various,  indeed,  are  the  prominences 
and  depressions  observable  on  the  dissection  of  the 
brain,  that  it  is  generally  esteemed  one  of  the 
most  difficult  subjects  of  anatomy ;  yet,  owing  to 
the  attention  paid  to  it  in  all  ages,  it  is  now  one  of 
the  structures  best  understood  by  the  anatomist. 
This  complicated  organ  presents  a  striking  illus- 
tration of  the  truth,  that  the  most  accurate  ana- 
tomical knowledge  does  not  necessarily  teach  the 
function.  The  elevated  actions,  which  the  ence- 
phalon has  to  execute,  have,  indeed,  attracted  a 
large  share  of  the  attention  of  the  physiologist, — 
too  often,  however,  without  any  satisfactory  result ; 
yet  it  may,  we  think,  be  safely  asserted,  that  we 
have  become  better  instructed  regarding  the  uses 
of  particular  parts  of  the  brain,  within  the  last 
few  years,  than  during  the  whole  of  the  century 
preceding. 

The  encephalon  being  of  extremely  delicate 
organization,  and  its  functions  easily  deranged,  it 
was  necessary  that  it  should  be  securely  lodged 
and  protected  from  injuries.  Accordingly,  it  is 
placed  in  a  round,  bony  case ;  and  by  an  admira- 
ble mechanism  is  defended  against  damage  from 
surrounding  bodies.  Amongst  these  guardian 
agents  or  tutamina  cerebri  must  be  reckoned : — 
the  hair  of  the  head;  the  skin;  muscles;  pericra- 
nium; bones  of  the  skull ;  the  diploe  separating  the 
two  tables  of  which  the  bones  are  composed,  and 
the  dura  mater. 

It  is  not  an  easy  matter  to  assign  probable  uses 
for  the  hair  on  various  parts  of  the  body.     On  the 
head,  its  function  seems  more  readily  appropria- 
ble.    It  deadens  the  concussion,  which  the  brain  Anterior  view  of  the  Brain 
would   experience   from   the   infliction   of   heavy 
blows,  and  prevents  the  skin  of  the   scalp  from 
being  injured  by  the  attrition  of  bodies, 
tary  service,  the  former  of  these  uses  has  been 
taken  advantage  of;  and  an  arrangement,  some-  J^Jve^  s.pon^Vwoii??1?! 
what  similar  to  that  which  exists  naturally  on  the   Fourth  pair  of  nerves.   10. 

•I          -i     i          i  T  -I        •   i  i  TIT  Lower  portion   of  medulla 

head,  has  been  adopted  with  regard  to  the  helmet,  oblongata.  11,11.  Medulla 
The  metallic  substance,  of  which  the  ancient  and  £££•  is^da  «?££! 
modern  helmets  are  formed,  is  readily  thrown  into 


and  Spinal  Marrow. 

1,  1.  Hemispheres  of  the 
T  ...      cerebrum.    2.  Great  middle 

In  mill-    fissure.      3.  Cerebrum.      4. 


74  NERVOUS  SYSTEM. 

vibration ;  and  this  vibration  being  communicated  to  the  brain  might, 
after  heavy  blows,  derange  its  functions  more  even  than  a  wound  in- 
flicted by  a  sharp  instrument.  To  obviate  this,  in  some  measure,  the 
helmet  has  been  covered  with  horse-hair  ;  an  arrangement  which  ex- 
isted in  the  helmet  worn  by  the  Roman  soldier.  There  can  be  no  doubt, 
moreover,  that  being  bad  conductors  of  caloric,  and  forming  a  kind  of 
felt  which  intercepts  the  air,  the  hairs  may  tend  to  preserve  the  head  of 
a  more  uniform  temperature.  They  are  likewise  covered  with  an  oily 
matter,  which  prevents  them  from  imbibing  moisture,  and  causes  them 
to  dry  speedily.  Another  use  ascribed  to  them  by  M.  Magendie,1  is 
more  hypothetical : — that,  being  bad  conductors  of  electricity,  they 
may  put  the  head  in  a  state  of  insulation,  so  that  the  brain  may  be  less 
aifected  by  the  electric  fluid  ! 

It  is  unnecessary  to  explain  in  what  manner  the  different  layers  of 
which  the  scalp  is  composed;  the  cellular  membrane  beneath;  the  pan- 
niculus  carnosus  or  occipito-frontalis  muscle ;  and  the  pericranium 
covering  the  bone,  act  the  parts  of  tutamina.  The  most  important  of 
these  protectors  is  the  bony  case  itself.  In  an  essay  written  by  a  dis- 
tinguished physiologist,2  we  have  some  beautiful  illustrations  of  the 
wisdom  of  God  as  displayed  in  the  mechanism  of  man,  and  of  his  skull 
in  particular;  and  although  some  of  his  remarks  may  be  liable  to  the 
censures  that  have  been  passed  upon  them  by  Dr.  Arnott,3  most  of  them 
are  admirably  adapted  to  the  contemplated  object.  It  is  impossible, 
indeed,  for  the  uninitiated  to  rise  from  the  perusal  of  his  interesting 
essay,  without  being  ready  to  exclaim  with  the  poet,  "How  wonderful, 
how  complicate  is  man !  how  passing  wonder  HE  that  made  him  such!" 
Sir  Charles  Bell  attempts  to  prove,  that  the  best  illustration  of  the  form 
of  the  head  is  the  dome ;  whilst  Dr.  Arnott  considers  it  to  be  "  the 
arch  of  a  cask  or  barrel,  egg-shell,  or  cocoa-nut,  &c.,  in  which  the  tena- 
city of  the  material  is  many  times  greater  than  necessary  to  resist  the 
influence  of  gravity,  and  comes  in  aid,  therefore,  of  the  curve  to  resist 
forces  of  other  kinds  approaching  in  all  directions,  as  in  falls,  blows, 
unequal  pressures,"  &c.  The  remarks  of  Dr.  Arnott  on  this  subject 
are  just ;  and  it  is  owing  to  this  form  of  the  cranium,  that  any  blow 
received  upon  one  part  of  the  skull  is  rapidly  distributed  to  every 
other ;  and  that  a  heavy  blow,  inflicted  on  the  forehead  or  vertex,  may 
cause  a  fracture,  not  in  the  parts  struck  but  in  the  occipital  or  sphe- 
noidal  bones. 

The  skull  does  not  consist  of  one  bone,  but  of  many.  These  are 
ioined  together  by  sutures, — so  called  from  the  bones  seeming  as  if 
they  were  stitched  together.  Each  bone  consists  likewise  of  two  tables; 
an  external,  fibrous,  and  tough;  and  an  internal,  of  a  harder  character 
and  more  brittle,  hence  called  tabula  vitrea.  The  two  are  separated 
from  each  other  by  a  cellular  or  cancellated  structure,  called  diploe. 
On  examining  the  mode  in  which  the  tables  form  a  junction  with  each 
other  at  the  sutures,  we  find  additional  evidences  of  design  exhibited. 

1  Precis  Elementaire,  edit.  cit.  i.  177. 

2  Sir  Charles  Bell,  in  Animal  Mechanics— Library  of  Useful  Knowledge,  London,  1829. 

3  Elements  of  Physics,  or  Natural  Philosophy,  General  and  Medical,  London,  1527 — re- 
printed in  this  country,  Philad.,  1841. 


ENCEPHALON. 


75 


3- 


The  edges  of  the  outer  table  are  serrated,  and  so  arranged  as  to  be 
accurately  dovetailed  into  each  other  ;  the  tough  fibrous  texture  of  the 
external  plate  being  well  adapted  for  such  a  junction.  On  the  other 
hand,  the  tabula  vitrea,  which,  on  account  of  its  greater  hardness, 
would  be  liable  to  fracture  and  chip  off,  is  merely  united  with  its  fellow 
at  the  suture,  by  what  is  called  harmony:  the  tables  are  merely  placed 
in  contact. 

The  precise  object  of  the  sutures  is  not 
apparent.  In  the  mode  in  which  ossifi- 
cation takes  place  in  the  bones  of  the 
skull,  the  radii  from  different  ossific 
points  must  necessarily  meet  by  the 
"law  'of  conjugation,"  in  the  progress  of 
ossification.  This  has,  by  many,  been 
esteemed  the  cause  of  the  sutures ;  but 
the  explanation  is  insufficient.  Howso- 
ever it  may  be,  the  kind  of  junction  af- 
fords a  beautiful  example  of  adaptation. 
During  the  foetal  state,  the  sutures  do 
not  exist.  They  are  fully  formed  in 
youth ;  are  distinct  in  the  adult  age ;  but 
in  after  periods  of  life  become  entirely 
obliterated,  the  bone  then  forming  a  solid 
spheroid.  It  does  not  seem  that  after 
the  sutures  are  established,  any  displace- 
ment of  the  bones  can  take  place ;  and 
observation  has  shown,  that  they  do  not 
possess  much,  if  any,  effect  in  putting  a 
limit  to  fractures.  In  all  cases  of  severe 
blows,  the  skull  appears  to  resist  as  if  it 
were  constituted  of  one  piece.  But  the 
separation  of  the  skull  into  distinct  bones,  bone. 
which  have  a  membranous  union,  is  of 
striking  advantage  to  the  foetus  in  par- 
turition. It  enables  the  bones  to  overlap 
each  other ;  and,  in  this  way,  to  occupy 

a  much  smaller  space  than  if  ossification  had  united  them  as  in  after 
life.  It  has,  indeed,  been  imagined  by  some,  that  there  is  this  advan- 
tage in  the  pressure  made  on  the  brain  by  the  investing  bones, — that 
the  foetus  does  not  suffer  from  the  violent  efforts  made  to  extrude  the 
child ;  but,  during  the  passage  through  the  pelvis,  is  in  a  state  of  fortu- 
nate insensibility;  and  pressure  suddenly  exerted  upon  the  brain  is 
certainly  attended  with  these  effects, — a  fact,  which  has  to  be  borne  in 
mind  in  the  management  of  apoplexy,  fracture  of  the  skull,  &c. 

The  uses  of  the  diploe,  which  separates  the  two  tables  of  the  skull, 
are  not  equivocal.  Composed  of  a  cancellated  structure,  it  is  well 
adapted  to  deaden  the  force  of  blows ;  and  as  it  forms,  at  the  same 
time,  a  bond  of  union  and  of  separation,  a  fracture  might  be  inflicted 
upon  the  outer  table  of  the  skull,  and  yet  be  prevented  from  extending 
to  the  tabula  vitrea.  Such  cases  have  occurred,  but  they  are  rare.  It 


Front  view  of  the  Skull. 

1.  Frontal  portion  of  the  frontal  bone. 
2.  Nasal  tuberosity.  3.  Supra-orbital 
ridge.  4.  Optic  foramen.  5.  Sphenoidal 
fissure.  6.  Spheno-maxillary  fissure.  7. 
Lachrymal  fossa,  and  commencement  of 
the  nasal  duct.  8.  Opening  of  the  anterior 
nares,  and  the  vomer.  9.  Infra-orbital 
foramen.  10.  Malar  bone.  11.  Symphysis 
of  the  lower  jaw.  12.  Mental  foramen. 
13.  Ramus  of  the  lower  jaw.  14.  Parietal 
15.  Coronal  suture.  16.  Temporal 
bone.  17.  Squamous  suture.  18.  Great 
alaof  the  sphenoid  bone.  19.  Commence- 
ment of  the  temporal  ridge.  20.  Zygoma 
of  the  temporal  bone.  21.  Mastoid  pro- 


76 


NERVOUS  SYSTEM. 


Fig.  4. 


will  generally  happen,  that  a  blow,  intended  to  cause  serious  bodily 
injury,  will  be  sufficient  to  break  through  both  tables,  or  neither. 

Lastly,  the  dura  mater,  which  has  been  reckoned  as  one  of  the  tuta- 
mina  cerebri,  lines  the  skull,  and  constitutes  a  kind  of  internal  perios- 
teum to  it.  It  may  also  be  inservient  to  useful  purposes,  by  deadening 
the  vibrations,  into  which  the  head  may  be  thrown  by  sudden  concus- 
sions; as  the  vibrations  of  a  bell  are  arrested  by  lining  it  with  a  soft 
material.  It  is  chiefly,  however,  to  protect  the  brain  against  itself, 
that  we  have  the  arrangement  which  prevails.  The  cerebrum,  as  well 
as  the  cerebellum,  consists  of  two  hemispheres;  and  its  posterior  part 
is  situate  immediately'  above  the  cerebellum.  It  is  obvious,  then,  that 
without  some  protection,  the  hemisphere  of  one  side  would  press  upon 
its  fellow,  when  the  head  is  inclined  to  the  opposite  side;  and  that  the 
posterior  lobes  of  the  brain  would  weigh  upon  the  cerebellum  in  the 
erect  attitude. 

The  hemispheres  are  separated  from  each  other  by  the  falx  cerebri, 

in  the  upper  margin  of  which  is  the 
superior  longitudinal  sinus.  The 
falx  passes  between  the  hemispheres. 
The  tentorium  cerebello  super  ext  en- 
sum  —  a  prolongation  of  the  dura 
mater  —  passes  horizontally  forwards 
so  as  to  support  the  posterior  lobes 
of  the  brain,  and  prevent  them  from 
pressing  injuriously  on  the  cerebellum. 
A  process  of  the  dura  mater  passes 
also  between  the  hemispheres  of  the 
cerebellum.  Independently  of  the 
protection  afforded  to  the  encepha- 
lon,  the  dura  mater  lodges  the  great 
sinuses  into  which  the  veins  discharge 
their  blood.  These  different  sinuses 
empty  themselves  into  the  torcular 
Serophili  or  confluence  of  the  sinu- 
ses; and  ultimately  proceed  to  con- 

Falx  Cerebri  and  Sinuses  of  upper  and  back    gtitute  the  lateral  sinuses,  which  pass 

part  of  Skull.  through  the  temporal  bone,  and  form 

1,  2.  3.  Section  of  the  bones  of  the  cranium,       ,         .  °  7-7 

showing  the  attachment  of  the  falx  major.     4!     the  internal  JUgUlar  Veins. 

fnfamina     QVP  rmf  nrmfinpfl   tn 
tUtamma    are  not  COnnnCU  tO 

Contents    of   the    Cranium.        The 


Anterior  portion  of  superior  longitudinal  sinus. 
5.  Middle  portion.    6.  Inferior  portion  ;  the  outer 


table  of  the  cranium  removed      7.  Commence- 

ment  of  the  inferior  longitudinal  sinus.    8.  Its  .-  ..  -  ... 

termination   in   the   straight   sinus.      9.    Sinus  SDine  appears  to   DC,  it    pOSSlble,   Still 

quartus  or  rectus.     10.  Vena  Galeni.     11.  One  •,  u    J          T        ±1  1      11 

of  the  lateral  sinuses.     12.  Torcular  Herophili.  better    protected.        In    the    SKUll,   W6 

13.    Sinus  of  the  falx  cerebelli.     14.    Internal  firm     hnnv  Pfl<;p  •    in    flip    <*r>ir)P 

jugular  vein.     15.    Dura  mater   of   the   spinal  See  a  nrm?    DOnJ    C3Se  9    **»   l          Spine, 

marrow.    16.  Tentorium  cerebeiii.    17,  17.   a    structure   admitting  considerable 

Falx  cerebri.  .  c      -i  ',1  •   i        e 

motion  ot  the  parts,  without  risk  ot 

pressure  to  the  marrow.  Accordingly,  the  spine  consists  of  numerous 
distinct  bones  or  vertebrae,  with  fibre-cartilaginous  —  technically  called 
inter  vertebral  —  substances  placed  between  each,  so  that,  although  the 
extent  of  motion  between  any  two  of  these  bones  may  be  small,  when 
all  are  concerned,  it  is  considerable.  The  great  use  of  this  interver- 


ENCEPHAION. 


77 


tebral  substance  is  to  prevent  the  jar,  that 
would  necessarily  be  communicated  to  the 
delicate  parts  within  the  cavities  of  the 
spine  and  cranium,  were  the  spine  composed 
entirely  of  one  bone.  In  falls  from  a  height 
upon  the  feet  or  breech,  these  elastic  cushions 
are  forcibly  compressed ;  but  they  immedi-  10- 

ately  return  to  their  former  condition,  and 
deaden  the  force  of  the  shock.  In  this  they 
are  aided  by  the  curvatures  of  the  spine, 
which  give  it  the  shape  of  the  Italic/,  and 
enable  it  to  resist — in  the  same  manner  as 
a  steel  spring — any  force  acting  upon  it  in 
a  longitudinal  direction.  So  well  is  the 
medulla  spinalis  protected  by  the  strong 
bony  processes  jutting  out  in  various  direc- 
tions from  the  spine,  that  it  is  extremely 
rare  to  meet  with  lesions  of  the  marrow; 
and  it  is  comparatively  of  late  years  that 
any  ex  professo  treatises  have  appeared  on 
the  subject. 

Besides  the  protection  afforded  by  the 
bony  structure  to  the  delicate  medulla,  M. 
Magendie1  has  pointed  out  another,  which 
he  was  the  first  to  detect.  The  canal, 
formed  by  the  dura  mater  around  the  spinal 
cord,  is  much  larger  than  is  necessary  to  ,  IQ/ 
contain  that  organ ;  but,  during  life,  the 
whole  of  the  intermediate  space  is  filled 
with  a  serous  fluid,  which  strongly  distends 
the  membrane,  so  that  it  will  frequently 
spirt  out  to  a  distance  of  several  inches, 
when  a  puncture  is  made  in  the  membrane. 
To  this  fluid  he  has  given  the  epithet  ce- 
phalo- spinal ;  and  he  conceives,  that  it  may 
act  as  one  of  the  tutamina  of  the  marrow — 
which  is,  as  it  were,  suspended  in  the  fluid — 
and  exert  upon  it  the  pressure  necessary 
for  the  healthy  performance  of  its  functions. 

Beneath  the  dura  mater  is  a  very  delicate 
membrane,  the  arachnoid,  belonging  to  the 
class  of  serous  membranes.  It  surrounds 
the  encephalon  in  every  part ;  but  is  best 
seen  at  the  base  of  the  brain. 

ItS    Chief  USe  is  to  Secrete  a  thin  fluid,  to    Lateral  View  of  the  Spinal  Column. 


1  Precis,  &c.,  edit.  cit.  i.  181.  For  an  elaborate  descrip- 
tion of  the  fluid,  see  Magendie,  Recherches  Physiolo- 
giques,  &c.,  sur  le  Liquide  cephalo-rachidien,  Paris,  1842; 
and  Dr.  Todd,  Cyclop,  of  Anat.  and  Physiol.,  part  xxv. 
p.  639,  Lond.,  1844. 


1.  Atlas.  2.  Dentata.  3.  Seventh 
cervical  vertebra.  4.  Twelfth  dorsal 
vertebra.  5.  Fifth  lumbar  vertebra. 
6.  First  piece  of  sacrum.  7.  Last 
piece  of  sacrum.  8.  Coccyx.  9.  A 
spinous  process.  10,  10.  Interverte- 
bral  foramina. 


78 


NERVOUS  SYSTEM. 


lubricate  the  brain.  This 
membrane  enters  into  all  the 
cavities  of  the  organ,  and 
in  them  fulfils  a  like  func- 
tion. When  the  fluid  accu- 
mulates to  a  great  extent, 
the  resulting  disease  is  hy- 
drocephalus  chronicus. 

Anatomists  usually  de- 
scribe a  third  tunic  of  the 
brain — the  pia  mater.  This 
is  generally  conceived  to 
consist  of  the  minute  termi- 
nations of  the  cerebral  arte- 

faceof  the  cerebellum,  showing  the  irbi»  vitae.    3.  Medulla  rieS,    &nd     those    of    the    COr- 

oblongata.    4.  Corpus  callosum,  continuous  with  5,  the  for-  rp<?r>rm diner     vpin«  •     fro-minr* 

nix.    6.  One  of  the  crura  of  the  fornix  descending  to  7,  one  ^Spending     VCinS  ,      lOrmmg 

of  the  corpora  albicantia.    8.  Septum  lucidum.    9.  Velum  at  the    SUrfaC6    of   the    brain 
interpositum,  communicating  with   the  pia  mater  of  the  ,  ,  .  . 

convolutions  through  the  fissure  of  Bichat.     10.  Section  of  a     VaSCUlar     network,    which 
the  middle  commissure  in  the  third  ventricle.     11.  Section  •     A      -v  i 

of  the  anterior  commissure.     12.  Section  of  the  posterior  paSSCS  into  the  CaVltlCSJ   and, 

commissure;  the  commissure  is  somewhat  above  and  to  the  in     flip   vpnfriplpa     fnrmc    +Ko 

left  of  the  number.     The  interspace  between  10  and  11  is  the  1LL    Ult  CB>  I( 

foramen  commune  anterius,  in  which  the  crus  of  the  fornix  pleXUS      chorOldeS      and     t eld 

(6)  is  situate.    The  interspace  between  10  and  12  is  the  fora-  •*•  7  .7  mi  -, 


Longitudinal  Section  of  the  Brain  on  the  Mesial  Line. 
1.  Inner  surface  of  the  left  hemisphere.    2.  Divided  sur- 


men  commune  posterius.     13.  Corpora  quadrigemina,  upon 
which  is  the  pineal  gland,  14.    15.  Iter  a  tertio  ad  quartum 


7  .7  m-i  •, 

CtlOTOlCteCl.        Ine      ClUra      and 
ertio  ad  quartum        '       y^,,^,.  WO,Y.O  en  Bailor!   Kir 
17.    Pons  Varolii,    Pia    ^later  Were  SO  Called  by 


UGCU     ^JtO-liU,    At.         J.C*.     J.LC 

ventriculum.      16.    Fourth  ventricle. 

through  which  are  passing  the  diverging  fibres  of  the  corpora  the  older  anatomists, 

pyramidalia.     18.   Crus  cerebri  of  the  left  side,  with  the  .      ' 

third  nerve  arising  from  it.    19.  Tuber  cinereum,  from  which  they    Were     COnCClVCd    to    be 

projects  the  infundibulum  having  the  pituitary  gland  ap-  ,1  c      -11     ,,  •> 

pended  to  its  extremity.    20.  One  of  the  optic  nerves.    21.  the    Origin    01    all    the    Other 

membranes  of  the  body. 

7  The   cerebrum    or    brain 

proper  has  the  form  of  an 
oval,  larger  behind.  On  its 
outer  surface  are  various  un- 
dulating eminences,  called 
convolutions,  because  they 
have  been  thought  to  re- 
semble the  folds  of  the  in- 
_  testines.  They  are  separated 

The  Convolutions  of  one  Side  of  the  Cerebrum,  as  seen  fr0m  each  other  by  depres- 
sions called  anfractuosities. 
They  form  the  hemispherical 
ganglion  of  Mr.  Solly.  In 
the  brain  of  man,  these  convolutions  are  larger  than  in  animals;  and 
the  anfractuosities  deeper.  In  different  brains,  the  number,  size,  and 
arrangement  of  these  vary.  They  are  not  the  same,  indeed,  in  the 
same  individual;  those  of  the  right  hemisphere  being  disposed  differently 
from  those  of  the  left. 

The  hemispheres,  it  has  been  seen,  are  separated  above  by  the  falx 
cerebri:  below,  they  are  united  by  a  white  medullary  commissure,  cor- 
pus callosum,  mesolobe  or  great  commissure, — great  transverse  commis- 
sure of  Mr.  Solly.  If  we  examine  the  brain  at  its  base,  we  find  that 
each  hemisphere  is  divided  into  three  lobes, — an  anterior,  which  rests 


from  above. 

1.  Anterior  lobe  of  the  cerebrum.    2.  Posterior  lobe. 
3.  Middle  lobe. 


ENCEPHALON. 


79 


Fig.  8. 


on  the  vault  or  roof  of  the  orbit, — a  middle  or  temporal,  filling  the  mid- 
dle and  lateral  parts  of  the  base  of  the  cranium,  and  separated  from 
the  former  by  a  considerable  depression,  called  fissure  of  Sylvius, — 
and  a  posterior,  which  rests  on  the  tentorium  cerebelli.  This  part  of 
the  cerebrum  is  divided  into  two  very  distinct  portions  by  the  medulla 
oblongata.  Anterior  to  it  are  the  crura  cerebri  or  cerebral  peduncles — 
by  most  anatomists  considered  to  be  a  continuation  of  the  anterior  fas- 
ciculi which  form  the  spinal  marrow  and  medulla  oblongata,  and  pro- 
ceeding to  form  the  hemispheres  of  the  brain.  Between  the  anterior 
extremities  of  the  peduncles  are  two  hemispherical  projections,  called 
eminentiae  mammillares,  which  are  possessed  by  man  exclusively ;  have 
the  shape  of  a  pea;  and  are  formed  of  white  nervous  tissue  externally, 
of  gray  within.  Anterior  to  these  again  is  the  infundibulum ;  and  a 
little  farther  forwards,  the  chiasma  of  the  optic  nerves  or  the  part  at 
which  these  nerves  come  in  contact. 

Laterally,  and  at  the  inferior  surface  of  the  anterior  lobes,  is  a 
groove  or  furrow,  running  from  behind  to  before,  and  from  without  to 
within,  in  which  the  olfactory  nerve  is  lodged.  At  the  extremity  of 
this  furrow  is  a  tubercle,  which  is  tri- 
fling in  man,  but  in  certain  animals  is 
equal  to  the  rest  of  the  brain  in  bulk. 
From  this  the  olfactory  nerve  has  been 
conceived  to  arise.  It  is  called  the  ol- 
factory tubercle  or  lobe. 

When  we  examine  the  interior  of  the 
brain,  we  find  a  number  of  parts  to 
which  the  anatomist  assigns  distinct 
names.  Of  these  the  following  chiefly 
concern  the  physiologist.  It  has  been 
already  remarked,  that  the  corpus  cal- 
losum  forms  at  once  the  bond  of  union 
and  of  separation  between  the  two 
hemispheres.  It  is  distinctly  perceived, 
in  the  form  of  a  long  and  broad  white 
band,  on  separating  these  parts  from 
each  other.  Beneath  the  corpus  callo- 
sum  is  the  septum  lucidum  or  median 
septum,  which  passes  perpendicularly 
downwards,  and  separates  from  each 
other  the  two  largest  cavities  of  the 
brain-the  lateral  _  ventricles.  It  ^  ^JfgSSSL^iS&^\SSSyf 

formed     Of   tWO    laminae,    which    leave    a    netalia.    4,5.  Anterior  and  posterior  extre- 

.,        -,  11*   i      ,1          J£/?.7     nrities  of  the  middle  fissure  of  the  cerebrum. 

Cavity    between    them,    Called     the    fifth    6.  Anterior  extremity  of  the  corpus  callo- 

The  fnrnir  or  inferior  lonai-  ?um:    7>  |*»  posterior  extremity  joining  the 

J.lie  JOrHUC  IT   lUjer  Wr  lunyi  fornix.      8,  8.  Point  to  where  the  corpus 

Commissure  Of  Mr.   Solly,  Whose  callosum  joins  the  lateral  medullary  matter 

„  .       J '  of  the  cerebrum.    9.  Its  place  of  junction 

Omce  IS  tO  Connect  the  anterior  and  pOS-  anteriorly.     10.  Posterior  point  of  union. 

n    .  -I  i          'i  11.  Middle  portion  of  the   corpora  striata 

tenor  parts  of  the  same  hemisphere,  as  (lateral ventricle).   12.  Tamartriata. 


Fornix,  &c.,  as  given  by  a  Transverse 
Section  of  the  Cerebrum. 


trnn«vpr«A    r>nrnrm«anrA«    <\f\  tVin«P  nf    Septum  lucidum. 

C 


Fornix.     16.   Posterior  crura.     1 


13. 
15. 
Plexus 


the  opposite  hemisphere,  is  placed  hori-  choroicies.   is.  Ergot  or  hippocampus 

*          .          ,      „    nor.     19.  Posterior    crura  of   the    lateral 

zontally  below  the  last.     The  band  of 


nor. 
ventricle. 


80 


NERVOUS  SYSTEM. 


Fig.  9. 


fibres  which  runs  in  each  hemisphere  above  the  corpus  callosum,  on 
the  edge  of  the  longitudinal  fissure,  is  the  superior  longitudinal  com- 
missure of  Mr.  Solly.  Its  use  is  supposed  to  resemble  that  ascribed 
to  the  inferior  longitudinal  commissure.  The  fornix  is  of  a  triangular 
shape;  and  constitutes  the  upper  paries  of  another  cavity  —  the  third  ven- 

tricle. Beneath  the  fornix,  and 
behind,  are  the  pineal  gland  and 
its  peduncles,  forming  the  pineal 
commissure  of  Mr.  Solly,  re- 
specting which  so  much  has  been 
said,  by  Descartes,1  and  others, 
as  the  seat  of  the  soul.  Within 
it  is  a  small  cavity;  and,  after 
six  or  seven  years  of  age,  it  al- 
ways contains  some  concretions. 
Again,  anterior  to  the  pineal 
gland,  and  immediately  below  the 
fornix,  is  another  cavity  —  the 
thirdventricle.  Itsbottom  is  very 
near  the  base  of  the  brain,  and 
is  formed  by  the  nervous  layer 
which  unites  the  peduncles  of 
the  brain  with  the  eminentige 
mammillares.  At  the  sides,  it 
has  the  thalami  nervorum  opti- 
corum. 

In  the  lateral  ventricles,  situ- 
ate on  each  side  of  the  corpus 
^^^^^  callosum,  some  parts  exist  which 

e  demand  attention.   In  the  upper 

Section  of  the  Cerebrum,  displaying  the  surfaces  of  . 

the  Corpora  Striata,  and  Optic  Thalami,  the  cavity  Or  anterior  nail,  COffi  monly  Called 
of  the  Third  Ventricle,  and  the  upper  surface  of  anterior  cornu  and  in  the  ante- 
the  Cerebellum.  .  ' 

nor  part  ot  this,  two  pyniorm 

a,  e.  Corpora  quadrigemina,  —  a  testis,  e  nates,     b.  .     *  r* 

Soft  commissure,   c.  Corpus  caiiosum.  /.  Anterior  eminences  are  seen,  of  a  brown- 

2:  ish-gray  colour,  which,  owing  to 
their  bein    formed  of  an  assem- 


commissure,  s.  Posterior  commissure,  p.  Pineal  blafiTC  of  alternate  layers  ofwhite 
gland  with  its  peduncles,  n,  n.  Processus  a  cerebello  ,  ,,  , 

ad  testes.     m,  m.  Hemispheres  of  the  cerebellum,     h      and    gray    SUDStanCC,   are    Called 

?eUrPeebeiTumrrmiform  *™'™'    "  N°tch  *****  *'  corpora  striata,  the  anterior  ce- 

rebral ganglions  of  Mr.  Solly. 

Behind  these,  are  two  whitish  medullary  bodies  called  thalami  ner- 
vorum opticorum  —  posterior  cerebral  ganglions  —  which  are  situate  be- 
fore the  corpora  quadrigemina,  and  envelope  the  anterior  extremities 
of  the  crura  cerebri. 

Three  main  sets  of  fibres  may  be  distinguished  in  the  medullary  sub- 
stance, of  which  the  great  mass  of  the  cerebrum  is  composed.  First, 
the  ascending  fibres,  which  proceed  from  the  sensory  tract  of  the  me- 
dulla spinalis,  and  diverge  from  the  thalami  optici  to  the  periphery  of 


1  Tractatus  de  Homine,  p.  5. 


/ 


MEDULLA  OBLONGATM. 


81 


An  under  View  of  the  Cerebellum,  seen  from  behind. 


crus  of  cerebellum,  e,  e.  Crura  cerebri.  i.  Notch  on 
tosterior  border,  k.  Commencement  of  horizontal  fissure. 
.  Flocculus,  or  subpeduncular  lobe.  m.  Medulla  oblon- 


the  brain;  secondly,  the  de- 
scending fibres,  which  con- 
verge from  the  periphery  to- 
wards the  corpora  striata, 
and  then  pass  downwards  to 
the  motor  tract  of  the  me- 
dulla spinalis;  and,  thirdly, 
the  commissural  fibres,  which 
establish  a  connexion  be- 
tween the  various  parts  of 
the  periphery,  and  of  the 
substance  of  the  brain.  The 
bulk  of  the  human  brain,  and 
of  that  of  the  higher  animals, 
is  greatly  dependent  upon  the 

1  .  •  i  i  The  medulla  oblongata,  m,  having  been  cut  off  a  short 

large    proportion    borne    by  waybeiowthepons.  (Ren./  c.PcSwVaroiii.  a.  Middle 
these  last  fibres  to  the  rest.1 
The     cerebellum     occupies 

,1         -I  .     .      i     /»  gata  cut  through,   q.  to  s.  The  inferior  vermiform  process, 

tne    lOWer    OCClpltal    lOSSSe,    Or  lying   in   the  vallecula.    p.  Pyramid,     r.  Uvula,    n,   n. 

f\f  tViP  pnvitir  f\f  tViA  Amygdalae,     s.  Nodule,  or  laminated  tubercle,    x.  Poste- 

OI  tilt;  LdiVli  Y7    Oi   llie  rjor  velum,  partly  seen.    w.  Right  and  left  hemispheres 

T-jpripofTi     flip     fpnrn-  of  cerebellum.    3  to  7.  Nerves.    3,  3.  Motores  oculorum. 

,    tent0-  5.  Trigeminal.    6.  Abducent  nerve.    7.  Facial  and  audi- 

num  cerebelli.  Its  size  and  tory  nerves. 
weight,  like  those  of  the 
brain,  differ  according  to  the  in- 
dividual, and  the  age  of  the 
subject  under  examination.  We 
do  not  observe  convolutions  in 
it.  It  appears  rather  to  consist 
of  laminae  in  superposition,  sepa- 
rated from  each  other  by  fur- 
rows. We  shall  see,  hereafter, 
that  the  number  of  cerebral 
convolutions  has  been  esteemed, 
in  some  respects,  to  accord  with 
the  intellect  of  the  individual; 
and  Malacarne  asserts,  that  he 
has  observed  a  similar  corre- 
spondence, as  regards  the  num- 
ber of  laminae  Composing  the  Ce-  Posterior  Superior  View  of  the  Pons  Varolii, 
rebellum;  that  he  found  Only  Cerebellum,  and  Medulla  Oblongata  and  M.  Spi- 

three  hundred  and  twenty-four     i,  i.  ijnum  cerebri.  2.  Pons  varoiii  or  tuber  an- 

in    the    Cerebellum    of  an    insane    nul,are-    3.  Its  middle  fowa.    4.  Oblique  band  of  me- 

.  dullary  matter  seen  passing  from  its  side.    5.  Exter- 

Whllst    in    Others    he    nal  surface  of  the  crus  cerebelli.    6.  Same  portion 


i     i  j  n       •    i  ,     deprived  of  outer  layer.    7.   Nervous  matter  which 

COUnted.    Upwards     OI     eigHt    unites  it  to  4.    8.  Trigeminus  or  fifth  pair  of  nerves. 

9.  Portion  of  the  auditory  nerve.     The  white  neurine 
seen  passing   from  the  oblique  band  which   comes 
From     the    medullary     Dart    Of    from  tne  corpus  restiforme  to  the  trigeminus  nerve  in 
,     ,,  i  '  i  •          front,  and  the  auditory  nerve  behind.     10,11.  Supe- 

"     Cerebellum,   tWO    large    White     rior  portion   of  the  hemispheres  of  the  cerebellum. 
,     ,        ,1  17-         v*       12.  Lobulus  amygdaloides.     13.  Corpus  olivare.     14. 

paSS     tO    the    pOnS    Varolll,     Corpus  pyramidale.    15.  Medulla  spinalis. 


VOL.  I. 


1  Carpenter,  Human  Physiology,  p.  215.     Lend.,  1842. 

-6 


82 


MEDULLA  OBLONGATA. 


having  the  same  disposition  as  the  crura  cerebri.  They  are  the  crura 
cerebelli. 

Owing  to  the  peculiar  arrangement  of  the  white  and  gray  cerebral 
substances,  when  one  of  the  hemispheres  of  the  cerebellum  is  divided 
vertically,  an  arborescent  appearance  is  presented, — the  trunks  of  the 
arborization  being  white,  the  surrounding  substance  gray.  This  ap- 
pearance is  called  arbor  vitas.  The  part  where  all  these  arborizations 
meet,  near  the  centre  of  the  cerebellum,  is  called  corpus  denticulatum 
vel  rhombo'idale.  Gall  was  of  opinion,  that  this  body  has  great  agency 
in  the  production  of  the  cerebellum.  Lastly,  the  cerebellum  covers  the 
posterior  part  of  the  medulla  oblongata,  and  forms  with  it  a  cavity, 
called  fourth  ventricle. 

The  medulla  oblongata  is  so  called,  because  it  is  the  continuation  of 


Analytical  Diagram  of  the  Encephalon — in  a  Vertical  Section.     (After  Mayo.) 

5.  Spinal  cord.  r.  Restiform  bodies  passing  to  c,  the  cerebellum,  d.  Corpus  dentatum  of  the  cere- 
bellum, o.  Olivary  body.  /.  Columns  continuous  with  the  olivary  bodies  and  central  part  of  the 
medulla  oblongata,  and  ascending  to  the  tubercula  quadrigemina  and  optic  thalami.  p.  Anterior  pyra- 
mids, v.  Pons  Varolii.  n,  b.  Tubercula  quadrigemina.  g.  Geniculate  body  of  the  optic  thalamus. 
t.  Processus  cerebelli  ad  testes.  a.  Anterior  lobe  of  the  brain,  q.  Posterior  lobe  of  the  brain. 


MEDULLA  OBLONGATA. 


83 


the  medulla  spinalis  in  the  cavity  of  the  cranium.  It  is  likewise  termed 
mesocephale,  from  its  being  continuous  with  the  spinal  marrow  in  one 
direction,  and  sending  towards  the  brain  strong  prolongations  —  crura 
'  cerebri  ;  and  to  the  cerebellum  similar  prolongations  —  crura  cerebelli  ; 
so  that  it  appears  to  be  the  bond  of  union  between  these  various  parts. 
In  its  lower  portion,  it  seems  to  be  merely  a  continuation  of  the  me- 
dulla spinalis,  except  that  it  is  more  expanded  superiorly  where  it  joins 
the  pons  Varolii.  This  portion  of  the  medulla  oblongata  is  called,  by 
some,  tail  of  the  medulla  oblongata;  by  others,  the  rachidian  bulb; 
and,  by  others  again,  it  is  regarded  as  the  medulla  oblongata.  Its 
lower  surface  rests  on  the  basilary  gutter  of  the  occipital  bone,  and 
exhibits  a  groove  which  divides  the  spinal  cord  into  two  portions.  On 
each  side  of  this  furrow  are  two  oblong  eminences, 
the  innermost  of  which  is  called  corpus  pyramidale, 
the  outermost,  corpus  olivare,  which  arise  from  the 
anterior  column  of  the  medulla  spinalis,  or  are  a 
continuation  and  subdivision  of  this  column.  These 
oval  bodies  are  surrounded  by  a  superficial  groove, 
which,  in  some  instances,  is  partially  interrupted  by 
some  arciform  fibres,  which  cross  it  at  its  lower  part. 
At  the  lower  third  of  the  medulla  oblongata,  fibres 
of  the  anterior  pyramids  decussate,  and  form  an 
anatomical  demarcation  between  the  medulla  oblon- 
gata and  the  spinal  cord.  The  decussation  takes 
place  by  from  three  to  five  bundles  of  fibres  from 
each  pyramidal  body.  This  decussation,  as  will  be 
seen,  hereafter,  is  interesting  in  regard  to  the  cross 
effect  induced  by  certain  diseases  of  the  brain.  On 
the  posterior  surface  of  the  medulla  oblongata,  the 
posterior  fasciculi  separate  to  form  the  fourth  ven- 
tricle: at  the  sides  of  this  ventricle  are  the  corpora  Anterior  View  of  the 
restiformia,  or  inferior  peduncles  of  the  cerebellum,  Medulla  Oblongata, 
—  so  called  because  they  seem  to  aid  in  the  forma- 
tion of  that  part  of  the  encephalon  ;  and  on  the  in- 
ner side  of  each  corpus  restiforme  is  the  small 
body  —  the  posterior  pyramid.  Again,  in  addition 
to  the  corpora  pyramidalia  and  olivaria  —  which  de- 
rive their  origin  from,  or  are  continuous  with,  the  ^sating  fibres.  oi. 

„        .  &    .  .  .  '        ,       tero-lateral    column     of 

anterior  fasciculi  ot  the  spinal  cord,  and  are  destined,  the  spinal  cord.  c.  An- 
according  to  some,  to  form  the  brain  —  and  the  cor- 
pora  restiformia,  which  are  continuations  of  the  . 
posterior  fasciculi,  and  are  destined  to  form  the  cere- 
bellum, there  exists,  according  to  some  anatomists,  other  fasciculi  in 
the  rachidian  bulb.  All  these  are  interesting  points  of  anatomy,  but 
are  not  of  so  much  importance  physiologically;  notwithstanding  even 
the  views  promulgated  by  Sir  Charles  Bell.1  He  considers  that  a 
column  exists  between  the  corpora  olivaria  and  corpora  restiformia, 

1  The  Nervous  System  of  the  Human  Body  :  from  Transactions  of  the  Royal  Society  from 
1821  to  1829,  London,  1830.     Reprinted  in  this  country,  Washington,  1833. 


showing  the  decus- 
sation of  the  Pyra- 
mids, and  of  the  up- 
per par  I  of  the  Spinal 
(Jord.  (After  Mayo.) 

p.  Anterior  pyramids. 
r.  Restiform  bodies,  o. 
Olivary  bodies,  d.  De- 


anterior   commis- 


84 


SPINAL  MARROW. 


which  extends  below  through  the  whole  spine,  but 
above  does  not  proceed  farther  than  the  point  where 
the  rachidian  bulb  joins  the  tuber  annulare  ;  and  that 
this  column  gives  origin  to  a  particular  order  of 
nerves — the  respiratory;  The  corpora  olivaria,  and 
the  posterior  corpora  pyramidalia,  are  regarded  by 
Mr.  Solly1  as  ganglia; — the  former  of  the  function  of 
respiration, — the  latter  of  the  sense  of  hearing. 

The  anterior  and  upper  half  of  the  medulla  ob- 
longata  bears  the  names  pons  Varolii,  tuber  annu- 
lare, and  nodus  cerebri;  and  to  this  are  attached, 
superiorly,  the  corpora  or  tubercula  quadrigemina. 
In  the  very  centre  of  the  pons,  the  crura  cerebri 
bury  themselves ;  and  by  many,  they  are  considered 
to  decussate ;  by  others,  to  be  prolongations  of  the 
anterior  column  of  the  spinal  marrow.  Sir  C.  Bell 
thinks,  that  the  pons  Varolii  stands  in  the  same  re- 
lation to  the  lateral  portions  of  the  cerebellum,  that 
the  corpus  callosum  does  to  the  cerebrum  ; — that  it 
is  the  great  commissure  of  the  cerebellum,  uniting 
its  lateral  parts,  and  associating  the  two  organs. 

The  medulla  oblongata  consists  chiefly  of  the  cen- 
tres of  the  nerves  of  respiration  and  deglutition, 
which,  as  elsewhere  shown,  are  strictly  reflex  in 
their  action. 

2.  The  spinal  marrow  extends,  in  the  vertebral 
canal  from  the  foramen  magnum  of  the  occipital 
bone  above  to  the  first  or  second  lumbar  vertebra, 
where  it  terminates  in  the  cauda  equina.  It  is 
chiefly  composed  of  medullary  matter,  but  not  entire- 
}y  so-  Within,  the  cineritious  substance  is  ranged 
.  immediately  below  irregularly,  but  has  a  crucial  form  when  a  section 
pyeramidsSsaBti0At  middle  is  made.  The  marginal  illustrations  exhibit  sections 
of  cervical  buib.  c.  Mid-  Of  the  spinal  cord  of  man  at  different  points;  and 

way    between     cervical       .  .  „  i        i  -^ 

and  lumbar  bulbs.    D.  the  proportion   oi  gray  and  white  matter  at  each. 

lblb'    E'v£y  From  the  calamus  scriptorius  in  the  fourth  ventricle, 

pos-  an(*  tne  rima  formed  by  the  corpora  pyramidalia  be- 

surface.      The  fore,  two  fissures   extend  downwards,  which  divide 

points   of  emergence   of,  .,  -,1,1  L'  mi        j. 

the  anterior  and  poste-  the  spinal  marrow  into  lateral  portions.  Ihe  two 
ntJSSfcSf. the  nerves  lateral  portions  are  divided  into  an  anterior  and  a 
posterior,  so  that  the  cord  has  four  distinct  portions. 
By  some,  indeed,  it  is  conceived  to  consist  of  three  columns — an  anterior, 
posterior,  and  a  middle  or  lateral. 

The  vertebral  canal  is  lined  by  a  strong  ligamentous  sheath,  running 
down  its  whole  length.  The  dura  mater  likewise  envelopes  the  medulla 
at  the  occipital  foramen,  being  firmly  united  to  the  ligaments ;  but  far- 
ther down  it  constitutes  a  separate  tube.  The  tunica  arachnoidea  from 

1  The  Human  Brain,  its  Configuration,  Structure,  Development,  and  Physiology,  &c.,  p. 
147,  London,  1836.  See,  on  this  subject,  Dr.  John  Reid,  on  the  Anatomy  of  the  Medulla 
Oblongata,  in  Edinb.  Med.  and  Surg.  Journ.,  Jan.,  1841,  p.  12. 


NERVES. 


85 


Fig.  15. 


the  brain  adheres  loosely  to  the  cord,  having  the  cephalo-spinal  fluid 
within  it ;  and  the  pia  mater  closely  embraces  it. 

3.  Nerves. — The  nerves  are  cords  of  the  same  nervous  substance  as 
that  which  composes  the 
encephalon  and  spinal 
marrow ;  extending  from 
these  parts,  and  distribu- 
ted to  the  various  organs 
of,  the.  body,  many  of 
them  interlacing  in  their 
course,  and  forming 
plexuses:  others  having 
knots  or  ganglions,  and 
almost  all  vanishing  in 
the  parts  to  which  they 
are  distributed.  The 
generality  of  English 
anatomists  reckon  thir- 
ty-nine pairs  of  nerves ; 
the  French,  with  more 
propriety,  forty-two. 
Of  these,  nine,  accord- 
ing .  to .  the  English — 
twelve,  according  to  the 
French- — draw  their  ori- 
gin from,  or  are  con- 
nected with,  the  ence- 
phalon; and  are  hence 
called  encephalic  nerves ;  Shows  the  under  Surface  °LBas®  of  the  Encephalon  freed  from 

•*!  its  Membranes. 

and  thirty,  from  the  me- 

•*   .       ,.  -,        A,  anterior,  B,  middle,  and  c,  posterior  lobe  of  cerebrum. — a. 

SpinallS  ',  and  The  fore  part  of  the  great  longitudinal  fissure,  b.  Notch  be- 
tween hemispheres  of  the  cerebellum,  c.  Optic  commissure. 
d.  Left  peduncle  of  cerebrum,  e.  Posterior  perforated  space. 
e  to  i.  Interpeduncular  space.  /,  f.  Convolution  of  Sylvian 
fissure,  h.  Termination  of  gyrus  fornicatus  behind  the  Sylvian 
fissure,  i.  Infundibulum.  I.  Right  middle  crus  or  peduncle 
C  £  of  cerebellum,  m,  m.  Hemispheres  of  cerebellum,  n.  Corpora 

mum  Dy  means  OI  lOra-  aibicantia.  o.  PonsVarolii,  continuous  at  each  side  with  middle 
rnina  at  ir«  hn«P  Thpv  crura  of  cerebellum,  p.  Anterior  perforated  space,  q' .  Horizon- 
be.  .Lliey  tai  fissure  of  cerebellum,  r.  Tuber  cinereum.  s,  *'.  Sylvian 
fissure,  t.  Left  peduncle  or  crus  of  cerebrum.  11,  u.  Optic 
,  ..  .  ,  ,  tracts,  v.  Medulla  oblongata.  x.  Marginal  convolution  of  the 

behind the    longitudinal  fissure.— 1  to  9  indicate  the  several  pairs  of  cerebral 

nerves,  numbered  according  to  the  usual  notation,  viz.,  1.  Olfac- 
tory nerve.  2.  Optic.  3.  Motor  nerve  of  eye.  4.  Pathetic.  5. 
Trifacial.  6.  Abducent  nerve  of  eye.  7.  Auditory,  and  7'.  Fa- 
cial. 8.  Glosso-pharyngeal,  S' .  Vagus,  and8".  Spinal  accessory 


hence     termed 

The   encephalic    nerves 

emerge   from    the    era- 


are  —  proceedin 
before   to 

•first  pair  or  olfactory, 
distributed  to  the  organ 
of  smell ;  the  second  pair  nerve 
or  optic,  the  expansion 
of  which  forms  the  retina  ;  the  third  pair,  motores  oculi  or  common 
oculo-muscular,  which  send  filaments  to  most  of  the  muscles  of  the  eye ; 
the  fourth  pair,  trochleares,  pathetici  or  internal  oculo-muscular,  dis- 
tributed to  the  greater  oblique  muscle  of  the  eye ;  the  fifth  pair,  tri- 
facial,  trigemini,  or  symmetrical  nerve  of  the  head,  (Bell,)  which  send 
their  branches  to  the  eye,  nose,  and  tongue ;  the  sixth  pair,  abducentes 
or  external  oculo-muscular,  which  are  distributed  to  the  abductor  or 
rectus  externus  oculi ;  the  facial  nerve,  portio  dura  of  the  seventh  pair, 


86 


NEKVES. 


nervus  communicans  faciei  or  respiratory  nerve  of  the  face,  distributed 
to  the  muscles  of  the  face  ;  the  acoustic  nerve,  auditory  nerve  or  portio 
mollis  of  the  seventh  pair,  which  passes  to  the  organ  of  hearing ;  the 
eighth  pair,  pneumogastric,  par  vagum  or  middle  sympathetic,  which  is 
dispersed  particularly  on  the  larynx,  lungs,  heart,  and  stomach  ;  the 
glosso-pharyngeal,  often  considered  as  part  of  the  last,  and  whose  name 
indicates  its  distribution  to  the  tongue  and  pharynx ;  the  great  hypo- 
glossal,  ninth  pair  or  lingual  nerve  distributed  to  the  tongue  ;  and  the 
spinal  accessory  of  Willis,  which  arises  from  the  spinal  cord  in  the  cer- 
vical region;  ascends  into  the  cranium,  and  issues  by  one  of  the  fora- 
mina to  be  distributed  to  the  muscles  of  the  neck.  All  these  proceed, 
perhaps,  from  the  medulla  oblongata; — the  brain  and  cerebellum  not 
furnishing  one. 

The  spinal  nerves  are  thirty  in  number  on  each  side.  They  make 
their  exit  by  the  intervertebral  foramina,  and  are  divided  into  eight 
cervical,  twelve  dorsal,  five  lumbar,  and  five  or  six  sacral. 

The  encephalic  nerves  are  irregular  in  their  formation,  and,  with  the 
exception  of  the  fifth  pair,  originate  from  one  root.  Each  of  the  spinal 
nerves  arises  from  two  fasciculi,  the  one  anterior,  and  the  other  poste- 
rior :  these  roots  are  separated  from  each  other  by  the  ligamentum 
denticular *e;  but  they  unite  beyond  this  ligament,  and  near  the  inter- 
vertebral  foramen  present  one  of  those  knots,  known  under  the  name 
of  ganglions  or  ganglia,  in  the  formation  of  which  the  posterior  root 
is  alone  concerned. 

When  the  nerves  have  made  their  exit  from  the  cranium  and  spine, 

they  proceed  to  the  organs  to  which 
they  have  to  be  distributed;  ramifying 
more  and  more,  until  they  are  ultimately 
lost  sight  of,  even  when  vision  is  aided 
by  a  powerful  microscope.  It  is  not 
positively  decided,  whether  the  nervous 
fibres  have  any  distinct  terminations 
either  in  the  nervous  centres,  or  in  the 
organs  to  which  they  are  distributed. 
In  the  gray  matter  of  the  brain  of  the 
vertebrata,  they  would  appear  to  form 
a  kind  of  plexus  of  loops  ;  and  the  ulti- 
mate fibres  do  not  seem  to  anastomose. 
The  following  has  been  described  as  the 
mode  in  which  the  nervous  fibres  are 
generally  distributed  to  the  peripheral 
organs.  The  trunks  subdivide  into 
small  fasciculi,  each  of  which  consists 
of  from  two  to  six  fibres,  and  these  form 
plexuses,  whose  arrangement  bears  a 
general  resemblance  to  that  of  the  ele- 
ments of  the  tissue  in  which  they  are 

Terminal  nerves,  on  the  sac  of  the  second    placed.        The    primitive    fibres    then    86- 

molar  tooth  of  the  lower  jaw,  in  the  sheep ,-   parate  \  and   each,   after  passing    over 

showing  the  arrangement  in  loops.     (After    *  '    ..  £    «  . 

Valentin.)  several  elementary  parts  of  the  contain- 


Fig.  16. 


NERVES. 


8T 


Fig.  17. 


ing  tissue,  or  after  forming  a  single  narrow  loop,  as  in  the  sensory 
papillae,  returns  to  the  same  or  to  an  adjoining  plexus,  and  pursues  its 
way  to  the  nervous  centre  from  which  it  set  out.  According  to  this 
view,  there  is  no  more  a  termination  of  nerves,  than  there  is  of  blood- 
vessels. Both  form  circles.  More  recent  observations  seem,  however, 
to  have  demonstrated,  that  in  different  situations  the  loop-like  appear- 
ance is  fallacious ;  and  that  the  ultimate  fibres  divide  into  fibrils,  the 
terminations  of  which  are  lost  in  the  tissues. 

Investigations,  again,  by  Henle  and  Kblliker1  show,  that  some  of 
the  peripheral  nervous  fibrils  term- 
inate in  small  bodies,  seated  espe- 
cially in  the  nerves  of  the  fingers 
and  toes,  which,  from  their  having 
been  discovered,  in  1830,  by  Pacini 
of  Padua,  have  been  called  Pa- 
cinian  corpuscles;  but  of  whose 
uses  little  can  be  said.  They  have 
not  been  observed  on  any  motor 
nerves,  so  that  they  would  not  seem 
to  have  anything  to  do  with  motion. 
They  exist  in  many  nerves  of  the 
sympathetic  class,  and  are  not  pre- 
sent on  many  sensitive  nerves ;  so 
that,  it  has  been  properly  inferred, 
they  are  probably  not  connected 
with  acuteness  of  sensation. 

Of  the  encephalic  nerves,  the 
olfactory,    auditory,  and   acoustic  the  Pacinian  corpuscles0. 

/»              .    i                "L.'T  B-  Unusual  form,  from  the  mesentery  of  the  cat; 
nerves     OI    Special     Sensibility showing  two  included  in  a  common  envelope:— 

clearly  pass  on  to  their  destination,  a' b  are  the  two  nen 
without  communicating  with  any  other  nerve.  The  spinal  nerves,  at 
their  exit  from  the  intervertebral  foramina,  divide  into  two  branches, 
an  anterior  and  a  posterior,  one  being  sent  to  each  aspect  of  the  body. 
The  anterior  branches  of  the  four  superior  cervical  pairs  form  the  cer- 
vical plexus,  from  which  all  the  nerves  of  the  neck  arise ;  the  last  four 
cervical  pairs  and  the  first  dorsal  form  the  brachial  plexus,  whence 
proceed  the  nerves  of  the  upper  extremities ;  whilst  the  branches  of 
the  five  lumbar  nerves,  and  the  five  sacral  form  the  lumbar  and  sciatic 
plexuses;  the  former  of  which  gives  rise  to  the  nerves  distributed  to 
the  parts  within  the  pelvis ;  the  second  to  those  of  the  lower  limbs. 
The  anterior  branches,  moreover,  at  a  little  distance  from  the  exit  of 
the  nerve  from  the  vertebral  canal,  communicate  with  an  important  and 
unique  portion  of  the  nervous  system,  the  great  sympathetic. 

Each  nerve  consists  of  numerous  fasciculi  surrounded  by  areolar 

1  Ueber  die  Pacinischen  Korperchen  an  den  Nerven  des  Menschen  und  der  Saugethiere, 
Zurich,  1844;  reviewed  in  Brit,  arid  For.  Med.  Rev.,  January,  1845,  p.  78;  and  Todd  and 
Bowman,  Physiological  Anat.  and  Physiology  of  Man,  i.  395,  London,  1845,  or  Amer.  edit.; 
and  W.  Bowman,  Cyclopaedia  of  Anat.  and  Physiol.,  by  Dr.  Todd,  pt.  xxvii.  p.  876,  Lond., 
Mar.,  1846. 


Pacinian  Corpuscles. 
A.  Nerve  from  the  finger,  natural  size ;  showing 


88 


SIR  CHARLES  BELI/S  DIVISION  OF  NERVES. 


membrane ;  and,  according  to  Beil,1  of  an  external  envelope,  called 

neurilemma,  which,  in  the 
opinion  of  most  anatomists,  is 
nothing  more  than  an  areolar 
envelope,  similar  to  that  which 
surrounds  the  vessels  and  mus- 
cular fibres. 

Until    of    late    years,    the 

Represents  a  Nerve  consisting  of  many  smaller  Cords    nerves  Were  Universally  divided, 
or  Funiculi  wrapped  up  in  a  common  cellular    aCCOrdinp*   to   their  Griffin,  into 

Gk^o  +  U  T       T.  T  -i 

encephalic   and    spinal;    but, 

igiyumculu.  drawn  out  from    mQre    recentlj?    anatomical    di- 

visions  have  been  proposed, 
based  upon  the*  uses  they  appear  to  fulfil  in  the  economy.  For  one  of 
the  most  beautiful  of  this  kind  we  are  mainly  indebted  to  Sir  Charles 
Bell.  It  has  been  already  seen,  that  the  encephalic  nerves  are  con- 
nected with  the  encephalon  by  one  root,  whilst  the  spinal  nerves  arise 
from  two  ;  the  one  connected  with  the  anterior  tract  of  the  spinal 
marrow,  the  other  with  the  posterior.  If  these  different  roots  be  ex- 
Fig.  20. 


U,",eT.l;ce 


ft«sBiVc.sS)fn"iculusdrawno'Itfrom 


A  portion  of  the  Spinal  Marrow,  show- 
ing the  Origin  of  some  of  the  Spinal 
Nerves. 

1.  Anterior  or  motor  root  of  a  spinal 
nerve. 

2.  Posterior  or  sensory  root. 

3.  Ganglion  connected  with  the  latter. 


Plans  in  outline,  showing  the  Front  A,  and 
the  Sides  B,  of  the  Spinal  Cord,  with  the 
Fissures  upon  it ;  also  sections  of  the 
Gray  and  White  Matter,  and  the  Roots 
of  the  Spinal  Nerves, 
a,  a.  Anterior,    p,  p.  Posterior  fissure.    6. 
Posterior,  and  c.  Anterior  horn  of  gray  mat- 
ter,   e.  Gray  commissure,    a,  e,  c.  Anterior 
white  column,      c,  e,  b.  Lateral   columns, 
a,  e,  b.  Antero-lateral  column,    b,  e,  p.  Pos- 
terior columns,     r.  Anterior,  and  s.  Poste- 
rior roots  of  a  spinal  nerve. 


perimented  on,  we  meet  with  results  varying  considerably.  If  we  divide 
the  anterior  root,  the  part  to  which  the  nerve  is  distributed  is  deprived 
of  motion ;  if  the  posterior  root  be  cut,  the  part  is  deprived  of  sensi- 
bility. We  conclude,  therefore,  that  each  of  the  spinal  nerves  consists 


De  Structura  Nervorum,  Hal.  1796. 


SVSTKM    01'   IIKSFIUATOKY    NKKVKS. 


KcrijAU,  OK     SY'AIMKTltirAI,    NKKYKS. 


SIR  CHARLES  BELL'S  DIVISION  OF  NERVES.  89 

of  filaments  destined  for  both  motion  and  sensibility;  that  the  ence- 
phalic nerves,  which  have  but  one  root,  are  destined  for  one  of  these 
exclusively,  and  that  they  are  either  nerves  of  motion,  or  of  sensation, 
according  as  their  roots  arise  from  the  anterior  or  the  posterior  tract 
of  the  medulla. 

It  has  already  been  remarked,  that  the  medulla  oblongata,  according 
to  some  anatomists,  is  composed  of  three  fasciculi  or  columns  on  each 
side  ; — an  anterior,  a  middle,  and  a  posterior;  and  it  has  been  affirmed 
by  Sir  Charles  Bell,  that  whilst  the  anterior  column  gives  origin  to 
nerves  of  motion  ;  and  the  posterior  to  nerves  of  sensibility;  the  middle 
gives  rise  to  a  third  order,  having  the  function  of  presiding  over  the 
respiratory  movements  ;  and  which  Sir  Charles,  accordingly,  calls  respi- 
ratory nerves.  To  this  third  order  belong, — the  accessory  nerve  of 
Willis  or  superior  respiratory ;  the  vagus;  the  glosso-pharyngeal;  the 
facial,  called  by  him  the  respiratory  nerve  of  the  face;  the  phrenic; 
and  another  having  the  same  origin — the  external  respiratory.  •  Sir 
Charles's  views,  if  admitted,  lead,  consequently,  to  the  belief,  that  there 
are  at  least  three  sets  of  nerves, — one  destined  for  sensation;  another 
for  motion ;  and  a  third  for  a  particular  kind  of  motion — the  respira- 
tory; and  that  every  nerve  of  motion  communicates  to  the  muscles,  to 
which  it  is  distributed,  the  power  of  aiding,  or  taking  part  in,  motions 
of  one  kind  or  another ;  so  that  a  muscle  maybe  paralyzed,  as  regards 
certain  movements,  by  the  section  of  one  nerve,  and  yet  be  capable  of 
others  of  a  different  kind,  by  means  of  the  nerves  that  are  uninjured. 
The  accompanying  plate  exhibits  the  system  of  respiratory  nerves,  as 
given  by  Mr.  Shaw,1  son-in-law  of  Sir  Charles  Bell,  who  was  prema- 
turely snatched  from  existence,  after  having  made  numerous  useful 
contributions  to  medical  and  surgical  science. 

A,  the  cerebrum,  B,  the  cerebellum,  C  C         8.  Branches  of  the  glosso-pharyngeal. 
C,  the  spinal  marrow,  D,  the  tongue,  E,  the         9.  Lingualis,  sending  branches  to  the  tongue, 

larynx,  F,  the  lungs,  G,  the  heart,  H,  the  sto-  and  to  the  muscles  on  the  fore  part  of  the 

mach,  I,  the  diaphragm.  larynx. 

111.  Par  vagum,  arising  by  a  single  set  of         10.  Origins  of  the  superior  external  respira- 

roots  and  passing  to  the  larynx,  lungs,  heart,  tory  or  spinal  accessory. 
and  stomach.  11.  Branches  of  the  last  nerve  proceeding 

2.  Superior  laryngeal  branches  of  the  par  to  the  muscles  of  the  shoulder. 

vagum.  12    12   12.  Internal  respiratory   or  phrenic 

3.  Recurrent  or  inferior  laryngeal  branches     passing  to  the  diaphragm. 

of  the  par  vagum.  The  origins  of  this  nerve  are  seen  to  be 

•  4.  Pulmonic  plexus  of  the  par  vagum.  much    higher   than    they  are  generally  de- 

5.  Cardiac  plexus  of  the  par  vagum.  scribed.          . 

6.  Gastric,  plexus  of  the  par  vagum.  13.  Inferior  external  respiratory,  to  the  mus- 

•  7.  Respiratory  nerve  or  portio  dura  passing  cles  on  the  side  of  the  chest. 
to  the  muscles  of  the  face,  arising  by  a  series 

of  single  roots. 

Yet  this  division  is  by  no  means  universally  admitted ;  and  even  by 
some  who  are  of  opinion,  that  the  sensitive  and  motor  filaments  arise 
from  distinct  tracts  of  the  spinal  cord,  it  is  denied  that  this  is  the  case 
with  those  that  originate  from  the  upper  part  of  the  cord;  there  being 
in  the  medulla  oblongata  a  blending  of  the  sensitive  and  motor  tracts 
which  cannot  easily  be  explained.  Pathological  cases,  too,  occasionally 

1  Manual  of  Anatomy,  &c.,  3d  edit.,  Lond.,  1822.     Reprinted  in  this  country. 


90  NERVOUS  SYSTEM. 

occur,  which  throw  great  difficulty  on  this  matter.  Two  of  the  kind 
have  been  related  by  Mr.  Stanley  and  Dr.  Budd,1  in  which  there  was 
disease  confined  to  the  posterior  column ;  yet  sensation  remained  un- 
impaired, whilst  the  power  of  motion  in  the  lower  extremities  was  lost. 

Much  evidently  remains  to  be  accomplished,  before  the  precise 
arrangement  of  the  columns  of  the  spinal  cord,  and  of  the  relations  of 
the  nerves  connected  with  them,  can  be  esteemed  established.  Sir 
Charles  Bell,2  indeed,  subsequently  renounced  his  first  opinion,  that 
the  posterior  roots  of  the  spinal  nerves  proceed  from  the  posterior 
column,  and  described  them  as  arising  from  the  middle  or  lateral  column ; 
affirming,  at  the  same  time,  that  it  is  not  impossible  that  the  posterior 
column  may  be  connected  with  the  sensitive  roots  of  the  spinal  nerves, 
although  he  has  not  hitherto  succeeded  in  tracing  it.  Messrs.  Grainger 
and  Swan  maintain,  that  both  sets  are  connected  with  the  lateral  columns 
only;  the  anterior  and  posterior  lateral  fissures  definitely  limiting  the 
two  roots.  Perhaps,  as  suggested  by  Dr.  Carpenter,3  both  these  state- 
ments may  be  too  exclusive.  The  anterior  roots  would  seem  to  have  a 
connexion  with  both  the  anterior  and  lateral  columns ;  and  the  posterior 
cannot  be  said  to  be  restricted  to  the  lateral  column,  some  of  their 
fibres  entering  the  posterior  division  of  the  cord. 

Most  physiologists  are  now  of  opinion,  both  from  experiment  and 
reflection,  that  there  is  no  special  column  destined  for  respiration,  and 
that  there  appears  to  be  nothing  so  peculiar  in  the  action  of  the  respi- 
ratory muscles,  that  they  should  require  a  distinct  set  of  nerves.4 

Sir  C.  Bell  proposed  a  further  arrangement  of  the  nerves,  more 
natural  and  philosophical  than  the  unmeaning  numeration  according 
to  the  system  of  Willis,  and  better  adapted  to  facilitate  the  com- 
prehension of  this  intricate  portion  of  anatomy.  According  to  this, 
all  the  nerves  of  the  body  may  be  referred  to  two  great  classes — the 
original,  primitive  or  symmetrical, — and  the  irregular  or  superadded. 
It  has  been  already  remarked,  that  a  division  of  the  spinal  cord  has 
been  presumed  to  correspond  to  the  cerebrum ;  and  another  to  the  cere- 
bellum. Now,  every  regular  nerve  has  two  roots,  one  from  the  anterior 
of  these  columns,  and  another  from  the  posterior.  Such  are  the  fifth 
pair ;  the  sub-occipital ;  the  seven  cervical ;  the  twelve  dorsal ;  the  five 
lumbar;  and  the  six  sacral, — that  is,  thirty-two  perfect,  regular,  or 
double  nerves, — including,  to  state  more  briefly,  all  the  spinal  nerves, 
and  one  encephalic — the  fifth  pair.  The  fifth  pair  is  found  to  arise 
from  the  encephalon  by  two  roots,  and  to  have  a  ganglion  upon  the 
posterior  root.  It  is,  accordingly,  classed  with  the  spinal  nerves ;  and, 
like  them,  according  to  Sir  Charles  Bell,  conveys  both  motion  and  sen- 
sibility to  the  parts  to  which  it  is  distributed.  These  regular  nerves 
are  common  to  all  animals,  from  the  zoophyte  to  man.  They  run  out 
laterally;  or  in  a  direction  perpendicular  to  the  longitudinal  division  of 
the  body;  and  never  take  a  course  parallel  to  it. 

The  other  class  is  called  irregular  or  superadded.     The  different 

1  Medico-Chirurgical  Transactions,  vol.  xxiii.,  Lond.,  1840. 

a  Nervous  System,  &c.,  3d  edit.,  p.  234.     London,  1836. 

3  Principles  of  Human  Physiology,  2d  Amer.  edit.,  p.  125.     Philad.,  1845. 

*  Dr.  Reid,  op.  cit.,  Jan.,  1838,  p.  175. 


GREAT  SYMPATHETIC. 


91 


nervous  cords,  proceeding  from  it,  are  distinguished  by  a  simple  fasci- 
culus or  single  root.  All  these  are  simple  in  their  origins ;  irregular 
in  their  distribution ;  and  deficient  in  that  symmetry  which  characterizes 
those  of  the  first  class.  They  are  superadded  to  the  original  class; 
and  correspond  to  the  number  and  complication  of  the  superadded 
organs.  Of  these,  there  are  the  third,  fourth,  and  sixth,  distributed  to 
the  eye ;  the  seventh,  to  the  face ;  the  ninth,  to  the  tongue ;  the  glosso- 
pharyngeal,  to  the  pharynx ;  the  vagus,  to  the  larynx,  heart,  lungs, 
and  stomach ;  the  phrenic,  to  the  diaphragm ;  the  spinal  accessory,  to 
the  muscles  of  the  shoulders ;  and  the  external  respiratory,  to  the  out- 
side of  the  chest.  The  reason  of  the  seeming  confusion  in  this  latter 
class  is  to  be  looked  for  in  the  complication  of  the  superadded  apparatus 
of  respiration,  and  in  the  variety  of  offices  it  has  to  perform  in  the 
higher  classes  of  animals. 

The  accompanying  plate  exhibits,  in  one  view,  the  nerves  destined  to 
move  the  muscles  in  all  the  varieties  of  respiration,  speech,  and  facial 
expression. 

In  the  plate  of  regular  or  symmetrical  nerves, 

A  is  the  cerebrum,  B,  the  cerebellum,  Fig.  22. 

C  C,  the  crura  cerebri,  D  D,  the  crura  cere- 
belli,  E  E  E,  the  spinal  marrow. 

1  1.  Branches  of  the  fifth  pair,  arising  from 
the  union  of  the  crura  cerebri  and  crura 
cerebelli,  and  having  a  ganglion  at  the  root. 

2  2.  Branches  of  the  sub-occipital  nerves, 
which  have  double  origins  and  a  ganglion. 

3  3.  Branches  of  the  four  inferior  cervical 
nerves,  and  of  the  first  dorsal,  forming  the 
axillary  plexus.  The  origins  of  these  nerves 
are  similar  to  those  of  the  fifth  and  of  the 
sub-occipital.      4444.  Branches  of  the 
dorsal  nerves,  which  also  arise  in  the  same 
manner.    5  5.  The  lumbar  nerves.  6  6.  The 
sacral  nerves. 

So  much  for  the  anatomy  of 
two  great  portions  of  the  nervous 
system.  There  remains  to  be 
considered  a  third,  and  by  no 
means  the  least  interesting  or 
important. 

4.  0-reat  Sympathetic. — This 
nerve,  called  also  trisplanchnic, 
splanchnic,  ganglionic,  great 
intercostal,  vegetative,  and  or- 
ganic, is  constituted  of  a  series 
of  ganglions,  joined  to  each  other 

by  a  nervous  trunk,  and  extending    Roots  of  a  Dorsal  Spinal  Nerve,  and  its  union  with 

down  the  side  of  the  spine,  from  Sympathetic. 

thf*    hn«lf>    n~F   tVip    nrn-mnm     ir\    tlia        e>  c.  Anterior  fissure  of  the  spinal  cord,    a.  Anterior 

.  tne  cranium  to  tne  root.  PI  Posterior  rootj  with \ts  gangiion.  a<.Ante- 

OS    COCCVSriS    Or    lowest    bone.        It    rior  branch-    P'-  Posterior  branch,     s.  Sympathetic. 
.°  . ,,  ,          n     i         e-  Its  double  junction  with  the  anterior  branch  of  the 

Communicates    With    each    of  the    spinal  nerve  by  a  white  and  a  gray  filament. 

spinal  nerves,  and  with  several 


92 


NERVOUS  SYSTEM. 


of  the  encephalic;  and  from  the 
ganglions,  formed  by  such  com- 
munication, sends  off  nerves, 
which  accompany  the  arteries, 
and  are  distributed  particularly 
to  the  organs  of  involuntary 
functions.  At  its  upper  part,  it 
is  situate  in  the  carotid  canal, 
where  it  appears  under  the  form 
of  a  ganglionic  plexus  ;  two  fila- 
ments of  which  proceed  to  join 
the  sixth  pair  of  encephalic 
nerves,  and  another  to  meet  the 
Vidian  twig  of  the  fifth  pair. 
By  means  of  the  fifth  pair,  it 
communicates  also  with  the  oph- 
thalmic ganglion,  which  Bichat 
considered  to  .belong  to  it.  On 
issuing  from  the  carotid  canal, 
the  nerve  passes  downwards, 
along  the  side  of  the  spine,  to 
the  sacrum ;  presenting  a  series 
of  ganglions; — three  in  the  neck, 
— the  superior,  middle,  and  in- 
ferior cervical;  twelve  in  the 
back, — the  thoracic;  five  in  the 
loins, — the  lumbar;  and  three 
or  four  in  the  sacrum, — the  sa- 
cral. When  it  reaches  the 
coccyx,  it  terminates  by  a  small 
ganglion,  called  coccygeal;  or  by 
uniting  with  the  great  sympa- 
thetic of  the  opposite  side. 

The  ganglions  are  of  an  irre- 
gular, but  generally  roundish, 
shape.  They  consist  of  nervous 
filaments,  surrounded  by  a  red- 
dish-gray, pulpy,  albuminous,  or 

Great  Sympathetic  Nerve. 

1.  Plexus  on  the  carotid  artery  in  the  carotid  foramen.  2.  Sixth  nerve  (motor  externus).  3.  First 
branch  of  the  fifth,  or  ophthalmic  nerve.  4.  A  branch  on.  the  septum  narium  going  to  the  incisive  fora- 
men. 5.  Recurrent  branch  or  Vidian  nerve  dividing  into  the  carotid  and  petrosalf  branches.  6.  Poste- 
rior palatine  branches.  7.  Lingual  nerve  joined  by  the  chorda  tympani.  8.  Portio  dura  of  the  seventh 
pair.  9.  Superior  cervical  ganglion.  10.  Middle  cervical  ganglion.  11.  Inferior  cervical  ganglion. 
12.  Roots  of  the  great  splanchnic  nerve  arising  from  the  dorsal  ganglia.  13.  Lesser  splanchnic  nerve. 
14.  Renal  plexus.  15.  Solar  plexus.  16.  Mesenteric  plexus.  17.  Lumbar  ganglia.  18.  Sacral  gan- 
glia. 19.  Vesical  plexus.  20.  Rectal  plexus.  21 .  Lumbar  plexus  (cerebro-spinal).  22.  Rectum. 
23.  Bladder.  24.  Pubis.  25.  Crest  of  the  ilium.  26.  Kidney.  27.  Aorta.  28.  Diaphragm.  29.  Heart. 
30.  Larynx.  31.  Submaxillary  gland.  32.  Incisor  teeth.  33.  Nasal  septum.  34.  Globe  of  the  eye. 
35,  36.  Cavity  of  the  cranium. 

felatinous  substance,  which  differs  from  the  gray  matter  of  the  brain, 
ir  E.  Home1  considers  their  structure  to  be  intermediate  between  that 


24 


1  Lect.  on  Comp.  Anat.,  v.  194,  Lond.,  1828. 


GREAT  SYMPATHETIC.  93 

of  brain  and  nerves ;  the  brain  being  composed  of  small  globules  sus- 
pended in  a  transparent  elastic  jelly;  the  nerves  made  up  of  single 
rows  of  globules,  and  the  ganglions,  consisting  of  a  congeries  of  nervous 
fibres  compacted  together.1  Volkmann  and  Bidder,  and  Reichert,2 
consider  the  sympathetic  nerve-fibres  to  be  distinct  in  size  and  structure 
from  the  cerebro-spinal ;  but  Valentin  maintains  there  is  no  difference. 
Authors  are  by  no  means  agreed  with  regard  to  the  uses  of  these  gan- 
glions. Willis,3  Haller,4  and  others,  considered  them  to  be  small  brains 
for  the  secretion  of  the  nervous  fluid  or  animal  spirits ;  an  opinion, 
which  has  been  embraced  by  Richerand,5  and  Cuvier;6  the  latter  of 
whom  remarks,  that  the  ganglia  are  larger  and  more  numerous  when 
the  brain  is  deficient  in  size.  Lancisi,7  and  Vicq  d'Azyr,  regarded 
them  as  a  kind  of  heart  for  the  propulsion  of  these  spirits,  or  as  reser- 
voirs for  keeping  them  in  deposit.  Scarpa8  treats  them  as  synonymous 
with  plexuses ;  but  plexuses  with  the  filaments  in  close  approximation ; 
and  plexuses  he  regards  as  ganglions,  the  filaments  of  which  are  more 
separated.  He  consequently  believes,  with  many  physiologists,  that 
their  office  is  to  commingle  and  unite  various  nervous  filaments  with 
each  other.  Dr.  Wilson  Philip9  thinks,  that  they  are  secondary  sources 
of  nervous  influence  ;  that  they  receive  supplies  of  it  from  all  parts  of 
the  brain  and  spinal  marrow,  and  transmit  the  united  influence  to  the 
organs  to  which  the  nerves  are  distributed ;  whilst  some  conceive,  that 
at  least  one  office  is  to  communicate  irritability  to  the  tissues.10  John- 
stone,11  Reil,12  Bichat,13  and  others,  are  of  opinion  that  their  use  is  to 
render  the  organs,  which  derive  their  nerves  from  them,  independent  of 
the  will. 

These  views  are  sufficiently  discordant ;  and  well  indicate  the  intrinsic 
obscurity  of  the  subject.  That  of  Dr.  Philip  is  the  most  probable. 
Containing  the  vesicular  or  gray  matter,  which  seems  to  be  everywhere 
concerned  in  the  production  of  nerve-power,  the  ganglia  may  be  re- 
garded as  agents  of  nervous  reinforcement ;  although  we  may  remain 
uncertain  as  to  the  mode  in  which  their  office  is  executed.14  It  is  affirmed 

1  See,  on  the  Histology  of  the  Organic  or  Sympathetic  Nervous  Fibres,  Mr.  Paget,  Brit,  and 
For.  Med.  Rev.,  July,  1842,  p.  279. 

2  Muller's  Archiv.,  1844,  cited  by  Mr.  Paget,  in  Brit,  and  For.  Med.  Rev.,  April,  1845,  p. 
572. 

3  Cerebri  Anatome,  cui  accessit  Nervorum  Descriptio,  &c.,  Lond.,  1664,  cap.  xxvi. 

f*  De  Vera  Nervi  Intercostalis  Origine,  Gotting.,  1793;  Collect.  Dissert.  Anat.,  ii.  939;  and 
Oper.  Minor,  i.  503.  «  See  Appendix  to  Eng.  edit.,  by  Dr.  Copland. 

6  Le9ons  d'Anatomie  Compar.  Introd.,  p.  26. 

7  Dissert,  de  Structura  Usuque  Gangliorura,  ad  J.  B.  Morgagnium,  in  Morgagni  Adver. 
Anat.,  v.  101,  Lugd.  Bat.,  1741. 

*  De  Nervis  Comment ,  cap.  ii.  320. 

9  Philosoph.  Transact,  for  1829;  and  Inquiry  into  the  Nature  of  Sleep  and  Death,  Lond., 
1834,  p.  14. 

10  Fletcher,  Rudiments  of  Physiology,  P.  ii.  a.  p.  68,  Edinb.,  1836. 

11  Philosophical  Transactions,  vols.  54,  57,  and  60 ;  Essays  on  the  Use  of  the  Ganglions 
of  the  Nerves,  Shrewsbury,  1771;  and  Medical  Essays  and  Observations  relating  to  the 
Nervous  System,  Evesham,  1795. 

u  Archiv.  fur  die  Physiol.,  s.  226,  vii.,  Halle,  1807. 

13  Anatomic  Generale,  torn.  i.  200,  and  ii.  405. 

14  See  the  excellent  article  by  Wagner,  entitled  Sympathischer  Nerv,  Ganglienstructur  und 
Nervenendigungen,  in  his  Handworterbuch  der  Physiologic,  17te  Lieferung,  s.  360,  Braun- 
schweig, 1847;  another  by  Budge  on  the  Sympathetic,  with  special  relation  to  the  Heart's 
action,  Ibid.,  s.  406 ;  and  on  the  Sympathetic  Ganglia  of  the  Heart  by  Wagner,  Ibid.,  s.  450. 


94  NERVOUS  SYSTEM. 

by  M.  Robin,  in  a  communication  made  by  him  to  the  Academie  des 
Sciences,  of  Paris,  in  June,  1847,  that  the  ganglia  of  the  great  sympa- 
thetic and  of  the  cerebro-spinal  nerves  enclose  the  same  kind  of  gan- 
glionary  globules,  and  of  elementary  tubes,  but  in  different  proportions ; 
and  hence  he  does  not  regard  them  as  separate  nervous  systems. 

Although  connected  with  the  brain  by  the  branches  of  the  fifth  and 
sixth  pairs  of  encephalic  nerves,  and  with  the  spinal  cord  by  the  spinal 
nerves,  the  sympathetic  does  not  appear  to  be  directly  influenced  by 
either ;  as  the  functions  of  the  parts  to  which  its  ramifications  are  dis- 
tributed continue  for  some  time  after  both  brain  and  spinal  marrow 
have  been  separated ;  nay,  as  in  the  case  of  the  heart  and  intestines, 
after  they  have  been  removed  from  the  body.  Yet  many  discussions 
have  been  indulged  regarding  the  origin  of  this  important  part  of  the 
nervous  system ; .  some  assigning  it  to  the  brain,  others  to  the  spinal 
marrow,  whilst  others  again  esteem  it  a  distinct  nerve,  communicating 
with  the  brain  and  spinal  cord,  but  not  originating  from  either;  receiving, 
according  to  M.  Broussais,1  by  the  cerebral  nerves,  the  excitant  influence, 
and  applying  it  to  movements  that  are  independent  of  the  centre  of 
perception.  In  like  manner,  he  affirms,  when  irritation  predominates 
in  the  viscera,  it  is  conveyed  by  the  ganglionic  to  the  cerebral  nerves, 
which  transmit  it  to  the  brain.  Reil  and  Bichat,  esteeming  the  sym- 
pathetic to  be  the  great  nervous  centre  of  involuntary  functions,  have 
termed  it  the  organic  nervous  system,  in  contradistinction  to  the  animal 
nervous  system,  which  presides  over  the  animal  functions ;  whilst  Lob- 
stein,2  who  has  published  an  ex  professo  work  on  the  subject,  assigns 
three  functions  to  it.  1.  To  preside  over  nutrition,  secretion,  the  action 
of  the  heart,  and  the  circulation  of  the  blood ;  2.  To  maintain  a  com- 
munication between  different  organs  of  the  body;  and  3.  To  be  the 
connecting  medium  between  the  brain  and  abdominal  viscera.  Remak,3 
who  believes  that  the  animal  economy  possesses  two  sensoriums, — the 
one  in  the  cerebro-spinal  axis,  the  other  in  the  ganglionic  system, — 
considers,  that  as  in  the  cerebro-spinal  system  of  nerves  two  orders  of 
phenomena  occur, — the  perception  of  sensation,  and  the  reaction  or 
reflection  of  volition  ;  so,  in  the  organic  nervous  system,  two  analogous 
actions  take  place, — organic  perception,  or,  as  it  has  been  called,  Hal- 
lerian  irritability,  and  reaction  or  organic  reflection,  as  shown  by  J. 
MUller.4 

From  the  result  of  his  own  researches,  Dr.  Carpenter5  inferred,  that 
the  sympathetic  system  does  not  exist  in  the  lowest  classes  of  animals 
in  a  distinct  form; — that  the  nervous  system  of  the  invertebrata,  taken 
as  a  whole,  bears  no  analogy  to  it,  and  that  as  the  divisions  of  this 
become  more  specialized,  some  appearance  of  a  separate  sympathetic 

1  A  Treatise  on  Physiology  applied  to  Pathology,  translated  by  Drs.  John  Bell,  and  R.  La 
Roche,  p.  257,  Philad.,  1832. 

a  De  Nervi  Sympath.  Human.,  &c.,  translated  by  Dr.  Pancoast,  Philadelphia,  1831. 

8  Ammon's  Monatschrift,  June,  1840;  and  Edinb.  Med.  and  Surg.  Journal,  Jan.,  1841,  p. 
249.  4  Elements  of  Physiology,  by  Baly,  i.  736,  Lond.,  1838. 

6  Dissertation  on  the  Physiological  Inferences  to  be  deduced  from  the  Structure  of  the 
Nervous  System  in  the  Invertebrated  Classes  of  Animals,  Edinb.,  1839;  reprinted  in  Dungli- 
son's  Med.  Library,  Philad.,  1839:  also,  his  Principles  of  Human  Physiology,  p.  Ill,  Lon- 
don, 1842. 


GKEAT  SYMPATHETIC.  95 

presents  itself,  but  it  is  never  so  distinct  as  in  the  vertebrata;  hence 
he  deduces,  and  with  probability,  that  as  the  sympathetic  system  is  not 
developed  in  proportion  to  the  predominant  activity  of  the  functions 
of  organic  life,  but  in  proportion  to  the  developement  of  the  higher 
division  of  the  nervous  system,  its  office  is  not  to  preside  over  the  former, 
but  to  bring  them  in  relation  with  the  latter;  so  that  the  actions  of  the 
organs  of  vegetative  life  are  not  dependent  upon  it,  but  influenced  by 
it  in  accordance  with  the  operations  of  the  system  of  animal  life. 

Again,  the  great  sympathetic  has  been  esteemed  to  be  the  visceral 
nerve  par  excellence,  or  the  one  that  supplies  the  different  viscera  with 
their  nervous  influence, — a  part  of  its  office  as  the  nervous  system  of 
involuntary  functions.  On  examining  the  course  of  the  great  sympa- 
thetic, we  find  many  filaments  proceeding  from  the  cervical  and  thoracic 
ganglions,  interlacing  and  forming  the  cardiac  plexus,  from  which  the 
nerves  of  the  heart  and  great  vessels  arise.  The  same  thoracic  gan- 
glions furnish  a  branch  to  each  intercostal  artery.  A  nerve  of  the 
great  sympathetic — called  the  great  splanchnic  or  visceral — proceeding 
from  some  of  the  thoracic  ganglions,  passes  through  the  pillars  of  the 
diaphragm  into  the  abdomen,  and  terminates  in  the  large  plexus  or 
ganglion,  called  the  semilunar ;  and  this  by  uniting  with  its  fellow  of 
the  opposite  side,  constitutes  the  still  more  extensive  interlacing, — the 
solar  plexus.  From  this,  numerous  filaments  proceed,  which — by  ac- 
companying the  coronaria  ventriculi,  hepatic,  splenic,  spermatic,  renal, 
superior  and  inferior  mesenteric,  and  hypogastric  arteries — are  distri- 
buted to  the  parts  supplied  with  blood  by  these  arteries, — the  stomach, 
liver,  spleen,  testes,  kidneys,  intestines,  &c.  Weber,1  however,  who 
examined  the  great  sympathetic  in  different  animals,  affirms,  that  the 
splanchnic  may  not  be  the  sole  visceral  nerve,  but  that  the  eighth  pair 
may  share  in  the  function.  He  states,  that  the  great  sympathetic  is 
less  developed,  the  lower  the  animal  is  in  the  scale;  whilst  the  eighth 
pair  is  more  and  more  developed  as  we  descend,  and  at  length  is  the 
only  visceral  nerve  in  some  of  the  mollusca.  Sir  A.  Cooper's2  experi- 
ments satisfied  him,  that  this  nerve  is  essential  to  the  digestive  process; 
but  of  this  we  shall  have  to  speak  hereafter.  In  the  prosecution  of 
those  experiments,  he  found,  that  when  the  great  sympathetic  was  tied 
on  a  dog,  but  little  effect  was  produced:  the  animal's  heart  appeared 
to  beat  more  quickly  and  feebly  than  usual;  but  of  this  circumstance 
he  could  not  be  positive,  on  account  of  the  natural  quickness  of  its 
action.  The  animal  was  kept  seven  days,  at  which  time  one  nerve  was 
ulcerated  through,  and  the  other  nearly  so,  at  the  situation  of  the 
ligatures.  Another  animal  on  which  the  sympathetic  had  been  tied 
nearly  a  month  before,  was  still  living  when  he  wrote.  When  the 
pneumogastric  or  eighth  pair,  the  phrenic,  and  the  great  sympathetic 
were  all  tied  on  each  side,  "the  animal  lived  little  more  than  a  quarter 
of  an  hour,  and  died  of  dyspnoea."3 

These  experiments  would  appear  to  show,  either  that  the  great  sym- 
pathetic is  not  so  indispensable  to  the  economy  as  has  been  imagined ; 

1  Anatom.  Comparat.  Nerv.  Sympath.,  Lips.,  1817. 

3  Guy's  Hospital  Reports,  vol.  i.  p.  457,  London,  1836.  3  Ibid.,  p.  471. 


96  NERVOUS  SYSTEM. 

or  that  it  is,  in  every  part,  a  generator  of  nervous  influence,  so  that 
if  its  connexion  with  the  brain  or  any  other  viscus  be  destroyed,  the 
divided  portions  may  still  possess  the  power  of  generating  nervous 
agency.  But  if  we  admit  this  as  regards  the  system  of  the  great  sym- 
pathetic, we  shall  find,  that  it  is  difficult  to  extend  it  to  detached  por- 
tions of  the  nervous  system  of  animal  life. 

It  must  be  confessed,  that  our  knowledge  of  the  uses  of  this  great 
division  of  the  nervous  system  is  far  from  being  precise;  for  whilst 
some  physiologists  believe  it  to  be  concerned  in  every  involuntary  and 
organic  action;  Dr.  Proctor1  thinks,  that  the  nearest  approach  to  a 
positive  determination  of  its  use  that  we  can  arrive  at  with  our  present 
limited  knowledge  is,  that  "it  is  for  the  purpose  of  regulating  the  tonic 
contraction  of  the  arterial  system,  and  for  nothing  else."  One  distin- 
guished observer,  M.  Magendie,2  inquires  whether  we  have  sufficient 
reason  for  the  belief,  that  it  is  a  nerve  at  all !  and  a  writer3  of  distinc- 
tion, Dr.  J.  C.  B.  Williams,  admits,  that  nothing  is  definitely  known 
as  to  the  properties  communicated  by  ganglionic  nerves;  and  he  adds, 
"Before  the  influence  of  the  ganglionic  system  can  be  employed  as  an 
element  in  pathology,  its  existence  must  be  proved,  and  its  properties 
defined  in  physiology:  this  has  not  been  done." 

According  to  the  experiments  of  M.  Flourens,4  the  semilunar  is  the 
only  ganglion  that  exhibits  any  great  sensibility ;  and  hence  it  has  been 
considered  as  a  sort  of  intervention  to  connect  the  viscera  with  the 
encephalon. 

M.  Lepelletier5  thinks  we  are  justified  in  dividing  the  nerves  into  five 
classes: — the  first,  comprising  the  nerves  of  special  sensibility, — the 
olfactory,  optic,  lingual  branch  of  the  fifth  pair,  and  auditory: — the 
second,  the  nerves  of  general  sensibility,  the  fifth  pair;  and  the  spinal 
nerves,  through  their  posterior  root: — the  third,  comprising  the  volun- 
tary motors;  the  spinal  nerves,  by  their  anterior  roots,  the  motores 
oculorum  or  common  oculo-muscular,  the  external  oculo-muscular,  and 
the  hypoglossal: — the  fourth,  instinctive  motors,  involuntary,  respira- 
tory nerves  of  Sir  Charles  Bell,  the  pathetic,  facial,  glosso-pharyngeal, 
pneumogastric,  and  spinal  accessory;  and  the  fifth,  nerves  of  vital 
association  and  nutrition — the  filaments  and  plexuses  of  the  ganglionic 
system.  Dr.  Fletcher6  adopts  a  different  arrangement.  He  divides 
them  into  ganglionic  and  c  erebro- spinal ;  the  latter  being  subdivided 
into  the  respiratory,  motiferous,  sensiferous,  and  regular;  the  last  in- 
cluding those  which  communicate  both  the  faculty  of  sensibility  and 
the  stimulus  of  volition. 

1  Medico-Chirurg.  Rev.,  Jan.,  1S45,  p.  182. 

3  Precis  de  Physiologic,  2de  edit,  i.  171.    Paris,  1825. 

3  Principles  of  Medicine,  3d  Amer.  edit,  by  Dr.  Clymer,  p.  200,  note,  Philad.,  1848. 

4  Recherches  Experimentales  sur  les  Proprietes  et  les  Fonctions  du  Systeme  Nerveux,&c., 
2d  edit,  p.  229,  Paris,  1842. 

e  Traite  de  Physiologic  Medicale  et  Philosophique,  iii.  250,  Paris,  1832. 
6  Rudiments  of  Physiology,  P.  ii.  a.  p.  71,  Edinb.,  1836. 


NERVOUS  SYSTEM. 


97 


GANGLIONIC. 


CEREBRO-SPINAL. 


Those  immediately  con- 

nected     respectively 

Respiratory. 

Motiferous. 

Sensiferous. 

Regular. 

with 

The  Ophthalmic, 

The  Pathetic, 

The  Motor  Ocu- 

The  Olfactory, 

The     Sub-occi- 

The Cavernous, 

The  Facial, 

jj 

The  Optic, 

pital, 

The  Otic, 

The         Glosso- 

A    part    of    the 

The  Ophthalmic 

The  seven  Cer- 

The Sphenopalatine, 

pharyngeal, 

lower  Maxil- 

branch of  the 

vical, 

The  Sub-maxillary, 
The  three  Cervical, 
The  Cardiac, 

The       Pneumo- 
gastric, 
The  Accessory, 

lary  branch  of 
the    Trigemi- 
nus, 

Trigeminus, 
The  Upper  Max- 
illary   branch 

The  twelve  Dor- 
sal, 
The    five  Lum- 

The twelve  Dorsal, 
The  Cceliac, 

The  Phrenic, 
and 

The  Abductor, 
The    Hypoglos- 

of  the  Trige- 
minus, 

bar,. 
The  five  Sacral. 

The  five  Lumbar, 

The  External 

sal. 

A    part    of   the 

The  five  Sacral,  and 

Respiratory. 

lower  Maxil- 

The Coccygeal 

lary  branch  of 

Ganglions. 

the    Trigemi- 

nus, 

The  Auditory. 

5.  True  Spinal,  Excito-Motory  or  Reflex  Nervous  System^ — Dr. 
Marshall  Hall1  has  proposed  another  division  of  the  nervous  system, 
which  is  calculated  to  explain  many  of  the  anomalous  circumstances; 
we  so  frequently  witness.  He  proposes  to  divide  all  the  nerves  into 

1.  The  cerebral  or  sentient  and  voluntary. 

2.  The  true  spinal  or  excito-motory. 

3.  The  ganglionic  or  nutrient  and  secretory. 

If  the  sentient  and  voluntary  functions  be  destroyed  by  a  blow  on 
the  head,  the  sphincter  muscles  still  contract  when  irritated,  because 
the  irritation  is  conveyed  to  the  spine,  and  the  reflex  action  takes  place 
to  the  muscle  so  as  to  throw  it  into   contraction.     But  if  the  spinal 
marrow  be  now  destroyed,  the  sphincters  remain  entirely  motionless ; 
because  the  centre  of  the  system  is  destroyed.     Dr.  Hall  thinks,  that 
a  peculiar  set  of  nerves  constitute,  with  the  true  spinal  marrow  as  their 
axis,  the  second  subdivision  of  the  nervous  system ;  and  "as  those  of 
the  first  subdivision  are  distinguished  into  sentient  and  voluntary,  these 
may  be  distinguished  into   excitor  and  motory.     The  first,  or  excitor 
nerves,  pursue  their  course  principally  from  internal  surfaces,  charac- 
terized by  peculiar  oxcitabilities,  to  the  vesicular  centre  of  the  medulla 
oblongata  and  medulla  spinalis ;  the  second  or  motor  nerves  pursue  a 
reflex  course  from  the  medulla  to  the  muscles,  having  peculiar  actions 
concerned  principally  in  ingestion  and  egestion.     The  motions  con- 
nected with  the  first  or  cerebral  subdivision  are  sometimes — indeed 
frequently — spontaneous;  those    connected  with  the  true    spinal  are, 
he  believes,  always  excited.     Dr.  Hall  thinks  that  there  is  good  rea- 
son for  viewing  the  fifth,  and  posterior  spinal  nerves  as  constituting  an 
external  ganglionic  system  for  the  nutrition  of  the  external  organs ; 
and  he  proposes  to  divide  the  ganglionic  subdivision  of  the  nervous  sys- 
tem into  1,  the  internal  ganglionic,  which  includes  that  usually  deno- 
minated the  sympathetic,  and  probably  filaments  of  thepneumogastric; 
and  2,  the  external  ganglionic,  embracing  the  fifth  and  posterior  spinal 
nerves.     To  the  cerebral  system  he  assigns  all  diseases  of  sensation, 
perception,  judgment,  and  volition, — therefore  all  painful,  mental,  and 
comatose,  and  some  paralytic  diseases.     To  the  true  spinal  or  excito- 

1  Lectures  on  the  Nervous  System,  London,  1836,  and  American  edit  ,Philad.,  1836.  Also, 
his  Lectures  on  the  Theory  and  Practice  of  Medicine,  in  the  London  Lancet  for  Feb.  3,  and 
Feb.  7,  1838. 

VOL.  I. — 7 


98  NERVOUS  SYSTEM. 

tnotory  system  belong  all  spasmodic  and  certain  paralytic  diseases. 
He  adds,  that  these  two  parts  of  the  nervous  system  influence  each 
other  both  in  health  and  disease,  as  they  both  influence  the  ganglionic 
system.1 

The  views  of  Dr.  Hall  on  the  excito-motory  function  have  been  em- 
braced by  Muller,2  Grainger,3  Carpenter,4  and  indeed,  with  more  or  less 
modification,  by  almost  all  physiologists.5  Dr.  Carpenter  inferred  from 
his  inquiries,  that  the  actions  most  universally  performed  by  a  nervous 
system  are  those  connected  with  the  introduction  of  food  into  the  di- 
gestive cavity,  and  that  we  have  reason  to  regard  this  class  of  actions 
as  every  where  independent  of  volition,  and  perhaps  also  of  sensation, 
— the  propulsion  of  food  along  the  oesophagus,  in  man,  being  of  this 
character ; — that  for  the  performance  of  any  action  of  this  nature,  a 
nervous  circle  is  requisite,  consisting  of  an  afferent  nerve,  on  the  peri- 
pheral extremities  of  which  an  impression  is  made, — a  ganglionic  cen- 
tre, where  the  white  fibres  of  which  that  nerve  consists  terminate  in 
gray  matter,  and  those  of  the  efferent  nerve  originate  in  like  manner ; 
and  an  efferent  trunk  conducting  to  the  contractile  structure  the  motor 
impulse,  which  originates  in  some  change  between  the  gray  and  white 
matter ; — that  in  the  lowest  animals  such  actions  constitute  nearly  the 
entire  function  of  the  nervous  system, — the  amount  of  those  involving 
sensation  and  volition  being  very  small ;  but  as  we  ascend  the  scale, 
the  evidence  of  the  participation  of  true  sensation  in  the  actions  neces- 
sary for  acquiring  food,  as  shown  by  the  developement  of  special  sen- 
sory organs,  is  much  greater;  but  that  the  movements  immediately 
concerned  with  the  introduction  of  food  into  the  stomach  remain  under 
the  control  of  a  separate  system  of  nerves  and  ganglia,  to  the  action 
of  which  the  influence  of  the  cephalic  ganglia — the  special  if  not  the 
only  seat  of  sensibility  and  volition — is  not  essential;  that,  in  like 
manner,  the  active  movements  of  respiration  are  controlled  by  a  sepa- 
rate system  of  nerves  and  ganglia,  and  are  not  dependent  upon  that  of 
sensation  and  volition,  although  capable  of  being  influenced  by  it ; — 
that  whilst  the  actions  of  these  systems  are,  in  the  lower  tribes,  almost 
entirely  of  a  simply  reflex  character,  we  find  them,  as  we  ascend,  gra- 
dually becoming  subordinate  to  the  will ;  and  that  this  is  effected  by 
the  mixture  of  fibres  proceeding  directly  from  the  cephalic  ganglia  with 
those  arising  from  their  own  centres  ; — that  the  locomotive  organs,  in 
like  manner,  have  their  own  centres  of  reflex  action,  which  are  inde- 
pendent of  the  influence  of  volition,  perhaps  also  of  sensation ; — that 
the  influence  of  the  will  is  conveyed  to  them  by  separate  nervous  fibres, 
proceeding  from  the  cephalic  ganglia,  and  that  similar  fibres  probably 
convey  to  the  cephalic  ganglia  the  impressions  destined  to  produce  sen- 

1  Principles  of  the  Theory  and  Practice  of  Medicine,  by  Marshall  Hall,  M.  D.,  F.R.S.,  p. 
243,  London,  1837,  and  American  edit,  by  Drs.  Bigelow  and  Holmes,  Bost.,  1839. 

2  Handbuch  der  Physiologic,  s.  333,  and  s.  688,  Coblenz,  1835,  1S37,  or  the  English  trans- 
lation by  Dr.  Baly,  i.  707,  London,  1838. 

3  On  the  Structure  and  Functions  of  the  Spinal  Cord,  London,  1837. 

4  Op.  cit. 

5  Todd  and  Bowman,  the  Physiological  Anatomy  and  Physiology  of  Man,  p.  312.    London, 
1845. 


NERVOUS  SYSTEM.  99 

sations; — that  the  stomato-gastric,  respiratory,  and  locomotive  centres 
are  all  united  in  the  spinal  cord  of  the  vertebrata,  where  they  form  one 
continuous  ganglionic  mass,  and  that  the  nerves  connected  with  all  these 
likewise  receive  fibres  derived  immediately  from  the  cephalic  ganglia; — 
and  lastly,  that  whenever  peculiar  consentaneousness  of  action  is  re- 
quired between  different  organs,  their  ganglionic  centres  are  united 
more  or  less  closely ;  and  that  the  trunks  themselves  are  generally  con- 
nected by  bands  of  communication. 

On  the  whole,  in  the  present  state  of  our  knowledge,  we  are  justified, 
perhaps,  in  adopting  the  systematic  summary  of  the  functions  of  the 
nervous  system,  and  the  general  purposes  to  which  it  is  inservient,  as 
given  by  the  writer  last  cited.1  1.  The  nervous  system  receives  im- 
pressions, which,  being  conveyed  by  its  afferent  fibres  to  the  sensorium, 
are  there  communicated  to  the  conscious  mind;  and  are  inservient,  in 
some  manner,  to  the  acts  of  that  mind.  As  the  result  of  these  acts, 
a  motor  impulse  is  transmitted  along  efferent  nerves  to  particular  mus- 
cles, which  excites  them  to  contraction.  Of  these  acts  the  encephalon, 
and  nerves  communicating  with  it,  are  the  organs.  2.  Certain  parts 
of  the  nervous  system  receive  impressions,  which  are  propagated  along 
afferent  fibres  that  terminate  in  ganglionic  centres  distinct  from  the 
sensorium.  In  these,  a  reflex  motor  impulse  is  thus  excited,  which  is 
transmitted  along  efferent  trunks  proceeding  from  those  centres,  and 
excites  muscular  contraction  without  any  necessary  intervention  of  sen- 
sation or  volition.  The  organs  of  this  function  are  the  gray  matter  of 
the  spinal  cord,  which  is  not  continuous  with  the  fibrous  structure  of 
the  brain,  and  the  trunks  connected  with  it.  It  is  the  true  spinal  or 
excito-motory  system  of  Dr.  Hall.  3.  There  is  yet  a  division  of  the 
nervous  system,  which  appears  to  have  for  its  object  to  combine  and 
harmonize  the  muscular  movements  immediately  connected  with  the 
maintenance  of  organic  life.  It  may  likewise  influence,  and  connect 
with  each  other  the  functions  of  nutrition,  secretion,  &c.  ;  although 
these — like  the  muscular  movements  immediately  connected  with  the 
maintenance  of  organic  life — are  doubtless  essentially  independent  of 
it ;  and — as  has  been  shown — can  be  carried  on  where  it  does  not  exist. 
The  organ  of  these  acts  is  the  great  sympathetic.  Of  late — as  will  be 
seen  hereafter — Dr.  Carpenter2  has  contended  with  much  force  for  the 
existence  of  a  series  of  sensory  ganglia,  separate  and  distinct  from  those 
that  compose  the  cerebrum  and  cerebellum — "  ganglia  of  the  nerves  of 
sensation,  common  and  special,  which  are  superposed,  as  it  were,  on 
the  medulla  oblongata,"  and  which,  together,  constitute  the  real  sen- 
sorium. 

It  has  been  urged  by  Dr.  Laycock,3  in  a  paper  read  before  the  Bri- 
tish Association  at  York,  in  accordance  with  views  published  by  him 
four  years  previously,  that  the  brain,  although  the  organ  of  conscious- 
ness, is  subject  also  to  the  laws  of  reflex  action;  and  that  in  this  re- 
spect it  does  not  differ  from  other  ganglia  of  the  nervous  sjsteni.  (  He 

1  Human  Physiology,  p.  79,  London,  1842.. 

a  Principles  of  Human  Physiology,  4th  Amer.  edit.,  p.  320,  Philad.,  1850. 

3  British  and  Foreign  Medical  Re vievf,  Jap(.,  184  X  p  298. 


100 


NERVOUS  SYSTEM. 


regards  the  cerebral  nerves,  and  especially  the  optic,  auditory,  and 
olfactory,  as  afferent  excitor  nerves,  along  which  impressions  pass  to 
the  central  axis ;  thence  to  be  communicated  to  the  motor  nerves,  and 
thus  give  rise  to  combined  muscular  acts,  or  to  irregular  spasmodic 
movements.  Hydrophobia  is  adduced  by  him  as  a  good  illustration  of 
these  cerebral  reflex  movements.  The  acknowledged  excito-motory 
phenomena  in  the  disease  may  be  induced. — First.  Through  the  nerves 
of  touch,  as  by  the  contact  of  water  with  the  surface  of  the  head, 
hands,  chest,  lips,  and  pharynx.  Secondly.  By  a  current  of  air  im- 
pinging on  the  face  or  chest.  Thirdly.  By  a  bright  surface,  as  a  mir- 
ror. Fourthly.  By  the  sight  of  water ;  and  Fifthly.  By  the  idea  of 
water,  as  when  it  is  suggested  to  the  patient  to  drink. 

The  author  has  been  in  the  habit  of  offering  as  an  example  of  the 
same  kind,  vomiting  induced  by  the  sight  of  a  disgusting  object. 
Here  the  impression  is  first  made  upon  the  brain  through  an  organ  of 
sense,  and  the  reflex  motor  phenomena  concerned  in  vomiting  are  in- 
stantaneously excited; — facts,  which  at  least  prove,  that  although  the 
gray  matter  of  the  spinal  marrow  may  continue  to  execute  its  func- 
tions, when  those  of  the  cerebro-spinal  nervous  system  are  suspended, 
— as  during  sleep  or  an  attack  of  epilepsy,  it  is  capable  of  being 
excited  to  action  by  impressions  made  through  the  latter,  in  the  same 
manner  as  by  impressions  made  on  the  afferent  spinal  nerves  themselves. 

From  all  that  has  been  said,  it  will  be  un- 
Fig.  24.  derstood,  that  each  nerve   as  it  issues  from 

the  spinal  canal  must  be  composed  of  various 
fasciculi : — one,  sensory  or  of  sensation,  con- 
nected with  the  posterior  medullary  tract, 
and  continuous  with  the  medullary  matter  of 
the  brain  ;  another,  connected  with  the  ante- 
rior medullary  tract,  and  conveying  the  in- 
fluence of  volition  from  the  brain  along  the 
spinal  cord  and  nerves  to  the  muscles ;  a 
third,  consisting  of  excitor  fibres,  terminating 
in  the  gray  or  ganglionic  matter  of  the  cord, 
and  conveying  impressions  to  it;  and  a 
fourth,  consisting  of  motor  fibres,  arising 
from  the  gray  matter  of  the  cord,  and  con- 
veying the  nervous  influence  reflected  to  the 
muscles. 

It  would  appear  that  a  part  of  each  root 

structure  of  the  Spinal  Cord,  ac-   enters  the  gray  matter  of  the  cord  ;  whilst  a 
cording  to  Stilling.  part  is  continuous  with  the  white  or  medullary 

A.  Posterior  fibres  continuous  matter;  and  Dr.  Stilling1  affirms — as  the  re- 

with  the  anterior  of  the  same  side,          ,         _  7,  •  ,  °,  f      ,         ,,,  ,. 

through  the  nucleus  of  the  cord,  suit  oi  his  researches — that  ot  the  tibres  oi 

B.  Posterior  fibres  continuous  with     ,1         -nnctArinr    rnnf<a    QHTTIP    fnrm     lnnn<5    in    tllP 
the  anterior  of  the  opposite  side.        M*®    pOSlCr 

gray  matter,    and   become    continuous   with 
thbsp  of  the  adterio?  -I'oot's  of  the  mme  side;  whilst  others  cross  the 

,*  Untersuchunge  i  uber  die  Textur  des  Ruckenmarks,  von  Dr.  B.  Stilling  und  Dr.  J.  Wal- 
\zk,s.5l.     Leipz,  1S42. 


NERVOUS  TISSUE.  101 

gray  matter,  and  become  Fis-  25- 

continuous  with  those  of 
the  anterior  roots  of  the 
opposite  side.  It  has  been 
shown,  too,  by  Mr.  New- 
port,1 that  there  are  other 
fibres,  which  pass  from  the 
posterior  into  the  anterior 

roots  of  Other  nerves,  above         Transverse  Section  of  the  Medulla.    (After  Stilling.) 
and     below,     both     On     the         The  transverse  gray  fibres  are  the  continuation  of  the  roots 
Same      and      the      OPDOSite     of  the  nerves  f  the  longitudinal  white  and  gray  fibres  are  in- 
dicated by  points. 

side. 

Much,  doubtless,  still  remains  to  be  accomplished,  before  we  can 
consider  views  in  regard  to  the  nervous  system  established.  Like  many 
important  questions  of  physiology,  they  may  be  regarded  as  in  a  tran- 
sition state ;  but  the  zeal  and  activity  of  physiological  inquirers  are 
daily  throwing  light  upon  many  points;  and  of  these  there  are  none 
surrounded  with  more  obscurity  than  those  that  appertain  to  the  nerv- 
ous system. 

All  the  parts  described  as  constituting  the  nervous  system — brain, 
cerebellum,  medulla  spinalis,  and  nerves — are  formed  of  the  primary 
nervous  fibre,  the  nature  of  which  has  been  already  described.  The 
neurine  or  substance  of  which  they  are  constituted  is  soft  and  pulpy ; 
but  the  consistence  varies  in  different  portions,  and,  in  the  whole,  at 
different  ages.  In  the  foetus  it  is  almost  fluid  ;  in  youth  of  greater 
firmness ;  and  in  the  adult  still  more  so.  This  softness  of  structure  in  the 
encephalon  of  the  foetus  is  by  no  means  inutile.  It  admits  of  the  pres- 
sure, which  takes  place,  to  a  greater  or  less  extent  in  all  cases  of  par- 
turition, whilst  the  head  is  passing  through  the  pelvis,  without  the  child 
sustaining  any  injury.  On  examining,  however,  the  consistence  of  dif- 
ferent brains,  it  is  necessary  to  inquire  into  the  period  that  has  elapsed 
since  the  death  of  the  individual,  as  the  brain  loses  its  firmness  by 
being  kept;  and  ultimately  becomes  semifluid.  It  is  likewise  rendered 
fluid  by  disease,  constituting  ramollissement  du  cerveau  or  mollescence 
of  the  brain,  to  which  the  attention  of  pathologists  has  been  directed 
of  late  years,  but  without  much  important  advantage  to  science. 

When  the  encephalon  is  fresh,  it  has  a  faint,  spermatic,  and  some- 
what tenacious  smell.  This,  according  to  M.  Chaussier,  has  persisted 
for  years  in  brains  that  have  been  dried. 

Neurine  has  been  subjected  to  analysis  by  M.  Vauquelin,2  and  found 
to  contain,  water,  80*00;  white  fatty  matter,  4*53;  red  fatty  matter, 
called  cerebrin,  0'70 ;  osmazome,  1*12 ;  albumen,  7*00 ;  phosphorus, 
1-50 ;  sulphur,  acid  phosphates  of  potassa,  lime,  and  magnesia,  5-15. 
M.  Couerbe's  analysis  of  that  of  the  brain3  gives,  1.  A  pulverulent 
yellow  fat,  stearconote ;  2.  An  elastic  yellow  fat,  cerancephalote ;  3. 
A  reddish-yellow  oil,  eleancephol ;  4.  A  white  fatty  matter,  cerebrate, 

1  Philosophical  Transactions,  1843,  and  Dr.  Carpenter,  2d  Amer.  edit.,  p.  125,  Philad., 
1845. 

3  Annales  de  Chim.,  Ixxxi.  37;  and  Annals  of  Philosophy,  i.  332. 
3  Annales  de  Clumie  et  de  Physique,  Ivi.  160. 


102  NERVOUS  SYSTEM. 

the  white  fatty  matter  of  Yauquelin,  the  myelocone  of  Kuhn  ;  5.  Cere- 
bral cholesterin — cJwlesterote ;  and  the  salts  found  by  Vauquelin, — 
lactic  acid,  sulphur,  and  phosphorus,  which  form  a  part  of  the  fats 
above-mentioned.1  In  the  spinal  cord,  there  is  more  fatty  matter,  and 
less  osmazome,  albumen,  and  water.  In  the  nerves,  albumen  predomi- 
nates, and  fatty  matters  are  less  in  quantity.  Researches  by  M.  Las- 
saigne  show,  that  water  constitutes  T7oths  of  the  nerves;  and  T8Gths  of 
the  brain  ;  whilst  the  proportion  of  albumen  in  the  former  is  T2o2utns  >  *n 
the  latter,  T  J^ths.  He  found  the  neurine  of  different  parts  of  the  brain 
to  be  composed  as  follows : 

The  whole  Brain.  White  portion.  Gray  portion. 

Water,  77-0  73'0  85-0 

Albumen,  96  9-9  7-5 

White  fatty  matter,  7-2  13'9  1-0 

Red  fatty  matter,  3-1  O9  3-7 

Osmazome,  lactic  acid,  and  salts,  2-0  10  1-4 

Earthy  phosphate,  M  1-3  1-2 

100-0  100-0  1000" 

M.  RaspaiP  has  pointed  out  two  other  differences.  First,  when  a 
nerve  is  left  upon  a  plate  of  glass  in  dry  air,  it  becomes  dry,  without 
putrefying,  whilst  cerebral  neurine  putrefies  in  twenty-four  hours  ;  and 
secondly,  the  dried  nerve  has  all  the  physical  characters  of  the  corneous 
substances, — nails,  hair,  and  other  analogous  bodies ;  and  in  their 
chemical  relations,  these  bodies  do  not  differ  sufficiently  to  repel  the 
analogy.  Neither  the  chemical  analysis  of  neurine,  nor  inquiry  into 
its  minute  structure  by  the  aid  of  the  microscope,  has,  however,  thrown 
light  upon  the  wonderful  functions  executed  by  this  elevated  part  of 
the  organism. 

It  would  seem,  that  neurine  is,  in  composition,  intermediate  between 
fat  and  the  compounds  of  protein :  it  contains  nitrogen,  which  is  not 
present  in  fats,  but  in  smaller  proportion  than  in  protein ;  and,  on  the 
other  hand,  it  is  much  richer  in  carbon  than  protein  or  its  compounds. 
Phosphorus,  too,  is  an  essential  ingredient.  According  to  recent  re- 
searches by  M.  Fremy,  there  is  in  cerebral  neurine  a  peculiar  acid,  ana- 
logous to  the  fatty  acids,  which  he  calls  cerebrie  acid,  and  which  contains 
nitrogen  and  phosphorus  :  this  is  mixed  with  an  albuminous  substance  ; 
with  an  oily  acid — oleo-phosphoric ;  with  cholesterin;  and  with  small 
quantities  of  olein  and  margarin,  and  oleic  and  margaric  acids.4 

To  the  naked  eye,  neurine  appears  under  two  forms ; — the  one  gray 
and  of  a  softer  consistence ;  the  other  white,  and  more  compact.  The 
former  is  called  the  vesicular,  gray,  cortical,  cineritious,  or  pulpy  sub- 
stance ;  the  latter,  the  tubular,  white,  medullary,  or  fibrous,  called 
"tubular"  in  consequence  of  its  consisting  of  tubes  of  great  minuteness, 
which  are  filled  with  a  kind  of  granular  pith  that  can  be  squeezed  from 
them, — a  view  adopted  by  most  histologists.  Dr.  James  Stark  has,5 

1  For  John's  Analysis  of  the  white  and  gray  cerebral  matter,  see  Journal  de  Chimie  Medi- 
cale,  Aout,  1835.  See,  also,  Simon's  Medical  Chemistry,  p.  81,  Lond.,  1845. 

a  Journal  de  Chim.  Medic.;  and  Pharmaceutisches  Central  Blatt,  Nov.  19,  1836,  s.  765. 

3  Chimie  Organique,  p.  217,  Paris,  1833. 

4  Journ.  des  Connais.  Med.-Chir.,  Jan.,  1841 ;  also  Turner  and  Liebig's  Chemistry,  7th 
edit.,  p.  1195,  Lond.,  1842. 

6  Proceedings  of  the  Royal  Society,  No.  56,  Lond.,  1843. 


STEKVOUS  TISSUE. 


108 


however,  affirmed,  as  the  result  of  his  examination,  that  the  matter 
which  fills  the  tubes  is  of  an  oily  nature,  differing,  in  no  essential 
respect,  from  butter  or  soft  fat,  and  remaining  of  a  fluid  consistence 
during  the  life  of  the 

animal,  or  whilst  it  re-  Fi»-  26- 

tains  its  natural  tem- 
perature; but  becoming 
granular  or  solid  when 
the  animal  dies.  The 
diameter  of  these  cylin- 
drical tubuli  has  been 
estimated  to  vary  from 
about  the  yjpth  to  the 
2Jota  of  a  line.  The 
nerves  are  wholly  com- 
posed of  it. 

The  tubular  nervous 
matter,  wherever  it  is 
found,  seems  to  consist 
of  fibres,  which  have  a 
definite  arrangement. 
Two  kinds  of  primitive 
fibre,  according  to  the 
researches  of  Messrs. 
Todd  and  Bowman,1  are 
present  in  the  nervous 
system,  which  they  dis- 
tinguish as  the  tubular 

-fihr?  nr  nerve  tiihe     f\r\<\  or  primitive  band. 

Jw  c.  Figure  (imaginary)  intended  to  represent  the  appearances  oc- 

the    CielatinOUS    fibre  casionally  seen  in  the  tubular  fibres.     1,  1.  Membrane  of  the  tube 

,       JP               •     r»     •      i        r_  seen  at  Pafts  where  the  white  substance  has  separated  from  it.    2. 

the  lOrmer  infinitely  the  A  part  where  the  white  substance  is  interrupted.    3.  Axi 

i  ,1  ing  beyond  the  broken  end  of  the  tube.    4.  Part  of  the  c< 

more  numerous,  and  the  the  tube  escaped. 
latter  found  chiefly  in 
the  sympathetic  system-     The  tubular 
fibres  vary  in  diameter  from  y^  ^th  even 

to  TTJ  J  o  otn  °f  an  incn  5  but  tneir  average 
width  is  from  ^^tnto  ^^th  of  an  inch. 
The  gelatinous  fibre  is  devoid  of  the 
whiteness  that  characterizes  the  tubular 
fibre ;  and  the  gray  colour  of  certain 
nerves,  it  has  been  thought,  is  dependent 
chiefly  upon  the  presence  of  a  large 
proportion  of  gelatinous  fibres.  Hence 
they  have  been  sometimes  termed  gray 
fibres.  These  are  in  general  smaller 
than  the  tubular  fibres, — their  dia- 
meter ranging  between  the  g^^th  and 
tne  4  o'o  oth  °f  an 


Tubular  Nerve-fibres. 

A.  Tubular  nerve-fibres,  showing  the  sinuous  outline  and  double 
contours. 

B.  Diagram  to  show  the  parts  of  a  tubular  fibre,  viz. :  1,  1.  Mem- 
branous tube.    2,2.  White  substance  or  medullary  sheath.    3.  Axis 


s  project- 
contents  of 


Fig.  27. 


C  5 


Gelatinous  Nerve-fibres. 

(a  and  b  magnified  340  diameters,  after 
Hannover ;  c  and  a  after  Remak.) 


1  Dr.  Todd,  Art.  Nervous  Centres,  in  Cyclop,  of  Anat.  and  Phys.,  Pt.  xxvi.,  p.  707 ;  and 
The  Physiological  Anatomy  and  Physiology  of  Man,  p.  208,  London,  1845. 


104 


NERVOUS  SYSTEM. 


Fig.  28. 


Ganglion  Corpuscles.  After  Valentin 
In  one  a  second  nucleus  is  visible 


Fig.  29. 


Histologists  are  generally  of  opinion,  that  the  central  portion  of  each 
nerve-fibre  differs  from  the  peripheral :  the  former  has  been  termed  by 
Rosenthal  and  Purkinje  the  axis- cy Under  ;  the  latter  is  the  medullary 
or  white  substance  of  Schwann,  and  to  it  the  white  colour  of  the  cere- 
bro-spinal  nerves  is  chiefly  due. 

The  researches   of  histologists  have   shown  that  vesicles  or  cells 

containing  nuclei  and  nucleoli,  and  called 
also  nerve  corpuscles  and  globules  and  gan- 
glion corpuscles  and  globules,  are  the  essen- 
tial elements  of  gray  or  vesicular  matter. 
These  are  found  in  the  nervous  centres, 
mingled  with  nerve-fibres,  and  imbedded  in 
a  dimly  shaded  or  granular  substance. 
They  give  to  the  ganglia  and  to  certain 
parts  of  the  brain  and  spinal  cord  the  pecu- 
liar grayish  or  reddish-gray  appearance  by 
which  they  are  characterized.  They  are 
large  nucleated  cells,  filled  with  a  finely 
?wonSoiSi°fseveralcontain80neor  granular  material;  some  of  which  is  often 

dark,  like  pigment ; — the  nucleus,  which  is 
vesicular,  containing  a  nu- 
cleolus.  The  marginal  figure 
(Fig.  28)  represents  some 
that  have  a  regular  outline. 
Others,  as  in  Fig.  29,  are  cau- 
date or  stellate,  and  have  tu- 
bular processes  issuing  from 
them,  filled  with  the  same 
kind  of  granular  matter  as 
is  contained  in  the  corpuscle. 
The  gray  substance  is  not 
always  at  the  exterior,  nor 
the  medullary  in  the  interior. 
In  the  medulla  spinalis,  their 
situation  is  the  reverse  of 
what  it  is  in  the  brain.  In 
the  invertebrata,  the  gray 
matter  forms  the  nuclei  of 
the  ganglia,  which  are  the 
centres  of  the  nervous  sys- 
tem ;  and  the  true  spinal 

Stellate  or  Caudate  Nerve  Corpuscles.  After  Hannover.  System,    which    Occupies   the 

a,  «.  From  the  deeper  part  of  the  gray  matter  of  the  con-  interior    of   the    Spinal    COrd, 

volutions  of  the  cerebellum.     The  larger  processes  are  di-  J^S  ]jeen  regarded  aS  a  chain 
rected  towards  the  surface  of  the  organ,     o.  Another  trom  .  .       , 

the  cerebellum,     c,  d.  Others  from  the  post-horn  of  gray  ol  Similar  ganglia.      It  IS  tne 
matter  of  the  dorsal  region  of  the  cord.     These  contain  pig-  alrparlv  sVlOWTl     of 

ment,  which  surrounds  the  nucleus  in  c.     In  all  the  speci-  Organ,   aS    already  SnOWn,   O 

mens  the  processes  are  more  or  less  broken.     Magnified  200  ,1  PXcitO-mOtOrV      nerVOUS 

diameters.  -f  .  , 

function.     Kuyscn  consider- 
ed, that  the  gray  portion  owes  its  colour  to  the  blood-vessels  that  enter 


CIRCULATION  IN  THE  ENCEPHALON.  105 

it  j1  and,  in  this  opinion,  Haller,  Adelon,2  and  others,3  concur ;  but  this 
is  not  probable,  and  it  has  not  been  by  any  means  demonstrated.4  The 
medullary  portion  has  the  appearance  of  being  fibrous  ;  and  it  has  been 
so  regarded  by  Leeuenhoek,5  Vieussens,  Steno,  and  by  Gall  and  Spur- 
zheim.6  Malpighi7  believed  the  gray  cortical  substance  to  be  an  assem- 
blage of  small  follicles,  intended  to  secrete  the  nervous  fluid ;  and  the 
white  medullary  substance  to  be  composed  of  the  excretory  vessels  of 
these  follicles ;  and  an  analogous  view  is  entertained  by  most  physiolo- 
gists of  the  present  day, — the  gray  matter  at  least  being  regarded  as 
the  generator  of  the  nervous  influence ;  the  white  matter  as  chiefly 
concerned  in  its  conduction.  Gall  and  Spurzheim  conjecture,  that  the 
use  of  the  gray  matter  is  to  be  the  source  or  nourisher  of  the  white 
fibres.  The  facts,  on  which  they  support  their  view,  are,  that  the  nerves 
appear  to  be  enlarged  when  they  pass  through  a  mass  of  gray  matter, 
and  that  masses  of  this  substance  are  deposited  in  all  parts  of  the  spinal 
cord  where  it  sends  out  nerves ;  but,  Tiedemann8  has  remarked,  that 
in  the  foetus  the  medullary  is  developed  before  the  cortical  portion,  and 
he  conceives  the  use  of  the  latter  to  be — to  convey  arterial  blood,  which 
may  be  needed  by  the  medullary  portion  for  the  due  execution  of  its 
functions.  After  all,  however,  it  must  be  admitted  with  Dr.  Allen 
Thomson,9  that  the  general  conclusion  deducible  from  all  the  facts  would 
seem  to  be,  that  whilst  the  gray  fibres  predominate  in  the  organic  or 
sympathetic  nerves,  and  the  tubular  fibres  in  the  cerebro-spinal  nerves, 
these  two  elements  are  mixed,  in  various  proportions,  in  the  great  divi- 
sions of  the  nervous  system ;  and  that,  therefore,  these  divisions,  al- 
though, in  a  great  measure,  structurally  different,  are  not  altogether 
distinct  from,  or  independent  of,  each  other.  "But" — he  properly 
adds — "  in  regard  to  the  whole  subject  of  the  structure  and  nature  of 
the  different  varieties  of  the  nervous  texture,  it  is  unquestionable  that 
much  still  remains  to  be  ascertained  by  laborious  investigation." 

Sir  Charles  Bell10  affirms,  that  he  has  found,  at  different  times,  all 
the  internal  parts  of  the  brain  diseased,  without  loss  of  sense ;  but  he 
has  never  seen  disease  general  on  the  surface  of  the  hemispheres  without 
derangement  or  oppression  of  mind  during  the  patient's  life ;  and  hence 
he  concludes,  that  the  vesicular  matter  of  the  brain  is  the  seat  of  the 
intellect,  and  the  tubular  of  the  subservient  parts.11  A  similar  use  has 
been  ascribed  to  the  vesicular  portion,  from  pathological  observations, 
by  MM.  Foville  and  Pinel  Grandchamp.12  This  view  would  afford  con- 
siderable support  to  the  opinions  of  Gall,  Spurzheim,  and  others,  who 
consider  the  organs  of  the  cerebral  faculties  to  be  constituted  of  ex- 

I  Oper.  Amstel.,  1727.  3  Pbysiologie  de  1'Homme,  2de  edit.,  i.  208,  Paris,  1829. 
3  Carpenter,  Human  Physiology,  p.  81,Lond.,  1842. 

<  Todd,  Cyclop,  of  Anat.  and  Physiol.,  Pt.  xxv.  p.  647,  Lond.,  1844. 
6  Philos.  Transact.,  1677,  p.  899. 

6  Recherches  sur  le  Systeme  Nerveux  en  general,  et  sur  celui  du  Cerveau  en  particulier, 
avec  figures,  Paris,  1809. 

'  Oper.  Malpighii,  and  Mangeti  Bibl.  Anat.,  i.  321. 

8  Anatomic  und  Bildungsgeschichte  des  Gehirns,  mit  Tafeln,  Niirnberg,  1816. 

9  Outlines  of  Physiology,  Pt.  i.  p.  155,  Edinb.,  1848. 

10  Anatomy  and  Physiology,  5th  American  edit.,  by  J.  D.  Godman,p.  29,  New  York,  1827. 

II  See  two  interesting  pathological  cases,  confirming  this  view  of  the  function  of  the  gray 
matter,  by  Dr.  Cowan,  in  Provincial  Medical  and  Surgical  Journal,  April  16,  1845. 

13  Sur  le  Systeme  Nerveux,  Paris,  1820. 


106 


NERVOUS  SYSTEM. 


pansions  of  the  columns  of  the  spinal  marrow  and  medulla  oblongata, 
and  to  terminate  by  radiating  fibres  on  the  periphery  of  the  brain ;  as 
well  as  to  those  of  M.  Desmoulins,1  and  others  who  regard  the  convolu- 
tions as  the  seat  of  the  mind.  We  have,  however,  cases  on  record,  that 
signally  conflict  with  this  view  of  the  subject ;  in  which  the  cortical 
substance  has  been  destroyed,  and  yet  the  moral  and  intellectual  mani- 
festations have  been  little,  if  at  all,  injured.  Many  years  ago,  the 
author  dissected  the  brain  of  an  individual  of  rank  in  the  British  army 
of  India,  in  the  anterior  lobes  of  which  neither  medullary  nor  cortical 
portion  could  be  distinguished, — both  one  and  the  other  appearing  to 
be  broken  down  into  a  semi-purulent,  amorphous  substance ;  yet  the 
intellectual  faculties  had  been  nearly  unimpaired ;  although  the  morbid 
process  must  have  been  of  some  duration. 

The  encephalon  affords  us  many  striking  instances  of  the  different 

effects    produced   by   sudden, 

Fig-  30-  and   by  gradual  interference 

with  its  functions.  Whilst  a 
depressed  portion  of  bone  or 
an  extravasation  of  blood  may 
suddenly  give  rise  to  the  abo- 
lition of  the  intellectual  and 
moral  faculties,  gradual  com- 
pression by  a  tumour  may 
scarcely  interfere  with  any  of 
its  manifestations. 

The  circulation  of  blood  in 
the  encephalon  requires  notice. 
The  arteries  are  four  in  num- 
ber,— two  internal  carotids, 
and  two  vertebrals:  to  these 
may  be  added  the  spinal  or 
middle  artery  of  the  dura 
mater,  arteria  meningsea  me- 
dia. The  carotid  arteries 
enter  the  head  through  the 
carotid  canals,  which  open  on 
each  side  of  the  sella  tur- 
cica,  or  of  the  chiasma  of  the 
optic  nerves.  The  vertebral 
arteries  enter  the  head  through 

1.  Vertebral  arteries.    2.  Twoanteriorspinalbranch.es  the    foramen     magnum     of   the 

uniting  to  form  a  single  vessel.    3.  One  of  the  posterior  r\r*n\r\\ts\]     hrmp  •    nrnrp     rm     fViP 

spinalarteries.     4.  Posterior  meningeal.    5.  Inferior  cere-  OCClpltal     DOnC  ,    I 

bellar.   6.  Basilar  artery  giving  off  its  transverse  branches  medulla  Oblongata  to  form  the 

basilary  artery,  which  passes 
forward  along  the  middle  of 
the  pons  varolii ;  and,  at  the 
anterior  part  of  the  pons,  gives 
off  lateral  branches,  which 


Circle  of  Willis. 


to  either  side.  7.  Superior  cerebellar  artery.  8.  Posterior 
cerebral.  9.  Posterior  communicating  branch  of  the  in- 
ternal  carotid.  10.  Internal  carotid,  showin  the  curva- 


ing 
hal 


tures  it  makes  within  the  skull.  11.  Ophthalmic  artery 
divided  across.  12.  Middle  cerebral  artery.  13.  Anterior 
cerebral  arteries  connected  by,  14.  Anterior  commumcat- 

ing  artery. 


Anatomie  des  Systemes  Nerveux  des  Animaux  a  Vertebres,  p.  599,  Paris,  1825. 


CEPHALO-SPINAL  FLUID.  107 

inosculate  with  corresponding  branches  of  the  carotids,  and  form  a  kind 
of  circle  at  the  base  of  the  brain,  which  has  been  called  circulus  arte- 
riosus  of  Willis.  The  passage  of  the  blood-vessels  is  extremely  tortu- 
ous, so  that  the  blood  does  not  enter  the  brain  with  great  impetus ;  and 
they  become  capillary  before  they  penetrate  the  organ, — an  arrange- 
ment of  importance,  when  we  regard  the  large  amount  of  blood  sent 
to  it.  This  has  been  estimated  as  high  as  one-eighth  of  the  whole  fluid 
transmitted  from  the  heart.  The  amount  does  not  admit  of  accurate 
appreciation,  but  it  is  considerable.  It  of  course  varies  according  to 
circumstances.  In  hypertrophy  of  the  heart,  the  quantity  is  sometimes 
increased  ;  as  well  as  in  ordinary  cases  of  what  are  called  determinations 
of  blood  to  the  head.  Here,  too  large  an  amount  is  sent  by  the  arterial 
vessels ;  but  an  equal  accumulation  may  occur,  if  the  return  of  the 
blood  from  the  head  by  the  veins  be  in  any  manner  impeded, — as  when 
we  stoop,  or  compress  the  veins  of  the  neck  by  a  tight  cravat,  or  by 
keeping  the  head  turned  for  a  length  of  time.  Congestion  or  accumu- 
lation of  blood  may  therefore  arise  from  very  different  causes. 

Sir  Astley  Cooper1  found  by  experiment,  that  the  vertebral  arteries 
are  more  important  vessels  as  regards  the  encephalon  and  its  functions 
in  certain  animals,  as  the  rabbit,  than  the  carotids.  The  nervous  power 
is  lessened  by  tying  them ;  and,  in  his  experiments,  the  animals  did 
not,  in  any  case,  survive  the  operation  more  than  a  fortnight.  In  the 
dog,  he  tied  the  carotids  with  little  effect,  but  the  ligature  of  the  verte- 
brals  had  a  great  influence.  The  effect  of  the  operation  was  to  render 
the  breathing  immediately  difficult  and  laborious  ;  owing,  in  Sir  Astley's 
opinion,  to  the  supply  of  blood  to  the  phrenic  nerves,  and  the  whole 
tractus  respiratorius  of  Sir  Charles  Bell,  being  cut  off.  The  animalv 
became  dull,  and  indisposed  to  make  use  of  exertion ;  or  to  take  food. 
Compression  of  the  carotids  and  the  vertebrals  at  the  same  moment, 
in  the  rabbit,  destroyed  the  nervous  functions  immediately.  This  was 
effected  by  the  application  of  the  thumbs  to  both  sides  of  the  neck,  the 
trachea  remaining  free  from  pressure.  Respiration  ceased  entirely, 
with  the  exception  of  a  few  convulsive  gasps.  The  same  fact  was 
evinced  in  a  clearer  and  more  satisfactory  manner  by  the  application 
of  ligatures  to  the  four  vessels,  all  of  which  were  tightened  at  the  same 
instant.  Stoppage  of  respiration  and  death  immediately  ensued. 

The  cerebral,  like  other  arteries,  are  accompanied  by  branches  of  the 
great  sympathetic.  The  researches  of  Purkinje,2  Volkmann,3  and 
Rainey,4  have  shown  the  existence  of  a  large  number  of  nerves  in  con- 
nection with  the  encephalic  and  spinal  arachnoid.  They  do  not  seem  to 
communicate  with  the  roots  of  the  spinal  nerves,  but  belong  exclusively 
to  the  sympathetic.5  The  encephalic  veins  are  disposed  as  already  de- 
scribed, terminating  in  sinuses  formed  by  the  dura  mater,  and  conveying 

1  Guy's  Hospital  Reports,  i.  472,  London,  1836. 

2  JMulIer's  Archiv.  fur  Anatomie,  p.  281,  Berlin,  1845. 

3  Art.  Nervenphysiologie,  Wagner's  Handworterbuch  der  Physiologie,  lOte    Lieferung, 
s.  494,  Braunschweig,  1845. 

<  Medico-Chirurgical  Transactions  for  the  year  1845. 

6  D.  Brinton,  Art.  Serous  and  Synovial  Membranes,  in  Cyclop,  of  Anat.  and  Physiol.,  Pt. 
xxxiv.  p.  525,  Lond.,  Jan.  1849. 


108 


NERVOUS  SYSTEM. 


Sinuses  of  the  Base  of  the  Skull. 

1.  Ophthalmic  veins.    2.  Cavernous 
sinus  of  one  side, 
the  figure  occupies 


Fig-  3L  their  blood  to  the  heart  by  means  of  the 

lateral  sinuses  and  internal  jugulars;  but  of 
the  peculiarities  of  the  circulation  in  the 
encephalon,  mention  will  be  made  in  the 
appropriate  place.  No  lymphatic  vessels 
have  been  detected  in  the  encephalon;  yet, 
that  absorbents  exist  there  is  proved  by  the 
dissection  of  apoplectic  and  paralytic  indi- 
viduals. In  these  cases,  when  blood  has 
been  effused,  the  red  particles  are  gradually 
taken  up,  with  a  portion  of  the  fibrinous 
part  of  the  blood,  leaving  a  cavity  called 
an  apoplectic  cell,  which  is  at  the  same  time 
the  evidence  of  previous  extravasation  and 
subsequent  absorption. 

The  whole  of  the  nervous  system  is  well 
supplied  "with  bloodvessels.  In  the  vesi- 
cular neurine  of  the  nervous  centres,  the 
capillaries  surround  the  ganglion  cells  or 
globules;  and  in  the  tubular  they  pass 
between  the  nerve-tubes,  being  connected 
at  intervals  by  transverse  branches. 

When  the  skull  of  the  new-born  infant, 
Supe-  which,  at  the  fontanelles,  consists  of  mem- 

7.  Internal  jugular    ,  ,  ,        ,         ',       ,,  . 

brane  only — or  the  head  of  any  one  who 
has  received  an  injury,  that  exposes  the 
brain — is  examined,  two  distinct  move- 
ments are  perceptible.  One,  which  is  gene- 
rally obscure,  is  synchronouswiththe  pulsation 
of  the  heart  and  arteries;  the  other,  much 
more  apparent,  is  connected  with  respiration, 
the  organ  seeming  to  sink  at  the  time  of  in- 
spiration, and  to  rise  during  expiration.  This 
phenomenon  is  not  confined  to  the  cerebrum, 
but  exists  likewise  in  the  cerebellum  and  spinal 
marrow.  The  motion  of  the  encephalon, 
synchronous  with  that  of  the  heart,  admits 
of  easy  explanation.  It  is  owing  to  the 
pulsation  of  the  circle  of  arteries  at  the  base  of  the  brain  elevating 
the  organ  at  each  systole  of  the  heart.  The  other  movement  is  not 
so  readily  intelligible.  It  has  been  attributed  to  the  resistance, 
experienced  by  the  blood  in  its  passage  through  the  lungs  during  expi- 
ration, owing  to  which  an  accumulation  of  blood  takes  place  in  the  right 
side  of  the  heart;  this  extends  to  the  veins  and  to  the  cerebral  sinuses, 
and  an  augmentation  of  bulk  is  thus  occasioned.  We  shall  see  hereafter, 
that  one  of  the  forces  conceived  to  propel  the  blood  along  the  vessels 
is  atmospheric  pressure.  According  to  that  view,  the  sinking  down  of 
the  brain  during  inspiration  is  explicable:  the  blood  is  rapidly  drawn 
to  the  heart;  the  quantity  in  the  veins  is  consequently  diminished;  and 
sinking  of  the  brain  succeeds. 


or  anterior  occipital  sinus. 

riorpetrosal  sinus 

vein.  s.  Foramen  magnum. 


Occi- 
BrophiU' 


Fig.  32. 


Capillary  Net-work  of  Nervous 
Centres. 


CEPHALO-SPINAL  FLUID.  109 

On  dissection,  we  find  that  the  encephalon  fills  the  cavity  of  the  cra- 
nium; during  life,  therefore,  it  must  be  pressed  upon,  more  or  less,  by 
the  blood  in  the  vessels,  and  by  the  serous  fluid  exhaled  by  the  pia  mater 
into  the  subarachnoid  tissue.  Thence  it  penetrates  into  the  ventricles, 
— according  to  M.  Magendie,  at  the  lower  end  of  the  fourth*  ventricle, 
at  the  calamus  scriptorius.  The  quantity  varies  according  to  the  age 
and  size  of  the  patient,  and  usually  bears  an  inverse  proportion  to  the 
size  of  the  encephalon.  It  is  seldom,  however,  less  than  two  ounces, 
and  often  amounts  to  five.  M.  Magendie  is  of  opinion,  that  the  fluid  is 
secreted  by  the  pia  mater,  and  states,  that  it  may  be  seen  transuding 
from  it  in  the  living  animal.  The  results  of  chemical  analysis  appear 
to  show,  that  it  differs  from  mere  serum.  It  is  obviously,  however, 
almost  impracticable — if  not  wholly  so — to  separate  the  consideration 
of  this  fluid  from  that  met  with  in  the  cavity  of  the  arachnoid. 

The  spinal  marrow  does  not,  as  we  have  seen,  fill  the  vertebral  canal; 
the  cephalo-spinal  fluid  exerts  upon  it  the  necessary  pressure;  added  to 
which,  the  pia  mater  seems  to  press  more  upon  this  organ  than  upon 
the  rest  of  the  cerebro-spinal  system.  A  certain  degree  of  pressure 
appears,  indeed,  necessary  for  the  due  performance  of  its  functions; 
and  if  this  be  either  suddenly  and  considerably  augmented,  or  dimi- 
nished, derangement  of  function  is  the  result.  M.  Magendie,1  however, 
asserts,  that  he  has  known  animals,  from  which  the  fluid  had  been  re- 
moved, survive  without  any  sensible  derangement  of  the  nervous  func- 
tions. It  is  this  fluid,  which  is  drawn  off  by  the  surgeon  when  he 
punctures  in  a  case  of  spina  bifida. 

When  the  brain  is  examined  in  the  living  body,  it  exhibits  properties, 
which,  some  years  ago,  it  would  have  been  esteemed  the  height  of  hardi- 
hood and  ignorance  to  ascribe  to  it.  The  opinion  has  universally  pre- 
vailed, that  'all  nerves  are  exquisitely  sensible.  Many  opportunities 
will  occur  for  showing,  that  this  sentiment  is  not  founded  on  fact ;  even 
the  encephalon  itself, — the  organ  in  which  perception  takes  place, — is 
insensible,  in  the  common  acceptation  of  the  term ;  that  is,  we  may 
prick,  lacerate,  cut,  and  even  cauterize  it,  yet  no  painful  impression 
will  be  produced.  Experiment  leaves  no  doubt  regarding  the  truth  of 
this,  and  we  find  the  fact  frequently  confirmed  by  pathological  cases. 
Portions  of  brain  may  he  discharged  from  a  wound  in  the  skull,  and 
yet  no  pain 'be  evinced.  In  his  "Anatomy  and  Physiology,"  Sir  C. 
Bell2  remarks,  that  he  cannot  resist  stating,  that  on  the  morning  on 
which  he  was  writing,  he  had  had  his  finger  deep  in  the  anterior  lobes 
of  the  brain ;  when  the  patient,  being  at  the  time  acutely  sensible,  and 
capable  of  expressing  himself,  complained  only  of  the  integument.  A 
pistol-ball  had  passed  through  the  head,  and  Sir  Charles,  having  ascer- 
tained, that  it  had  penetrated  the  dura  mater  by  forcing  his  finger  into 
the  wound,  trephined  on  the  opposite  side  of  the  head,  and  extracted  it. 

By  the  experiments,  instituted  by  MM.  Magendie,3  Flourens  and 

I  Precis  Elementaire,  seconde  edit.,  i.  192;  and  Recherches  Physiologiques  et  Cliniques 
sur  le  Liquide  Cephalo  rachidien  cm  Cerebro  spinal,  Paris,  1842. 

II  Fifth  Airier,  edit,  by  J.  D.  Godman,  ii.  6,  1827. 
3  Precis  Elementaire,  i.  325. 


110  SENSATIONS. 

others,  it  has  been  shown,  that  an  animal  may  live  days,  and  even  weeks, 
after  the  hemispheres  have  been  removed;  nay,  that  in  certain  animals, 
as  reptiles,  no  change  is  produced  in  their  habitudes  by  such  abstraction. 
They  move  about  as  if  unhurt.  Injuries  of  the  surface  of  the  cere- 
bellum exhibit,  that  it  also  is  not  sensible;  but  deeper  wounds,  and 
especially  such  as  interest  the  peduncles,  have  singular  results, — to  be 
explained  hereafter.  The  spinal  cord  is  not  exactly  circumstanced  in 
this  manner.  Its  sensibility  is  exquisite  on  the  posterior  surface ;  much 
less  on  the  anterior,  and  almost  null  at  the  centre.  Considerable  sen- 
sibility is  also  found  within,  and  at  the  sides  of,  the  fourth  ventricle; 
but  this  diminishes  as  we  proceed  towards  the  anterior  part  of  the 
medulla  oblongata,  and  is  very  feeble  in  the  tubercula  quadrigemina 
of  the  mammalia. 

It  has  been  shown,  that  the  spinal  nerves,  by  means  of  their  poste- 
rior roots,  convey  general  sensibility  to  the  parts  to  which  they  are  dis- 
tributed. But  there  are  other  nerves,  which,  like  the  brain,  are  them- 
selves entirely  devoid  of  general  sensibility.  This  has  given  occasion 
to  a  distinction  of  nerves  into  those  of  general  and  of  special  sensi- 
bility. Of  nerves,  which  must  be  considered  insensible  or  devoid  of 
general  sensibility,  we  may  instance  the  optic,  olfactory,  and  auditory. 
Each  of  these  has,  however,  a  special  sensibility ;  and  although  it  may 
exhibit  no  pain  when  irritated,  it  is  capable  of  being  impressed  by 
appropriate  stimuli — by  light,  in  the  case  of  the  optic  nerve  ;  by 
odours,  in  that  of  the  olfactory ;  and  by  sound,  in  that  of  the  auditory. 
Yet  we  shall  find,  that  every  nerve  of  special  sensibility  seems  to  re- 
quire the  influence  of  a  nerve  of  general  sensibility ;  the  fifth  pair. 

Many  nerves  appear  devoid  of  sensibility,  as  the  third,  fourth,  and 
sixth  pairs;  the  portio  dura  of  the  seventh;  the  ninth  pair  of  encephalic 
nerves ;  and,  as  has  been  shown,  all  the  anterior  roots  of  the  spinal 
nerves. 

The  parts  of  the  encephalon,  concerned  in  muscular  motion,  will  fall 
under  consideration  hereafter. 

2.    PHYSIOLOGY  OF  SENSIBILITY. 

Sensibility  we  have  defined  to  be — the  function  by  which  an  animal 
experiences  feeling,  or  has  the  perception  of  an  impression.  It  in- 
cludes two  great  sets  of  phenomena ;  the  sensations,  properly  so  called, 
and  the  intellectual  and  moral  manifestations.  These  we  shall  investi- 
gate in  succession. 

a.  Sensations. 

A  sensation  is  the  perception  of  an  impression  made  on  a  living 
tissue ; — or,  in  the  language  of  Gall,  it  is  the  perception  of  an  irrita- 
tion. By  the  sensations  we  receive  a  knowledge  of  what  is  passing 
within  or  without  the  body ;  and,  in  this  way,  our  notions  or  ideas  of 
them  are  obtained.  When  these  ideas  are  reflected  upon,  and  compared 
with  each  other,  we  exert  thought  and  judgment;  and  they  can  be  re- 
called with  more  or  less  vividness  and  accuracy  by  the  exercise  of 
memory. 


ACCOMPLISHED  IN  THE  ENCEPHALON.  Ill 

The  sensations  are  numerous,  but  they  may  all  be  comprised  in  two 
divisions, — the  external  and  the  internal.  Vision  and  audition  afford 
us  examples  of  the  former,  in  which  the  impression  made  upon  the 
organ  is  external  to  the  part  impressed.  Hunger  and  thirst  are  in- 
stances of  the  latter,  the  cause  being  internal;  necessary  ;  and  depend- 
ing upon  influences  seated  in  the  economy  itself.  Let  us  endeavour  to 
discover  in  what  they  resemble  each  other. 

In  the  first  place,  every  sensation,  whatever  may  be  its  nature, — ex- 
ternal, or  internal, — requires  the  intervention  of  the  encephalon.  The 
distant  organ — as  the  eye  or  ear — may  receive  the  impression,  but  it 
is  not  until  this  impression  has  been  communicated  to  the  encephalon, 
that  sensation  is  effected.  The  proofs  of  this  are  easy  and  satisfactory. 
If  we  cut  the  nerve  proceeding  to  any  sensible  part,  put  a  ligature 
around  it,  or  compress  it  in  any  manner; — it  matters  not  that  the 
object,  which  ordinarily  excites  a  sensible  impression,  is  applied  to  the 
part, — no  sensation  is  experienced.  Again,  if  the  brain,  the  organ  of 
perception,  be  prevented  in  any  way  from  acting,  it  matters  not  that 
the  part  impressed,  and  the  nerve  communicating  with  it,  are  in  a  con- 
dition necessary  for  the  due  performance  of  the  function,  sensation  is 
not  effected.  We  see  this  in  numerous  instances.  In  pressure  on  the 
brain,  occasioned  by  fracture  of  the  skull ;  or  in  apoplexy,  a  disease 
generally  dependent  upon  pressure,  we  find  all  sensation,  all  mental 
manifestation,  lost ;  and  they  are  not  regained  until  the  compressing 
cause  has  been  removed.  The  same  thing  occurs  if  the  brain  be  stu- 
pefied by  opium ;  and,  to  a  less  degree,  in  sleep,  or  when  the  brain  is 
engaged  in  intellectual  meditations.  Who  has  not  found,  that  in  a 
state  of  reverie  or  brown  study,  he  has  succeeded  in  threading  his  way 
through  a  crowded  street,  carefully  avoiding  every  obstacle,  yet  so  little 
impressed  by  the  objects  around  as  not  to  retain  the  slightest  recollec- 
tion of  them  !  On  the  other  hand,  how  vivid  are  the  sensations  when 
attention  is  directed  to  them  !  Again,  we  have  numerous  cases  in  which 
the  brain  itself  engenders  the  sensation,  as  in  dreams,  and  in  insanity. 
In  the  former,  we  see,  hear,  speak,  use  every  one  of  our  senses  appa- 
rently ;  yet  there  has  been  no  impression  from  without.  Although  we 
may  behold  in  our  dreams  the  figure  of  a  friend  long  since  dead,  there 
can  obviously  be  no  impression  made  on  the  retina  from  without.1 

The  whole  history  of  spectral  illusions,  morbid  hallucinations,  and 
maniacal  phantasies,  is  to  be  accounted  for  in  this  manner.  Whether, 
in  such  cases,  the  brain  reacts  upon  the  nerves  of  sense,  and  produces 
an  impression  upon  them  from  within,  similar  to  what  they  experience 
from  without  during  the  production  of  a  sensation,  will  form  a  subject 
for  future  inquiry.  Pathology  also  affords  several  instances  where  the 
brain  engenders  the  sensation,  most  of  which  are  precursory  signs  of 
cerebral  derangement.  The  appearance  of  spots  flying  before  the 
eyes,  of  spangles,  depravations  of  vision,  hearing,  &c.,  and  a  sense  of 
numbness  in  the  extremities,  are  referable  to  this  cause ;  as  well  as  the 
singular  fact  well  known  to  the  operative  surgeon,  that  pain  is  often 

1  Adelon,  Art.  Encephale  (Physiologic),  in  Diet,  de  Med.,  vii  514,  Paris,  1823,  and  Phy- 
siol.  de  1'Homme,  torn.  i.  p.  239,  2de  edit.,  Paris,  18'29. 


112  ,  SENSATIONS. 

felt  in  part  of  a  limb,  months  after  the  ,limb  has  been  removed  from 
the  body. 

These  facts  prove,  that  every  sensation,  although  referred  to  some 
organ,  must  be  perfected  in  the  brain.  The  impression  is  made  upon 
the  nerve  of  the  part,  but  the  appreciation  takes  place  in  the  common 
sensorium. 

There  are  few  organs  which  could  be  regarded  insensible,  were 
we  aware  of  the  precise  circumstances  under  which  their  sensibility 
is  elicited.  The  old  doctrine — as  old  indeed  as  Hippocrates1 — was, 
that  the  tendons  and  other  membranous  parts  are  among  the  most 
sensible  of  the  body.  This  opinion  was  implicitly  credited  by  Boer- 
haave,  and  his  follower  Van  Swieten  ;2  and  in  many  cases  had  a 
decided  influence  on  surgical  practice  more  especially.  As  the  bladder 
consists  principally  of  membrane,  it  was  agreed  for  ages  by  lithoto- 
mists,  that  it  would  be  improper  to  cut  or  divide  it ;  and,  therefore,  to 
extract  the  stone  dilating  instruments  were  used,  which  caused  the  most 
painful  lacerations  of  the  parts.  Haller3  considered  tendons,  liga- 
ments, periosteum,  bones,  meninges  of  the  brain,  different  serous  mem- 
branes, arteries  and  veins,  entirely  insensible;  yet  we  know,  that  they 
are  exquisitely  sensible  when  attacked  with  inflammation.  One  of  the 
most  painful  affections  to  which  man  is  liable  is  the  variety  of  whitlow 
that  implicates  the  periosteum  ;  and  in  all  affections  of  the  bone  which 
inflame  or  press  forcibly  upon  that  membrane,  there  is  excessive  sensi- 
bility. It  would  appear,  that  the  possession  of  vessels  or  vascularity 
is  a  necessary  condition  of  the  sensibility  of  any  tissue. 

Many  parts,  too,  are  affected  by  special  irritants;  and,  after  they 
have  appeared  insensible  to  a  multitude  of  agents,  show  great  sensi- 
bility when  a  particular  irritant  is  applied.  Bichat  endeavoured  to 
elicit  the  sensibility  of  ligaments  in  a  thousand  ways,  and  without  suc- 
cess ;  but  when  he  subjected  them  to  distension  or  twisting,  they  im- 
mediately gave  evidence  of  it.  It  is  obvious,  that  before  we  determine 
that  a  part  is  insensible,  it  must  have  been  submitted  to  every  kind  of 
irritation.  M.  Adelon  affirms,  that  there  is  no  part  but  what  may  become 
painful  by  disease.  From  this  assertion  the  cuticle  might  be  excepted. 
If  we  are  right,  indeed,  in  our  view  of  its  origin  and  uses,  as  described 
hereafter,  sensibility  would  be  of  no  advantage  to  it ;  but  the  contrary. 
In  the  present  state,  then,  of  our  knowledge,  we  are  justified  in  assert- 
ing, that  bones,  cartilages,  and  membranes  are  not  sensible  to  ordi- 
nary external  irritants,  when  in  a  state  of  health, — or  in  other  words, 
that  we  are  not  aware  of  the  irritants,  which  are  adapted  to  elicit  their 
sensibility. 

That  sensibility  is  due  to  the  nerves  distributed  to  a  part  is  so  gene- 
rally admitted  as  not  to  require  comment.  Dr.  Todd4  has  affirmed, 
that  the  anatomical  condition  necessary  for  the  developement  of  the 
greater  or  less  sensibility  in  an  organ  or  tissue  is  the  distribution  in  it 
of  a  greater  or  less  number  of  sensitive  nerves ;  and  that  the  anato- 
mist can  determine  the  degree  to  which  this  property  is  enjoyed  by  any 

1  Foesii  CEconom.  Hippocr.  "  Nsypov."  a  Aphorism.  164,  and  165,  and  Comment. 

3  Oper.  Minor.,  torn.  i. 

4  Art.  Sensation,  Cyclopedia  of  Anat.  and  Physiology,  pt.  xxxiv.  p.  511,  Jan.,  1849. 


ACCOMPLISHED  IN  THE  ENCEPHALON.  113 

tissue  or  organ  by  the  amount  of  nervous  supply,  which  his  research 
discloses.  It  may  well  be  doubted,  however,  whether  such  sensibility 
be  by  any  means  in  proportion  to  the  number  of  nerves  received  by 
a  part.  Nay,  some  parts  are  acutely  sensible  in  disease  into  which 
nerves  cannot  be  traced.  To  explain  these  cases,  Reil1  supposed  that 
each  nerve  is  surrounded  at  its  termination  by  a  nervous  atmosphere, 
by  which  its  action  is  extended  beyond  the  part  in  which  it  is  seated. 
This  opinion  is  a  mere  creation  of  the  imagination.  We  have  no  evi- 
dence of  any  such  atmosphere  ;  and  it  is  more  philosophical  to  presume, 
that  the  reason  we  do  not  discover  nerves  may  be  owing  to  the  imper- 
fection of  our  vision. 

We  may  conclude,  that  the  action  of  impression  occurs  in  the  nerves 
of  the  part  to  which  the  sensation  is  referred.  As  to  the  mode  in 
which  this  impression  affects  them  we  are  ignorant.  Microscopic  ex- 
amination of  the  nerves  connected  with  sensory  organs  would  seem  to 
show,  that  they  come  into  relation  with  a 
substance  very  analogous  to  the  gray  mat-  Fig-  33- 

ter  of  the  encephalon,  although  its  elements 
are  somewhat  differently  arranged.  The 
nervous  fibres,  too,  appear  to  terminate  in 
close  approximation  with  a  vascular  plexus ; 
and  a  granular  structure  is  present,  which — 
as  in  the  cortical  portion  of  the  brain — 
seems  to  be  intermediate.  This  point  has 
been  regarded  as  the  origin  of  the  afferent 
fibres ;  and  as  the  seat  of  changes  made  by  Distribution  of  Capillaries  at  the 

external  impressions.2  surface  of  the  skin  of  the  finger. 

The  facts  mentioned  show,  that  the  ac- 
tion of  perception  takes  place  in  the  encephalon  ;  and  that  the  nerve  is 
merely  the  conductor  of  the  impression  between  the  part  impressed 
and  that  organ.  If  a  ligature  be  put  round  a  nerve,  sensation  is  lost 
below  the  ligature ;  but  it  is  uninjured  above  it.  If  two  ligatures  be 
applied,  sensibility  is  lost  in  the  portion  included  between  the  liga- 
tures ;  but  it  is  restored  if  the  upper  ligature  be  removed.  The  spinal 
marrow  is  sensible  along  the  whole  of  its  posterior  column,  but  it  also 
acts  only  as  a  conductor  of  the  impression.  M.  Flourens  destroyed  the 
spinal  cord  from  below,  by  slicing  it  away ;  and  found,  that  sensibility 
was  gradually  extinguished  in  the  parts  corresponding  to  the  destroyed 
medulla,  but  that  the  parts  above  evidently  continued  to  feel.  Per- 
ception, therefore,  occurs  in  the  encephalon ;  and  not  in  the  whole,  but 
in  some  of  its  parts.  Many  physiologists — Haller,  Lorry,  Rolando,  and 
Elourens3 — sliced  away  the  brain,  and  found  that  the  sensations  continued 
until  the  knife  reached  the  level  of  the  corpora  quadrigemina ;  and,  again, 
it  has  been  found,  that  if  the  spinal  cord  be  sliced  away  from  below 
upwards,  the  sensations  persist  until  we  reach  the  medulla  oblongata. 

1  Exercitat.  Anatom.  Fascic.,  i.  p.  28,  and  Archiv.  fur  die  Physiologic,  B.  iii. 

9  Carpenter,  Human  Physiology,  p.  85,  Lond.,  1842. 

3  Rolando,  Saggio  sopra  la  vera  Struttura  del  Cervello,  Sassari,  1809;  and  Flourens,  Re- 
cherches  Experimental  sur  les  Proprietes  et  les  Fonctions  du  Systeme  Nerveux,  &c.,  2de 
edit.,  Paris,  1842. 
VOL.  I. — 8 


114  SENSATIONS. 

It  is,  then,  between  these  parts,  that  we  must  place  the  cerebral  organs 
of  the  senses,  and  it  is  with  this  part  of  the  cephalo-spinal  axis,  that 
the  nerves  of  the  senses  are  actually  found  to  communicate.  Mr. 
Lawrence1  saw  a  child  with  no  more  encephalon  than  a  bulb,  which 
was  a  continuation  of  the  medulla  spinalis,  for  about  an  inch  above 
the  foramen  magnum,  and  with  which  all  the  nerves  from  the  fifth  to 
the  ninth  pair  were  connected.  The  child's  breathing  and  temperature 
,were  natural;  it  discharged  urine  and  faeces;  took  food,  and  at  first 
moved  very  briskly.  It  lived  four  days. 

If  we  divide  the  posterior  roots  of  the  spinal  nerves  and  the  fifth 
pair,  general  sensibility  is  lost ;  but  if  we  divide  the  nerves  of  the 
senses,  we  destroy  only  their  functions.  We  can  thus  understand  why, 
after  decapitation,  sensibility  may  remain  for  a  time  in  the  head. 
It  is  instantly  destroyed  in  the  trunk,  owing  to  the  removal  of  all  com- 
munication with  the  encephalon ;  but  the  fifth  pair  is  entire,  as  well  as 
the  nerves  of  the  organs  of  the  senses.  Death  must  of  course  follow 
almost  instantaneously  from  loss  of  blood ;  but  there  is  doubtless 
an  appreciable  interval  during  which  the  head  may  continue  to  feel ; 
or,  in  other  words,  during  which  the  external  senses  may  act.2  M. 
Julia  Fontanelle3  has  indeed  concluded,  from  a  review  of  all  the  obser- 
vations made  on  this  matter,  that,  contrary  to  the  common  opinion, 
death  by  the  guillotine  is  one  of  the  most  painful ;  that  the  pains  of 
decollation  are  horrible,  and  endure  even  until  there  is  an  entire  ex- 
tinction of  animal  heat  !  It  need  scarcely  be  said,  that  all  these  infer- 
ences are  imaginative,  and  perhaps  equally  fabulous  with  the  oft-told 
story  of  Charlotte  Corday  scowling  at  the  executioner  after  her  head 
was  removed  from  her  body  by  the  guillotine ;  and  this  conclusion  is 
strongly  confirmed  by  the  results  of  experiments  on  a  robber — who  was 
beheaded  with  the  sword — by  Drs.  BischofF,  Heerman,  and  Jolly,  who 
inferred  that  consciousness  must  have  ceased  instantaneously.4  But  if 
such  be  the  case  with  man,  it  most  assuredly  is  not  so  with  the  inferior 
animals.  Ample  evidence  will  be  afforded  hereafter  to  show,  that 
both  sensation  and  volition  may  persist  in  the  rattlesnake  and  alligator 
long  after  the  head  has  been  removed  from  the  body.  Singular  facts  in 
regard  to  the  latter  animal  have  been  recorded  by  Dr.  Leconte,5  and 
more  recently,  by  Dr.  Dowler,6  of  New  Orleans. 

It  has  been  remarked,  that  the  cerebral  hemispheres  may  be  sliced 
away  without  abolishing  the  senses.  The  experiments  of  Rolando  and 
Flourens,  which  have  been  repeated  by  M.  Magendie,  show,  however, 
that  the  sight  is  an  exception ; — that  it  is  lost  by  their  removal.  If  the 
right  hemisphere  be  sliced  away,  the  sight  of  the  left  eye  is  lost;  and 
conversely; — one  of  the  facts  that  prove  the  decussation  of  the  optic 

1  Medico  Chirurg.  Transact.,  v.  166. 

2  Berard,  Rapports  du  Physique  et  du  Moral,  p.  93,  Paris,  1823. 

3  Phoebus,    Art.  Enthauptung,    in    Encyclopad.  Worterb.  der  Medicin.  Wissenchaft.  xi. 
204,  Berlin,  1835. 

4  A  condensed  account  of  Dr.  BischofTs  Remarks,  from  Mailer's  Archiv.,  by  S.  L.  L.  Big. 
ger,  is  in  the  Dublin  Journal  of  Medical  iSoience,  Sept.,  1839,  p.  1. 

5  New  York  Journal  of  Medicine,  for  Nov.,  1845,  p.  335,  and  Sir  Charles  Lyell,  Travels 
in  North  America,  Amer.  edit.,  i.  237.     New  York,  1849. 

6  Contributions  to  Physiology,  New  Orleans.  1849,  from  New  Orleans  Journal  of  Medi- 
cine. 


SENSORY  GANGLIA. 


115 


Fig.  34. 


nerves.  The  experiments  of  these  gentlemen  show,  that  vision,  more 
than  the  other  senses,  requires  a  connexion  with  the  organ  of  the  intel- 
lectual faculties — the  cerebral  hemispheres;  and  this,  as  M.  Magendie 
has  ingeniously  remarked,  because  vision  rarely  consists  in  a  single  im- 
pression made  by  light,  but  is  connected  with  an  intellectual  process, 
by  which  we  judge  of  the  distance,  size,  shape,  &c.,  of  bodies.  It  has 
been  well  suggested  and  maintained  by  Dr. 
Carpenter,1  that  whilst  the  cerebral  ganglia 
are  the  organs  of  the  higher  intellectual  and 
moral  acts ;  there  is  a  series  of  ganglia,  con- 
nected with  the  reception  of  impressions 
from  without,  which  are  seated  near  the  base 
of  the  brain,  and  are  hence,  termed  by  him 
sensory  ganglia.  As  we  descend  in  the  ani- 
mal scale,  these  ganglia  become  more  marked; 
whilst  the  cerebral  hemispheres  become  less 
and  less;  until  ultimately  the  animal  appears 
to  have  its  encephalic  organs  limited  almost 
wholly  to  those  that  are  concerned  in  the 
reception  of  impressions  from  without,  and 
the  originating  of  motor  impulsions  from 
within.  These  ganglia  are  seated  at  the 
base  of  the  brain:  from  the  origin  of  the 
auditory  nerves  to  those  of  the  olfactory. 


Brain  of  Squirrel,  laid  open. 

The  hemispheres,  B,  drawn  to 
either  side  to  show  the  subjacent 
parts,  c.  The  optic  lobes.  D.  Cerebel- 
lum, thai.  Thalamus  opticus.  c  s. 
Corpus  striatum. 


Fig.  35. 


Fig.  36. 
Pike. 


Brain  of  Turtle. 

A.  Olfactive  ganglia.    B.  Cerebral  hemi- 
spheres, c.  Optic  ganglia.  D.  Cerebellum. 


Brains  of  Fishes. 

..  Olfactive  lobes  or  ganglia.    B.  Cerebral  hemi- 
spheres,    c.  Optic  lobes.   D.  Cerebellum. 


Dr.  Carpenter  is  disposed  to  regard  the  optic  thalami  as  ganglia  for  the 
reception  of  tactile  impressions,  and  the  corpora  striata  as  ganglia  cori- 

1  Principles  of  Human  Physiology,  4th  Amer.  edit.,  p.  370,  Philad.,  1850. 


116  SENSATIONS. 

nected  with  motion.  He  esteems  them  to  be,  moreover,  the  centre  of 
consensual  or  instinctive  movements,  or  of  automatic  movements  involv- 
ing sensation; — a  topic  which  will  receive  attention  elsewhere. 

Having  arrived  at  a  knowledge  that  in  man  and  the  upper  class  of 
animals,  perception  is  effected  in  a  part  of  the  encephalon,  our  acquaint- 
ance with  this  mysterious  process  ends.  We  know  not,  and  we  probably 
never  shall  know,  the  action  of  the  brain  in  accomplishing  it.  It  is  cer- 
tainly not  allied  to  any  physical  phenomenon;  and  if  we  are  ever  justi- 
fied in  referring  functions  to  the  class  of  organic  and  vital,  it  may  be 
those,  that  belong  to  the  elevated  phenomena,  which  have  to  be  con- 
sidered under  the  head  of  animal  functions.  We  know  them  only  by 
their  results :  yet  we  are  little  better  acquainted  with  many  topics  of 
physical  inquiry; — with  the  nature  of  the  electric  fluid  for  example. 

The  organs,  then,  that  form  the  media  of  communication  between 
the  parts  impressed  and  the  brain,  are  the  nerves  and  spinal  marrow. 
M.  Broussais,1  indeed,  affirmed,  that  every  stimulation  capable  of  causing 
perception  in  the  brain,  runs  through  the  whole  of  the  nervous  system 
of  relation;  and  is  repeated  in  the  mucous  membranes,  whence  it  is 
again  returned  to  the  centre  of  perception,  which  judges  of  it  according 
to  the  view  of  the  viscus  to  which  the  mucous  membrane  belongs;  and 
adapts  its  action  as  it  perceives  pleasure  or  pain. 

We  are  totally  unacquainted  with  the  material  character  of  the  fluid, 
which  passes  with  the  rapidity  of  lightning  along  nervous  cords;  and 
it  is  as'  impossible  to  describe  its  mode  of  transmission,  as  it  is  to  depict 
that  of  the  electric  fluid  along  a  conducting  wire.  As  in  the  last  case, 
we  are  aware  of  such  transmission  only  by  the  result.  Still,  hypotheses, 
as  on  every  obscure  matter  of  inquiry,  have  not  been  wanting.2  Of 
these,  three  are  chiefly  deserving  of  notice.  The  first,  of  greatest  anti- 
quity, is,  that  the  brain  secretes  a  subtile  fluid,  which  circulates  through 
the  nerves,  called  animal  spirits,  and  which  is  the  medium  of  commu- 
nication between  the  different  parts  of  the  nervous  system ;  the  second 
regards  the  nerves  as  cords,  and  the  transmission  as  effected  by  means 
of  the  vibrations  or  oscillations  of  these  cords;  whilst  the  third  ascribes 
it  to  the  operation  of  electricity. 

1.  The  hypothesis  of  animal  spirits  has  prevailed  most  extensively. 
It  was  the  doctrine  of  Hippocrates,  Galen,  the  Arabians,  and  of  most 
of  the  physicians  of  the  last  centuries.  Des  Cartes3  adopted  it  energe- 
tically ;  and  was  the  cause  of  its  more  extensive  diffusion.  The  great 
grounds  assigned  for  the  belief  were; — first,  that  as  the  brain  receives 
so  much  more  blood  than  is  necessary  for  its  own  nutrition,  it  must  be 
an  organ  of  secretion;  secondly,  that  the  nerves  seem  to  be  a  conti- 
nuation of  the  tubular  matter  of  the  brain;  and  it  has  already  been 
remarked,  that  Malpighi  considered  the  cortical  neurine  to  be  follicular, 
and  the  medullary  to  consist  of  secretory  tubes.  It  was  not  unnatural, 
therefore,  to  regard  the  nerves  as  vessels  for  the  transmission  of  these 
spirits.  As,  however,  the  animal  spirits  had  never  been  met  with  in  a 

1  Traite  de  Physiologic,  &c.,  Paris,  1822;  or  translation  by  Drs.  Bell  and  La  Roche,  3d 
Amer.  edit.,  p  63,  Philad.,  1832. 

a  Fletcher's  Rudiments  of  Physiology,  P.  ii.  b.  p.  68,  Edinb.,  1836. 
3  Tractatus  de  Homine,  p.  17,  Lugd.  Bat.,  1604. 


HYPOTHESIS  OF  VIBRATIONS.  117 

tangible  shape,  ingenuity  was  largely  invoked  in  surmises  regarding 
their  nature;  and,  generally,  opinions  settled  down  into  the  belief  that 
they  were  of  an  ethereal  character.  For  the  various  views  that  have 
been  held  upon  the  subject,  the  reader  is  referred  to  Haller,1  who  was 
himself  an  ardent  believer  in  their  existence,  and  has  wasted  much  time 
and  space  in  an  unprofitable  inquiry  into  their  nature.  The  truth  is, 
that  we  have  not  sufficient  evidence,  direct  or  indirect,  of  the  existence 
of  any  nervous  fluid  of  the  kind  described.  Allusion  has  been  already 
made  to  the  views,  in  regard  to  the  tubular  structure  of  the  white  neu- 
rine,  admitted  by  most  observers:  Berres,2  affirms  that  the  forms,  which 
the  nervous  substance  assumes  under  the  magnifying  glass,  can  only  be 
compared  to  those  of  canals  and  vesicles;  but  whether  they  be  hollow  he 
does  not  attempt  to  decide.  M.  Raspail3  has  concluded,  that  the  opinion 
of  their  being  hollow,  and  containing  a  fluid,  is  unsupported  by  facts; 
for  although  he  admits,  that  M.  Bogros  succeeded  in  injecting  the  nerves 
with  mercury,  he  thinks  that  the  passage  of  the  metal  along  them  was 
owing  to  its  having  forced  its  way  by  gravity.  Modern  histologists 
accord  with  great  unanimity  as  to  the  tubular  structure  of  the  medullary 
neurine ;  but  we  have  no  reason  for  considering  the  brain  the  organ  of 
any  ponderable  secretion.  Yet  the  term  "animal  spirits,"  although 
their  existence  is  not  now  believed,  is  retained  in  popular  language. 
We  speak  of  a  man  who  has  a  great  flow  of  animal  spirits,  but  without 
regarding  the  hypothesis  whence  the  expression  originated. 

The  term  nervous  fluid  is  still  used  by  physiologists.  By  this,  how- 
ever, they  simply  mean  the  medium  of  communication  or  of  convey- 
ance, by  which  the  nervous  influence  is  carried  with  the  rapidity  of 
lightning  from  one  part  of  the  system  to  another ;  but  without  com- 
mitting themselves  as  to  its  character  ; — so  that,  after  all,  the  idea  of 
animal  spirits  is  in  part  retained,  although  the  term,  as  applied  to  the 
nervous  fluid  is  generally  exploded.  Dr.  Good4  directly  admits  them 
under  the  more  modern  title ;  Mr.  J.  W.  Earle5  firmly  believes  in  the 
existence  of  a  circulation  in  the  nervous  system, — and  it  is  not  easy  to 
conceive,  that  the  brain  does  not  possess  the  function  of  elaborating 
some  fluid, — galvanoid  or  other, — which  is  the  great  agent  in  the  nerv- 
ous function. 

2.  The  hypothesis  of  vibrations  is  ancient,  but  has  been  by  no  means 
as  generally  admitted  as  the  last.  Among  the  moderns,  it  has  received 
the  support  of  Condillac,6  Hartley,7  Blumenbach,8  and  others ;  some 
supposing,  that  the  nervous  matter  itself  is  thrown  into  vibrations ; 
others,  that  an  invisible  and  subtile  ether  is  diffused  through  it,  which 
acts  the  sole  or  chief  part.  As  the  latter  is  conceived,  by  many,  to 
be  the  mode  in  which  electricity  is  transmitted  along  conducting  wires, 

1  Elementa  Physiologise,  x.  8. 

3  Oesterreich.  Med.  Jahrbuch.,  B.  ix.,  cksd  in  Brit,   and  Foreign  Med.  Review,  January, 
1838,  p.  219.  3  Chimie  Organique,  p.  218.     Paris,  1833. 

4  Study  of  Medicine,  with  Notes  by  S.  Cooper,  Doane's  Amer.  edit.,  vol.  ii.,  in  Proem  to 
Class  iv.  Neurotica,  New  York,  1835. 

5  New  Exposition  of  the  Functions  of  the  Nerves,  by  James  William  Earle,  Part.  I.   Lon- 
don, 1833.  6  CEuvres,  Paris,  1822. 

'  Observations  on  Man,  &c.,  chap.  i.  sect.  1.     London,  1791. 
8  Institutiones  Physiologicse,  §  226. 


118  SENSATIONS. 

it  is  not  liable  to  the  same  objections  as  the  former.  Simple  inspec- 
tion, however,  of  a  nerve  at  once  exhibits,  that  it  is  incapable  of  being 
thrown  into  vibrations.  It  is  soft ;  never  tense  ;  always  pressed  upon 
in  its  course ;  and,  as  it  consists  of  filaments  destined  for  very  differ- 
ent functions,— sensation,  voluntary  and  involuntary  motion,  &c. — we 
cannot  conceive  how  one  of  these  filaments  can  be  thrown  into  vibra- 
tion without  the  effect  being  extended  laterally  to  others ;  and  great 
confusion  being  thus  induced.  The  view  of  Dr.  James  Stark1  in  regard 
to  the  structure  of  the  tubes  of  the  nerves,  has  led  him  to  adopt  a 
modification  of  the  theory  of  vibrations.  Believing,  that  the  matter 
which  fills  the  tubes  is  of  an  oily  nature, — and  as  oily  substances  are 
known  to  be  non-conductors  of  electricity ;  and  farther,  as  the  nerves  have 
been  shown  by  the  experiments  of  Bischoff  to  be  amongst  the  worst 
possible  conductors  of  electricity, — he  contends,  that  the  nervous 
energy  can  be  neither  electricity  nor  galvanism,  nor  any  property  re- 
lated to  them ;  and  he  conceives,  that  the  phenomena  are  best  explained 
on  the  hypothesis  of  undulations  or  vibrations  propagated  along  the 
course  of  the  tubes  by  the  oily  globules  they  contain. 

3.  The  last  hypothesis  is  of  later  date, — subsequent  to  the  disco- 
veries in  animal  electricity.  The  rapidity  with  which  sensation  and 
volition  are  communicated  along  the  nerves,  could  not  fail  to  suggest  a 
resemblance  to  the  mode  in  which,  the  electric  and  galvanic  fluids  fly 
along  conducting  wires.  Yet  the  great  support  of  the  opinion  was  in 
the  experiments  of  Dr.  Wilson  Philip2  and  others,  from  which  it  ap- 
peared, that  if  the  nerve  proceeding  to  a  part  be  destroyed, — and  the 
secretion,  which  ordinarily  takes  place  in  the  part  be  thus  arrested, — 
the  secretion  may  be  restored  by  causing  the  galvanic  fluid  to  pass 
from  one  divided  extremity  of  the  nerve  to  the  other.  The  experi- 
ments, connected  with  secretion,  will  be  noticed  more  at  length  here- 
after. It  will  likewise  be  shown,  that  in  the  effect  of  galvanism  upon 
the  muscles,  there  is  a  like  analogy  ; — that  the  muscles  may  be  made 
to  contract  for  a  length  of  time  after  the  death  of  the  animal,  and 
even  when  a  limb  is  removed  from  the  body,  on  the  application  of  the 
galvanic  stimulus;  whilst  comparative  anatomy  exhibits  to  us  great 
development  of  nervous  structure  in  electrical  animals,  which  astonish 
us  by  the  intensity  of  the  electric  shocks  they  are  capable  of  commu- 
nicating. 

Physiologists  of  the  present  day  generally,  we  think,  accord  with 
the  electrical  hypothesis.  The  late  Dr.  Young,3  so  celebrated  for  his 
knowledge  in  numerous  departments  of  science,  adopted  it  prior  to 
the  interesting  experiments  of  Dr.  Philip ;  and  Mr.  Abernethy,4  whilst 
he  is  strongly  opposing  the  doctrines  of  materialism,  goes  so  far  as 
to  consider  some  subtile  fluid  not  merely  as  the  agent  of  nervous 
transmission,  but  as  forming  the  essence  of  life  itself.  By  putting  a 
ligature,  however,  around  a  nervous  trunk,  its  functions,  as  a  con- 
ductor of  nervous  influence,  are  paralyzed,  whilst  it  is  still  capable 

1  Proceedings  of  the  Royal  Society,  No.  56,  Lond.,  1843. 

2  Philosoph.  Trans,  for  1815,  and  Lond.  Med.  Gazette  for  March  18,  and  March  25,  1837. 

3  Med.  Literature,  p.  93.     Lond.,  1813. 

4  Physiological  Lectures,  exhibiting  a  view  of  Mr.  Hunter's  Physiology,  &c.     Lond.,  1817  . 


EXTERNAL  SENSATIONS.  119 

of  conveying  electricity;  and,  moreover,  when  wires  are  inserted 
into  an  exposed  nerve,  and  their  opposite  extremities  are  attached  to 
the  galvanometer,  no  movement  of  the  needle  has  been  observed  by 
Person,  Muller,  Matteucci,  and  by  Todd  and  Bowman.1  Dr.  Bostock,2 
too,  has  remarked,  that  before  the  electrical  hypothesis  can  be  con- 
sidered proved,  two  points  must  be  demonstrated;  first,  that  every 
function  of  the  nervous  system  may  be  performed  by  the  substitution 
of  electricity  for  the  action  of  nerves ;  and  secondly,  that  all  nerves 
admit  of  this  substitution.  This  is  true,  as  concerns  the  belief  in  the 
identity  of  the  nervous-  and  electrical  fluids ;  but  we  have,  even  now, 
evidence  sufficient  to  show  their  similarity  ;  and  that  we  are  justified 
in  considering  the  nervous  fluid  to  be  electroid  or  galvanoid  in  its  na- 
ture, emanating  from  the  brain  by  some  action  unknown  to  us,  and 
transmitted  to  the  different  parts  of  the  system  to  supply  the  expendi- 
ture, which  must  be  constantly  taking  place. 

Reil,3  Senac,4  Prochaska,  Scarpa,5  and  others  are  of  opinion,  that 
the  nervous  agency  is  generated  throughout  the  nervous  system ;  and 
that  every  part  derives  sensation  and  motion  from  its  own  nerves.  We 
have  satisfactorily  shown,  however,  that  a  communication  with  the  ner- 
vous centres  is  absolutely  necessary  in  all  cases,  and  that  we  can  imme- 
diately cut  off  sensation  in  the  portion  of  a  nerve  included  between  two 
ligatures,  and  as  instantly  restore  it  by  removing  the  upper  ligature, 
and  renewing  the  communication  with  the  brain. 

a.  External  Sensations. 

The  external  sensations  are  those  perceptions  which  are  occasioned 
by  the  impressions  of  bodies  external  to  the  part  impressed.  They  are 
not  confined  to  impressions  made  by  objects  external  to  us.  The  hand 
applied  to  any  part  of  the  body;  any  two  of  its  parts  brought  into  con- 
tact; the  presence  of  its  own  secretions  or  excretions  may  equally  excite 
them.  M.  Adelon,6  has  divided  them  into  two  orders — first,  the  senses, 
properly  so  called,  by  the  aid  of  which  the  mind  acquires  its  notion  of 
external  bodies,  and  of  their  different  qualities ;  and  secondly,  those  sen- 
sations which  are  still  caused  by  the  contact  of  some  body ;  and  yet 
afford  no  information  to  the  mind. 

It  is  by  the  external  senses,  that  we  become  acquainted  with  the 
bodies  that  surround  us.  They  are  the  instruments  by  which  the  brain 
receives  its  knowledge  of  the  universe ;  but  they  are  only  instruments, 
and  cannot  be  considered  as  the  sole  regulators  of  the  intellectual  sphere 
of  the  individual.  This  we  shall  see  is  dependent  upon  another  and 
still  higher  nervous  organ, — the  brain. 

The  external  senses  are  generally  considered  to  be  five  in  number ; 
for,  although  others  have  been  proposed,  they  may  perhaps  be  reduced 
to  some  modification  of  these  five, — tact  or  touch,  taste,  smell,  hearing, 

1  The  Physiological  Anatomy  and  Physiology  of  Man,  p.  242.     Lond.,  1845. 

2  An  Elementary  System  of  Physiology,  3d  edit.,  p.  148.     Lond.,  1836. 

3  De  Structura  Nervorum,  Hal.,  1796. 

4  Traite  de  la  Structure  du  Coaur,  &c.,  liv.  iv.  chap.  8.     Paris,  1749. 
s  Tabulse  Neurologicae.     Ticin.,  1794,  §  22. 

«  Physiologic  de  1'  Homme,  torn.  i.  p.  259,  2de  edit.     Paris,  1'829. 


120  EXTEBNAL  SENSATIONS. 

and  vision.  All  these  have  some  properties  in  common.  They  are 
situate  at  the  surface  of  the  body,  so  as  to  be  capable  of  being  acted 
upon  with  due  facility  by  external  bodies.  They  all  consist  of  two  parts  : 
— the  one,  physical,  -which  modifies  the  action  of  the  body,  that  causes 
the  impression;  the  other  nervous  or  vital,  which  receives  the  impres- 
sion, and  conveys  it  to  the  brain.  In  the  eye  and  the  ear,  we  have 
better  exemplifications  of  this  distinction  than  in  the  other  senses.  The 
physical  portion  of  the  eye  is  a  true  optical  instrument,  which  modifies 
the  light,  before  it  impinges  upon  the  retina.  A  similar  modification 
is  produced  by  the  physical  portion  of  the  ear  on  the  sonorous  vibra- 
tions, before  they  reach  the  auditory  nerve ;  whilst  in  the  other  senses, 
the  physical  portion  forms  a  part  of  the  common  integument  in  which 
the  nervous  portion  is  seated,  and  cannot  be  easily  distinguished.  Some 
of  them,  again,  as  the  skin,  tongue,  and  nose,  are  symmetrical,  that  is, 
composed  of  two  separate  and  similar  halves,  united  at  a  median  line. 
Others,  as  the  eye  and  ear,  are  in  pairs;  and  this,  partly  perhaps,  to 
enable  the  distances  of  external  objects  to  be  appreciated.  We  shall 
find,  at  least,  that  there  are  certain  cases,  in  which  both  the  organs  are 
necessary  for  accurate  appreciation. 

Two  of  the  senses — vision  and  audition — have,  respectively,  a  nerve 
of  special  sensibility;  and,  until  of  late  years,  the  smell  has  been 
believed  to  be  similarly  situate.  In  the  present  state  of  our  knowledge, 
we  cannot  decide  upon  the  precise  nerve  of  taste,  although  it  will  be 
seen  that  a  plausible  opinion  may  be  indulged  on  the  subject.  The 
general  sense  of  touch  or  feeling  is  certainly  seated  in  the  nerves  of 
general  sensibility  connected  with  the  posterior  roots  of  the  spinal 
nerves  and  the  fifth  encephalic  pair ;  and  according  to  some,1  in  the 
glosso-pharyngeal  and  pneumogastric  nerves.  The  other  senses  seem 
intimately  connected  with  one  nerve  of  general  sensibility, — the  fifth 
pair.  This  is  especially  the  case  with  those  senses  that  possess  nerves 
of  special  sensibility ;  for,  if  the  fifth  pair  be  cut,  the  function  is 
abolished  or  impaired,  although  the  nerve  of  special  sensibility  may 
remain  entire. 

Being  instruments  by  which  the  mind  becomes  acquainted  with  ex- 
ternal bodies,  it  is  manifestly  of  importance,  that  the  senses  should  be 
influenced  by  volition.  Most  of  them  are  so.  The  touch  has  the  plia- 
ble upper  extremity,  admirably  adapted  for  the  purpose.  The  tongue 
is  movable  in  almost  every  direction.  The  eye  can  be  turned  by  its 
own  immediate  muscles  towards  objects  in  almost  all  positions.  The 
ear  and  the  nose  possess  the  least  individual  motion;  but  the  last  four, 
being  seated  in  the  head,  are  capable  of  being  assisted  by  the  muscles 
adapted  for  its  movements. 

All  the  senses  may  be  exercised  passively  and  actively.  By  direct- 
ing the  attention,  we  can  render  the  impression  more  vivid;  and  hence 
the  diiference  between  simply  seeing  or  passive  vision,  and  looking 
attentively ;  between  hearing  and  listening  ;  smelling  and  snuffing ; 
touching  and  feeling  closely.  It  is  to  the  active  exercise  of  the  senses, 
that  we  are  indebted  for  many  of  the  pleasures  and  comforts  of  social 
existence.  Yet,  to  preserve  the  senses  in  the  vigour  and  delicacy, 

1  Longet,  Traite  de  Physiologic,  ii.  176,  note.     Paris,  1850. 


SENSE  OF  TOUCH.  121 

•which  they  are  capable  of  acquiring  by  attention,  the  impressions  must 
not  be  too  constantly  or  too  strongly  made.  The  occasional  use  of  the 
sense  'of  smell,  under  the  guidance  of  volition,  may  be  the  test  on  which 
the  chemist,  perfumer,  or  wine-merchant,  may  rely  in  the  discrimi- 
nation of  the  numerous  odorous  characteristics  of  bodies ;  but,  if  the 
olfactory  nerves  be  constantly,  or  too  frequently,  stimulated  by  excit- 
ants, of  this  or  any  other  kind,  dependence  can  no  longer  be  placed 
upon  them  as  a  means  of  discrimination.  The  maxim  that  "  habit 
blunts  feeling,"  is  true  only  in  such  cases  as  the  last.  Education  can. 
indeed,  render  it  extremely  acute/  Volition,  on  the  other  hand,  en- 
ables us  to  deaden  the  force  of  sensations.  By  corrugating  the  eye- 
brows and  approximating  the  eyelids,  we  can  diminish  the  quantity  of 
light  when  it  is  too  powerful.  We  can  breathe  through  the  mouth, 
when  a  disagreeable  odour  is  exhaled  around  us;  or  can  completely  shut 
off  its  passage  by  the  nostrils,  with  the  aid  of  the  upper  extremity. 
Over  the  hearing  we  have  less  command  as  regards  its  individual  ac- 
tion :  the  upper  extremity  is  here  always  called  into  service,  when  we 
desire  to  dimmish  the  intensity  of  any  sonorous  impression. 

Lastly.  It  is  a  common  observation,  that  the  loss  of  one  sense  occa- 
sions greater  vividness  in  others.  This  is  only  true  as  regards  the  senses 
that  administer  chiefly  to  the  intellect, — those  of  touch,  audition,  and 
vision,  for  example.  Those  of  smell  and  taste  may  be  destroyed  ;  and 
yet  the  more  intellectual  senses  may  be  uninfluenced.  In  the  singular 
condition  of  artificial  somnambulism  or  hypnotism,  the  author  has  seen 
the  various  senses  rendered  astonishingly  acute. 

The  cause  of  the  superiority  of  the  remaining  intellectual  senses, 
when  one  has  been  lost,  is  not  owing  to  any  superior  organization  in 
those  senses ;  but  is  another  example  of  the  influence  of  education. 
The  remaining  senses  are  exerted  attentively  to  compensate  for  thfc 
privation ;  and  they  become  surprisingly  delicate. 

"We  proceed  to  the  consideration  of  the  separate  senses,  beginning 
with  that  of  tact  or  touch,  because  it  is  most  generally  distributed,  and 
may  be  regarded  as  that  from  which  the  others  are  derived.  They  are 
all,  indeed,  modifications  of  the  sense  of  touch.  In  the  taste,  the  sapid 
body;  in  the  smell,  the  odorous  particle;  in  the  hearing,  the  sonorous 
vibration ;  and  in  the  sight,  the  particle  of  light,  must  impinge  upon 
or  touch  the  nervous  part  of  the  organ,  before  sensation  can,  in  any  of 
the  cases,  be  effected. 

SENSE  OF  TACT  OR  TOUCH — PALPATION. 

The  sense  of  tact  or  touch  is  the  general  feeling  or  sensibility,  pos- 
sessed by  the  skin  especially,  which  instructs  us  regarding  the  tempe- 
rature and  general  qualities  of  bodies.  By  some,  touch  is  restricted 
to  the  sense  of  resistance  alone ;  and  hence  they  have  conceived  it 
necessary  to  raise  into  a  distinct  sense  one  of  the  attributes  of  tact  or 
touch.  The  sense  of  heat,  for  example,  has  been  separated  from  tact ; 
but  although  the  appreciation  of  external  bodies  by  tact  or  touch  differs 

1  Berard,  Rapport  du  Physique  et  du  Moral,  p.  245;  Paris,  1823. 


122  SENSE  OF  TOUCH. 

— as  will  be  seen — in  some  respects  from  our  appreciation  of  their 
temperature,  its  consideration  properly  belongs  to  the  sense  we  are 
considering,  in  the  acceptation  here  given  to  it,  and  adopted  by  -all  the 
French  physiologists.  According  to  them,  tact  is  spread  generally  in 
the  organs,  and  especially  in  the  cutaneous  and  mucous  surfaces.  It 
exists  in  all  animals ;  whilst  touch  is  exercised  only  by  parts  evidently 
destined  for  that  purpose,  and  is  not  present  in  every  animal.  It  is 
nothing  more  than  tact  joined  to  muscular  contraction  and  directed 
by  volition.  So  that,  in  the  exercise  of  tact,  we  may  be  esteemed  pas- 
sive; in  that  of  touch,  active. 

The  organs  concerned  in  touch,  execute  other  functions  besides ;  and 
in  this  respect  touch  differs  from  the  other  senses.  Its  chief  organ, 
however,  is  the  skin  ;  and  hence  it  is  necessary  to  inquire  into  its  struc- 
ture, so  far  as  is  requisite  for  our  purpose. 

1.    ANATOMY  OF  THE  SKIN,  HAIR,  NAILS,  ETC. 

The  upper  classes  of  animals  agree  in  possessing  an  outer  envelope 
or  skin,  through  which  the  insensible  perspiration  passes ;  a  slight  de- 
gree of  absorption  takes  place;  the  parts  beneath  are  protected;  and 
the  sense  of  touch  is  accomplished.  In  man,  the  skin  is  generally 
considered  to  consist  of  four  parts, — the  cuticle,  rete  mucosum,  corpus 
papillare,  and  corium ;  but  when  reduced  to  its  simplest  expression,  the 
whole  of  the  integument,  with  the  mucous  membrane,  which  is  an  ex- 
tension of  it,  may  be  regarded  as  a  continuous  membrane,  more  or  less 
involuted,  more  or  less  modified  by  the  elementary  tissues  which  com- 
pose it  or  are  in  connexion  with  it,  and  within  which  all  the  rest  of  the 
animal  is  contained.  It  consists  of  two  elements — a  basement  tissue 
or  membrane,  composed  of  simple  membrane,  uninterrupted,  homo- 
geneous, and  transparent ;  covered  by  an  epithelium  or  pavement"  of 
nucleated  particles.1 

1.  The  epidermis  or  cuticle  is  the  outermost  layer.  It  is  a  dry, 
membranous  structure,  devoid  of  vessels  and  nerves  ;  yet  it  is  described 
by  some  recent  investigators  as  a  tissue  of  a  somewhat  complex  organiza- 
tion, connected  with  the  functions  of  exhalation  and  absorption ;  but  its 
vitality  is  regarded  to  be  on  a  par  with  that  of  vegetables.  The  absence 
of  nerves  proper  to  it  renders  it  insensible ;  it  is  coloured ;  and  exhales 
and  absorbs  in  the  manner  of  vegetables.  It  is,  so  far  as  we  know, 
entirely  insensible ;  resists  putrefaction  for  a  long  time,  and  may  be 
easily  obtained  in  a  separate  state  from  the  other  layers  by  maceration 
in  water.  It  is  the  thin  pellicle  raised  by  a  blister. 

The  cuticle  is  probably  a  secretion  or  exudation  from  the  true  skin, 
which  concretes  on  the  surface ;  becomes  dried,  and  affords  an  efficient 
protection  to  the  corpus  papillare  beneath.  It  is  composed,  according 
to  some,  of  concrete  albumen ;  according  to  others,  of  mucus ;  and  is 
pierced  by  oblique  pores  for  the  passage  of  hairs,  and  for  the  orifices  of 
exhalant  and  absorbent  vessels.  MM.  Breschet  and  Roussel  de  Vauzeme2 
affirm,  that  there  is  a  special  "llennogenous  or  mucifie  apparatus"  for 

1  Todd  and  Bowman,  The  Physiological  Anatomy  and  Physiology  of  Man,  p.  404,  London, 
1845. 
3  Nouvelles  Recherches  sur  la  Structure  de  la  Peau,  par  M.  Breschet,  Paris,  1835. 


ORGANS  OF  TOUCH. 


123 


the  secretion  of  this  mucous  matter,  composed  of  a  glandular  paren- 
chyma or  organ  of  secretion  situate  in  the  substance  of  the  derma,  and 


Fig.  38. 


Fig.  39. 


Vertical  Section  of  Epidermis,  from 
Palm  of  the  Hand. 

a.  Outer  portion,  composed  of  flattened 
scales,  b.  Inner  portion,  consisting  of 
nucleated  cells,  c.  Tortuous  perspiratory 
tube,  cut  across  by  the  section  higher  up. 
— Magnified  155  diameters. 


Surface  of  the  Skin  of  the  Palm, 
showing  the  Ridges,  Furrows, 
Cross-grooves,  and  Orifices  of  the 
Sweat-ducts. 

The  scaly  texture  of  the  cuticle  is 
indicated  by  the  irregular  lines  on  the 
surface. — Magnified  20  diameters. 


of  excretory  ducts,  which  issue  from  the  organ,  and  deposit  the  mucous 
matter  between  the  papillae ;  but  such  an  apparatus  is  not  usually 
admitted. 

It  is  probable,  that  the  cuticle  is  placed  at  the  surface  of  the  body, 
not  simply  to  protect  the  corpus  papillare  ;  but  to  prevent  the  constant 
imbibition  and  transudation  that  might  take  place  did  no  such  envelope 
exist.  It  exfoliates,  in  the  form  of  scales,  from  the  head  ;  and  in  large 
pieces,  from  every  part  of  the  body,  after  certain  cutaneous  diseases. 

M.  Flourens,1  who  has  closely  and  accurately  investigated  the  amv 
tomy  of  the  cutaneous  envelope,  considers  that  the  skin  of  the  coloured 
races  has  an  apparatus,  which  is  wanting  in  the  white  variety  of  th^ 
species.  This  apparatus  he  names  pigmental, — appareil  pigmental. 
It  is  composed  of  a  layer  (lame)  or  membrane  which  bears  the  pig- 
ment, and  of  the  pigment  itself.  Above  it  are  two  cuticles.  In  the 
white  variety  the  pigmental  apparatus  is  wanting,  and  consequently  the 
skin  is  more  simple  than  that  of  the  coloured  races.  The  skin  of  the 
white  variety  approaches  that  of  the  coloured  in  some  remarkable 
points.  First. — The  superficial  layer  or  lame  of  the  derma  is  every- 
where of  a  peculiar  appearance,  which  is  different  from  that  of  the 

1  Anatomie  Generale  de  la  Peau  et  des  Membranes  Muqueuses,  p.  34,  Paris,  1843. 


124 


SENSE  OF  TOUCH. 


Fig-  40- 


s  c 


Fig.  41. 


rest  of  the  derma.  Secondly. — Around  the  nipple  of  the  white  woman, 
the  superficial  layer  of  the  derma  presents  the  same  granular  appear- 
ance as  the  pigmental  membrane  of  the  coloured  races.  And  thirdly. 
—The  pigmental  layer  around  the  nipple  of  the  white  woman  is  placed, 
afc  in  the  coloured  races,  under  the  two  cuticles. 

Modern  histologists  consider  the 
epidermis  to  be  composed  of  a  series 
of  flattened,  scale-like  cells,  epider- 
mic cells,  which,  when  first  formed, 
are  of  a  spheroidal  shape;  but  gra- 
dually dry  up.  These  form  various 
layers.  According  to  Mi  Raspail,1  it 
Vertical  Section  of  the  Cuticle  from  the  consists  of  a  collection  of  vesicles  de- 
prived of  their  contents,  closely  ap- 

a.  Deep  cells,  loaded  with  pigment,  b.  Cells  ^i;^    fnrrpfVior     rlri^rl     nnrl    rlivnwnnflF 

at  a  higher  level,  paler  and  more   flattened.  pU^d    tOgCtner,   dried,  and    tillOWn 

c.  Cells  at  the  surface  scaly  and  colourless  as  in  the  form  of  brannj  SCaleS.  He 
in  the  white  races. — Magnified  300  diameters.  _  ,  »•  -  „  , 

regards  it  as  the  outer  layer  or  the 
corium. 

The  epidermoid  tissues  have  the 
simplest  structure  of  any  solids. 

Analysis  has  shown,  that  the  che- 
mical constitution  of  the  membranous 
epidermis  of  the  sole  of  the  foot  is 
the  same  as  that  of  the  compact  horny 
matter  of  which  nails,  hair,  and  wool 
are  composed. 

2.  The  corpus  or  rete  mucosum, 
rete  Malpighii,  mucous  web,  is  gene- 
rally regarded  as  constituting  the 
next  layer.  It  was  considered  by 
Malpighi  to  be  mucus,  secreted  by 
the  papillae,  and  spread  on  the  surface 
of  the  corpus  papillare,  to  preserve  it 
in  the  state  of  suppleness  necessary 
for  the  performance  of  its  functions. 

Section  of  the  Skin.  In  this  rete  mucosum,  the  colouring 

i.  cuticle,  showing  the  oblique  lamin.  of  ™tt™  °?  ^  dark  races  seems  to  ex- 

which  it  is  composed  and  the  imbricated  dis-  jgt.  it  IS  blaCK  in  the  AlHCan,  Or 
position  of  the  ridges  upon  its  surface.  2.  ,-,  ^  T\,-I  •  •  j 

kete  mucosum.  3.  TWO  of  the  quadrilateral  rather  in  the  Mmopian;  and 

papillary  masses  seen  in  the  palm  of  the  hand  rtr.lrt,-I¥.rv/l    i-r,    -fli/^    miilattn  2 

or   sole  of  the  foot ;    they  are    composed   of  COlOUred    in    TOO    mUiatlO. 

minute  conical  papillae.    4.   Deeper   layer  of  considers    it    tO    be    COniDOSed    of   four 

the  cutis,  the  corium.    5.  Adipose  vesicles ;  ,  .               .        r.                    ,      . 

showing  their  appearance  beneath  the  micro-  layei'SJ     DUt  thlS    notion    IS  not  admit- 

scope.    6.  Perspiratory  gland  with  its  spiral  ,11                 ±         •   A_           J                   i 

duct,  as  seen  in  the  palm  of  the  hand  or  sole  ted    by  anatOmiStS,   and   Scarcely  COn- 

of  the  foot.     7.  Another  perspiratory  gland  ppy-nc  flip    DTPSfnt    inouirv         1V4     Bre- 

scaip.  s.  TWO  hairs  from  the  scalp,  enclosed  schet  affirms,  that  there  is  a  special 

in  their  follicles;  their  relative  depth  in  the  ,  7       ./. 

skin  preserved.   9.  A  pair  of  sebaceous  glands      "  CnromatOgenOUS    Or     COlonjlC     appa- 

opening  by  short  e    rat^    f()r    producmg    the    Colouring 

1  Chimie  Organique,  p.  245,  Paris,  1833. 

a  Sir  E.  Home,  Lect.  on  Comp.  Anar.,  y.  278. 

3  Reclierches  Anatomiques  sur  le  Systeme  Cutane  de  rHomme,  Paris,  1811. 


ORGANS  OF  TOUCH.  125 

matter,  composed  of  a  glandular  or  secreting  parenchyma,  situate  a 
little  below  the  papillae,  and  presenting  special  excretory  ducts,  which 
pour  out  the  colouring  matter  on  the  surface  of  the  derma. 

Modern  observers  deny,  that  there  is  any  such  distinct  layer.  Some 
regard  it  as  the  deepest  or  most  recently  formed  part  of  the  cuticle. 
M.  Flourens1  considers,  that  the  term  corpus  mucosum  ought  to  be  re- 
placed by  that  of  pigmental  apparatus, — appareil  pigmental;  and  that 
the  term  rete  or  corpus  reticulare  in  the  signification  of  a  special 
network  situate  between  the  derma  and  the  two  cuticles,  ought  to  be 
banished  from  anatomy.  The  nature  of  the  pigment  will  be  referred 
to  hereafter,  under  SECRETION. 

The  rete  mucosum  is  considered  to  be  the  last  formed  portion  of  the 
cuticle. 

3.  The   corpus  papillare,  or  what   M.  Breschet  calls   the   "  neu- 
rothelic   or   mammillary   nervous  apparatus,'  is   seated  next   below 
the   rete   mucosum.      It   consists   of  a   collection  of  small   papillae, 
formed  by  the  extremities  of  nerves  and  vessels,  which,  after  having 
passed  through  the  corium  beneath,  are  grouped  in  small  pencils  or 
villi  on  a  spongy,  erectile  tissue.     These  pencils  are  disposed  in  pairs, 
and,    when   not   in   action,    are    relaxed,    but 

become  erect  when  employed  in  the  sense  of  Fis-  42. 

touch.  They  are  very  readily  seen,  when  the 
cutis  vera  is  exposed  by  the  action  of  a  blister; 
and  are  always  evident  at  the  palmar  surface 
of  the  hand,  and  especially  at  the  tips  of  the 
fingers,  where  they  have  a  concentric  arrange- 
ment. These  villi  are  sometimes  called  papillse. 
They  are,  in  reality,  prolongations  of  the  skin  ;  .  Papillae  of  the  palm,  the  Cu- 

s*  ,.1  TV/I-      TTII  9i  tide  being  detached.— Magni- 

and   consequently — as    M.    Flourens2   has  re-  fied  35  diameters. 

marked  —  uthe    pretended    corpus  papillare, 

taken  as  a  body,  apart  and  distinct  from  the  derma,  is  but  an  idle 

name." 

4.  The  corium,  cutis  vera,  derma,  true  skin,  is  the  innermost  layer 
of  the  skin.     It  consists  of  a  collection  of  dense  fibres,  intersecting 
each  other  in  various  directions ;  and  leaving  between  them  holes  for 
the  passage  of  vessels  and  nerves.     It  forms  a  firm  stratum,  giving 
the  -whole   skin   the  necessary  solidity  for  accomplishing  its  various 
ends  ;  and  consists  chiefly  of  gelatin  ; — hence  it  is  used  in  the  manu- 
facture of  glue.     Gelatin,  when  united  with  tannic  acid,  forms  a  sub- 
stance which  is  insoluble  in  water ;  and  it  is  to  this  combination  that 
leather  owes  the  properties  it  possesses.     The  hide  is  first  macerated 
in  lime-water  to  remove  the  cuticle  and  hairs,  and  leave  the  corium  or 
gelatin.     This  is  then  placed  in  an  infusion  of  oak  bark,  which  con- 
tains tannic  acid.     The  tannic  acid  and  the  skin  unite  ;  and  leather  is 
the  product. 

These  four  strata  constitute  the  skin,  as  it  is  commonly  called;  yet 
all  are  comprised  in  the  thickness  of  two  or  three  lines.  The  cutis 
vera  is  united  to  the  structures  below  by  areolar  tissue ;  and  this,  with 

1  Op.  cit.,  p.  38.  .  2  Op.  cit.,  p.  38. 


126 


SENSE  OF  TOUCH. 


the  layers  external  to  it,  forms  the  common  integument.  In  certain 
parts  of  the  body,  and  in  animals  more  particularly,  the  cutis  vera  is 
adherent  to  muscular  fibres,  inserted  more  or  less  obliquely.  These 
form  the  muscular  web,  mantle  or  panniculus  carnosus.  The  layer  is 
well  seen  in  the  hedge-hog  and  porcupine,  in  which  it  rolls  up  the  body, 
and  erects  the  spines;  and  in  birds,  raises  the  feathers.  In  man,  it  can 
hardly  be  said  to  exist.  Some  muscles,  however,  execute  a  similar  func- 
tion. By  the  occipito-frontalis,  many  persons  can  move  the  hairy  scalp ; 
and  by  the  dartos  the  skin  of  the  scrotum  can  be  corrugated.  These 
two  parts,  therefore,  act  as  panniculi  carnosi. 

In  the  skin  are  situate  numerous  sebaceous  follicles  or  crypts,  which 
separate  an  oily  fluid  from  the  blood,  and  pour  it  over  the  surface  to 
lubricate  and  defend  it  from  the  action  of  moisture.  They  are  most 
abundant,  where  there  are  folds  of  the  skin,  or  hairs,  or  where  the  sur- 
face is  exposed  to  friction.  We  can  generally  see  them  on  the  pavilion 
of  the  ear,  and  their  situation  is  often  indicated  by  small  dark  spots  on 
the  surface,  which,  when  pressed  between  the  fingers,  may  be  forced 
out  along  with  the  sebaceous  secretion,  in  the  form  of  small  worms. 
By  the  vulgar,  indeed,  these  are  considered  to  be  worms.  The  follicular 
secretions  will  engage  attention  hereafter. 


Fig.  43. 


Sections  of  Hair. 

a.  Transverse  section  of  a  hair  of  the 
head,  showing  the  exterior  cortex,  the  me- 
dulla or  pith  with  its  scattered  pigment, 
and  a  central  space  filled  with  pigment. 
b.  A  similar  section  of  a  hair,  at  a  point 
where  no  aggregation  of  pigment  in  the 
axis  exists,  c.  Longitudinal  section,  with- 
out a  central  cavity,  showing  the  imbrica- 
tion of  the  cortex,  and  the  arrangement  of 
the  pigment  in  the  fibrous  part.  d.  Sur- 
face, showing  the  sinuous  transverse  lines 
formed  by  the  edges  of  the  cortical  scales. 
d  .  A  portion  of  the  margin,  showing  their 
imbrication.  —  Magnified  loO  diameters. 
(Todd  and  Bowman.) 


The  consideration  of  the  hair  belongs 
naturally  to  that  of  the  skin.  The  roots 
are  in  the  form  of  bulbs;  taking  their 
origin  in  small  follicles  or  open  sacs, 
hair  follicles,  formed  by  the  inversion  of 
the  cutis,  and  lined  by  a  reflexion  of  the 
epidermis.  Around  each  bulb  there  are 
two  capsules,  the  innermost  of  which  is 
vascular  and  a  continuation  of  the  corium. 
The  hair  itself  consists  of  a  horny,  ex- 
ternal covering,  and  a  central  part,  called 
medulla  or  pith.  When  we  take  hold  of 
a  hair  by  the  base,  with  the  thumb  and 
forefinger,  and  draw  it  through  them  from 
the  root  towards  the  point,  it  feels  smooth 
to  the  touch;  but  if  we  draw  it  through 
from  the  point  to  the  root,  we  feel  the 
surface  rough;  arid  it  offers  considerable 
resistance.  It  is,  therefore,  concluded, 
that  the  hair  is  bristled,  imbricated  or 
consists  of  eminences  pointing  towards 
its  outer  extremity,  and  it  is  upon  this 
structure,  that  the  operation  of  felting  is 
dependent — the  hairs  being  mechanically 
entangled  and  retained  in  that  state  by 
the  inequalities  of  their  surface.  Certain 
observers  have,  however,  failed  in  detect- 
ing this  striated  appearance  by  the  aid 


HAIR. 


127 


of  the  microscope ;  and  Dr.  Bostock1  affirms,  that  he  had  an  opportunity 
of  viewing  the  human  hair,  and  the  hair  of  various  kinds  of  animals,  in 
the  excellent  microscope  of  Mr.  Bauer,  but  without  being  able  to  observe 


Thin  Layer  from  the  Scalp. 

a,  a.  Sebaceous  glands,    b.  Hair,  with 
its  follicle,  c.     (Gurlt.) 


Magnified  view  of  the  Root  of  the  Hair. 

(Kohlrausch.) 

a.  Stem  or  shaft  of  hair  cut  across,  b.  Inner,  and  e. 
Outer  layer  of  the  epidermic  lining  of  the  hair  follicle, 
called  also  the  root-sheath,  d.  Dermic  or  external  coat 
of  the  hair  follicle,  shown  in  part.  e.  Imbricated  scales 
about  to  form  a  cortical  layer  on  the  surface  of  the  hair. 


it.  Bichat,2  however,  and  more  recently,  Dr.  Goring,3  and  most  histolo- 
gists,  have  assigned  this  as  their  structure;  and  the  author  has  had 
repeated  opportunities  for  confirming  it  with  his  own  admirable  micro- 
scope, made  by  Smith,  of  London. 

Modern  observers  believe,  that,  as  in  other  structures,  growth  takes 
place  from  cells,  which  are  a  modification  of  those  of  the  epidermis. 
The  primary  cells  become  elongated,  and  generate  within  themselves 
fasciculi  of  fibres  or  secondary  cells,  which  interlace  to  form  the  hair 
cylinder.  The  walls  of  these  fibre-cells  are  at  first  soft  and  permeable; 
and  the  lower  part  of  the  hair,  which  is  composed  of  them,  seems  to 
admit  the  passage  of  fluid  without  much  difficulty.  At  a  short  distance 
from  the  base,  the  horny  character  of  the  hair,  caused  by  the  deposit  of 
horny  matter  in  the  interior  of  the  fibres,  becomes  apparent.  "There 
is  then,  at  the  base,  a  continual  formation  of  soft  fibrous  tissue,  by 
which  the  length  of  the  cylinder  is  increased;  whilst  at  a  short  distance 
above  it,  there  is  a  continual  consolidation  of  this  (as  it  progressively 
arrives  at  that  point)  by  the  deposit  of  a  peculiar  secretion  in  its 
substance."4 


»  Physiology,  p.  52,  3d  edit.,  Lond.,  1836. 

3  Journal  of  Science,  New  Series,  vol.  i.  433. 

<  Carpenter,  Human  Physiology,  §  637.     Lond.,  1842. 


Anat.  General.,  torn,  iv.,  §  2. 


128  SENSE  OF  TOUCH. 

The  colour  of  the  hair  is  different  in  different  races  and  individuals. 
By  some,  this  is  considered  to  depend  upon  the  fluids  contained  in  the 
pith.  M.  Vauquelin1  analyzed  the  hair  attentively,  and  found  it  to  con- 
sist chiefly  of  an  animal  matter,  united  to  a  portion  of  oil,  which  appeared 
to  contribute  to  its  flexibility  and  cohesion.  Besides  this,  there  is  another 
substance,  of  an  oily  nature,  from  which  he  considers  the  colour  of  the 
hair  is  derived.  The  animal  matter,  according  to  that  chemist,  is  a 
species  of  mucus;  but  other  chemists  believe  it  to  be  chiefly  albumen. 
Vauquelin  found,  that  the  colouring  matter  is  destroyed  by  acids ;  and 
he  suggests,  that  when  it  has  suddenly  changed  colour  and  become  gray, 
in  consequence  of  any  mental  agitation,  this  may  be  owing  to  the  pro- 
duction of  an  acid  in  the  system,  which  acts  upon  the  colouring  matter. 
The  explanation  is  hypothetical,  and  is  considered,  and  characterized 
as  such  by  Dr.  Bostock;  but  it  must  be  admitted,  that  the  same  objec- 
tion applies  to  the  view  he  has  substituted  for  it.  He  conceives  it 
"more  probable  that  the  effect  depends  upon  a  sudden  stagnation  in 
the  vessels,  which  secrete  the  colouring  matter;  while  the  absorbents 
continue  to  act,  and  remove  that  which  already  exists."  There  is,  how- 
ever, no  more  real  evidence  of  "stagnation  of  vessels"  than  there  is  of 
the  formation  of  an  acid.  Our  knowledge  is  limited  to  the  fact,  that 
a  sudden  and  decided  change  in  the  whole  pileous  system  may  occur 
after  great  or  prolonged  mental  agitation. 

"  My  hair  is  gray,  but  not  with  years, 
Nor  grew  it  white  in  a  single  night, 
As  men's  have  grown  from  sudden  fears." 

Byron's  "Prisoner  of  Chillon." 

"  Danger,  long  travail,  want  and  wo, 
Soon  change  the  form  that  best  we  know  : 
For  deadly  fear  can  time  outgo, 

And  blanch  at  once  the  hair. 
Hard  toil  can  roughen  form  and  face, 
And  want  can  quench  the  eye's  bright  grace, 
Nor  does  old  age  a  wrinkle  trace 

More  deeply  than  despair." 

Scott's  "  Marmion.r* 

It  is  stated  by  M.  Be  Lamartine,3  that  such  a  change  occurred  in  a 
single  night  to  the  queen  of  Louis  the  16th — the  unfortunate  Marie 
Antoinette — when  the  royal  party  was  arrested  at  Yarennes,  in  1791. 

But  a  similar,  though  more  gradual  change,  is  produced  by  age.  We 
find  some  persons  entirely  gray  at  a  very  early  period  of  life ;  and,  in 
old  age,  the  change  happens  universally.  It  is  not  then  diflicult  to 
suppose,  that  some  alteration  in  the  nutrition  of  the  hair  may  super- 
vene, resembling  that  which  occurs  in  the  progress  of  life.  Dr.  Bostock 
doubts  the  fact  of  such  sudden  conversions ;  but  the  instances  are  too 
numerous  for  us  to  consider  them  entirely  fabulous.  Still,  it  is  difficult 
to  comprehend  how  parts,  which,  like  the  extremities  of  the  hair,  are 

1  Annales  de  Chimie,  torn.  Iviii.  p.  41,  Paris,  1806. 

3  For  many  such  cases  see  M.  E.  Wilson,  a  Practical  Treatise  on  Healthy  Skin,  p.  95. 
London,  1845. 

3  "La  reine  ne  dormit  pas.  Toutes  ses  passions,  de  femme,  de  mere,  de  reine,  la  colere, 
la  tevreur,  la  desespoir,  se  livrerent  un  tel  assaut  dans  son  ame,  que  ses  cheveux,  blonds  la 
vieille,  furent  blancs  le  lendemain." — Histoire  des  Girondins,  i.  116.  Paris,  1847. 


HAIR.  129 

foreign  to  nutrition,  can  change  so  rapidly.  M.  Lepelletier1  ascribes 
it  to  two  very  different  causes.  First,  to  defective  secretion  of  the 
colouring  fluid,  without  any  privation  of  nutrition.  In  this  case,  the 
hairs  may  live  and  retain  their  hold,  as  we  observe  in  young  individuals : 
— and  secondly,  to  the  canals,  which  convey  the  fluid  into  the  hair, 
being  obliterated,  as  in  old  age.  The  same  cause,  acting  on  the  nutritious 
vessels  of  the  bulb,  produces,  successively,  privation  of  colour,  death, 
and  loss  of  those  epidermoid  productions. 

According  to  other  physiologists,  the  seat  of  colour  is  in  the  horny 
covering  of  the  hair ;  and,  in  the  largest  hairs  or  spines  of  the  porcu- 
pine, this  seems  to  be  the  case,  the  pith  being  white,  and  the  horny 
covering  coloured.  There  is  often  an  intimate  relationship  observed 
between  the  colour  of  the  hair  and  that  of  the  rete  mucosum.  A  fair 
complexion  is  accompanied  with  light  hair ;  a  swarthy  with  dark ; — 
and  we  see  the  connexion  still  more  signally  displayed  in  those  animals 
that  are  spotted — the  colour  of  the  hair  being  variegated  like  that  of 
the  skin. 

Hairs  differ  materially  according  to  the  part  of  the  body  on  which 
they  grow.  In  some  parts  they  are  short,  as  in  the  armpits ;  whilst 
on  the  head  it  is  not  easy  to  say  what  would  be  the  precise  limit  to  the 
growth,  were  they  left  entirely  to  nature.  In  the  Malay,  it  is  by  no 
means  uncommon  to  see  them  touch  the  ground. 

The  hair  has  various  names  assigned  to  it,  according  to  the  part  on 
which  it  appears, — beard,  whiskers,  mustachios,  eyebrows,  eyelashes, 
&c.  In  many  animals  it  is  long  and  straight ;  in  others  crisped,  when 
it  is  called  wool.  If  stiff,  it  is  termed  a  bristle;  if  inflexible,  a  spine. 
It  is  entirely  insensible,  and,  excepting  in  the  bulbous  portion,  is  not 
liable  to  disease.  Dr.  Bostock  affirms,  that  under  certain  circumstances 
hairs  are  subject  to  a  species  of  inflammation,  when  vessels  may  be 
detected,  at  least  in  some  of  them,  and  they  become  acutely  sensitive. 
Their  sensibility  under  any  known  circumstances  may  be  doubted. 
They  appear  to  be  anorganic,  except  at  the  root ;  and,  like  the  cuticle, 
resist  putrefaction  for  a  length  of  time.  The  parts  that  do  not  receive 
vessels  are  nourished  by  transudation  from  those  that  do.  Bichat  and 
Gaultier  were  of  the  opinion  of  Dr.  Bostock ; — misled,  apparently,  by 
erroneous  reports  concerning  plica  polonica;  but  Baron  Larrey2  has 
satisfactorily  shown  that  plica  is  confined  to  the  bulbs  :  the  hairs  them- 
selves continue  devoid  of  sensibility. 

It  is  difficult  to  assign  a  plausible  use  for  the  hair.  That  of  the  head 
has  already  engaged  attention ;  but  the  hair,  which  appears  on  certain 
parts  at  the  age  of  puberty  and  not  till  then,  and  that  on  the  chin  and 
upper  lip  of  the  male  sex  only,  set  our  ingenuity  at  defiance.  In  this 
respect,  the  hair  is  not  unique.  Many  physiologists  regard  certain 
parts,  which  exist  in  one  animal,  apparently  without  function,  but 
which  answer  useful  purposes  in  another,  to  be  vestiges  indicating  the 
harmony  that  reigns  through  nature's  works.  The  generally  useless 
nipple  and  mamma  of  one  sex  might  be  looked  upon  in  this  light ;  but 

1  Trait£  de  Physiologie  Medicale  et  Philosophique,  torn.  iii.  p.  42,  Paris,  1832. 
a  Memoires  de  Chirurgie  Militaire,  t.  iii.  108,  Paris,  1812. 
VOL.  I. — 9 


130 


SENSE  OF  TOUCH. 


the  tufts  of  hair  on  various  parts  cannot,  in  any  way,  be  assimilated  to 
the  hairy  coating  that  envelopes  the  bodies  of  animals ;  and  is,  in  them, 
manifestly  intended  as  a  protection  against  cold. 


Fig.  46. 


There  is  another  class  of  bodies  connected  with  the  skin,  and  ana- 
logous in  nature  to  the  last  described, — the 
nails.  These  serve  a  useful  purpose  in  touch, 
and  consequently  require  notice  here.  In 
the  system  of  De  Blainville,  they  constitute 
a  subdivision  of  the  hairs,  which  he  dis- 
tinguishes into  simple  and  compound, — 
simple,  when  each  bulb  is  separated,  and 
has  a  distinct  hair; — compound,  when  seve- 
ral pileous  bulbs  are  agglomerated,  so  that 
the  different  hairs,  as  they  are  formed,  are 
cemented  together  to  constitute  a  solid  body 
of  greater  or  less  size, — nail,  scale,  horn, 

Section  of  the  Skin  on  the  end  of  &c«    **  ,man> the  nail  alone  exists  ;  the  chief 
the  Finger.  and  obvious  use  ot  which  is  to  support  the 

The  cuticle  and  nail,  n,  detached    pulp    of   the    finger,    whilst    it    is     exercising 

from  the  cutis  and  matrix,  m.  touch.     Animals  are  provided  with  horns, 

beaks,  hoofs,  nails,  spurs,  scales,  &c.     All 

these,  like  the  hair,  grow  from  roots ;  and  are  considered  to  be  analogous 
in  their  physical  and  vital  properties.  Meckel,  and  De  Blainville, 
Bonn,  Walther,  Lavagna,  and  others,  are  of  opinion,  that  the  teeth  are 
of  the  same  class ;  and  that  they  belong,  originally,  to  the  skin  of  the 
mouth. 

The  nails,  near  their  origin,  are  seen,  under  the  microscope,  to  con- 
sist of  primary  cells,  almost  identical  with  those  of  the  epidermis;  these 
gradually  dry  into  scales;  and  the  growth  of  the  nail  appears  to  be 
effected  by  the  constant  generation  of  cells  at  its  root  and  under  sur- 
face; and  as  successive  layers  are  pushed  forward,  each  cell  becomes 
larger,  flatter,  and  drier,  and  more  firmly  fixed  than  those  around  it.1 
The  chemical  composition  of  the  epidermis  and  the  nails  is  similar  to 
that  of  the  hair:  yet  according  to  Mulder,2  there  are  material  differ- 
ences in  their  properties ; — the  latter,  being  almost  insoluble  in  strong 
acetic  acid,  in  which  the  other  two  are  readily  soluble :  hence — he  infers — 
the  composition  of  hair  and  of  horn  and  whalebone  must  differ  materi- 
ally; and,  that,  accordingly,  Scherer's  conclusion,  that  they  are  all 
identical  is  incorrect.  The  following  are  the  results  of  the  analysis  of 
each  of  these  bodies. 


C. 

H. 
N. 
O. 

s. 


Epidermis. 

50.28 

6.76 

17.21 

25.01 

0.74 


Horn. 
51.03 

6.80 
16.24 
22.51 

3.42 


Whalebone. 
51.86 

6.87 
15.70 
21.97 

3.60 


Hair. 

50.65 

6.36 

17.14 

20.85 

5.00 


For  physiological  purposes,  the  above  description  is  sufficient.     A  few 

'  Henle,  edit,  cit.,  i.  289,  Paris,  1843. 

9  The  Chemistry  of  Vegetable  and  Animal  Physiology,  translated  by  Fromberg,  p.  527. 
Edinb.  and  London,  1849. 


MUCOUS  MEMBRANES.  131 

words  will  be  necessary  regarding  the  mucous  membranes,  which  resem- 
ble the  skin  so  much  in  their  properties,  as  to  be,  with  propriety,  termed 
dermoid.  If  we  trace  the  skin  into  the  various  outlets,  we  find,  that  a 
continuous,  soft,  velvety  membrane — epithelium — exists  through  their 
whole  extent;  and,  if  the  channel  has  two  outlets,  as  in  the  alimentary 
canal,  this  membrane,  at  each  outlet,  commingles  with  the  skin;  and 
appears  to  differ  but  slightly  from  it.  So  much,  indeed,  do  they  seem 
to  form  part  of  the  same  organ,  that  physiologists  have  described-  the 
absorption,  that  takes  place  from  the  intestinal  mucous  membrane,  as 
external.  They  cannot,  however,  in  the  higher  order  of  animals,  be 
considered  completely  identical ;  nor  is  the  same  membrane  alike  in  its 
whole  extent.  They  have  all  been  referred  to  two  great  surfaces ; — the 
g astro-pulmonary — comprising  the  membranes  of  the  outer  surface  of 
the  eye,  ductus  ad  nasum,  nose,  mouth,  and  respiratory  and  digestive 
passages ;  and  the  genito-urinary — which  line  the  whole  of  the  genital 
and  urinary  apparatuses.  In  addition  to  these,  a  membrane  of  similar 
character  lines  the  meatus  auditorius  externus,  and  the  excretory  ducts 
of  the  mammae. 

The  analogy  between  the  skin  and  mucous  membranes  is  farther 
shown  by  the  fact,  that  if  we  invert  the  polypus,  the  mucous  membrane 
gradually  assumes  the  characters  of  skin;  and  the  same  circumstance 
is  observed  in  habitual  descents  of  the  rectum  and  uterus. 

In  the  mucous  membranes — especially  at  their  extremities,  which 
appear  to  be  alone  concerned  in  the  sense  of  touch — the  same  super- 
position of  strata  is  generally  considered  to  exist  as  in  the  skin — viz., 
epidermis  or  epithelium,  rete  mucosum,  corpus  papillare,  and  cutis 
vera.  They  have,  likewise,  similar  follicles,  called  mucous;  but  nothing 

A  Fig.  47.  B 


Separated  Epithelium  Cells  from  Pavement-Epithelium  of  the  Mucous 

mucous  membrane  of  mouth.  Membrane  of  the  smaller  bronchial  tubes. 

b.  With  nuclei,    c.  And  nucleoli.  a.  Nuclei  with  double  nucleoli. 

analogous  to  the  hairs ;  unless  we  regard  the  teeth  to  be  so,  in  corre- 
spondence with  the  views  of  Meckel,  De  Blainville,  and  others. 

The  attention  of  anatomists  has  been  closely  directed  to  the  ultimate 
structure  of  the  mucous  system.  In  the  mucous  tissues  two  structures 
have  been  separately  described,  especially  by  Mr.  Bowman,1  who  has 
thrown  much  light  on  the  subject.  These  are  the  basement  membrane — 
as  he  terms  it — and  the  epithelium.  The  former  is  a  simple,  homoge- 
neous expansion,  transparent,  colourless,  and  of  extreme  tenuity,  situate 

1  Cyclopaedia  of  Anat.  and  Physiology,  pt.xxiii.  p.  486,  April,  1842. 


132 


SENSE  OF  TOUCH. 


on  its  parenchymal  surface,  and  giving  it  shape  and  strength.  This 
serves  as  a  foundation  on  which  the  epithelium  rests.  It  may  frequently 
be  demonstrated  with  very  little  trouble  in  the  tubuli  of  the  glands, 
especially  of  the  kidney,  which  are  but  very  slightly  adherent,  by  their 
external  surface,  to  the  surrounding  tissue. 

M.  Flourens1  considers  that  every  mucous  membrane  is  composed  of 
three  laminae  or  layers, — the  derma,  epidermis,  and  corpus  mucosum 
situate  between  the  derma  and  epidermis.  The  corpus  mucosum  of 
mucous  membranes  is  continuous  at  all  the  outlets  of  the  body,  and  is 
identical  with  the  second  epidermis;  differing,  therefore,  from  the  corpus 
mucosum  of  the  skin,  a  term  which — as  elsewhere  remarked — he  thinks 
ought  to  be  abolished. 

Histological  examination  exhibits  the  epithelium  to  consist  of  cells, 
which  are  termed  epithelial,  and  have  various  shapes.  The  two  chief 
are  tesselated  or  pavement  epithelium,  and  cylinder  or  conical  epithe- 
lium. Epithelium  is  not,  however,  confined  to  mucous  membranes, 
but,  of  late  years,  has  been  found  to  exist  elsewhere;  it  is  always 
in  contact  with  fluids,  and  of  a  soft,  pliant  cha- 
racter. Tesselated  epithelium  covers  the  serous 
and  synovial  membranes,  the  lining  membrane  of 
the  blood-vessels,  and  the  mucous  membranes, 
except  where  cylinder  epithelium  exists.  It  is 
spread  over  the  mouth,  pharynx  and  oesophagus, 
conjunctiva,  vagina,  and  entrance  of  the  female 
urethra.  The  cells  composing  it  are  usually  po- 
lygonal; and  are  well  seen  in  the  marginal  figure. 
Cylinder  epithelium  is  found  in  the  intestinal 
canal,  beyond  the  cardiac  orifice,  in  the  larger 
ducts  of  the  salivary  glands,  in  the  ductus  com- 
munis  choledochus,  prostate,  Cowper's  glands, 
vesiculse  seminales,  vas  deferens,  tubuli  uriniferi, 
and  urethra  of  the  male ;  and  lines  the  urinary 
passages  of  the  female  from  the  orifice  of  the 
urethra  to  the  beginning  of  the  tubuli  uriniferi 
of  the  kidneys.  In  all  these  situations,  it  is  continuous  with  tesselated 

Fig.  49. 


Fig.  48. 


Tesselated  Epithelium. 

Extremity  of  one  of  the  tu- 
buli uriniferi,  from  the  kidney 
of  an  adult ;  showing  its  tes- 
selated epithelium.  —  Magni- 
fied 250  diameters.  (Wagner.) 


Scales  of  Tesselated  Epithelium.     (After  Henle.) 

A.  Section  of  epithelium  of  conjunctiva  with  some  scales  loosened.    B.  Scales  from  surface  of  cheek, 
c.  The  more  deeply  seated  scales  from  the  human  conjunctiva. 

epithelium,  which  lines  the  more  delicate  ducts  of  the  various  glands. 
The  cells  have  the  form  of  long  cylinders  or  truncated  cones,  arranged 
side  by  side,  the  apices  attached  to  the  mucous  membrane  or  to  flat 


Op.  cit.,  p.  80. 


PHYSIOLOGY  OP  TOUCH. 
Fig.  50. 


133 


Diagram  of  the  Structure  of  an  Involuted  Mucous  Membrane,  showing  the  continuation  of  its 
elements  in  the  follicles  and  villi. 

F,  P.  Two  follicles,    b.  Basement  membrane,    c.  Submucous  tissue,    e.  Epithelium,    v.  Vascular 
layer,    n.  Nerve,    v.  Villus,  covered  with  epithelium,    v'.  Villus,  whose  epithelium  has  been  shed. 

epithelial  cells  lying  upon  it ;  the  base  being  free.     Each  cell,  nearly 
midway  between  the  base  and  apex,  encloses  a  flat  nucleus  with  nucleoli. 

Fig.  51. 


Cylinders  of  Intestinal  Epithelium.     (After  Henle.) 

A.  From  the  cardiac  region  of  the  human  stomach.    B.  From  jejunum,    c.  Cylinders  seen  when 
looking  on  their  free  extremities.    D.  Ditto,  as  seen  in  a  transverse  section  of  a  villus. 

Epithelium  is  sometimes  furnished  with  cilia,  or  is  said  to  be  ciliated. 
The  nature  and  uses  of  these  cilia,  as  well  as  the  different  varieties  of 
mucous  membrane,  will  be  described  hereafter. 

2.    PHYSIOLOGY  OF  TAGT  AND  TOUCH. 

In  describing  the  physiology  of  the  sense  of  touch,  it  will  be  conve- 
nient to  revert  to  the  distinction  already  made  between  the  sense  when 
passively  and  actively  exerted  ;  or  between  tact,  and  touch.  The  mode, 


134 


SENSE  OF  TOUCH. 


however,  in  which  the  impression  is  made  is  in  each  case  alike,  and 
equally  simple.  It  is  merely  necessary,  that  the  substance,  which 
causes  it,  should  be  brought  in  contact  with  what  may  be  termed  the 
physical  part  of  the  organ — the  cuticle ;  the  nervous  part  is  seated  in 
the  corpus  papillare,  for  if  the  nerves  proceeding  to  this  layer  of  the 
skin  be  cut,  the  sense  is  destroyed.  In  the  exercise  of  touch,  each  of 
the  layers  seems  to  have  its  appropriate  office:  the  corium,  the  inner- 
most layer,  the  base  on  which  the  others  rest,  offers  the  necessary  re- 
sistance, when  bodies  are  applied  to  the  surface;  the  rete  rnucosum  is 
unconcerned  in  the  function :  the  erectile  tissue,  on  which  the  papillae 
are  grouped,  probably  aids  them  in  their  appreciation  of  bodies ;  and 
the  epidermis  modifies  the  tactile  impression  which  might  become  too 
intense,  or  be  painful,  did  this  anorganic  envelope  not  exist.  The  de- 
gree of  perfection  of  the  sense  is  greatly  influenced  by  the  state  of 
the  cuticle.  Where  thin — as  upon  the  lips,  glans  penis,  clitoris,  &c. — 
the  sense  is  very  acute ;  where  thick  and  hard,  it  is  obtuse ;  and  where 
removed — as  by  blistering — the  contact  of  bodies  gives  pain,  but  does 
not  occasion  the  appropriate  impression  of  touch. 

Professors  Weber1  and  Valentin2  have  shown  that  the  tactile  power  of 
the  skin  is  not  proportionate  to  its  sensibility.  The  mammae,  for  ex- 
ample, are  easily  tickled,  and  susceptible  of  great  pain  when  irritated ; 
yet  they  are  moderately  endowed  with  the  sense  of  touch.  The  differ- 
ent parts  of  the  skin,  too,  vary  in  their  tactile  power.  The  left  hand, 
in  most  persons,  is  more  sensible  to  temperature  than  the  right,  proba- 
bly owing  to  the  epidermis  being  thinner  from  less  use.  Weber  made 
various  experiments  for  the  purpose  of  determining  the  relative  sensi- 
bility of  different  portions  of  the  skin,  by  touching  the  surface  with 
the  legs  of  a  pair  of  compasses,  the  points  of  which  were  inserted  into 
pieces  of  cork.  The  person's  eyes  being  closed  at  the  time,  the  legs 
were  brought  together  so  as  to  be  separated  by  different  distances. 
The  following  are  some  of  the  results  of  his  experiments. 


Lines 

Point  of  middle  finger  £ 

Point  of  tongue  £ 

Palmar  surface  of  third  finger       -  1 

Red  surface  of  lips  -  -  2 

Palmar  surface  of  middle  finger   -  2 

Dorsal  surface  of  third  finger         •  3 

Tip  of  the  nose     -  -  3 

Dorsum  and  edge  of  tongue  •  4 

Part  of  lips  covered  by  skin  -  4 

Palm  of  hand         -  5 . 

Skin  of  cheek         ...  5 

Extremity  of  great  toe       -  -  5 

Hard  palate  ...  6 

Dorsal  surface  of  fore  finger 

Dorsum  of  hand    ...  8 


Mucous  membrane  of  gums 

Lower  part  of  forehead  - 

Lower  part  of  occiput 

Back  of  hand 

Neck,  under  lower  jaw   - 

Vertex     - 

Skin  over  patella 

Skin  over  sacrum 

acromion 

Dorsum  of  foot    - 
Skin  over  sternum 
Skin  beneath  occiput 
Skin  over  spine,  in  back 
Middle  of  the  arm 
thigh 


Lines. 

9 

10 
12 
14 
15 
15 
16 
18 
18 
18 
20 
24 
30 
30 
30 


Weber  found,  that  the  distance  between  the  legs  of  the  compasses 

1  See  art.  Tastsinn  und  das  Gemeinge/uhl,  in  Wagner's  Handworterbuch  der  Physiologie, 
22ste  Lieferung.  s.  539.  Braunschweig,  1849.  His  earlier  experiments  are  detailed  and 
confirmed 'by  Dr.  Allen  Thomson,  in  Edinb.  Med.  and  Surg.  Journal,  for  July,  1833. 

9  Lehrbuch  der  Physiologie  des  Menschen,  ii.  565.  Braunschweig,  1844;  and  Grundriss 
der  Physiologie,  s.  331.  Braunschweig,  1846. 


APPRECIATION  OF  TEMPERATURE.  135 

seemed  to  be  greater,  although  it  was  really  less,  when  they  were  placed 
upon  more  sensitive  parts. 

It  has  been  supposed,  that  some  of  the  recorded  instances  of  great 
resistance  to  heat  have  been  caused  by  unusual  thickness,  and  com- 
pactness of  cuticle,  together  with  a  certain  degree  of  insensibility  of 
the  skin.  The  latter  may  be  an  important  element  in  the  explanation  ; 
but  some  of  the  feats,  executed  by  persons  of  the  character  alluded  to, 
could  hardly  have  been  influenced  by  the  former,  as  the  resistance 
seemed  almost  equally  great  in  the  delicately  organized  mucous  mem- 
branes. A  Madame  Girandelli, — who  was  exhibited  in  Great  Britain 
many  years  ago, — was  in  the  habit  of  drawing  a  box  with  a  dozen 
lighted  candles  along  her  arm,  putting  her  naked  foot  upon  melted 
lead,  and  of  dropping  melted  sealing-wax  upon  her  tongue,  and  im- 
pressing it  with  a  seal,  without  appearing  to  experience  uneasiness;  and 
several  years  ago  (1832),  a  man  of  the  name  of  Chabert  excited  in 
this  country  the  surprise  which  followed  his  exhibitions  in  London  a 
year  or  two  previously,  and  gave  him  the  appellation  of  the  "  Fire 
King."  In  addition  to  the  experiments  performed  by  Madame  Giran- 
delli, Chabert  swallowed  forty  grains  of  phosphorus  ;  washed  his  fingers 
in  melted  lead  ;  and  drank  boiling  Florence  oil  with  perfect  impunity. 
For  the  phosphorus  he  professed  to  take  an  antidote,  and  doubtless  did 
so.  It  is  probable,  also,  that  agents  were  used  by  him  to  deaden  the 
painful  impressions  ordinarily  produced  by  hot  bodies  applied  to  the 
surface.  A  solution  of  borax  or  alum  spread  upon  the  skin  is  said  to 
exert  a  powerful  effect  of  the  kind;  but,  in  addition  to  the  use  of  such 
agents,  there  must  be  a  degree  of  insensibility  of  the  corpus  papillare; 
otherwise  it  is  difficult  to  understand  why  those  hot  substances  did  not 
painfully  inflame  the  surface.  We  see,  daily,  striking  differences  in 
individuals  in  the  degree  of  sensibility  of  the  mucous  membrane  of  the 
mouth  and  gullet,  and  are  frequently  surprised  at  the  facility  with  which 
certain  persons  swallow  fluids  of  a  temperature  that  would  excite  the 
most  painful  sensations  in  others.  In  this,  habit  has  unquestionably 
much  to  do. 

In  the  mucous  membranes,  tact  is  effected  in  the  same  way  as  in  the 
skin.  The  layers,  of  which  it  is  constituted,  participate  in  like  man- 
ner; but  the  sense  is  more  exercised  at  the  extremities  of  the  mem- 
brane than  internally.  The  food,  received  into  the  mouth,  is  felt 
there ;  but  after  it  has  passed  into  the  gullet  it  excites  hardly  any  tac- 
tile impression;  and  it  is  not  until  it  has  reached  the  lower  part  of  the 
membrane,  in  the  shape  of  excrement,  that  its  presence  is  again  indi- 
cated by  this  sense. 

Pathologically,  we  have  some  striking  instances  of  this  difference  in 
different  parts  of  the  mucous  membrane.  If  an  irritation  exists  within 
the  intestinal  canal,  the  only  indication  we  may  have  of  it  is  itching  of 
the  nose,  or  at  one  extremity  of  the  membrane.  In  like  manner,  a  cal- 
culus in  the  bladder  is  indicated  by  itching  of  the  glans  penis;  and  a 
similar  exemplification  is  offered  during  the  passage  of  a  gall-stone 
through  the  ductus  communis  choledochus.  On  its  first  entrance,  the 
p^i  experienced  is  of  the  most  violent  character;  this,  after  a  time 
strosides, — as  soon,  indeed,  as  the  calculus  has  got  fairly  into  the  canal. 


136  SENSE  OF  TOUCH. 

One  of  the  great  purposes  of  the  sense  of  tact  is  to  enable  us  to 
judge  of  the  temperature  of  bodies.  This  office  it  executes  alone.  No 
other  sense  participates  in  it.  It  requires  no  previous  exercise ;  is  felt 
equally  by  the  infant  and  the  adult,  and  requires  only  the  proper  de- 
velopment of  its  organs.  The  relative  temperature  of  bodies  is  accu- 
rately designated  by  the  instrument  called  the  thermometer;  but  very 
inaccurately  by  our  own  sensations;  and  the  reason  of  this  inaccuracy 
is  sufficiently  intelligible.  In  both  cases,  the  effect  is  produced  by  the 
disengagement  of  a  subtile  fluid,  called  caloric  or  the  matter  of  heat, 
which  pervades  all  bodies,  and  is  contained  in  them  to  a  greater  or  less 
extent.  This  caloric  is  constantly  passing  and  repassing  between  bodies, 
either  by  radiation  or  by  conduction,  until  there  is  an  equilibrium  of 
caloric  and  all  have  the  same  temperature  as  indicated  by  the  ther- 
mometer. Hence,  objects  in  the  same  apartment  will  exhibit,  cseteris 
paribus,  a  like  temperature  by  this  test.  From  this  law,  however,  the 
animal  body  must  be  excepted.  The  power  which  it  possesses  of  gene- 
rating its  own  heat,  and  of  counteracting  the  external  influences  of 
temperature,  preserves  it  constantly  at  the  same  point. 

Although,  however,  all  objects  may  exhibit  the  same  temperature, 
in  the  same  apartment,  when  the  thermometer  is  applied  to  them  ;  the 
sensations  communicated  by  them  may  be  very  different.  Hence  the 
difficulty,  which  the  uninstructed  have  in  believing,  that  they  are  actually 
of  identical  temperature ; — that  a  hearth-stone,  for  instance,  is  of  the 
same  degree  of  heat  as  the  carpet  in  the  same  chamber.  The  cause  of 
the  different  sensations  experienced  in  the  two  cases  is,  that  the  hearth- 
stone is  a  much  better  conductor  of  the  matter  of  heat  than  the  carpet. 
The  consequence  is,  that  caloric  is  more  rapidly  abstracted  by  it  from 
the  part  of  the  body  which  comes  in  contact  with  it,  and  the  stone 
appears  to  be  the  colder  of  the  two.  For  the  same  reason,  when  these 
two  substances  are  raised  in  temperature  above  that  of  the  human  body, 
the  hearth-stone  will  appear  the  hotter  of  the  two ;  because,  it  conducts 
caloric  and  communicates  it  more  rapidly  to  the  body  than  the  carpet. 

When  the  temperature  of  the  surrounding  air  is  higher  than  98°,  we 
receive  caloric  from  the  atmosphere,  and  experience  the  sensation  of 
heat.  The  human  body  is  capable  of  being  penetrated  by  the  caloric 
of  substances  exterior  to  it,  precisely  like  those  substances  themselves ; 
but,  within  certain  limits,  it  possesses  the  faculty  of  consuming  the  heat, 
and  retaining  the  same  temperature.  When  the  temperature  of  the 
atmosphere  is  only  as  high  as  our  own — an  elevation  which  it  not  un- 
frequently  attains  in  many  parts  of  the  United  States — we  still  expe- 
rience the  sensation  of  unusual  warmth  ;  yet  no  caloric  is  communicated 
to  us.  The  cause  of  this  feeling  is,  that  we  are  accustomed  to  live  in 
a  medium  of  a  less  elevated  temperature,  and  consequently  to  give  off 
caloric  habitually  to  the  atmosphere. 

Lastly,  in  an  atmosphere  of  a  temperature  much  lower  than  that  of 
the  body,  heat  is  incessantly  abstracted  from  us ;  and,  if  rapidly,  we 
have  the  sensation  of  cold.  From  registers,  kept  by  the  illustrious 
founder  of  the  University  of  Virginia,  Mr.  Jefferson,  at  his  residence 
at  Monticello,1  lat.  37°  58',  long.  78°  40',  it  appears  that  the 

1  Virginia  Literary  Museum,  p.  36,  Charlottesville,  1830. 


APPRECIATION  OF  TEMPERATURE.  13T 

temperature  of  that  part  of  Virginia,  is  about  55J°  or  56° ;  and  that 
the  thermometer  varies  from  5J°  in  the  coldest  month,  to  94°  in  the 
warmest.  Now,  the  temperature  of  the  human  body  being  98°,  it  fol- 
lows, that  heat  must  be  incessantly  parting  from  us,  and  that  we  ought, 
therefore,  to  experience  constantly  a  sensation  of  cold;  and  this  we 
should  unquestionably  do,  were  we  not  protected  by  clothing,  and  aided 
by  artificial  temperature  during  the  colder  seasons.  Yet,  accustomed 
as  the  body  is  to  give  off  caloric,  there  is  a  temperature,  in  which, 
clothed  as  we  are,  we  do  not  feel  cold,  although  we  may  be  disengaging 
heat  to  some  extent.  This  temperature  may  perhaps  be  fixed  somewhere 
between  70°  and  80°  in  the  climate  of  the  middle  portions  of  the  United 
States.  So  much,  however,  are  our  sensations  in  this  respect  dependent 
upon  the  temperature  which  has  previously  existed,  that  the  comfortable 
point  varies  at  different  seasons.  If  the  thermometer,  for  instance,  has 
ranged  as  high  as  98°,  and  has  maintained  this  elevation  for  a  few  days, 
a  depression  of  15°  or  20°  will  be  accompanied  by  feelings  of  discom- 
fort ;  whilst  a  sudden  elevation  from  30°  to  75°  may  occasion  an  op- 
pressive feeling  of  heat.  In  northern  Siberia,  M.  von  Wrangel1  found, 
that  only  a  few  degrees  of  frost  was  currently  denominated  "warm 
weather;"  and  that  after  having  been  accustomed  to  the  winter  tempe- 
rature of  that  climate,  it  seemed  to  him,  that  10°  of  cold,  22°  below 
the  freezing  point  of  Fahrenheit,  was  a  mild  temperature.  During  the 
voyages,  made  by  Captain  Parry  and  others  to  discover  a  northwest 
passage,  it  was  found,  that  after  having  lived  for  some  days  in  a  tempe- 
rature of  15°  or  20°  below  0,  it  felt  comfortable  when  the  thermometer 
rose  to  zero. 

These  are  the  great  sources  of  the  deceptive  nature  of  our  sensations 
as  to  warmth  and  cold  which  enable  us  to  judge  merely  of  the  com- 
parative conditions  of  the  present  and  the  past ;  and  hence  it  is,  that 
a  deep  cellar  appears  warm  in  winter  and  cold  in  summer.  At  a  certain 
distance  below  the  surface,  the  temperature  of  the  earth  indicates  the 
medium  heat  of  the  climate ;  yet,  although  this  may  be  stationary,  oiu* 
sensations  on  descending  to  it  in  winter  and  summer  would  be  by  no 
means  the  same.  If  two  men  were  to  meet  on  the  middle  of  the  South 
American  Andes, — the  one  having  descended,  and  the  other  ascended, 
— their  sensations  would  be  very  different.  The  one,  who  had  descended, 
coming  from  a  colder  to  a  warmer  atmosphere,  would  experience  warmth ; 
whilst  the  other,  who  had  ascended,  would  feel  correspondently  cool. 
An  experiment,  often  performed  in  the  chemical  lecture-room,  exhibits 
the  same  physiological  fact.  If,  after  having  held  one  hand  in  iced, 
and  the  other  in  warm  water,  we  plunge  both  into  water  of  a  medium 
heat,  it  will  seem  warm  to  the  one  hand,  and  cold  to  the  other. 

But  our  sensations  are  not  guided  solely  by  bodies  surrounding  us. 
They  are  often  greatly  dependent,  especially  in  disease,  on  the  state  of 
the  animal  economy  itself.  If  the  power,  which  the  system  possesses 
of  forming  heat,  be  morbidly  depressed — or  if,  in  consequence  of  old 
age,  or  of  previous  sickness,  calorification  does  not  go  on  regularly  and 
energetically,  a  temperature  of  the  air,  which  to  the  vigorous  is  agree- 

1  Reise  des  kaiserlich  Russischen  Fiotten  Lieutenants  F.  v.  Wrangel,  langs  der  Nordkiiste 
von  Siberien,  u.  s.  w.  Berlin,  1839,  translated  in  Harper's  Family  Library. 


138  SENSE  OF  TOUCH. 

able,  may  produce  an  unpleasant  impression  of  cold.  Under  opposite 
circumstances,  a  feeling  of  heat  exists. 

In  regard  to  the  mode  in  which  the  temperature  of  bodies  is  appre- 
ciated, there  are  peculiarities,  which  would  favour  the  idea  of  the  sense 
of  heat  being  distinct  from  that  of  tact  or  touch.  Professor  Weber, 
for  example,  found  that  the  left  hand  is  more  sensitive  than  the  right, 
although  the  sense  of  touch  is  more  acute  in  the  latter  ;  and  that  if  the 
two  hands,  at  the  time  of  like  temperature,  be  plunged  into  separate 
basins  of  water,  the  one  in  which  the  left  hand  is,  will  appear  to  be 
the  warmer,  even  although  its  temperature  may  be  somewhat  lower  than 
that  of  the  other.  It  would  seem,  too,  from  Weber's  experiments,  that 
in  regard  to  sensations  of  heat  and  cold,  a  weaker  impression  made 
upon  a  large  surface  appears  more  powerful  than  a  stronger  made  upon 
a  small  surface;  and,  accordingly,  to  judge  of  nice  shades  of  difference 
in  the  temperature  of  a  fluid,  the  whole  hand  will  enable  a  variation  to 
be  detected,  that  would  be  inappreciable  to  the  finger.  A  difference 
of  one-third  of  a  degree  it  is  affirmed,  may  be  easily  detected,  when 
the  same  hand  is  placed  successively  in  two  vessels  of  water,  or  any 
other  fluid.1 

These  and  other  phenomena  of  an  analogous  kind  have  led  to  the 
suggestion,  that  every  nerve  of  sensation  is  composed  of  several 
nerves,  each  of  which  may  have  its  special  function ;  and  that  the 
nerves  of  touch  comprise  some  which  appreciate  temperature,  others, 
which  perceive  the  resistance  of  bodies,  and  others  which  effect 
touch  properly  so  called.  In  proof  of  this  a  recent  writer  urges  that 
either  of  these  faculties  may  be  lost,  without  the  other  being  so.  Thus, 
when  the  arm  has  been  "  asleep,"  and  sensibility  is  returning  to  it, 
the  hand  first  perceives  temperature,  then  the  resistance  of  bodies, 
and  it  is  not  until  some  time  afterwards  that  the  faculty  of  touch,  pro- 
perly so  called,  is  exercised.  In  the  lower  extremities  the  contrary 
takes  place;  the  sense  of  touch  first  returns;  then  a  sensation  of 
pricking  is  experienced,  followed  by  the  perception  of  temperature,  and 
the  power  of  appreciating  resistance  returns  last.  It  may  be  added, 
that  many  cases  are  recorded,  in  which  the  sense  of  temperature  has 
been  lost,  whilst  the  ordinary  sense  of  tact  remained;  and,  as  remarked 
by  Dr.  Carpenter,2  it  is  an  additional  evidence  in  favour  of  the  distinct- 
ness of  nervous  fibres  to  convey  the  impressions  of  temperature,  that 
these  are  frequently  affected, — a  person  being  sensible  of  heat  or  of 
chilliness  in  some  part  of  the  body, — without  any  real  alteration  of  its 
temperature,  whilst  there  is  no  corresponding  affection  of  the  tactile 
sensations. 

By  tact  we  are  likewise  capable  of  forming  a  judgment  of  many  of 
the  qualities  of  bodies, — such  as  their  size,  consistence,  weight,  distance, 
and  motion.  This  faculty,  however,  is  not  possessed  exclusively  by  the 
sense  in  question.  We  can  judge  of  the  size  of  bodies  by  the  sight ;  of 
distance,  to  a  certain  extent,  by  the  ear,  &c.  To  appreciate  these  cha- 
racters, it  is  necessary,  that  the  sense  should  be  used  actively;  that  we 
should  call  into  exercise  the  admirable  instrument  with  which  we  are 

1  E.  H.  Weber,  Art.  Tastsirm  und  das  Gemeingefiihl  in  Wagner's  Handworterbuch  der 
Physiologie,  22ste  Lieferung,  s.  549.  Braunschweig,  1849. 

a  Principles  of  Physiology,  2d  Amer.  edit.,  p.  229.    Philad.,  1845. 


THE  HAND  THE  GREAT  ORGAN.  139 

provided  for  that  purpose ;  and  in  many  of  them  we  are  greatly  in- 
structed by  the  muscular  sense. 

In  treating  of  the  external  senses  generally,  it  was  remarked,  that 
we  are  capable  of  judging,  by  their  aid,  of  impressions  made  on  us  by 
portions  of  our  own  body.  By  the  sense  of  touch  we  can  derive  infor- 
mation regarding  its  temperature,  shape,  consistence,  &c.  An  opinion 
has,  indeed,  been  advanced,  that  this  sense  is  best  adapted  for  proving 
our  own  existence,  as  every  time  that  two  portions  of  the  body  come 
in  contact,  two  impressions  are  conveyed  to  the  brain,  whilst  if  we 
touch  an  extraneous  body,  there  is  but  one. 

The  tact  of  mucous  membranes  is  extremely  delicate.  The  great 
sensibility  of  the  lips,  tongue,  tunica  conjunctiva,  Schneiderian  mem- 
brane, lining  membrane  of  the  trachea  and  urethra,  is  familiar  to  all. 
Excessive  pain  is  produced  in  them  by  the  contact  of  extraneous  bodies ; 
yet,  in  many  cases,  they  signally  exemplify  the  effect  of  habit  in  blunt- 
ing sensation.  The  first  introduction  of  a  bougie  into  the  urethra 
generally  produces  intense  irritation ;  but  after  a  few  repetitions  the 
sensation  may  become  scarcely  disagreeable. 

To  appreciate  accurately  the  shape  and  size  of  objects,  it  is  neces- 
sary, that  they  should  be  embraced  by  a  part  of  the  body,  which  can 
examine  their  surfaces,  and  be  applied  to  them  in  every  direction.  In 
man,  the  organ  well  fitted  for  this  purpose  is  the  hand.  This  is  situate 
at  the  free  extremity  of  a  long  and  flexible  member,  which  admits  of 
its  being  moved  in  every  direction,  and  renders  it  not  only  well  adapted 
for  the  organ  of  touch,  but  for  that  of  prehension.  Man  alone  pos- 
sesses a  true  hand;  for  although  other  animals  have  organs  of  prehen- 
sion very  similar  to  his,  they  are  much  less  complete.  Aristotle  and 
Galen  termed  it  the  instrument  of  instruments,  and  its  construction 
was  considered  worthy  of  forming  the  subject  of  one  of  the  "  Bridge- 
water  Treatises"  "  On  the  Power,  Wisdom,  and  Goodness  of  God,  as 
manifested  in  the  Creation," — a  task  assigned  to  Sir  Charles  Bell. 

The  chief  superiority  of  the  hand  consists  in  the  size  and  strength 
of  the  thumb,  which  stands  out  from  the  fingers,  and  can  be  brought 
in  opposition  to  them,  so  as  to  enable  us  to  grasp  bodies,  and  to  execute 
various  mechanical  processes  under  the  guidance  of  the  intellect.  So 
important  was  the  thumb  esteemed  by  Albinus,1  that  he  called  it  a 
lesser  hand  to  assist  the  larger — "manus  parva  majori  adyutrix." 

In  addition  to  the  advantages  referred  to,  the  hand  is  furnished  with 
a  highly  sensible  integument.     The  papillae 
are  largely  developed,  especially  at  the  ex-  Fig.  52. 

tremities  of  the  fingers,  where  they  are  ranged 
in  concentric  circles,  and  rest  upon  a  spongy 
tissue,  by  many  considered  to  be  erectile,  and 
serving  as  a  cushion,  and  are  well  supplied 
with  capillary  vessels.  (See  Figs.  33  and  52.) 
At  the  posterior  extremity  of  the  fingers, 
are  the  nails,  which  support  the  pulps  of  the 
fingers  behind ;  and  render  the  contact  with  . 

i  i      -,•     '  .  ,.  rm  •    i  Capillary  Net- work  at  margin  of 

external  bodies  more  immediate.    This  happy  lips. 

1  De  Sceleto,  p.  465. 


140  SENSE  OF  TOUCH. 

organization  of  the  soft  parts  of  the  hand  alone  concerns  the  sense  of 
touch  directly.  The  other  advantages,  which  it  possesses,  relate  to 
the  power  of  applying  it  under  the  guidance  of  volition. 

Of  the  mode  in  which  touch  is  effected  it  is  not  necessary  to  treat. 
Being  nothing  more  than  tact,  exerted  by  an  appropriate  instrument, 
the  physiology  of  the  two  must  be  identical. 

Metaphysicians  have  differed  widely  regarding  the  services  that  ought 
to  be  attributed  to  the  touch.  Some  have  greatly  exaggerated  them, 
considering  it  the  sense  par  excellence,  the  first  of  the  senses.  It  is  an 
ancient  notion  to  ascribe  the  superiority  of  man  over  animals  and  his 
pre-eminence  in  the  universe — his  intelligence,  in  short — to  the  hand. 
Anaxagoras  asserted,  and  Helvetius1  revived  the  idea,  "that  man  is  the 
wisest  of  animals  because  he  possesses  hands."  The  notion  has  been 
embraced,  and  expanded  by  Condillac,2  Buffon,3  and  many  modern  phy- 
siologists and  metaphysicians.  Buffon  assigned  so  much  importance 
to  the  touch,  that  he  believed  the  cause  why  one  person  has  more  intel- 
lect than  another  is  his  having  made  a  more  prompt  and  repeated  use 
of  his  hands  from  early  infancy.  Hence,  he  recommended,  that  infants 
should  use  them  freely  from  the  moment  of  birth.  Other  metaphysi- 
cians have  considered  the  hand  the  source  of  mechanical  capabilities ; 
but  the  same  answer  applies  to  all  these  views.  It  can  only  be  re- 
garded as  an  instrument  by  which  information  of  particular  kinds  is 
conveyed  to  the  brain;  and  by  which  other  functions  are  executed, 
under  the  direction  of  the  will.  The  idiot  often  has  the  sense  more 
delicate  than  the  man  of  genius  or  than  the  best  mechanician,  whilst 
the  most  ingenious  artists  have  by  no  means  the  most  delicate  touch. 
We  have,  indeed,  some  striking  cases  to  show,  that  the  hand  is  not  en- 
titled to  this  extravagant  commendation.  Not  many  years  ago,  a  Miss 
Biffin  was  exhibited  in  London,  who  was  totally  devoid  of  upper  and 
lower  extremities;  yet  she  was  unusually  intelligent  and  ingenious.  It 
was  surprising  to  observe  the  facility  with  which  she  hem-stitched; 
turning  the  needle  with  the  greatest  rapidity  in  her  mouth,  and  insert- 
ing it  by  means  of  the  teeth.  She  painted  miniatures  faithfully,  and 
beautifully ; — holding  the  pencil  between  her  head  and  neck.  All  her 
motions  were,  in  fact,  confined  to  the  tongue  and  lips,  and  to  the  muscles 
of  the  neck.  M.  Magendie4  alludes  to  a  similar  case.  He  says,  that 
there  was,  in  Paris,  at  the  time  he  wrote,  a  young  artist,  who  had  no  signs 
of  arm,  forearm,  or  hand,  and  whose  feet  had  one  toe  less  than  usual, 
— the  second;  yet  his  intelligence  was  in  no  respect  inferior  to  that  of 
boys  of  his  age ;  and  he  even  gave  indications  of  distinguished  ability. 
He  sketched  and  painted  with  his  feet.  Not  many  years  ago,  a  Miss 
Honeywell,  born  without  arms,  travelled  about  this  country.  She  had 
acquired  so  much  dexterity  in  the  use  of  the  scissors,  as  to  be  able,  by 
holding  them  in  her  mouth,  to  cut  likenesses,  watch-papers,  flowers,  &c. 
She  also  wrote,  drew,  and  executed  all  kinds  of  needlework  with  the 
utmost  ease  and  despatch.  How  fatal  are  such  authentic  examples  to 
the  views  of  Helvetius  and  others! 

1  De  1'Homme,  &c.,  torn.  i.  2  Traite  des  Sensations,  P.  i. 

3  Histoire  Naturelle,  torn.  vi.  4  Precis  Elementaire,  2de  edit.,  i.  154,  Paris,  1825. 


THE  GEOMETRICAL  SENSE.  141 

But,  it  has  been  said,  that  touch  is  the  least  subject  to  error  of  all 
the  senses:  it  is  the  regulating — the  geometrical  sense.  In  part  only 
is  this  accurate.  It  certainly  possesses  the  advantage  of  allowing  the 
organ  of  sense  to  be  brought  into  immediate  contact  with  the  body  that 
excites  the  impression ;  whilst,  in  the  case  of  olfaction,  the  organ  receives 
the  impression  of  an  emanation  from  the  body;  and,  in  vision  and 
audition,  only  the  vibration  of  an  intervening  medium.  Yet  some  of 
the  errors  into  which  touch  falls  are  as  grievous  as  those  that  happen  to 
the  other  senses.  How  inaccurate  is  its  appreciation  of  the  temperature 
of  bodies !  We  have  attempted  to  show,  that  it  affords  merely  relative 
knowledge, — the  same  substance  appearing  hot  or  cold  to  us,  according 
to  the  temperature  of  the  substance  previously  touched.  Nay,  infalli- 
bility so  little  exists,  that  we  have  the  same  sensation  communicated  by 
a  body  that  rapidly  abstracts  caloric  from  us,  as  by  one  that  rapidly 
supplies  it.  By  touching  frozen  mercury,  which  requires  a  temperature 
of  — 40°  of  Fahrenheit  to  be  congealed,  we  experience  the  sensation  of 
a  burn.  Again,  if  we  cross  the  fingers  and  touch  a  rounded  body — a 
marble,  for  instance — with  two  of  the  pulps  at  the  same  time ;  instead  of 
experiencing  the  sensation  of  one  body,  we  feel  as  if  there  were  two, — 
an  illusion  produced  by  the  lateral  portions  of  fingers  being  brought 
in  apposition,  which  are  naturally  in  a  different  situation,  and  at  a 
distance  from  each  other;  and,  as  these  two  parts  habitually  receive 
distinct  impressions  when  separated,  they  continue  to  do  so  when  ap- 
plied to  opposite  sides  of  the  rounded  body. 

It  has  been  asserted,  that  the  touch  is  the  great  corrector  of  the 
errors  into  which  the  other  senses  fall.  But  let  us  inquire,  whether,  in 
this  respect,  it  possesses  any  decided  superiority  over  them.  For  this 
purpose,  the  distinction  of  the  sensory  functions  into  immediate  and 
mediate  has  been  adopted.  Each  sense  has  its  immediate  function,  which 
it  possesses  exclusively ;  and  for  which,  no  other  can  be  substituted.  The 
touch  instructs  us  regarding  resistance;  the  taste  appreciates  savours; 
the  smell,  odours ;  audition,  sound ;  and  vision,  colours.  These  are  the 
immediate  functions  of  the  senses,  each  of  which  can  be  accomplished 
by  its  own  organs,  but  by  no  other.  As  concerns  the  immediate  func- 
tions of  the  senses,  therefore,  the  touch  can  afford  no  correction.  Its 
predominance,  as  regards  the  mediate  functions  of  the  senses,  is  like- 
wise exaggerated.  The  mediate  functions  are  those  that  furnish  im- 
pressions to  the  mind;  and  by  aid  of  which  it  acquires  its  notions  of 
bodies.  The  essential  difference  between  these  two  sets  of  functions  is, 
that  the  mediate  can  be  effected  by  several  senses  at  once,  and  may  be 
regarded  as  belonging  to  the  cerebrum.  Vision,  olfaction,  and  audition 
participate  in  enabling  us  to  judge  of  distances,  as  well  as  touch;  the 
sight  instructs  us  regarding  shape,  &c.  It  has  been  affirmed  by  meta- 
physicians, that  touch  is  necessary  to  several  of  the  senses  to  give  them 
their  full  power,  and  that  we  could  form  no  notion  of  the  size,  shape, 
and  distance  of  bodies,  unless  instructed  by  this  sense.  The  remarks 
already  made  have  proved  the  inaccuracy  of  this  opinion.  The  farther 
examination  of  it  will  be  resumed  under  Vision.  The  senses  are,  in 
truth,  of  mutual  assistance.  If  the  touch  falls  into  error,  as  in  the 


142  SENSE  OF  TOUCH. 

case  of  inaccurate  appreciation  of  temperature,  the  sight,  aided  by 
appropriate  instruments,  dispels  it.  If  the  crossed  fingers  convey  to 
the  brain  the  sensation  of  two  rounded  bodies,  when  one  only  exists, 
the  sight  apprises  us  of  the  error;  and  if  the  sight  and  touch  united 
impress  us  with  a  belief  in  the  identity  of  two  liquids,  the  smell  or  the 
taste  will  often  detect  the  erroneous  inference. 

But,  it  has  been  said  by  some,  touch  is  the  only  sense  that  gives  us 
any  notion  of  the  existence  of  bodies.  M.  Destutt-Tracy1  has  satis- 
factorily opposed  this,  by  showing  that  such  notion  is  a  work  of  the 
mind,  in  acquiring  which  the  touch  does  not  assist  more  immediately 
than  any  other  sense.  "The  tactile  sensations,"  he  observes,  "have 
not  of  themselves  any  prerogative  essential  to  their  nature,  which  dis- 
tinguishes them  from  others.  If  a  body  affects  the  nerves  beneath  the 
skin  of  my  hand,  or  if  it  produces  certain  vibrations  in  those  distributed 
on  the  membranes  of  my  palate,  nose,  eye,  or  ear,  it  is  a  pure  impres- 
sion which  I  receive ;  a  simple  affection  which  I  experience  ;  and  there 
seems  to  be  no  reason  for  believing  that  one  is  more  instinctive  than 
another ;  that  one  is  more  adapted  than  another  for  enabling  me  to 
judge  that  it  proceeds  from  a  body  exterior  to  me.  Why  should  the 
simple  sensation  of  a  puncture,  burn,  titillation,  or  pressure,  give  me 
more  knowledge  of  the  cause,  than  that  of  a  colour,  sound,  or  internal 
pain?  There  is  no  reason  for  believing  it."  There  are,  indeed,  nu- 
merous classes  of  bodies,  regarding  whose  existence  the  touch  affords 
us  no  information,  but  which  are  detected  by  the  other  senses. 

On  the  whole,  then,  we  must  conclude,  that  the  senses  mutually  aid 
each  other  in  the  execution  of  certain  of  their  functions ;  that  each  has 
its  province,  which  cannot  be  invaded  by  others ;  and  that  too  much 
preponderance  has  been  ascribed  to  the  touch  by  metaphysicians  and 
physiologists.  Ministering,  however,  as  it  does,  so  largely  to  the  mind, 
it  has  been  properly  ranked  with  vision  and  audition  as  an  intellectual 
sense.2 

By  education,  the  sense  of  touch  is  capable  of  acquiring  extraordinary 
acuteness.  To  this  circumstance  must  be  ascribed  the  surprising  feats 
we  occasionally  meet  with  in  the  blind.  For  all  their  reading  and 
writing  they  are,  indeed,  indebted  to  this  sense.  Saunderson — who  lost 
his  eyesight  in  the  second  year  of  his  life,  and  was  Professor  of  Mathe- 
matics at  Cambridge,  England — could  discern  false  from  genuine 
medals;  and  had  a  most  extensive  acquaintance  with  numismatics.3 
As  an  instance  of  the  correct  notions,  which  may  be  conveyed  to  the 
mind  of  the  forms  and  surfaces  of  a  great  variety  of  objects,  and  of 
the  sufficiency  of  these  notions  for  accurate  comparison,  Dr.  Carpenter4 
mentions  the  case  of  a  blind  friend,  who  has  acquired  a  very  complete 
knowledge  of  conchology,  both  recent  and  fossil ;  and  who  is  not  only- 
able  to  recognize  every  one  of  the  numerous  specimens  in  his  own  cabi- 
net, but  to  mention  the  nearest  alliances  of  a  shell  previously  unknown 

1  Elemens  dldeologie,  lere  Partie  p.  114,  2de  edit.     Paris,  1804. 
a  Gall.,  Stir  les  Fonctions  du  Cerveau,  i.  99,  Paris,  1825. 

3  Abercrombie's  Inquiries  concerning  the  Intellectual  Powers;  Amer.  edit.,  p.  55,  New 
York,  1832. 

4  Principles  of  Human  Physiology,  4th  American  edit.,  §  525,  Philad.,  1850. 


IN  ANIMALS.  143 

to  him,  when  he  has  thoroughly  examined  it  by  the  touch.  Baczko, 
referred  to  by  Rudolphi,1  who  describes  his  own  case,  could  discriminate 
between  samples  of  woollen  cloth  of  equal  quality  but  of  different 
colours.  The  black  appeared  to  him  among  the  roughest  and  hardest : 
to  this  succeeded  dark  blue  and  dark  brown,  which  he  could  not,  how- 
ever, distinguish  from  each  other.  The  colours  of  cotton  and  silk  stuffs 
he  was  unable  to  discriminate  ;  and  he  properly  enough  doubts  the  case 
of  a  Count  Lynar,  blind,  who,  it  was  said,  was  capable  of  judging  of 
the  colour  of  a  horse  by  the  feel.  The  only  means  the  blind  can  possess 
of  discriminating  colours  must  be  through  the  physical  differences  of 
surface,  which  render  it  capable  of  reflecting  one  ray  or  combination 
of  rays,  whilst  it  absorbs  the  rest ;  and  if  these  differences  were  insuf- 
ficient to  enable  Baczko  to  detect  the  differences  between  cotton  and 
silk  fabrics,  it  is  not  probable,  that  the  sleek  surface  of  the  horse  would 
admit  of  such  discrimination. 

In  animals  the  organ  of  touch  varies.  The  monkey's  resembles  that 
of  man.  In  other  quadrupeds,  it  is  seated  in  the  lips,  snout,  or  pro- 
boscis. In  molluscous  animals,  the  tentacula;  and  in  insects,  the  antennae 
or  feelers,  are  organs  of  touch,  possessing,  in  some,  very  great  sensi- 
bility. Bats  appear  to  have  this  to  an  unusual  degree.  Spallanzani 
observed  them,  even  after  their  eyes  had  been  destroyed  and  the  ears 
and  nostrils  closed,  flying  through  intricate  passages,  without  striking 
the  walls,  and  dexterously  avoiding  cords  and  lines  placed  in  the  way. 
The  membrane  of  the  wings  is,  in  the  opinion  of  Cuvier  and  many 
others,2  the  organ  that  receives  an  impression  produced  by  a  change  in 
the  resistance  of  the  air.  M.  Jurine  concludes,  that  neither  hearing 
nor  smell  is  the  channel  through  which  they  obtain  perception  of 
the  presence  and  situation  of  surrounding  bodies.  He  ascribes  this 
extraordinary  faculty  to  the  great  sensibility  of  the  skin  of  the  upper 
jaw,  mouth,  and  external  ear,  which  are  furnished  with  large  nerves ; 
whilst  Sir  Anthony  Carlisle  attributes  it  to  the  extreme  delicacy  of 
hearing  possessed  by  the  animal  ;3  a  view  which  is  confirmed  by  ex- 
periments instituted  by  the  author's  friend,  Professor  J.  K.  Mitchell, 
of  Philadelphia.  Certain  experiments  by  Mr.  Broughton,4  sanction 
the  idea  that  this  may  be,  in  part,  dependent  upon  their  whiskers. 
These,  which  are  found  on  the  upper  lip  of  feline  and  other  animals, 
are  plentifully  supplied  with  nerves,  which  seem  to  proceed  from  the 
second  branch  of  the  fifth  pair,  and  are  lost  in  the  substance  of  the 
hairs.  In  an  experiment,  made  by  Mr.  Broughton  on  a  kitten,  he  found 
that  whilst  the  whiskers  were  entire,  it  was  capable  of  threading  its 
way,  blindfold,  from  a  labyrinth  in  which  it  was  designedly  placed ;  but 
it  was  totally  unable  to  do  so  when  the  whiskers  were  cut  off.  It  struck 
its  head  repeatedly  against  the  sides  ;  ran  against  all  the  corners ;  and 
tumbled  over  steps  placed  in  the  way,  instead  of  avoiding  them,  as  it 
did  prior  to  the  removal  of  the  whiskers. 

From  facts  like  these  Mr.  Broughton  drew  the  conclusion,  that  cer- 

1  Grundriss  der  Physiologie,  2er  Band,  s.  85,  Berlin,  1823. 

2  Carpenter,  Human  Physiology,  p.  253,  Lond.,  1842. 

a  See  Roget's  Animal  and  Vegetable  Physiology,  ii.  399,  Amer.  edit.,  Philad.,  1836. 
•»  London  Medical  and  Physical  Journal,  for  1823. 


144  SENSE  OF  TOUCH. 

tain  animals  are   supplied  with  whiskers  for  the  purpose  of  enabling 
them  to  steer  clear  of  opposing  bodies  in  the  dark. 

SENSE  OE  TASTE  OR  GUSTATION. 

The  sense  of  taste  teaches  us  the  quality  of  bodies  called  sapidity. 
It  is  more  nearly  allied  to  touch  in  its  mechanism  than  any  other  of  the 
senses,  as  it  requires  the  immediate  contact  of  the  body  with  the  organ 
of  taste,  and  the  organ  is,  at  the  same  time,  capable  of  receiving  tactile 
impressions  distinct  from  those  of  taste.  Of  this  we  have  a  striking 
example,  if  we  touch  various  portions  of  the  tongue  with  the  point  of  a 
needle.  We  find  two  distinct  perceptions  occasioned.  In  some  parts 
the  sensation  of  a  pointed  body  without  savour ;  and  in  others,  a  me- 
tallic taste  is  experienced.  Pathological  cases,  too,  exhibit,  that  the 
sense  of  taste  may  be  lost,  whilst  general  sensibility  remains, — and  con- 
versely. The  organ  of  gustation  is  not,  therefore,  restricted  to  that 
sense,  but  participates  in  touch.  Yet  so  distinct  are  those  functions, 
that  touch  can,  in  no  wise,  supply  the  place  of  its  fellow  sense,  in  de- 
tecting the  sapidity  of  bodies.  This  last  is  the  immediate  instruction 
afforded  by  gustation. 

1.   ANATOMY   OF   THE   ORGANS   OF   TASTE. 

The  chief  organ  of  taste  is  the  tongue,  or  rather  the  mucous  mem- 
brane covering  the  upper  surface,  and  sides  of  that  organ.  The  lips, 
inner  surface  of  the  cheeks,  palate,  and  fauces,  participate  in  the  func- 
tion, especially  when  particular  savours  are  concerned.  M.  Magendie1 
includes  the  esophagus  and  stomach;  but  we  know  not  on  what  grounds: 
his  subsequent  remarks,  indeed,  controvert  the  idea.  The  lingual 
branch  of  the  fifth  pair  is,  according  to  him,  incontestably  the  nerve 
of  taste;  and,  as  this  nerve  is  distributed  to  the  mouth,  we  can  under- 
stand, why  gustation  should  be  effected  there;  but  not  how  it  can  be 
accomplished  in  the  oesophagus  and  stomach.  The  tongue  consists 
almost  entirely  of  muscles,  which  give  it  great  mobility,  and  enable  it 
to  fulfil  the  various  functions  assigned  to  it;  for  it  is  not  only  an  organ 
of  taste,  but  of  mastication,  deglutition,  and  articulation.  The  muscles 
being  under  the  influence  of  volition,  enable  the  sense  to  be  executed 
passively  or  actively. 

As  regards  gustation,  the  mucous  membrane  is  the  portion  immedi- 
ately concerned.  This  is  formed,  like  the  mucous  membranes  in  gene- 
ral, of  the  different  layers  already  described.  The  corpus  papillare 
requires  farther  notice.  If  the  surface  of  the  tongue  be  examined,  it 
will  be  found  to  consist  of  myriads  of  fine  papillae  or  villi,  that  give  the 
organ  a  velvety  appearance.  These  papillae  are,  doubtless,  like  those 
of  the  skin,  formed  of  the  final  ramifications  of  nerves,  and  of  the  ra- 
dicles of  exhalant  and  absorbent  vessels,  united  by  means  of  a  spongy 
erectile  tissue.  Great  confusion  exists  among  anatomists  in  their  de- 
scriptions of  the  papillae  of  the  tongue.  Those  certainly  concerned  in 
the  sense  of  taste  may,  however,  be  included  in  two  divisions: — 1st,  the 
conical  or  pyramidal, — the  finest  sort  by  some  called  filiform;  and  2dly, 

1  Precis  de  Physiol.,  i.  139. 


ORGANS  OF  TASTE. 


145 


the  fungiform.     The  former  are  Fig.  53. 

broader  at  the  base  than  at  the 

top  ;  and  are  seen  over  the  whole 

surface  of  the  tongue,  from  the 

tip  to  the  root.  The  latter,  which 

are  larger  at  the  top   than  the 

base,  and  resemble  the  mushroom, 

—  whence     their     name,  —  are 

spread  about,  here  and  there,  on 

the  surface  of  the  organ.    These 

must   be    distinguished   from    a 

third  set,  the  papillse  capitatse  or 

circumvallatde,  which  are  situate 

near  the  base  of  the   tongue  in 

two  V  shaped  lines  at  the  base 

of  the  organ.     They  are  circu- 

lar elevations  from  ^th  to  y^th 

of  an  inch  wide,  each  with  a  cen- 

tral  depression,  and   Surrounded    Front  View  of  the  UPI^r  Surface  of  the  Tongue, 
by  a  circular  fissure,  at  the  OUt-  as  well  as  of  the  Palatine  Arch. 

Side  Of  Which,   again,  is  a  Slight-        1,  I-  Posterior  lateral  half  arches,  with  the  palato- 
.         ,  ,      1      •  ,1  11         pharyngei  muscles  and  tonsils.    2.  Epiglottic  carti- 

ly  elevated  ring;   the  Central  ele-    lage,  seen  from  before.    3,3.  Ligament  and  mucous 

ration  and  the  ring  being  formed 
of  close  set  simple  papilla.    The 

epithelium  Of  the  tongue  IS  Of  the 

i          •>  .    .          ?M         ,-,  f 

teSSelateO.     Variety,    like    that    OI 

the  epidermis.     Over    the  fun- 

giform  papillse,  it  forms  a  thin- 

ner layer  than  elsewhere  ;  so  that  they  stand  out  more  prominently  than 

the  rest.     That  which  covers  the  conical  papillse,  according  to  Messrs. 

Todd  and  Bowman,1  has  a  singu- 

lar arrangement;  being  extreme-  Fig.  54. 

ly  dense  and  thick,  and  project- 

ing    from  their  sides  and  tops 

in  the  form  of  long,  stiif,  hair- 

like    processes;   many  of  which 

bear  a   strong   resemblance    in 

structure  to  hairs;  and  some  ac- 

tually contain  hair  tubes. 

All  the  nerves  that  pass  to 
the  parts  whose  office  it  is  to  ap- 
preciate savours,  must  be  con- 
sidered to  belong  to  the  gusta- 
tory apparatus.  These  are  the 
inferior  maxillary;  several  bran- 
ches of  the  superior,  filaments 


I  IS 

pillae  conicse,  seu  maximae.  7.  The  white  point  at  the 
end  of  the  line,  and  all  like  it.  are  the  papillae  funsri- 
formes.  8.  Side  of  the  tongue,  and  rugae  transverse 


View  of  a  Papilla  of  the  smallest  class,  magnified 
25  diameters. 

The  loops  of  blood-vessels  are  here  shown,  each 
loop  containing  usually  only  one  vessel. 


from    the    spheno-palatine    and 

naso-palatine  ganglions ;  the  lingual  branch  of  the  fifth  pair,  com- 


*  The  Physiological  Anat.  and  Physiology  of  Man,  i.  439,  Lond.,  1848,  or  Amer.  edit.,  p.  382. 
VOL.  I. — 10 


146 


SENSE  OF  TASTE. 


Vertical  Section  of  one  of  the  Gustatory  Papillae  of  the  largest 
class,  showing:  its  conical  form,  its  sides,  and  the  fissure 
between  the  different  Papillae. 

The  length  of  some  of  the  divided  blood-vessels,  a  tranvserse 
section  of  others,  and  the  vessels  which  rise  up  from  the  surface 
like  loops  or  meshes,  are  also  shown. 


Fig.  56. 


The  Hypoglossal ;  Lingual  branch  of  fifth  pair ;  Glosso-Pha- 
ryngeal  and  deep-seated  Nerves  of  the  Neck. 

1.  The  hypoglossal  nerve.    2.  Branches  communicating  with  the 

fustatory  nerve.  3.  A  branch  to  the  origin  of  the  hyoid  muscles. 
.  The  descendens  noni  nerve.  5.  The  loop  formed  with  the  branch 
from  the  cervical  nerves.  6.  Muscular  branches  to  the  depressor 
muscles  of  the  larynx.  7.  A  filament  from  the  second  cervical 
nerve,  and  8,  a  filament  from  the  third  cervical,  uniting  to  form  the 
communicating  branch  with  the  loop  from  the  descendens  noni. 
9.  The  auricular  nerve.  10.  The  inferior  dental  nerve.  11.  Its 
mylo-hyoidean  branch.  12.  The  gustatory  nerve.  13.  Thechorda- 
tympani  passing  to  the  gustatory  nerve.  14.  The  chorda-tympani 
leaving  the  gustatory  nerve  to  join  the  sub-maxillary  ganglion. 
15.  The  sub-maxillary  ganglion.  16.  Filaments  of  communication 
-with  the  lingual  nerve.  17.  The  glosso-pharyngeal  nerve.  18. 
The  pneumogastric  or  par  vagum  nerve.  19.  The  three  upper  cer- 
vical nerves.  20.  The  four  inferior  cervical  nerves.  21.  The  first 
dorsal  nerve.  22,  23.  The  brachial  plexus.  24,  25.  The  phrenic 
nerve.  26.  The  carotid  artery.  27.  The  internal  jugular  vein. 


monly  called  the  gus- 
tatory nerve;  the  whole 
of  the  ninth  pair  or 
hypoglossal;  and  the 
glosso-pharyngeal.  To 
which  of  these  must  be 
assigned  the  function 
of  gustation,  we  shall 
inquire  presently. 

Like  the  skin  and 
mucous  membranes  in 
general,  that  of  the 
tongue  and  mouth  con- 
tains, in  its  substance, 
numerous  mucous  fol- 
licles, which  secrete  a 
fluid  that  lubricates  the 
organ,  and  keeps  it  in  a 
condition  adapted  for 
the  accomplishment  of 
its  functions.  Some  of 
these  are  placed  very 
conspicuously  in  the 
mucous  membrane  of 
the  tongue.  They  are 
the  papillse  capitatse  of 
some  anatomists — er- 
roneously named,  as 
they  are  not  formed 
like  papillae,  and  exe- 
cute a  very  different 
office.  They  are  mu- 
cous follicles,  and 
ought  to  be  so  called. 
The  fluids,  exhaled 
from  the  mucous  mem- 
brane of  the  mouth, 
and  the  secretion  of 
the  different  salivary 
glands,  likewise  aid  in 
gustation ;  but  they  are 
more  concerned  in  mas- 
tication and  insaliva- 
tion,  and  will  require 
notice  under  another 
head. 


147 


a  I    A  c 

Papillae  of  the  Tongue. 

A..  Vertical  section  near  the  middle  of  the  dorsal  surface  of  the  tongue:  a,  a.  Fungiform  papillae. 
6.  Filiform  papillae,  with  their  hair-like  processes,  c.  Similar  ones  deprived  of  their  epithelium.— 
Magnified  2  diameters. 

B.  Filiform  compound  papillae  :  a.  Artery,  v.  Vein.  c.  Capillary  loops  of  the  secondary  papillae. 
6.  Line  of  basement  membrane,  d.  Secondary  papilla?,  deprived  of  e,  e,  the  epithelium,  f.  Hair-like 

illos.— Magnified  25  diameters,  g.  Separated  nucleated 


processes  of  epithelium  capping 

particles  of  epithelium,  magnified  300  diameters. 

1,  2.  Hairs  found  on  the  surface  of  the  tongue.    3,  4,  5.  Ends  of  hair-like  epithelial  processes,  show- 

'-  -.,  but  in  all  a  coalescence  of  the  particles 
iiameters. 


ing  varieties  in  the  imbricated  arrangement  of  the  particles, 
towards  the  point.    5.  Incloses  a  soft  hair. — Magnified  160  di 

2.    SAVOURS. 

Before  proceeding  to  explain  the  physiology  of  gustation,  it  may  be  ne- 
cessary to  inquire  briefly  into  the  nature  of  bodies  as  connected  with  their 
sapidity ;  or,  in  other  words,  into  savours,  which  are  the  cause  of  sapidity. 

The  ancients  were  of  opinion,  that  the  cause  of  sapidity  is  a  peculiar 
principle,  which,  according  to  its  combination  with  the  constituents  of 
bodies,  gives  rise  to  various  savours.  This  notion  has  been  long  aban- 
doned ;  and  chiefly,  because  we  observe  no  general  or  common  charac- 
ters amongst  sapid  bodies,  which  ought  to  be  were  they  pervaded  by  the 
same  principle;  and  because  bodies  may  be  deprived  of  their  sapidity 
by  subjecting  them  to  appropriate  processes.  Many  of  our  culinary 
processes  have  been  instituted  for  this  purpose :  the  infusion  of  tea  is 
indebted  for  all  its  attractions  to  the  power  we  possess  of  separating,  by 
boiling  water,  the  savoury  from  the  insipid  portions  of  the  plant.  A 
sapid  principle  must,  therefore,  be  esteemed  an  integrant  molecule  of 
a  body ;  not  the  same  in  all  cases,  but  as  heterogeneous  in  its  nature 
as  the  impressions  made  upon  the  organ  of  taste. 


148  SENSE  OF  TASTE. 

When  the  notion  was  once  entertained,  that  a  sapid  principle  is  an 
integrant  molecule,  sapidity  was  attempted  to  be  explained  by  its  shape. 
It  was  said,  for  instance,  that  if  the  savour  be  sweet,  the  molecule  must 
be  round;  if  sharp,  angular;  and  so  forth.  Sugar  was  said  to  possess  a 
spherical, — acids,  a  pointed,  or  angular  molecule.  We  know,  however, 
that  substances  which  resemble  each  other  in  the  primitive  shape  of  their 
crystal,  impress  the  organ  of  taste  differently ;  and  that  solution,  which 
must  destroy  most — if  not  all — the  influence  from  shape,  induces  no 
change  in  the  savour. 

Others  have  referred  sapidity  to  a  kind  of  chemical  action  between 
the  molecules,  and  the  nervous  fluid.  This  view  has  been  suggested  by 
the  fact,  that,  as  a  general  principle,  sapid,  like  chemical  bodies,  act 
only  when  in  a  state  of  solution ;  that  the  same  savours  usually  belong 
to  bodies  possessed  of  similar  chemical  properties,  as  is  exemplified  by 
the  sulphates  and  nitrates;  and  that,  in  the  action  of  acids  on  the  tongue 
and  mouth,  we  witness  a  state  of  whiteness  and  constriction,  indicative 
of  a  first  degree  of  combination.  All  these  circumstances,  however, 
admit  of  another  explanation.  There  are  unquestionably  many  sub- 
stances, which  do  combine  chemically, — not  with  a  nervous  fluid,  of 
whose  existence  we  know  nothing, — but  with  the  mucus  of  the  mouth ; 
and  the  sapidity  resulting  from  such  combination  is  appreciated  by  the 
nerves  of  taste ;  but  there  are  many  bodies,  which  are  eminently  sapid, 
and  yet  afford  us  instances  of  very  feeble  powers  of  chemical  com- 
bination ;  nay,  in  numerous  cases,  we  have  not  the  least  evidence  that 
such  powers  exist.  Vegetable  infusions  or  solutions  are  strong  ex- 
amples of  the  kind, — of  which  syrup  may  be  taken  as  the  most  fami- 
liar. The  effect  of  solution  is  easily  intelligible ;  the  particles  of  the 
sapid  body  are  in  this  way  separated,  and  come  successively  into 
contact  with  the  gustatory  organ ;  but  there  is  some  reason  to  believe, 
that  solution  is  not  always  requisite  to  give  sapidity.  Metals  have 
generally  a  peculiar  taste,  which  has  been  denominated  metallic  ;  and 
this,  even  if  the  surface  be  carefully  rubbed,  so  as  to  free  it  from  oxide, 
which  is  more  or  less  soluble.  Birds,  too,  whose  organs  of  taste  are 
as  dry  as  the  corn  they  select  from  a  mass  of  equally  arid  substances, 
are  probably  able  to  appreciate  savours.  The  taste  produced  by  touch- 
ing the  wires  of  a  galvanic  pile  with  the  tongue  has  been  offered  as 
another  instance  of  sapidity  exhibited  by  dry  bodies.  This  is,  more 
probably,  the  effect  of  the  chemical  action  on  the  fluids  covering  the 
mucous  membrane  of  the  tongue,  which  always  follows  such  contact. 
Such  chemical  change  must,  however,  be  confined  to  these  fluids;  and, 
when  once  produced,  the  nerve  of  taste  is  impressed  by  the  savour  de- 
veloped in  the  same  manner  as  it  is  in  cases  of  morbid  alterations  of 
the  secretion  of  the  mucous  membrane.  In  both  cases,  a  body  pos- 
sessing considerable  and  peculiar  sapidity  may  fail  to  impress  the 
nerves  altogether,  or  may  do  so  inaccurately.  The  notion  of  any  che- 
mical combination  with  the  nervous  fluid  must  of  course  be  discarded, 
as  there  is  not  the  slightest  evidence  in  favour  of  the  hypothesis ;  yet 
the  epithet  chemical  was  once  applied  to  this  sense  on  the  strength  of 
it;  in  opposition  to  the  senses  of  touch,  vision,  and  audition,  which 
were  called  mechanical,  and  supposed  to  be  produced  by  vibrations  of 
the  nerves  of  those  senses. 


CLASSIFICATION  OF  SAVOURS.  149 

The  savours,  met  with  in  the  three  kingdoms  of  nature,  are  innu- 
merable. Each  body  has  its  own,  by  which  it  is  distinguished :  few 
instances  occur  in  which  any  two  can  be  said  to  be  identical.  This 
is  the  great  source  of  difficulty,  when  we  attempt  to  throw  them  into 
classes,  as  has  been  done  by  physiologists.  Of  these  classifications, 
the  one  by  Linnaeus1  is  best  known :  it  will  elucidate  the  unsatisfactory 
character  of  the  whole.  He  divides  sapid  bodies  into  sicca,  aquosa, 
viscosa,  salsa,  acida,  styptica,  dulcia,  pinguia,  amara,  acria,  and  nau- 
seosa.  He  gives  also  examples  of  mixed  savours,  acido-acria,  acido- 
amara,  amaro-acria,  amaro-acerba,  amaro-dulcia,  dulci- styptic  a,  dulci- 
acida,  dulci-acria,  and  acri-viscida ;  and  remarks,  that  the  majority 
are  antitheses  to  each  other,  two  and  two, — as  dulcia  and  acria  ;  pin- 
guia  and  styptica;  viscosa  and  salsa;  and  aquosa  and  sicca.  Boer- 
haave2  again  divides  them  into  primary  and  compound;  the  former 
including  the  sour,  siveet,  bitter,  saline,  acrid,  alkaline,  vinous,  spiritu- 
ous, aromatic,  and  acerb  ; — the  latter  resulting  from  the  union  of  cer- 
tain primary  savours.  There  is  no  accordance  amongst  physiologists 
as  to  those  that  should  be  esteemed  primary,  and  those  secondary  and 
compound  ;  although  the  division  appears  to  be  admissible.  The  acerb, 
for  example — which  is  considered  primary  by  Boerhaave — is  by  others, 
with  more  propriety,  classed  among  secondary  or  compound,  and  be- 
lieved to  consist  of  a  combination  of  the  acrid  and  acid.  We  under- 
stand, however,  sufficiently  well  the  character  of  the  acid,  acrid,  bitter, 
acerb,  sweet,  &c.;  but  when,  in  common  language,  we  have  to  depict 
other  savours,  we  are  frequently  compelled  to  take  some  well-known 
substance  as  a  standard  of  comparison. 

According  to  M.  Adelon,3  the  only  distinction  we  can  make  amongst 
them  is, — into  the  agreeable  and  disagreeable.  Yet  of  the  unsatisfac- 
tory nature  of  this  classification  he  himself  adduces  numerous  proofs. 
It  can  only,  of  course,  be  applicable  to  one  animal  species,  often  even 
to  an  individual  only ;  and  often  again  only  to  such  individual  when 
in  a  given  condition.  Some  animals  feed  upon  substances,  that  are  not 
only  disagreeable  but  noxious  to  others.  The  most  poisonous  plants 
have  an  insect  which  devours  them  greedily  and  with  impunity :  the 
southern  planter  is  well  aware,  that  this  is  the  case  with  his  to- 
bacco, unless  the  operation  of  worming  be  performed  in  due  season. 
The  old  adage,  that  "one  man's  meat  is  another  man's  poison,"  is 
metaphorically  accurate.  Each  individual  has,  by  organization  or  asso- 
ciation, dislikes  to  particular  articles  of  food,  or  shades  of  difference 
in  his  appreciation  of  tastes,  which  may  be  esteemed  peculiar ;  and, 
in  certain  cases,  these  peculiarities  are  signal  and  surprising. 

Of  the  strange  differences,  in  this  respect,  that  occur  in  the  same 
individual  under  different  circumstances,  we  have  a  forcible  instance  in 
the  pregnant  female,  who  often  ardently  desires  substances,  that  were 
previously  perhaps  repugnant  to  her,  or,  at  all  events,  not  relished. 
The  sense,  too,  in  certain  diseases — especially  of  a  sexual  character,  or 
such  as  are  connected  with  the  state  of  the  sexual  functions — becomes 
strangely  depraved,  so  that  substances,  which  can  in  no  way  be  ranked 

1  Amoenit.  Academ.,  ii.  335.  a  Prselect.  Academ.,  torn.  iv. 

3  Physiologic  de  1'Homme,  seconde  6dit,  i.  301,  Paris,  1829.    , 


150  PHYSIOLOGY  OF  TASTE. 

as  eatables  are  greedily  sought  after.  A  young  lady  was  under  the 
care  of  the  author,  whose  bonne  louche  was  slate  pencils.  In  other 
cases,  we  find  chalk,  brickdust,  ashes,  dirt,  &c.,  preferred.  Habit,  too, 
has  considerable  effect  in  our  decisions  regarding  the  agreeable.  The 
Roman  liquamen  or  garum,  the  most  celebrated  sauce  of  antiquity,  was 
prepared  from  half  putrid  intestines  of  fish ;  and  one  of  the  varieties 
of  the  Ortoj  2a<j>iov,  laserpitium,  is  supposed  to  have  been  assafoetida.1 
Even  at  this  day,  certain  orientals  are  fond  of  the  flavour  of  this  nauseous 
substance.  Putrid  meat  is  the  delight  of  some  nations ;  and  a  rotten  egg, 
especially  if  accompanied  with  the  chick,  is  esteemed  by  the  Siamese. 
In  civilized  countries,  we  find  game,  in  a  putrescent  state,  eaten  as  a 
luxury :  this,  to  those  unaccustomed  to  it,  requires  a  true  education.  The 
same  may  be  said  of  the  pickled  olive,  and  of  several  cheeses— -fromage 
de  Gruyere,  for  example — so  much  esteemed  by  the  inhabitants  of  con- 
tinental Europe. 

M.  Magendie2  asserts,  that  the  distinction  of  savours  into  agreeable 
and  disagreeable  is  the  most  important, — as  substances  whose  taste  ap- 
pears agreeable  to  us  are  generally  useful ;  whilst  those  whose  taste  is 
disagreeable  are  commonly  noxious.  As  a  general  rule  this  is  true, 
but  there  are  many  signal  exceptions  to  it. 

3.    PHYSIOLOGY  OF  TASTE. 

The  physiology  of  taste  being  so  nearly  allied  to  that  of  touch 
effected  by  mucous  membranes,  it  will  not  be  necessary  to  repeat  the 
uses  of  the  various  layers  of  which  the  membrane  of  the  mouth 
consists.  In  order  that  taste  may  be  satisfactorily  executed,  it  is 
necessary  that  the  membrane  should  be  in  a  state  of  integrity ;  for  if 
the  cuticle  be  removed,' gustation  is  not  effected;  and  the  morbid  sen- 
sation of  pain  is  substituted.  It  is  also  indispensable  that  the  fluids 
poured  into  the  cavity  of  the  mouth  should  be  in  necessary  quantity, 
and  possess  proper  physical  characteristics.  We  can  farther  appreciate 
the  advantages  of  mastication  and  insalivation,  by  which  solid  bodies 
are  divided  into  minute  portions;  dissolved  when  soluble,  and  brought 
successively  in  contact  with  the  organ  of  taste.  The  gustatory  nerves 
thus  receive  the  impression,  and  by  them  it  is  transmitted  to  the 
brain.  These  nerves  go  to  the  formation  of  the  papillae,  which,  we  have 
seen,  are  situate  in  a  spongy,  erectile  tissue.  As  in  the  sense  of 
tact  and  touch,  it  is  probable  that  this  erectile  tissue  is  not  passive 
during  the  exercise  of  taste  ;  and  that  the  papillae,  through  it,  assume 
a  kind  of  erection.  M.  Magendie3  believes  this  view  to  be  void  of  founda- 
tion ;  but  Sir  C.  Bell4  has  properly  remarked,  that  if  we  take  a  pencil, 
dip  it  in  a  little  vinegar ;  and  touch,  or  even  rub  it  strongly  on  the  sur- 
face of  the  tongue,  where  these  papillae  do  not  exist,  the  sensation  of 
the  presence  of  a  cold  liquid  is  alone  experienced;  but  if  we  touch  one 
of  the  papillae  with  the  point  of  the  brush,  and,  at  the  same  time,  use 
a  magnifying  glass,  it  is  seen  to  stand  erect,  and  the  acid  taste  is  felt 
to  pass,  as  it  were  backward,  to  the  root  of  the  tongue.  This  experi- 

1  See  an  article  on  the  Gastronomy  of  the  Romans,  by  the  author,  in  Amer.  Quarterly 
Review,  ii.  422,  Philad.,  1827. 

9  Precis  Elementaire,  i.  139.  3  Precis,  &c.,  i.  141. 

4  Anatomy  and  Physiol.,  Godmanjs  5th  Amer.  edit.,  ii.  283,  New  York,  1827. 


PHYSIOLOGY  OF  TASTE.  151 

ment  confirms  the  one  with  the  point  of  the  needle  before  referred  to, 
and  shows  that  the  parts  of  the  tongue  which  possess  the  power  of 
receiving  tactile  impressions  are  distinct  from  those  concerned  in 
gustation.  The  fine  conical  papillae,  by  some  called  filiform,  seated 
at  the  sides  and  tip  of  the  tongue,  have  been  generally  esteemed  the 
most  exquisitely  sensible. 

The  sense  of  taste  is  almost  wholly  accomplished  in  the  membrane 
covering  the  tongue.1  M.  A.  Verniere2  found,  in  experiments  which  he 
instituted,  the  mucous  membrane  of  the  palatine  arch,  gums,  cheeks, 
lips,  and  middle  and  dorsal  region  of  the  tongue  constantly  insensible 
to  savours  ;  whilst  gustatory  sensibility  was  possessed  by  the  membrane 
covering  the  sublingual  glands,  the  inferior  surface,  point,  edges  and 
base  of  the  tongue ;  the  pillars  and  two  surfaces  of  the  velum  palati, 
the  tonsils  and  pharynx.  Subsequently,  MM.  Guyot  and  Admyrauld3 
found,  from  a  series  of  experiments  made  upon  themselves,  that  the 
lips,  inner  surface  of  the  cheeks,  palatine  arch,  pharynx,  pillars  of  the 
velum  palati,  and  dorsal  and  inferior  surface  of  the  tongue  are  inca- 
pable of  appreciating  savours ;  and  that  the  seat  of  gustation  is  at  the 
posterior  and  deep-seated  part  of  the  tongue,  beyond  a  curved  line, 
whose  concavity  anteriorly  passes  through  the  foramen  caecum,  and 
joins  the  two  margins  of  the  tongue  anterior  to  the  pillars ; — at  the 
edges  of  the  tongue ;  and  on  a  surface  of  about  two  lines  uniting  them 
with  the  dorsal  surface : — at  the  apex  with  an  extension  of  four  or  five 
lines  on  the  dorsal,  and  of  one  or  two  on  the  inferior  surface;  and 
lastly,  at  a  small  space  of  the  velum  palati  situate  nearly  at  the  centre 
of  its  anterior  surface.  M.  Guyot,  moreover,  found,  that  the  same 
sapid  body  does  not  produce  the  same  sensation  on  every  part  of  the 
gustatory  organ.  We  find,  indeed,  that  certain  bodies  affect  one  part 
of  the  mouth,  and  others  another.  Acids  act  more  especially  on  the 
lips  and  teeth ;  acrid  bodies,  as  mustard,  on  the  pharynx.  These  experi- 
ments were  repeated  by  M.  Longet,4  with  every  precaution  pointed  out 
by  MM.  Verniere,  Guyot,  and  Admyrauld.  The  results  agreed  generally 
with  those  of  M.  Verniere.  He  could  not,  however,  discover  any  gus- 
tatory sensibility  in  the  mucous  membrane  covering  the  superior  surface 
of  the  velum  palati,  the  sublingual  glands  and  inferior  surface  of  the 
tongue;  and  he  does  not  regard  the  superior  and  middle  region  of  the 
tongue  as  absolutely  devoid  of  gustatory  sensibility. 

That  the  sense  is  not  restricted  to  the  tongue  we  have  direct  evidence 
in  those  cases  in  which  the  tongue  has  been  wanting.  M.  Roland,  of  Sau- 
mur,5  gives  the  case  of  a  child,  six  years  of  age,  who  lost  the  organ  in 
smallpox;  and  yet  could  speak,  spit,  chew,  swallow,  and  taste.  De 
Jussieu6  exhibited  to  the  Academie  des  Sciences  of  Paris,  in  1718,  a 
Portuguese  girl,  born  without  a  tongue,  who  also  possessed  these  facul- 
ties. In  a  case  mentioned  byM.  Berdot,  and  cited  by  Rudolphi,7  in  which 

1  Bidder,  Art.  Schmecken,  in  Wagner's  Handworterbuch  der  Physiologie,  13ste  Lieferung 
s.  2.  Braunschweig,  1846.  a  Journal  des  Progres,  &c.,  iii.  208,  and  iv.  219.  Paris,  1827. 

3  Memoire  sur  le  Siege  du  Gout  chez  I'Homme,  Paris  1830,  and  Archives  Generates  de 
Medecine,  Janvier,  1837. 

*  Traite  de  Physiologie,  torn.  ii.  p.  166.     Paris,  1850. 
Aglossostomographie,  Paris,  1630. 

6  Mem.  de  TAcadem.  des  Sciences,  p.  6.  Paris,  1718. 

7  Grundriss  der  Physiologie,  2er  Band.  Iste  Abtheil.  s.  92.     Berlin,  1823. 


152  PHYSIOLOGY  OF  TASTE. 

no  part  of  the  tongue  existed,  the  individual  could  appreciate  the  bit- 
terness of  sal  ammoniac;  and  the  sweetness  of  sugar;  and  Blumenbach1 
refers  to  that  of  a  young  man,  who  was  born  without  a  tongue ;  and 
yet,  when  blindfolded,  could  distinguish  between  solutions  of  salt, 
sugar,  and  aloes,  put  upon  the  palate.2 

Certain  bodies  leave  their  taste  in  the  mouth  for  a  length  of  time 
after  they  have  been  swallowed.  This  arriere-gout — N achgeschmack 
of  the  Germans — is  sometimes  felt  in  the  whole  mouth ;  at  others,  in  a 
part  only;  and  is  probably  owing  to  the  papillae  having  imbibed  the 
savour, — for  the  substances  producing  the  effect  belong  principally  to 
the  class  o*f  aromatics.  This  imbibition  frequently  prevents  the  savour 
of  another  substance  from  being  duly  appreciated ;  and,  in  the  admi- 
nistration of  nauseous  drugs,  we  avail  ourselves  of  the  knowledge  of  the 
fact,  either  by  previously  giving  an  aromatic  so  as  to  forestall  the 
nauseous  impression,  or,  by  combining  powerful  aromatics  with  it,  which 
strongly  impress  the  nerves,  and  produce  a  similar  result. 

There  is  a  common  experiment,  which  has  been  the  foundation  of 
numerous  wagers,  and  elucidates  this  subject;  or  at  least  demonstrates, 
that  the  effect  produced  upon  the  nerve  by  the  special  irritant  continues, 
as  in  the  case  of  the  other  senses,  for  some  time  after  it  has  made  its 
impression,  so  that  the  nerve  becomes,  for  a  time,  comparatively  insen- 
sible to  the  action  of  other  sapid  bodies.  It  consists  in  giving  to  one — 
blindfold — brandy,  rum,  and  gin,  or  other  spirituous  liquors  in  rapid 
succession,  and  seeing  whether  he  can  discriminate  one  from  another. 
A  few  contacts  are  sufficient  to  impregnate  the  nerve  so  completely  that 
distinction  becomes  confounded. 

It  has  been  remarked,  that  numerous  nerves  are  distributed  to  the 
organ  of  taste :  the  ninth  pair,  lingual,  and  other  branches  of  the  fifth,  and 
glosso-pharyngeal.  (See  Fig.  56.)  An  interesting  question  arises — which 
of  these  is  the  nerve  of  taste;  or  are  more  than  one,  or  the  whole,  con- 
cerned? Of  old,  the  lingual  nerve  of  the  fifth  pair  was  universally  consi- 
dered to  accomplish  the  function ;  the  other  nerves  being  looked  upon  as 
simple  motors.  Boerhaave  and  others  assigned  the  office  to  the  ninth, 
and  considered  the  others  to  be  motors.  The  filaments  of  the  fifth 
have  been  described  as  traceable  even  in  the  papillae;  but  others  have 
denied  this.  Opinions  have  generally  settled  down  upon  the  lingual 
branch  of  the  fifth  pair.  Such  is  the  view  of  Sir  Charles  Bell,  who 
considers  the  ninth  pair,  which  arises  from  the  anterior  column  of  the 
spinal  marrow,' the  nerve  of  motion  for  the  tongue;  the  lingual  branch 
of  the  fifth,  a  nerve  having  a  posterior  root,  the  nerve  of  taste ;  and 
the  glosso-pharyngeal,  the  nerve  by  which  the  tongue  is  associated 
with  the  pharynx  in  the  function  of  deglutition.  Bellingeri3  thinks 
the  last  nerve  gives  the  organic  and  involuntary  character  to  the 
tongue.  In  this  it  is  aided  by  branches  of  the  fifth  pair  and  pneumo- 
gastric.  The  hypoglossal  he  regards  as  the  nerve  of  the  voluntary 
motions  of  the  organ  for  articulate  speech,  and  modulated  sound  in 
singing, — an  inference  which  has  seemed  to  be  confirmed  by  the  fact, 

1  Comparative  Anatomy,  by  Lawrence,  p.  323,  Lond.,  1807, 

2  BrillatSavarin,  Physiologic  du  Gout,  p.  38.     Paris,  1843. 

3  Dissert.  Inaugural.  Turini,  1823,  noticed  in  Edinb.  Med.  and  Surg.  Journal  for  July, 
1834,  p.  129. 


NERVE  OF  TASTE.  153 

that  in  fishes  (pieces  muti)  it  is  wanting.  It  is  likewise  maintained, 
that  the  fifth  is  the  first  encephalic  nerve,  which  appears  in  the  lower 
classes  of  animated  nature;  as  the  taste  is  the  first  of  the  special 
senses  noticed  in  them ;  that,  at  first,  the  nerve  consists  only  of  the 
lingual  branch ;  and  farther,  that  its  size,  in  animals,  is  generally  in  a 
ratio  with  that  of  the  organs  of  taste  and  mastication. 

Certain  experiments  by  M.  Magendie1  would  seem  to  settle  the  ques- 
tion definitely.  On  dividing  the  lingual  branch  of  the  fifth  pair  on  ani- 
mals, he  found  that  the  tongue  continued  to  move,  but  that  they  lost 
the  faculty  of  appreciating  savours.  The  palate,  gums,  and  internal 
surface  of  the  cheeks,  however,  preserved  the  faculty,  because  supplied 
with  other  branches  of  the  fifth.  But  when  the  trunk  of  the  nerve 
was  cut  within  the  cranium,  the  power  of  recognising  savours  was  com- 
pletely lost  in  every  part  of  the  mouth, — even  in  the  case  of  highly 
acrid  and  caustic  bodies.  He  found,  too,  that  the  loss  of  sense  occur- 
red in  all  those  who  had  the  fifth  pair  morbidly  affected, — a  fact,  which 
has  been  confirmed  by  observations  of  others.2 

Experiments  on  dogs  by  Professor  Panizza,  of  Pavia,  led  him  to  infer, 
that  the  hypoglossal  is  the  nerve  of  motion  for  the  tongue  ;  the  lingual 
branch  of  the  fifth  pair,  the  nerve  of  general  sensibility;  and  the 
glosso-pharyngeal,  the  neuve  of  gustation.3  The  views  of  Panizza  have 
been  embraced  by  Messrs.  Elliotson,4  Wagner,5  Valentin,  Bruns, 
Broughton,6  and  others,  and  have  been  recently  confirmed  by  the  ex- 
periments and  observations  of  Stannius  ;7  and  Mr.  Broughton  has 
summed  up  what  he  considers  to  be  the  final  results  of  all  the  comparative 
inquiries.  The  communicating  nerve  of  the  face  (portio  dura),  and  the 
fifth  pair,  arising  by  distinct  roots,  send  off  branches  as  they  emerge 
from  the  bed  of  the  parotid  gland,  some  of  which  unite  in  parallel  lines, 
and  others  do  not,  each  ramification  retaining  the  original  property  of 
its  own  root  unmixed;  the  one  destined  to  govern  certain  motions  of 
different  parts  of  the  face ;  the  other  devoted  to  tactile  sensibility,  as 
far  as  regards  the  superficial  parts  of  the  face..  Thus  far,  there  is  no 
disagreement :  the  whole  development  has  been  arrived  at  by  repeated 
experiments  by  different  persons.  In  the  next  place,  it  appears,  that 
the  hypoglossal  governs  the  motions  of  the  tongue ;  deglutition ;  and 
mastication,  without  interfering  with  common  sensation  and  taste.  The 
instinctive  and  voluntary  motions  of  the  tongue  are  all  destroyed  by 
dividing  this  nerve.  The  next  position  is,  that  the  lingual  branches  of 
the  fifth  pair  are  devoted  to  tactile  sensibility,  or  the  common  sensation 

1  Precis.,  i.  144,  and  Journal  de  Physiologie,  t.  iv. 

a  Mr.  Bishop,  in  Lond.  Med.  Gazette  ibr^Dec.  12,  1835;  and  Romberg,  Miiller's  Archiv., 
1838,  H.  iii. 

3  Ricerche  Sperimentali  sopra  i  Nervi,  translated  in  Edinb.  Med.  and  Surg.  Journal,  for 
Jan.,  1836,  p.  70;  see  also,  Amer.  Journal  of  the  Med.  Sciences,  May,  1836,  p.  188;  and 
Mayo,  Outlines  of  Human  Physiology,  4th  edit.,  p.  314,  London,  1837. 

*  Human  Physiology,  p.  536,  Lond.  1840. 

6  Traite  de  Nevrologie,  trad,  par  Jourdan,  p.  433,  Paris,  1843,  and  Lehrbuch  der  Physio- 
logie des  Menschen,  ii.  679.  Braunschweig,  1844. 

«  Edinburgh  Medical  and  Surgical  Journal,  April,  1836,  p.  431.  A  case  in  which  there 
was  complete  insensibility  of  every  part  supplied  by  the  fifth  pair,  and  the  sense  of  taste 
was  perfect,  is  given  in  Bullet,  dell  Scienz.  Medich.,  Aprile,  1841,  cited  in  Brit,  and  For. 
Med.  Rev.,  Oct.,  1842,  p.  545.  See,  also,  Bidder,  Art.  Schmecken,in  Wagner's  Handwcirter- 
buch  der  Physiologie,  loc.  cit.  v  Muller's  Archiv.,  s.  132-138,  Berlin,  1848. 


154  PHYSIOLOGY  OF  TASTE. 

of  the  tongue.  Their  division  does  not  affect  the  motions  of  that  organ 
or  its  power  of  taste ;  both  remain  entire.  Lastly,  when  the  glosso- 
pharyngeal  nerve  is  divided,  the  sense  of  taste  is  lost ;  whilst,  the  other 
nerves  being  uninjured,  motion  and  tactile  sensibility  remain.  Pro- 
fessor Panizza  found,  that  when  the  glosso-pharyngeal  nerves  were 
divided,  the  animal  could  not  taste  coloquintida. 

From  a  series  of  experiments,  however,  similar  to  those  of  Panizza 
and  Mr.  Broughton,  Mr.  Mayo  inferred,  in  conformity  with  an  opinion 
previously  expressed  by  him,1  that  the  lingual  branch  of  the  fifth  is  the 
proper  nerve  of  taste,  and  that  it  possesses  also  general  sensibility; 
that  the  ninth  or  hypoglossal  is  the  nerve  of  voluntary  motion ;  whilst 
the  glosso-pharyngeal  is  in  part  a  nerve  of  voluntary  motion  and  in 
part  of  general  sensibility,  but  not  of  taste.2  Again  :  the  experiments 
and  researches  of  Dr.  John  Reid,3  have  satisfied  him,  that  after  the 
perfect  section  of  the  glosso-pharyngeal  nerves  on  both  sides,  the  sense 
of  taste  is  sufficiently  acute  to  enable  the  animal  to  recognise  bitter 
substances ;  and  his  inference  is,  that  this  nerve  may  participate  with 
others  in  the  function  of  taste ;  but  that  it  assuredly  is  not  the  special 
nerve  of  that  sense.  Prof.  J.  Muller4  esteems  it  certain,  both  from  his 
own  experiments  and  those  of  M.  Magendie  and  others,  as  well  as  from 
pathological  observations,  that  the  lingual  branch  of  the  fifth  is  the 
principal  nerve  of  taste  of  the  tongue ;  but  he  does  not  regard  it  proved, 
that  the  glosso-pharyngeal  has  no  share  in  the  perception  of  taste  at 
the  posterior  part  of  the  tongue,  and  in  the  fauces.  Dr.  Carpenter,5 
from  a  consideration  of  how  nearly  the  sense  of  taste  is  allied  to  that 
of  touch,  and  bearing  in  mind  the  distribution  of  the  two  nerves,  thinks 
it  not  difficult  to  arrive  at  the  conclusion,  that  both  nerves  are  concerned 
in  the  function  ;6  and  that  there  seems  good  reason  to  believe  the 
glosso-pharyngeal  to  be  exclusively  that  through  which  the  impressions 
made  by  disagreeable  substances  taken  into  the  mouth  are  propagated 
to  the  medulla  oblongata,  so  as  to  produce  nausea,  and  excite  efforts  to 
vomit ; — whilst  M.  Longet7  regards  the  lingual  branch  of  the  fifth  and 
the  glosso-pharyngeal  as  necessary  for  the  general  and  special  sensibility 
of  the  gustatory  organs,  "  the  action  of  the  one  perfecting  that  of  the 
other,  both  as  respects  the  general  sensibility  and  the  gustatory  sensi- 
bility of  the  tongue."  It  may  be  proper  to  add,  that  experiments  seem  to 
show,  that  the  glosso-pharyngeal  possesses  also  a  direct  motor  influence. 
Such  is  the  inference  of  Messrs.  J.  Muller,  Volkmann,  and  Hein.  The 
last  observer,  whose  experiments  were  carefully  performed,  states  that 
his  results  accord  completely  with  those  of  Volkmann.  When  the  roots 
of  the  glosso-pharyngeal  nerve  were  irritated  in  the  recently  cut-off 
heads  of  calves  and  dogs,  after  removing  the  brain  and  medulla  ob- 

1  Anatomical  and  Physiological  Commentaries,  p.  2,  Lond.,  1822. 

3  Bostock's  Physiology,  3d  edit.,  p.  732,  Lond.,  1836;  and  Mayo,  Outlines  of  Physiology, 
4th  edit.,  p.  314,  Lond.,  1837. 

3  Edinburgh  Medical  and  Surg.  Journal,  for  Jan.,  1838,  p.  129.     See,  on  this  disputed  topic, 
Alcock,  in  Dublin  Journal,  for  Nov.,  1836,  and  J.  Guyot,  Archives   Generates  de  Medecine, 
Janvier,  1837. 

4  Elements  of  Physiology,  by  Baly,  P.  v.  p.  1321,  Lond.,  1839. 

5  Human  Physiology,  p.  173,  and  p.  253,  Lond.,  1842. 

6  Todd  and  Bowman,  The  Physiological  Anatomy  and  Physiology  of  Man,  p.  442,  London, 
1845. 

7  Traite  de  Physiologic,  ii.  297,  Paris,  1850. 


IMMEDIATE  FUNCTION  OF  TASTE.  155 

longata,  and  separating  their  roots  from  those  of  the  pneumogastric, 
contractions  always  ensued  in  the  stylo-pharyngeus  muscle.  From  all 
the  facts  adduced  by  recent  observers,  Mr.  Paget1  thinks  it  probable, — 
First.  That  the  glosso-pharyngeal  is  chiefly  the  nerve  of  taste,  and,  in 
a  less  degree,  a  nerve  of  common  sensation ;  and  Secondly.  That, 
according  to  the  experiments  of  MM.  MUller  and  Hein,  it  is  the  motor 
nerve  of  the  stylo-pharyngeus,  and  probably  also  of  the  palato-glossus. 

Lastly,  M.  de  Blainville  supposes,  that  the  sense  of  taste  is,  per- 
haps, neither  sufficiently  special  nor  sufficiently  limited  in  extent  to 
have  a  separate  nervous  system;  and  therefore  that  all  the  nerves  of 
the  tongue  are  equally  inservient  to  the  sense,  as  the  different  nerves 
of  the  skin,  which  proceed  from  numerous  pairs,  are  equally  inservient 
to  touch  or  tact.2 

Such  is  the  existing  state  of  uncertainty  regarding  this  interesting 
point  of  physiology:  the  view  of  Panizza  appears,  however,  to  the 
author,  to  be  most  in  accordance  with  analogy;  and  in  all  respects  most 
worthy  of  adoption.  From  the  experiments  and  observations  of  Bellin- 
geri,  Montault,  Diday,  C.  Bernard,  and  Verga,3  it  would  appear,  that 
the  filaments  of  the  chorda  tympani,  which  are  united  and  confounded 
with  those  of  the  lingual  branch  of  the  fifth  pair,  are  in  an  inexplicable 
manner  connected  with  gustation.  When  the  facial  nerve  has  been 
paralyzed,  or  divided  above  the  origin  of  the  tympanic  branch,  the 
sense  of  taste  has  been  impaired.  The  functions  of  the  chorda  tym- 
pani are  by  no  means  determined; — some  esteeming  it  as  a  sensory, 
others  as  a  motor  nerve;  whilst  others,  again,  believe  it  to  possess  both 
sensory  and  motor  properties. 

The  immediate  function  of  taste,  as  has  been  remarked,  is  to  give 
the  sensation  of  savours.  This  function,  like  touch,  is  instinctive; 
requires  no  education ;  cannot  be  supplied  by  any  of  the  other  senses, 
and  is  accomplished  as  soon  as  the  tongue  has  acquired  the  necessary 
degree  of  development.  To  this  it  may  be  replied,  that  the  very  young 
infant  is  not  readily  affected  by  savours.  In  all  cases,  however,  cer- 
tain sapid  bodies  excite  their  usual  impression;  and,  in  the  course  of  a 
few  months,  when  the  organ  becomes  developed,  the  sense  acquires  a 
high,  and  often  inconvenient,  degree  of  acuteness. 

The  mediate  or  auxiliary  offices  of  gustation  are  few,  and  limited  in 
extent.  It  does  not  afford  much  instruction  to  the  mind.  The  chemist 
and  mineralogist  occasionally  gain  information  through  it;  but  it  is 
never  considered  to  merit  the  rank  of  an  intellectual  sense :  on  the  con- 
trary, it  is  classed  with  olfaction  as  a  corporeal  sense. 

To  appreciate  a  savour  accurately,  the  sapid  substance  must  remain 
for  a  time  in  the  mouth:  when  rapidly  swallowed,  the  impression  is 
feeble,  and  almost  null.  Of  this  fact  we  take  advantage  when  com- 
pelled to  swallow  nauseous  substances ;  whilst  we  retain  a  savoury  arti- 
cle long  in  the  mouth,  in  order  that  we  may  extract  its  sweets.  How 
different,  too,  is  the  consent  of  the  auxiliary  organs  under  these  two 
circumstances!  Whilst  a  luscious  body  augments  the  secretion  of  the 

1  Brit,  and  For.  Med.  Rev.,  April,  1845,  p.  580. 

3  Adelon,  op.  cit.,  i.  309.  s  Cited  by  M.  Longet,  op.  cit,  p.  365,  Paris,  1850. 


156  SENSE  OF  TASTE. 

salivary  glands,  or  causes  the  "  mouth  to  water,"  as  it  has  been  called 
— projecting  the  saliva,  at  times,  to  a  distance  of  some  feet  from  the 
mouth,  and  disposing  every  part  to  approach  or  mingle  with  it — a 
nauseous  substance  produces  constriction  of  every  secretory  organ  ;  an 
effect  which  extends  even  to  the  stomach  itself,  so  that  it  often  rejects 
the  offending  article,  as  soon  as  it  reaches  the  cavity.  We  can  thus 
understand  how,  cseteris  paribus,  an  article,  that  is  pleasing  to  the 
palate,  may  be  more  digestible  than  one  that  excites  disgust ;  and  con- 
versely. Of  the  "  consent  of  parts,"  exerted  between  the  stomach  and 
the  -organ  of  taste,  we  have  a  familiar  illustration  in  the  fact, — that 
whatever  may  be  the  gout,  with  which  we  commence  a  meal  on  a  fa- 
vourite article  of  diet,  we  find  that  the  relish  is  blunted  as  the  stomach 
becomes  filled ;  and  hence  the  Romans  were  in  the  habit  of  leaving  the 
table  once  or  twice  during  a  meal,  and,  after  having  unloaded  the 
organ,  of  returning  again  to  the  charge — "vomunt  ut  edant,  edunt  ut 
vomant." 

If  we  place  a  sapid  substance  in  the  mouth,  and  then  close  the  nos- 
trils, the  taste  is  diminished, — a  fact,  which  has  given  rise  to  the  gene- 
rally prevalent  and  correct  opinion,  that  an  intimate  relation  exists 
between  the  smell  and  taste.  They  are,  however,  distinct.  Most 
sapid  substances  have  an  odour  or  "flavour,"  which  is  not  appreciated 
when  we  prevent  the  air  from  passing  through*  the  nasal  fossae.  This 
renders  the  impression  on  the  gustatory  nerves  still  less  marked,  but  it 
exists.  Gustation  is  likewise  diminished  by  the  new  sensation  produced 
in  the  nostrils  by  their  closure;  so  that  the  same  amount  of  attention 
is  not  directed  to  the  sense  of  taste. 

Among  animals  we  see  great  diversities  in  this  sense.  Whilst  none 
possess  the  refined  taste  of  man ;  there  are  many,  which  are  capable, 
by  taste  or  smell,  of  knowing  plants  that  are  nutritive  from  those  that 
are  noxious  to  them ;  and  it  is  unusual  for  us  to  find  that  an  animal  has 
died  from  eating  such  as  are  unquestionably  poisonous  to  it.  Yet,  as 
we  have  remarked,  a  substance,  that  is  noxious  to  one,  may  be  eaten 
with  impunity  by  another;  and,  if  we  select  animals,  and  place  them  in 
a  field  containing  plants,  all  of  which  are  ranked  as  poisons,  and  are 
poisonous  to  a  majority  of  them,  we  find  that  not  only  has  a  selection 
been  made  by  each  animal  of  that  which  is  innocuous  to  it,  but  that 
the  substance  has  furnished  nourishment  to  it,  whilst  it  might  have 
proved  fatal  to  others.  All  this  must  be  dependent  upon  peculiar,  and 
inappreciable  organization. 

The  sense  of  taste  is  more  under  the  influence  of  volition  than  any 
other.  It  is  provided  with  a  muscular  apparatus,  by  which  it  can  be 
closed  or  opened  at  pleasure;  and,  in  addition,  ordinarily  requires  the 
assistance  of  the  upper  extremity  to  convey  the  sapid  substance  to  the 
mouth.  The  sense  can,  therefore,  be  exercised  either  passively  or 
actively;  and,  by  cultivation,  it  is  capable  of  being  largely  developed. 
The  spirit  taster  to  extensive  commercial  establishments  exhibits  the 
truth  of  this  in  a  striking  manner.  In  his  vocation,  he  has  not  only  to 
taste  numerous  samples,  but  to  appreciate  the  age,  strength,  flavour, 
and  other  qualities  of  each:  and  the  practised  individual  is  rarely  wrong 
in  his  discrimination.  With  almost  all,  if  not  all,  these  "tasters,"  the 
custom  is  to  take  a  small  quantity  of  the  liquor  into  the  mouth;  throw 


ACUTENESS  OF  TASTE.  157 

it  rapidly  around  that  cavity,  and  eject  it.  A  portion,  irr  this  way, 
comes  in  contact  with  every  part  of  the  membrane;  and  of  course  im- 
presses not  only  the  lingual,  but  the  other  ramifications  of  the  fifth  pair. 

The  gourmet  of  the  French — somewhat  more  elevated  in  the  scale 
than  our  ordinary  epicure — prides  himself  upon  his  discrimination  of 
the  nicest  shades  of  difference  and  excellence  in  the  materials  set  before 
him.  Many  gourmets  profess  to  be  able  to  pronounce,  by  sipping  a 
few  drops  of  wine,  the  country  whence  it  comes,  and  its  age;  and, 
according  to  Stelluti,  can  tell,  by  the  taste,  whether  birds  put  upon  the 
table  are  domesticated  or  wild, — male  or  female.1  Dr.  Kitchener2 
asserts,  that  many  epicures  are  capable  of  saying  in  what  precise  reach 
or  stretch  of  the  Thames  the  salmon  on  the  table  has  been  caught,  and 
Sir  Astley  Cooper  was  in  the  habit  of  relating  the  remarkable  case  of 
a  professional  friend,  who  could  discriminate  by  the  taste  the  beef  fur- 
nished by  a  particular  London  butcher.3 

This  acuteness  of  sense  is  by  no  means  desirable.  Doomed  to  meet, 
in  his  progress  through  life,  with  such  a  preponderance  of  what  demands 
obtuseness  rather  than  acuteness  of  feeling,  the  epicure  must  be  liable 
to  continual  annoyances  and  discomforts,  which  the  less  favoured  can 
never  experience. 

In  disease,  gustation  often  becomes  greatly  depraved ;  and  the  various 
morbid  tastes  have  been  accounted  for  by  depraved  secretions  in  the 
mouth,  acting  as  foreign  sapid  substances  on  the  papillae.  Certain 
tastes,  however,  cannot  be  explained  in  this  way,  and  must  be  regarded 
as  nervous  phenomena.  If  the  epithelium  be  covered  with  a  fur,  taste 
may  be  lost  or  impaired,  and  be  instantaneously  restored  as  soon  as  the 
coating  is  removed.  M.  Magendie  observed,  that  dogs,  after  the  injec- 
tion of  milk  into  their  veins,  licked  their  lips,  and  gave  other  evidences 
of  tasting.  When  Dr.  E.  Hale,  in  an  experiment  referred  to  in  another 
part  of  this  work,  injected  castor  oil  into  one  of  his  veins,  he  distinctly 
tasted  the  oil  a  short  time  afterwards.  Messrs.  Todd  and  Bowman4 
suggest  that  such  phenomena,  if  uniformly  present,  might  be  occasioned 
by  the  transudation  of  the  fluid  from  the  vessels  to  the  nerves  of  the 
papillae ;  and  this  may  be  the  true  explanation,  although  it  is  not  easy 
to  see  that  such  transudation  could  occur  in  the  case  of  castor  oil. 

SENSE  OF  SMELL  OR  OLFACTION. 

The  object  of  this  sense  is  to  appreciate  the  odorous  properties  of 
bodies.  It  differs  from  the  last  in  the  circumstance  that  the  body  does 
not  come  into  immediate  contact.  It  is  only  necessary  that  an  odorous 
emanation  from  it  shall  impinge  upon  the  organ  of  sense.  Still,  it 
does  not  essentially  vary  in  its  physiology  from  the  sense  of  taste. 

1.  ANATOMY  OF  THE  ORGAN  OF  SMELL. 

The  organ  of  smell  is  a  mucous  membrane,  which  lines  the  nasal 
cavities,  and  is  called  Schneiderian  or  pituitary.  It  resembles  that 
which  covers  the  organ  of  taste,  except  that  the  nervous  papillae  are 
more  delicate,  to  correspond  with  the  greater  tenuity  of  the  body  that 

1  American  Quarterly  Review,  ii.  427.  2  Cook's  Oracle,  3d  edit.,  p.  229,  Lond.,  1821. 

3  Life  of  Sir  Astley  Cooper,  Bart.,  by  Bransby  Blake  Cooper,  Esq.,  F.  R.  S.,  ii.  137,  Lond.,  1843. 

4  The  Physiological  Anatomy  and  Physiology  of  Man,  p.  448,  Lond.,  1845. 


158 


SENSE  OF  SMELL. 


58- 


has  to  make  the  impression.  The 
membrane  lines  the  whole  of  the 
bony  cavities  called  nasal  fossse, 
which  are  constantly  open  anteriorly 
and  posteriorly,  to  permit  the  air 
that  traverses  them  to  proceed  to  the 
lungs.  The  anterior  aperture  is 
covered  by  a  kind  of  pent-house  or 
capital,  for  the  purpose  of  collecting 
the  odorous  particles.  This  capital 
is  called  the  nose.  The  essential 
part  of  the  organ  is  the  pituitary  or 
olfactory  membrane,  —  the  other 
parts  being  superadded  to  perfect  the 
sense. 

The  bony  portions  of  the  nose  are 
separated  from  each  other  by  the 
vomer.  This  bony  septum  is  pro- 
longed, by  means  of  cartilage,  to 
the  anterior  extremity  of  the  nose, 

Qn    fV,nf-    fhA   Yia«sal    fn«;<3fp    irp 
>    tnat    tft6   nasal 


Vertical  Section  of  the  Middle  Part  of  the 
Nasal  Fossae,  giving  a  Posterior  View  of 
the  Arrangement  of  the  Ethmoidal  Cells, 
&c. 

1.  Anterior  fossae  of  the  cranium.  2.  The 
same  covered  by  the  dura  mater.  3.  Dura  mater 
turned  up.  4.  Crista  galli  of  the  ethmoid  bone. 
5.  Its  cribriform  plate.  6.  Its  nasal  lamella. 
7.  Middle  spongy  bones.  8.  Ethmoidal  cells. 
9.  Os  planum.  10.  Inferior  spongy  bones.  11. 
Vomer.  12.  Superior  maxillary  bone.  13.  Its 

union  with  the  ethmoid.     14.  Anterior  parietes    into  like  parts,  which  haVC  no 
of  the  antrum  Highmorianum,  covered  by  its  .         r  .   ,    '         ,  , 

membrane.  15.  Its  fibrous  layer.  16.  Its  mucous  niCatlOn  With  each  Other,  but  Open 
membrane.  17.  Palatine  process  of  the  superior  j.  ,1  ,  •  i  •  ,  j.'L-  j. 

maxillary  bone.  18.  Roof  of  the  mouth,  cov-  together,  posteriorly,  into  the  top 
ered  by  the  mucous  membrane.  19.  Section  of  nf  fVi/i  -nil  Ji  rvn  Y  \VithiTi  papli  nf 

this  membrane.    A  bristle  in  the  orifice  of  the    Ot     ttl6      Pnar  Jnx-          W  1WL 

antrum  Highmorianum.  the    nares    are    two    convoluted    or 

turbinated    bones — generally    called 

ossa  spongiosa  vel  turlinata;  and,  by  the  French,  cornets.  These 
are  situate  one  above  the  other ;  the  superior  formed  of  a  plate  of  the 
ethmoid' bone — the  inferior  a  distinct  bone.  They  divide  the  general 
cavity  of  each  nostril  into  three  passages  or  meatus.  The  inferior 
meatus  is  broad  and  long ;  the  least  oblique,  and  least  tortuous ;  the 
middle  is  narrow,  almost  as  long,  but  more  extensive  from  above  to 
below ;  and  the  superior  is  much  shorter,  more  oblique,  and  still  nar- 
rower. The  narrowness  of  these  passages  in  the  living  subject  is  so 
great,  that  the  slightest  tumefaction  of  the  membrane  renders  the 
passage  of  air  through  the  fossae  extremely  difficult.  This  is  the  cause 
of  the  difficulty  of  breathing  through  the  nose,  that  attends  "  a  cold 
in  the  head."  Into  the  two  upper  passages,  cavities  in  certain  bones 
open,  which  considerably  enlarge  the  extent  of  the  fossae.  These  are 
called  sinuses;  and  are  the  maxillary,  palatine,  frontal,  sphenoidal, 
ethmoidal, — the  last  being  sometimes  termed  ethmoidal  cells. 

All  the  cavities  are  lined  by  the  delicate  pituitary  membrane,  or  by 
a  prolongation  of  it.  •  In  the  nasal  fossae  it  augments  the  thickness  of 
the  turbinated  bones.  It  resembles  the  mucous  membranes  in  general 
in  its  composition ;  and  adheres  firmly  to  the  bones  and  cartilages, 
which  it  covers.  Its  aspect  is  velvety,  owing  to  a  multitude  of  minute 
papillae ;  and  it  receives  a  great  number  of  vessels  and  nerves.  The 
sinuses  are  lined  by  a  prolongation  apparently  of  the  same  membrane, 
differing,  however,  in  some  respects  from  the  other.  The  whole  of  the 


ORGAN  OF  SMELL. 


150 


membrane  is  the  seat 
of  the  secretion  of 
nasal  mucus,  which, 
doubtless,  performs  a 
part  in  olfaction  as  im- 
portant as  the  secretion 
from  the  mucous  mem- 
brane of  the  mouth 
does  in  gustation. 

The  same  nerve  is 
not  distributed  over 
the  whole  of  this  mem- 
brane. In  some 
parts,  the  olfactory, 
ethmoidal,  or'  first 
pair  can  be  traced ;  in 
others,  we  see  only 
filaments  of  the  fifth 
pair.  The  first  of 
these  have  not  always 
been  regarded  as  the 
nerves  of  smell.  An- 
ciently, 

to   be 


Fig.  59. 


View  of  the  Olfactory  Nerve,  with  its  Distribution  on  the  Septum 
Nasi.  The  nares  have  been  divided  by  a  longitudinal  section 
made  immediately  to  the  left  of  the  septum,  the  right  nares 
being  preserved  entire. 


tuita  or  phlegm,  which 
was  supposed  to  be  se- 
creted by  the  brain. 


ful 


1.  The  frontal  sinus.    2.  The  nasal  bone.     3.  The  crista  galli  pro- 
n   p      cess  of  the  ethmoid  bone.    4.  The  sphenoidal  sinus  of  the  left  sido. 
5.  The  sella  turcica.    6.  The  basilar  process  of  the  sphenoid  and  occi* 
pital  bones.     7.   The  posterior  opening  of  the  right  nares.    8.  The 
_%    .       opening  of  the  Eustachian  tube  in  the  upper  part  of  the  pharynx.     9. 

for  the  passage  Of  pi-  The  soft  palate,  divided  through  its  middle.  10.  Cut  surface  of  the 
hard  palate,  a.  The  olfactory  peduncle,  b.  Its  three  roots  of  origin. 
c.  Olfactory  ganglion,  from  which  the  filaments  proceed  that  spread 
out  in  the  substance  of  the  pituitary  membrane,  d .  The  nasal  nerve, 
a  branch  of  the  ophthalmic  nerve,  descending  into  the  left  nares  from 
the  anterior  foramen  of  the  cribriform  plate,  and  dividing  into  its  ex- 

.  ternal  and  internal  branch,    e.  The  naso-palatine  nerve,  a  branch  of 

At     the     present    Clay,     the  spheno-palatine  ganglion  distributing  twigs  to  the  mucous  rnem- 
c\       }  f      brane  of  the  septum  nasi  in  its  course  to  (/)  the  anterior  palatine  fora- 
LOE-    men,  where  it  forms  a  small  gangliform  swelling  (Cloquet's  ganglion) 

Onlv     aS      regards    by  its  union  with  its  fellow  of  the  opposite  side.    g-.  Branches  of  the 
f ,   .  &  naso-palatine  nerve  to  the  palate,    h.  Posterior  palatine  nerves,    i,  i. 

their  origin;  some  de-  The  septum  nasi. 
riving  them  from  the 

anterior  lobes  of  the  brain;  others  from  the  corpora  striata,  which 
have,  in  consequence,  been  called  thalami  nervorum  ethmo'idalium; 
and  others,  again,  with  Willis  and  Gall,1  and  with  probability,  referring 
them,  like  every  other  nerve  of  sense,  to  the  medulla  oblongata.  M. 
B^clard  affirms,  that  in  a  hydrocephalic  patient,  where  a  part  of  the 
brain  had  been  destroyed  by  disease,  he  actually  saw  this  origin.2  The 
nerve  proceeds  directly  forwards  until  it  reaches  the  upper  surface  of 
the  cribriform  plate  of  the  ethmoid  bone,  where  it  divides  into  a  number 
of  filaments,  that  pass  through  the  foramina  in  the  plate,  and  attain  the 
nasal  fossae;  where  they  are  dispersed  on  the  upper  and  middle  part  of 
the  Schneiderian  membrane;  but  cannot  be  traced  on  the  lower.  Most 
anatomists  are  of  opinion,  that  here  they  constitute,  with  vessels  of 
exhalation  and  absorption,  the  papillae;  whilst  others,  as  Scarpa,  not 
having  been  able  to  trace  them  thither,  have  been  of  opinion,  that  the 
filaments  interlace  to  constitute  a  kind  of  proper  membrane.  Our 

1  Recherches  snr  le  Systeme  Nerveux  en  general  et  stir  celui  du  Cerveau  en  particulier, 
par  F.  J.  Gall  et  G.  Spurzheim,  Paris,  1809. 

a  Adelon,  Physiologic  de  THomme,  edit,  cit.,  i.  330. 


160 


SENSE  OF  SMELL. 


Fig.  60 


Fig.  61. 


A  portion  of  the  Pituitary  Membrane 
of  the  Nasal  Septum,  magnified  9 
times,  showing  the  Number,  Sizes. 
and  Arrangement  of  the  Mucous 
Crypts. 


A  portion  of  the  Pituitary  Membrane  with 
its  Arteries  and  Veins  injected. — Magni- 
fied 15  diameters. 

The  natural  size  of  this  piece  is  seen  at  the 
bottom  of  the  cut. 

1,1,  1.  Orifices  of  three  mucous  crypts  sur- 
rounded by  veins  and  arteries. 


Fig.  62. 


means  of  observation  cannot  be  considered  sufficient  to  enable  us  to 
decide  this  question  positively.  The  nerve  has  not  been  traced  on  the 
os  spongiosum  inferius;  on  the  inner  surface  of  the  middle  spongy  bone, 
or  in  any  of  the  sinuses. 

The  olfactory  filaments,  according  to  Messrs.  Todd  and  Bowman,1 

form  a  considerable  part  of  the  entire 
thickness  of  the  Schneiderian  mem- 
brane, and  differ  widely  from  the  ordi- 
nary encephalic  nerves  in  structure. 
They  contain  no  white  substance  of 
ScTiwann;  are  not  divisible  into  ele- 
mentary fibrillae;  are  nucleated  and 
finely  granular  in  texture,  and  invested 
with  a  sheath  of  homogeneous  mem- 
brane; and  are  regarded  by  those  gen- 
tlemen as  direct  continuations  of  the 
vesicular  matter  of  the  olfactory  bulb 
or  ganglion;  and  they  "venture  to 
hint,"  that  the  amalgamation  of  the 
elements  of  the  peripheral  part  of  the 
nervous  apparatus  in  the  larger  branches, 
In  acetic  acid-Ma^nified  and  probably  in  the  most  remote  distri- 
bution, as  well  as  the  nucleated  charac- 
ter indicative  of  an  essential  continuity  of  tissue  with  the  vesicular 
matter  of  the  lobe,  are  in  accordance  with  the  oneness  of  the  sensation 
resulting  from  simultaneous  impressions  on  different  parts  of  this  organ 
of  sense,  and  seem  to  show,  that  it  would  be  most  correct  to  speak  of 
the  first  pair  of  nerves  as  a  portion  of  the  nervous  centre  put  forward 


Olfactory  Filaments  of  the  Dog. 


1  Op.cit.,ii.  5-11. 


ODOURS.  161 

beyond  the  cranium,  in  order  that  it  may  there  receive,  as  at  first  hand, 
the  impressions  of  which  the  mind  is  to  become  cognizant. 

Besides  the  first  pair  of  nerves,  the  pituitary  membrane  receives 
several  branches  from  the  fifth  encephalic  pair ;  for  example,  the  nasal 
twig  of  the  ophthalmic  branch  of  the  fifth,  and  filaments  from  the  frontal 
branch  of  the  same ;  from  the  spheno-palatine  ganglion ;  the  palatine 
nerve ;  the  vidian  nerve ;  and  from  the  anterior  dental  branch  of  the 
superior  maxillary.  One  of  these  twigs  enters  the  anterior  naso-pala- 
tine  canal ;  and,  in  its  course  to  the  roof  of  the  mouth,  passes  through 
a  small  ganglion,  which  has  been  described  by  M.  H.  Cloquet  under  the 
name  naso-palatine,  and  wrhich  he  conceives  to  be  the  organ  of  sympathy 
between  the  senses  of  smell  and  taste. 

The  pituitary  membrane  is  kept  moist  by  nasal  mucus,  as  well  as  by 
the  exhalation  that  constantly  takes  place  from  it.  It  receives  the 
superfluous  tears  by  means  of  the  ductus  ad  nasum, — a  duct  passing 
from  the  inner  canthus  of  the  eye,  and  opening  into  the  nasal  fossae 
below  the  lower  spongy  bone.  The  constant  evaporation  which  must 
take  place  from  the  membrane,  owing  to  the  passage  of  the  air  during 
respiration,  requires  that  the  secretion  should  be  continuous  and  copious, 
otherwise  the  membrane  would  become  dry. 

The  nasal  fossae  communicate  externally  by  means  of  the  nostrils, 
the  shape,  size,  and  direction  of  which  vary,  so  as  to  give  rise  to  the 
aquiline,  Roman,  pug,  and  other  varieties  of  nose.  At  the  extremity 
of  the  nostrils  long  hairs  are  situate — technically  called  vibrissde — whose 
function,  it  is  conceived,  may  be  to  sift,  as  it  were,  the  air  passing 
through  during  respiration,  and  thus  prevent  extraneous  bodies  from 
entering  the  fossae.  The  nostrils  are  also  capable  of  being  expanded 
or  contracted  by  appropriate  muscles. 

In  this  sense,  there  is  a  more  clear  separation  between  the  physical 
and  nervous  part  of  the  apparatus  than  in  either  of  those  already  con- 
sidered;— the  nose  proper  forming  the  physical  portion;  and  the  nerves 
of  smell  the  organic  or  nervous. 

2.  ODOURS. 

The  comprehension  of  the  physiology  of  olfaction  will  not  be  complete 
without  an  inquiry  into  odours,  or  those  emanations  from  odorous  bodies, 
that  give  them  their  character,  and  impress  the  organ  of  smell. 

It  was  long  maintained,  as  in  the  case  of  savours,  that  odours  are 
dependent  upon  a  peculiar  principle,  which,  according  to  its  particular 
combination  with  the  constituents  of  bodies,  gives  rise  to  various  odours. 
To  this  principle  the  terms  aroma  and  spiritus  rector  have  been  assigned; 
but  the  notion  has  been  long  abandoned,  because  no  general  or  common 
characters  are  observable  amongst  odorous  bodies,  which  should  be 
expected  were  they  indebted  for  their  odour  to  the  same  principle. 
Walther,  a  German  physiologist,  expresses  the  opinion,  that  an  odorous 
body  is  such  by  virtue  of  a  vibratory  motion,  analogous  to  that  made 
by  a  sonorous  body.  We  have,  however,  the  most  satisfactory  evidence, 
that  there  are  special  odours,  as  there  are  special  savoury  molecules. 
We  can  prevent  an  odorous  body  from  impressing  our  olfactory  nerves 
by  covering  it  with  a  glass  receiver.  Odours  can  be  separated  by  in- 

VOL.  I.— 11 


162  SENSE  OF  SMELL. 

fusion  and  distillation.  The  fact,  moreover,  has  been  directly  proved  by 
an  experiment  of  M.  Berthollet.  On  nearly  filling  a  tube  with  mercury, 
and  placing  a  piece  of  camphor  at  the  top  of  the  tube,  he  found  that, 
after  a  time,  the  mercury  descended,  the  camphor  had  diminished  in  size, 
and  the  space  above  the  metal  was  occupied  by  an  odorous  gas.1 

But  what  is  the  cause  of  the  disengagement  of  these  odorous  mole- 
cules ?  By  most  writers  on  this  subject  it  has  been  considered  to  be 
owing  to  the  solvent  action  of  caloric  on  the  odorous  body.  The  opinion 
that  all  bodies  are  odorous  is  as  old  as  Theophrastus;  and  it  is  one  which 
it  is  difficult  not  to  embrace,  if  we  add — provided  they  are  subjected 
to  the  appropriate  agents  for  disengaging  the  odorous  particles ;  and 
the  probability  is,  that  the  reason  we  esteem  particular  bodies  inodor- 
ous is,  that  our  olfactory  nerves  are  not  organized  with  sufficient  deli- 
cacy to  enable  us  to  distinguish  their  odorous  properties.  Heat  assists 
the  escape  of  odorous  particles  from  a  variety  of  bodies ;  and  hence 
it  has  been  maintained,  that  every  body  which  is  volatile  must  be  odor- 
ous. M.  Adelon2  asserts,  that  this  is  not  the  case ;  but  it  is  difficult  to 
accord  with  him.  The  fact  of  our  not  appreciating  the  odour  is  no 
proof  of  its  non-existence.  In  truth,  bodies  that  are  inodorous  to  one 
animal  or  individual  may  not  be  so  to  another.  In  cases,  too,  in  which 
smell  is  morbidly  acute,  a  substance  may  appear  overwhelmingly  odor- 
ous, which  may  appear  devoid  of  smell  to  a  healthy  individual.  M. 
H.  Cloquet3  refers  to  the  case  of  a  celebrated  Parisian  physician,  who 
was  subject  to  violent  attacks  of  hemicrania  or  megrim,  and  who  was 
dreadfully  tormented,  during  one  of  the  paroxysms,  by  the  smell  of 
copper,  exhaled  from  a  pin  that  had  been  dropped  on  the  bed ! 

Caloric  seems  to  be  only  one  of  the  causes  of  the  disengagement  of 
odours.  Some  are  retained  by  so  feeble  a  degree  of  affinity,  that  they 
appear  to  be  exhaled  equally  at  all  temperatures.  Light  influences 
their  escape  in  particular  cases ;  some  plants  giving  off  their  fragrance 
during  the  day ;  others  perfuming  the  air  only  at  night.  Dampness, 
in  many  instances,  assists  their  escape, — hence  the  fragrance  of  a  gar- 
den after  a  summer's  shower;  and  the  smell  afforded  by  all  argillaceous 
substances  when  breathed  upon, — a  fact,  the  knowledge  of  which  is 
of  importance  to  the  chemist. 

Lastly; — substances,  that  appear  to  us  devoid  of  odour,  may  exhale  a 
strong  one,  when  rubbed  together.  All  these  circumstances  tend  greatly 
to  prove,  that  every  substance  is  possessed  of  odorous  qualities,  although 
we  may  not  be  aware  of  the  precise  mode  for  causing  their  emanation, 
or  our  olfactory  nerves  may  not  be  sufficiently  delicate  to  appreciate 
them. 

Around  odorous  bodies,  the  molecules,  as  they  escape,  form  an  atmo- 
sphere, which,  of  course,  will  be  denser,  the  nearer  it  is  to  the  body. 
These  particles  are  diffused  around, — not,  probably,  in  the  same  man- 
ner as  light  or  sound,  but  as  one  fluid  mixes  with  another;  and,  when 
the  air  is  still,  it  is  conceived,  their  strength  will  be  inversely  as  the 

1  Cloquet,  Art.  Odeurs,  Diet,  des  Sciences  Medicales,  torn,  xxxvii.,  p.  89,  Paris,  1819. 

•  Op.  cit.,  i.  322. 

a  Osphresiologie  ou  Traite  des  Odeurs,  Paris,  1821. 


ODOURS.  163 

square  of  the  distance  from  the  substance  that  exhales  them.  There 
is  a  great  difference,  however,  in  odours  as- regards  their  diffusibility  in 
the  atmosphere.  Some  extend  to  a  great  distance,  whilst  others  are 
confined  within  a  small  compass.  The  odours  of  many  flowers  are  so 
delicate  as  not  to  be  appreciated,  unless  they  are  brought  near  the 
olfactory  organs ;  whilst  that  of  cinnamon  is  said  to  have  been  detected 
at  sea,  at  the  distance  of  twenty-five  miles  from  Ceylon.  Lord  Valen- 
tia1  affirms,  that  he  himself  distinctly  smelt  the  aromatic  gale  at  nine 
leagues'  distance ; — but  Dr.  Ruschenberger2  was  not  equally  fortunate. 
The  author  was  informed  by  Commodore  Stewart,  of  the  Navy,  that 
he  had  discovered  the  spicy  emanations  when  two  hundred  miles  from 
Ceylon;  and  the  terebinthinate  odours  of  the  pines  of  Virginia,  when 
one  hundred  miles  from  the  coast;  and  the  author's  friend,  Dr.  Wil- 
cocks,  of  Philadelphia,  when  at  sea  in  1844,  and  two  hundred  miles  to 
the  westward  of  the  coast  of  Ireland,  observed,  as  did  many  others  of 
the  passengers,  a  smoky  odour,  which  lasted  for  several  days  in  suc- 
cession. On  appealing  to  the  captain  for  the  cause  of  the  phenomenon, 
he  informed  them  that  he  had  frequently  remarked  it  before ;  and 
that  it  was  owing  to  the  long  continuance  of  easterly  winds,  which 
carried  the  odour  of  burning  peat  from  Ireland  far  out  to  sea.3  Facts 
of  this  kind  are  employed  by  the  natural  philosopher  to  exhibit  the 
excessive  divisibility  of  matter.  Scales,  in  which  a  few  grains  of 
musk  have  been  weighed,  have  retained  the  smell  for  twenty  years 
afterwards,  although  they  must  have  been  constantly  exhaling  odorous 
molecules  during  the  whole  of  this  period.  Haller4  kept  some  papers, 
for  more  than  forty  years,  which  had  been  perfumed  by  a  single  grain 
of  amber;  and,  at  the  end  of  that  time,  they  did  not  appear  to  have 
lost  any  of  their  odour.  ITiat  distinguished  physiologist  and  mathe- 
matician calculated,  that  every  inch  of  their  surface  had  been  im- 
pregnated by  SATO'S  4^0^  °f  a  grain  of  amber,  and  yet  they  had 
scented  for  14,600  days  a  stratum  of  air  at  least  a  foot  in  thickness. 
But  how  much  larger  must  these  molecules  be  than  those  of  light — 
provided  we  regard  it  as  consisting  of  molecules — seeing  that  glass  is 
capable  of  arresting  the  former,  but  suffers  the  other  to  penetrate  it  in 
every  direction. 

Nor  need  we  be  so  much  surprised  at  the  excessive  diffusibility  of 
odorous  particles,  when  we  call  to  mind  the  facts  on  record  in  regard 
to  the  transmission  through  the  air  of  fine  particles  of  sand.  Gene- 
rally, according  to  Mr.  Darwin,5  the  atmosphere  of  the  Cape  Yerd 
Islands  is  hazy ;  and  this  is  caused  by  the  falling  of  impalpably  fine 
dust,  which  was  found  to  have  slightly  injured  the  astronomical  instru- 
ments. The  morning  before  they  anchored  at  Porto  Praya,  he  collected 
a  little  packet  of  this  brown-coloured  fine  dust,  which  appeared  to  have 

1  Voyages  and  Travels  in  India.     London,  1809. 

3  Embassy  to  the  courts  of  Muscat  and  Siam,  &c.,  p.  154.     Philad.,  1838. 

3  Medical  Examiner,  March,  1846,  p.  159. 

4  Elementa  Physiolog.,  torn.  v.  lib.  xiv.  sect.  2,  p.  157.     Lausann.,  1769. 

5  Journal  of  Researches  into  the  Natural  History  and  Geology  of  the  countries  visited 
during  the  voyage  of  H.  M.  S.  Beagle  round  the  world,  &c.     Amer.  edit.,  i.  5.     New  York, 
1846. 


164  SENSE  OF  SMELL. 

been  filtered  from  the  wind  by  the  gauze  of  the  vane  at  the  mast-head. 
Sir  Charles  Lyell  also  gave  him  four  packets  of  dust  which  fell  on  a  vessel 
a  few  hundred  miles  northward  of  these  islands.  Professor  Ehrenberg 
found,  that  this  dust  consisted,  in  great  part,  of  infusoria  with  silicious 
shields,  and  of  the  silicious  tissue  of  plants.  In  five  little  packets 
which  Mr.  Darwin  sent  him,  he  ascertained  no  less  than  sixty-seven 
different  organic  forms !  The  infusoria,  with  the  exception  of  two  ma- 
rine species,  were  all  inhabitants  of  fresh  water. 

Mr.  Darwin  has  found  no  less  than  fifteen  different  accounts  of  dust 
having  fallen  on  vessels  when  far  out  in  the  Atlantic.  From  the  direc- 
tion of  the  wind  whenever  it  has  fallen,  and  from  its  having  always 
been  observed  during  those  months  when  the  harmattan  is  known  to 
raise  clouds  of  dust  high  in  the  atmosphere,  it  is  pretty  certain  that  it 
must  proceed  from  Africa.  It  is,  however — as  Mr.  Darwin  remarks — 
a  singular  fact,  that,  although  Professor  Ehrenberg  is  acquainted  with 
many  species  of  infusoria  peculiar  to  Africa,  he  found  none  of  these  in 
the  dust  sent  him;  but,  on  the  other  hand,  discovered  in  it  two  species 
which  he  knew  as  living  only  in  South  America.  "  The  dust,"  says 
Mr.  Darwin — "  falls  in  such  quantity  as  to  dirty  everything  on  board, 
and  to  hurt  people's  eyes;  vessels  even  have  run  on  shore  owing  to  the 
obscurity  of  the  atmosphere.  It  has  often  fallen  on  ships  when  seve- 
ral hundred,  and  even  more  than  a  thousand  miles  from  the  coast  of 
Africa,  and  at  points  sixteen  hundred  miles  distant  in  a  north  and  south 
direction.  In  some  dust,  which  was  collected  on  a  vessel  three  hundred 
miles  from  the  land,  I  was  much  surprised  to  find  particles  of  stone 
above  the  thousandth  of  an  inch  square,  mixed  with  finer  matter.  After 
this  fact,  one  need  not  be  surprised  at  the  diffusion  of  the  far  lighter 
and  smaller  sporules  of  cryptogamic  plants." 

The  air  is  not  the  only  vehicle  for  odours.  It  has  been  seen,  that 
they  adhere  to  solid  bodies  ;  and  that,  in  many  cases,  they  can  be 
separated  by  aqueous  or  spirituous  distillation.  The  art  of  the  per- 
fumer consists  in  fixing  and  preserving  them  in  the  most  agreeable  and 
convenient  vehicles.  Yet,  it  was  at  one  time  strenuously  denied,  that 
they  could  be  conducted  through  water ;  and,  as  a  natural  consequence 
of  this,  that  fishes  could  smell.  M.  Dumeril,  for  example,  maintained, 
that  odours,  being  essentially  of  a  volatile  or  gaseous  nature,  cannot 
exist  in  fluids ; — and,  moreover,  that  fishes  have  no  proper  olfactory 
organ ; — that  the  part  which  is  commonly  considered  in  them  to  be 
such  is  the  organ  of  taste.  This  opinion  is  entertained  by  few.  We 
have  seen  that  odours  can  be  retained  in  fluids,  and  not  many  natural- 
ists of  the  present  day  will  be  hardy  enough  to  deny  that  fishes  have 
an  organ  or  sense  of  smell.  At  all  events,  few  anglers,  who  have  used 
the  oil  of  rhodium,  or  other  attractive  bait,  will  be  disposed  to  give  up 
the  results  of  their  experience  without  stronger  grounds  than  any  that 
have  been  assigned  by  the  advocates  of  that  view  of  the  subject.  Be- 
sides, air  is  contained  in  considerable  quantity  in  water,  so  that  odor- 
ous substances  might  reach  the  olfactory  organs  through  it. 

When  it  was  determined,  that  odours  consist  in  special  molecules 
given  off  from  bodies,  it  was  attempted  to  explain  their  action  on  the 
pituitary  membrane  in  the  same  manner  as  that  of  savours  on  the 


ODOURS.  165 

membrane  of  the  tongue.  It  was  conceived  that  the  shape  of  the  mole- 
cules of  a  pungent  odour  is  pointed,  that  of  an  agreeable  one,  round. 
Others,  again,  were  of  opinion,  that  olfaction  is  owing  to  some  chemi- 
cal union  between  the  odorous  molecule  and  the  nervous  fluid,  or  be- 
tween it  and  the  nasal  mucus.  None,  however,  have  attempted  to 
specify  the  precise  chemical  composition  that  renders  a  body  odorous. 
The  sensations  do  not  present  the  most  favourable  occasions  for  exhi- 
biting chemical  agency  ;  and,  in  this  particular  sense,  it  is  probably  no 
farther  concerned  than  in  the  sense  of  touch;  and  not  so  much  as  in 
that  of  taste.  It  is  sufficient  for  the  odorous  particle — animal,  vege- 
table, or  mineral — to  come  in  contact  with  the  olfactory  nerves,  in 
order  that  the  odour  shall  be  appreciated ;  and  we  may,  in  vain,  look 
for  chemical  action  in  many  of  those  animal  and  vegetable  perfumes, — 
as  musk,  amber,  camphor,  vanilla,  &c. — which  astonish  us  by  their 
intensity  and  diffusibility. 

The  same  remarks,  that  were  made  on  the  classification  of  savours, 
are  applicable  to  that  of  odours.  They  are  not  less  numerous  and 
varied ;  and  each  substance,  as  a  general  rule,  has  its  own,  by  which 
it  is  distinguished.  Numerous  attempts  have  been  made  to  group  them; 
but  all  have  been  unsatisfactory.  The  classification  proposed  by  Lin- 
nseus,1  was — into  Odores  aromatici,  those  of  the  flowers  of  the  pink, 
bay  leaves,  &c. ;  0.  fragrantes,  those  of  the  lily,  jessamine,  &c. ;  0. 
ambrosiaci,  those  of  amber,  musk,  &c.;  0.  alliacei,  those  of  garlic, 
assafoetida,  &c. ;  0.  hircini,  (like  that  of  the  goat,)  those  of  the  Orchis 
hircina,  Chenopodium  vulvaria,  &c. ;  0.  tetri,  repulsive  or  virous, — 
those  of  the  greater  part  of  the  family  solanese;  and  lastly,  0.  nau- 
seosi,  those  of  the  flowers  of  the  veratrum,  &c.  A  simple  glance  at 
this  division  will  exhibit  its  glaring  imperfections.  No  two  persons 
could  agree  to  which  of  any  two  of  the  cognate  classes  a  particular 
odour  should  be  referred.  None  of  the  other  classifications,  that  have 
been  proposed,  are  more  satisfactory.  M.  Fourcroy  divided  them  into 
extractive  or  mucous,  fugaceous  oily,  volatile  oily,  aromatic  and  acid, 
and  hydro  sulphureous  ; — and  Lorry  into  camphorated,  narcotic,  ethe- 
real, volatile  acid,  and  alkaline.  The  distinction  into  animal,  vegetable, 
and  mineral,  is  not  more  commendable.  Musk  is  the  product  of  an 
animal  of  the  ruminant  family ;  but  the  odour  is  not  confined  to  that 
animal.  It  is  contained  in  the  civet;  in  the  flesh  of  the  crocodile;  and 
in  the  musk-rat.  Haller  asserts,  that  his  own  perspiration  smelt  of  it. 
It  is  met  with,  likewise,  in  the  vegetable  kingdom; — in  Erodium  mos- 
chatum,  in  the  seeds  of  Abelmoschus,  the  flowers  of  Rosa  moschata, 
and  Adoxa  moschatellina,  and  in  some  of  the  varieties  of  the  melon 
and  pear;  and,  what  is  perhaps  more  surprising,  in  mineral  sub- 
stances;— as  in  certain  preparations  of  gold;  and  in  some  earths  of 
which  tea-pots  are  made  in  China  and  Japan.  The  odour  of  garlic, 
again,  is  found  not  only  in  that  vegetable,  but  in  assafoetida,  in 
arsenic,  when  thrown  upon  hot  coals ;  and  in  Bufo  pluvialis,  a  species 
of  toad. 

In  by  far  the  majority  of  cases,  we  can  only  designate  an  odour  by 

1  Arncenitat.  Academic.  Erlang,  1787,  1790. 


166  SENSE  OF  SMELL. 

comparing  it  with  that  of  some  well-known  substance ;  hence  the  epi- 
thets musky,  alliaceous,  spermatic,  &c.  M.  Adelon  asserts,  that  the 
sole  classification  which  can  be  adopted,  is  into  the  agreeable  and  dis- 
agreeable. But  even  the  miserably  imperfect  division  proposed  by 
Haller1  is  better  than  this:  he  made  three  classes — Odores  suaveo- 
lentes,  0.  medii,  and  0.  foetores.  The  truth  is,  that  all  the  objections 
made  to  the  division  of  savours  into  agreeable  and  disagreeable,  are 
equally  applicable  to  odours.  Assafoetida,  we  have  seen,  was  employed 
by  the  ancients  as  a  condiment ;  and,  although  with  us  it  has  the  name 
devil's  dung,  it  is  by  many  of  the  Asiatics,  called  food  of  the  gods. 
We  find,  too,  certain  animals  that  are  almost  enchanted  by  particular 
odours.  The  cat,  for  example,  if  catmint — Nepeta  cataria, — or  the 
root  of  valerian —  Valeriana  officinalis — be  placed  in  its  way.  Again, 
odours,  generally  thought  agreeable,  are  to  some  persons  intolerable. 
To  many,  as  to  Professor  Muller,2  mignonette  has  but  an  herb-like 
odour.  The  smell  of  the  callicanthus  is  to  most  individuals  pleasant; 
but  exceedingly  disagreeable  to  some;  and,  according  to  Arnold,3  whilst 
the  flower  of  Iris  Persica  was  pronounced  to  possess  an  agreeable 
odour  by  forty-one  out  of  fifty-four  persons,  four  considered  it  to  have 
little  scent ;  by  eight  it  was  declared  to  be  devoid  of  odour,  and  by  one 
to  be  disagreeable.  These  differences,  like  those  in  the  appreciation 
of  savours  by  animals,  must  be  referred  to  minute  and  inappreciable 
differences  of  organization. 

Odours  have  been  considered  to  be  possessed  of  medicinal  and  even 
of  poisonous  properties.  Some  individuals,  whose  peculiarity  of  con- 
stitution renders  them  very  liable  to  the  action  of  ipecacuanha  or 
jalap,  experience  the  emetic  effects  of  the  former,  or  the  cathartic 
qualities  of  the  latter,  by  merely  smelling  them  for  a  short  time; 
and  the  majority  of  individuals,  by  pounding  jalap  or  rhubarb  find 
themselves  sooner  or  later  more  or  less  affected.  By  smelling  strong 
alcohol  for  a  considerable  time,  intoxication  may  be  induced,  as  not 
unfrequently  happens  to  the  spirit-taster,  who  is  young  in  his  vocation. 
It  has  also  been  asserted,  that  the  constant  application  of  this  sense  to 
the  discrimination  of  teas  in  the  English  East  India  Company's  ware- 
houses has  laid  the  foundation  for  numerous  head  affections ;  but  the 
report  originated  in  prejudice,  or  in  accidental  coincidences,  and  has 
not  been  found  to  be  accurate. 

In  all  cases  in  which  we  see  medicinal  or  poisonous  effects  actually 
produced  by  substances  inhaled  through  the  nostrils,  we  cannot  attempt 
to  explain  them  by  the  simple  impression  made  by  the  odorous  parti- 
cles on  the  olfactory  nerves.  They  must  be  accounted  for  by  minute 
particles  of  the  medicinal  or  poisonous  substance  being  diffused  in  the 
atmosphere,  and  coming  in  contact  with  the  mucous  membrane,  through 
which  they  are  absorbed,  and  in  this  manner  enter  the  circulation. 

Odours  have,  likewise,  been  considered  to  possess  nutritive  proper- 
ties ;  and  this,  chiefly,  perhaps,  from  the  effect  known  to  be  produced 

1  Elementa  Physiolog.,  torn.  v.  lib  xiv.  p.  162,  Lausann.,  1769. 

2  Elements  of  Physiology,  by  Baly,  p.  1317.     Loud.,  1839. 

3  Physiology,  ii.  561,  cited  by  Dr.  Carpenter,  art.  Smell,  in  Cyclopaedia  of  Anatomy  and 
Physiology,  pt.  xxxvi.  p.  703.     London,  June,  1849. 


PHYSIOLOGY  OF  OLFACTION.  167 

by  savoury  smells  upon  the  appetite.  It  is  not  probable,  that  absorp- 
tion can  occur  to  a  sufficient  extent  to  account  for  the  apparent  satia- 
tion. The  fact  can  only  be  explained  by  the  effect  upon  the  nervous 
system,  which  influences  the  appetite  materially,  as  we  see  in  the  effect 
of  various  mental  emotions.  The  first  impact  of  a  nauseous  odour,  or 
even  the  view  of  a  disgusting  object,  frequently  converts  the  keenest 
appetite  into  loathing.  Yet,  anciently,  it  was  believed,  that  life  might 
be  sustained  for  a  time,  by  simply  smelling  nutritious  substances. 
Democritus  is  said  to  have  lived  three  days  on  the  vapour  of  hot 
bread ;  and  Bacon  refers  to  a  man  who  supported  an  abstinence  of 
several  days  by  inhaling  the  odour  of  a  mixture  of  aromatic  and  alli- 
aceous herbs.  Two  hundred  years  ago  these  notions  were  entertained 
to  a  great  extent;  and  they  suggested  the  viaticum  for  travellers  pro- 
ceeding to  the  moon,  according  to  the  plan  proposed  by  Dr.  John  Wil- 
kins,  Bishop  of  Chester.1  "If  we  must  needs  feed  upon  something," 
he  remarks,  "why  may  not  smells  nourish  us?"  Plutarch  and  Pliny, 
and  divers  other  ancients,  tell  us  of  a  nation  in  India  that  lived  only  upon 
pleasing  odours ;  and  it  is  the  common  opinion  of  physicians  that  these 
do  strangely  both  strengthen  and  repair  the  spirits."  Fuller,2  a  learned 
cotemporary  of  the  bishop,  affords  an  amusing  instance  of  litigation, 
arising  from  this  supposed  nourishing  character  of  odours.  A  poor 
man  being  very  hungry,  stayed  so  long  in  a  cook's  shop  who  was  dish- 
ing up  the  meat,  that  his  stomach  was  satisfied  with  the  smell  thereof. 
The  choleric  cook  demanded  of  him  pay  for  his  breakfast;  the  poor  man 
denied  having  had  any;  and  the  controversy  was  referred  to  the  deci- 
sion of  the  next  man  that  should  pass  by,  who  chanced  to  be  the  most 
notorious  idiot  in  the  whole  city:  he,  on  the  relation  of  the  matter, 
determined  that  the  poor  man's  money  should  be  put  betwixt  two  empty 
dishes,  and  that  the  cook  should  be  recompensed  with  the  jingling  of 
the  money,  as  the  man  had  been  satisfied  by  the  smell  of  the  'cook's 
meat. 

It  need  scarcely  be  said,  that  if  the  vapour  from  alimentary  sub- 
stances be  capable,  in  any  manner,  of  serving  the  purposes  of  nutrition, 
it  can  only  be  by  passing  into  the  blood-vessels  of  the  lungs. 

3.    PHYSIOLOGY   OF   OLFACTION. 

In  order  that  the  sense  of  smell  may  be  duly  exercised,  it  is  neces- 
sary that  the  emanation  from  an  odorous  body  shall  not  only  impinge 
upon  the  pituitary  membrane,  but  that  it  shall  do  so  with  some  degree 
of  force.  It  must,  in  other  words,  be  drawn  in  with  the  inspired  air. 
Perrault3  and  Lower4  found,  that  by  making  an  opening  into  the  tra- 
chea of  animals,  and  preventing  the  inspired  air  from  passing  through 
the  nasal  fossae,  smell  was  not  effected;  and  that  dogs,  which  were  the 
subjects  of  the  experiment,  readily  ate  food  they  had  previously  re- 

1  The  Discovery  of  a  New  World,  or  a  Discourse  tending  to  prove,  that  'tis  possible  there 
may  be  another  Habitable  World  in  the  Moon,  with  a  Discourse  concerning  the  possibility 
of  a  passage  thither.  Lond.,  1638. 

*  Holy  State,  London,  1640. 

3  Ess.  de  Phys.,  iii.  29. 

4  Needham,  de  Format.  Fcetus,  p.  165;  and  Haller,  edit,  cit,  v.  173. 


168  SENSE  OF  SMELL. 

fused.  These  experiments  were  repeated  by  Professor  Chaussier,  and 
with  like  results.1  They  explain  why  we  use  effort  to  draw  in  air 
loaded  with  an  odour  that  is  agreeable  to  us;  and,  on  the  contrary, 
arrest  the  respiration,  or  make  it  pass  entirely  through  the  mouth 
when  odours  are  disagreeable.  Still  they  are  occasionally  so  diffusible 
and  expansible,  that  they  reach,  notwithstanding,  the  olfactory  mem- 
brane; and  we  are  compelled  to  shut  them  off  by  calling  in  the  aid  of 
the  upper  extremity.  The  air  being  the  ordinary  medium  for  the  con- 
veyance of  odorous  molecules,  we  can  understand  why  the  organ  of 
smell  should  form  a  part  of  the  air  passages. 

The  use  of  the  nose  is  to  direct  the  air,  charged  with  odours,  to- 
wards the  upper  part  of  the  nasal  fossae.  Its  situation  is  well  adapted 
for  the  reception  of  emanations  from  bodies  beneath  it,  and  its  appro- 
priate muscles  allow  the  nostrils  to  be  more  or  less  expanded  or  con- 
tracted. These  uses  assigned  to  the  nose  are  demonstrated  by  the 
fact,  that  they,  whose  noses  are  deformed — especially  the  flat-nosed — 
or  whose  nostrils  are  directed  forwards,  instead  of  downwards,  have 
commonly  the  sense  feebly  developed.  The  loss  of  the  nose,  too, 
either  by  accident  or  disease,  has  been  found  to  destroy  the  sense  com- 
pletely; and  by  no  means  the  least  advantage  of  the  rhinoplastic  ope- 
ration is  the  enjoyment  afforded  by  the  improvement  of  this  sense. 
M.  Be'clard  affirms,  that  an  artificial  nose,  formed  of  paper  or  other 
appropriate  materials,  is  sufficient  to  restore  it,  so  long  as  the  substi- 
tute is  attached.2  It  is  proper  to  remark,  however,  that  in  a  case  which 
fell  under  the  author's  observation,  although  the  nose  had  been  lost  by 
syphilis,  the  smell  persisted;  and  two  cases  of  a  similar  kind  occurred 
to  M.  P.  H.  Berard.3 

The  mode  in  which  olfaction  is  effected  appears  to  be  as  follows: — 
The  inspired  air,  loaded  with  odorous  particles,  traverses  the  nasal 
fossae;  and,  in  its  passage,  comes  in  contact  with  the  pituitary  mem- 
brane, through  the  medium  of  the  nasal  mucus.  The  use  of  this  mucus 
seems  to  be,  not  only  to  keep  the  organ  properly  lubricated,  but  to 
arrest  the  particles  as  they  pass, — not  by  any  chemical  attraction,  but 
in  a  mechanical  manner.  The  olfactory  nerves  being  distributed  on 
the  membrane,  receive  the  impression  of  the  molecules,  and,  in  this 
manner,  sensation  is  accomplished. 

The  use  of  the  different  spongy  or  turbinated  bones  would  seem  to 
be  to  enlarge  the  olfactory  surface.  According  to  some,  however,  they 
form  channels  to  direct  the  air  towards  the  openings  of  the  sinuses. 
The  sinuses,  themselves,  afford  subjects  for  physiological  discussion. 
By  many  they  are  considered  to  add  to  the  extent  of  olfactory  surface: 
by  others,  to  furnish  the  nasal  mucus.  No  hesitation  would  be  felt  in 
pronouncing  both  the  spongy  bones  and  sinuses  to  be  useful  in  olfaction, 
were  it  not  that  the  olfactory  nerves  or  first  pair  have  not  been  traced 
on  the  pituitary  membrane  covering  the  middle  and  inferior  spongy 
bones,  or  on  that  lining  the  different  sinuses ; — that  the  sinuses  are 

1  Adelon,  op.  cit.,  i.  335. 

2  Magendie,  Precis  Elementaire,  2de  edit.,  i.  136,  Paris,  1825. 

»  Art.  Olfaction,  Diet,  de  Medecine,  2de  edit.,  xxii.  9,  Paris,  1840. 


PHYSIOLOGY  OP  OLFACTION.  169 

wanting  in  the  infant,  which,  notwithstanding,  appreciates  odours; — 
that  they  exist  only  in  the  mammalia; — and  that  experiments  would 
seem  to  show,  that  the  upper  part  of  the  olfactory  organ  is  more  parti- 
cularly destined  for  the  function,  and  that  the  sinuses,  which,  as  well 
as  the  membrane  covering  the  middle  and  lower  spongy  bones,  are 
supplied  by  filaments  from  the  fifth  pair  of  nerves,  are  not  sensible  to 
odours. 

Messrs.  Todd  and  Bowman1 — from  the  fact,  that  on  the  septum  narium 
and  turbinated  bones  bounding  the  direct  passage  from  the  nostrils  to 
the  throat,  the  lining  membrane  is  rendered  thick  and  spongy  by  the 
presence  of  ample  and  capacious  submucous  plexuses  of  both  arteries 
and  veins,  of  which  the  latter  are  by  far  the  larger  and  more  tortuous — 
surmise,  and  Dr.  Carpenter2  thinks,  with  much  probability,  that  the  chief 
use  of  these  may  be  to  impart  warmth  to  the  air,  before  it  enters  the  pro- 
per olfactive  portion  of  the  cavity ;  as  well  as  to  afford  a  copious  supply 
of  moisture,  which  maybe  exhaled  by  the  abundant  glandulae  seated  in  the 
membrane.  "The  remarkable  complexity  of  the  lower  turbinated  bones 
in  animals  with  active  scent,  without  any  ascertained  distribution  of  the 
olfactory  nerves  upon  them,  has" — they  remark — "given  countenance  to 
the  supposition,  that  the  fifth  pair  may  possess  some  olfactory  endowment, 
and  seems  not  to  have  been  explained  by  those  who  rejected  that  idea. 
If  considered  as  accessory  to  the  perfection  of  the  sense  in  the  way  above 
alluded  to,  this  striking  arrangement  will  be  found  consistent  with  the 
view,  which  thus  limits  the  power  of  smell  to  the  first  pair  of  nerves." 

That  the  upper  part  of  the  nasal  fossae  is  the  great  seat  of  smell  is 
proved  by  the  facts  referred  to  regarding  the  uses  of  the  nose.  Dessault 
mentions  the  case  of  a  young  female,  who  had  a  fistula  in  the  frontal 
sinuses,  and  who  could  not  perceive  an  odorous  substance,  when  pre- 
sented at  the  orifice  of  the  fistula,  because  there  was  no  communication 
with  the  proper  portion  of  the  nasal  fossae,  although  she  was  capable  of 
breathing  through  the  opening.  M.  Deschamps,  the  younger,  relates 
the  case  of  a  man,  who  had  a  fistula  of  the  frontal  sinus,  through  which 
ether  might  be  injected  without  its  odour  being  appreciated,  provided 
all  communication  had  been  previously  cut  off  between  the  sinus  and 
the  upper  part  of  the  nasal  fossae;  but  if  this  precaution  had  not  been 
taken,  the  sense  was  more  vivid,  when  the  odours  passed  through  the 
fistulous  opening,  than  when  they  reached  the  organ  by  the  ordinary 
channel.  Again; — M.  Kicherand3  found  that  highly  odoriferous  injec- 
tions, thrown  through  a  fistulous  opening  in  the  maxillary  sinus  or 
antrum  of  Highmore,  produced  no  olfactory  sensation  whatever. 

All  these  facts  would  seem  to  lead  to  the  belief,  that  the  upper  part  of 
the  nasal  fossae,  on  which  the  first  pair  or  olfactory  nerves  are  distribu- 
ted, is  the  chief  seat  of  olfaction,  and  that  the  inferior  portions  of  these 
fossae,  as  well  as  the  different  sinuses  communicating  with  them,  are  not 
primarily  concerned  in  the  function:  but,  doubtless,  offer  secondary 
advantages  of  no  little  importance.  This  conclusion,  would,  however, 
seem  to  admit,  what  is  not  by  any  means  universally  admitted,  that  the 

1  Physiological  Anatomy  and  Physiology  of  Man,  ii.  3. 

2  Art.  Smell,  Cyclop,  of  Anat.  and  Physiol.,  Pt.  xxxvi.  p.  694,  Lond.,  June,  ]  849, 

3  Elemens  de  Physiologic,  <klit.  13eme  par  Berard,  p.  202,  Bruxelles,  1837. 


170  SENSE  OF  SMELL. 

olfactory  is  the  sole  or  chief  nerve  of  smell.  Especially  difficult  is  it 
to  embrace  this  view,  and  not  to  believe  that  the  spongy  bones  and 
sinuses,  on  which  the  fifth  pair  are  distributed,  are  agents  in  perfecting 
the  sense,  when  we  find  them  so  largely  developed  in  animals  that  possess 
unusual  delicacy  of  smell,  as  the  dog  and  elephant.  It  has  already  been 
remarked,  that  the  ancients  believed  the  olfactory  nerves  to  be  canals 
for  conveying  away  the  pituita  or  phlegm  from  the  brain.  Diemerbroeck, 
also,  maintained  this  view.1  At  the  early  part  of  the  last  century, 
however,  the  olfactory  was  supposed  to  be  the  proper  nerve  of  smell, 
and  the  opinion  prevailed,  with  few  dissentient  voices,  until  within  the 
last  few  years.  Inspection  of  the  origin  and  distribution  of  the  nerve 
seems  to  indicate  it  as  admirably  adapted  for  special  sensibility  con- 
nected with  smell.  It  is  largely  developed  in  animals  in  proportion  to 
their  acuteness  of  the  sense,  and  is  distributed  on  the  very  part  of  the 
pituitary  membrane  to  which  it  is  necessary  to  direct  air,  loaded  with 
odorous  emanations,  in  order  that  they  may  be  appreciated.  M.  Ma- 
gendie2  has,  however,  endeavoured  to  show  by  experiment,  that  the  sense 
of  smell  is  in  no  wise,  or  little,  dependent  upon  the  olfactory  nerve,  but 
upon  branches  of  the  fifth  pair.  Prior  to  the  institution  of  his  experi- 
ments, he  had  observed  with  astonishment,  that  after  he  had  removed 
the  cerebral  hemispheres,  with  the  olfactory  nerves  of  animals,  they 
still  preserved  this  sense.  He  had  noticed,  too,  that  it  continued  in 
lunatics,  who  had  fallen  into  a  state  of  stupor,  and  in  whom  the  sub- 
stance of  the  brain  appeared,  on  dissection,  greatly  disorganized.  These 
facts  induced  him  to  expose  the  olfactory  nerves  on  living  animals,  and 
to  experiment  upon  them;  and  he  found,  in  the  first  place,  that  the 
nerves  were  insensible  to  puncture,  pressure,  and  the  contact  of  the  most 
odorous  substances.  He  afterwards  satisfied  himself,  that  after  their 
division  the  pituitary  membrane  not  only  preserved  its  general  sensibi- 
lity, appreciated  the  contact  of  bodies,  but  also,  strong  odours,  those  of 
ammonia,  acetic  acid,  oil  of  lavender,  Dippel's  oil,  &c.  On  the  other 
hand,  having  divided  the  fifth  pair  of  nerves  within  the  cranium,  and 
left  the  olfactory  nerves  entire,  he  remarked,  that  the  pituitary  mem- 
brane had  lost  its  general  sensibility ;  was  no  longer  sensible  to  contact 
of  any  kind;  and  had  lost  the  power  of  appreciating  odours.  From 
these  experiments,  he  considered  himself  justified  in  inferring,  that  the 
olfactory  nerve  does  not  preside  over  the  general  sensibility  of  the 
nose;  that  it  has,  at  the  most,  a  special  sensibility  as  concerns  odours; 
and  that  if  the  olfactory  be  the  nerve  of  smell,  it  requires  the  influence 
of  the  fifth  pair,  in  order  that  it  may  act.  Lastly ;  he  asks,  may  not  the 
general  and  special  sensibility  be  comprised  in  the  same  nerve  in  the 
sense  of  smell,  as  they  are  in  that  of  taste; — in  the  fifth  pair? 

These  experiments  are  interesting;  but  they  by  no  means  establish, 
that  the  fifth  pair  is  the  olfactory  nerve.  The  numerous  facts,  already 
mentioned,  attract  us  irresistibly  to  the  first  pair  or  olfactory,  as  they 
have  been  exclusively  called.  It  has  been  already  remarked,  that  the 
fifth  is  concerned  in  all  the  facial  senses;  that  it  conveys  to  them  general 

1  Anatome  Corporis  Humani,  lib.  iii.  cap.  8,  Ultraject.,  1672. 
8  Precis  Elementaire,  2de  edit.,  i.  132. 


IMMEDIATE  FUNCTION  OF  SMELL.  171 

sensibility  or  feeling ;  and  that  some  of  them  are  unquestionably  sup- 
plied with  nerves  of  special  sensibility; — the  eye  with  the  optic;  and 
the  ear  with  the  auditory;  but  that  neither  the  one  nor  the  other  can 
exert  its  special  function,  without  the  integrity  of  the  fifth.  The  olfac- 
tory nerve  is  probably  in  this  category, — is  the  nerve  of  special  sensi- 
bility. It  is  true,  that  in  the  experiments  of  M.  Magendie  the  animal 
appeared  to  be  affected  by  odorous  substances,  after  the  division  of  the 
first  pair;  but  a  source  of  fallacy  existed  here,  in  discriminating  accu- 
rately between  the  general  and  special  sensibility.  Some  of  the  sub- 
stances employed  were  better  adapted  for  eliciting  the  former  than  the 
latter ; — ammonia  and  acetic  acid,  for  example. 

The  immediate  function  of  the  sense  of  smell  is  to  appreciate  odours. 
In  this  it  cannot  be  supplied  by  any  other  sense.  The  function  is  in- 
stinctive; requires  no  education;  and  is  exerted  as  soon  as  the  parts 
have  attained  the  necessary  degree  of  development.  In  many  respects 
the  sense  is  intimately  connected  with  that  of  taste;  and  the  impres- 
sions made  upon  each  are  frequently  confounded.  In  the  nutritive 
function,  the  smell  serves  as  a  kind  of  advanced  guard  or  sentinel  to 
the  taste ;  and  warns  us  of  the  disagreeable  or  agreeable  nature  of  the 
aliment;  but  if  a  substance  repugnant  to  the  smell  be  agreeable  to  the 
taste,  the  smell  soon  loses  its  aversion,  or  at  least  becomes  less  disa- 
greeably impressed.  The  smell  is  not,  however,  in  man  so  useful  as  a 
sentinel  to  the  taste,  as  it  is  to  animals:  there  are  many  bodies, — those 
containing  prussic  acid  for  example, — which  are  extremely  pleasing  by 
the  odours  they  exhale,  and  yet  are  noxious  to  man.  In  the  animal 
kingdom,  this  sense  is  greatly  depended  upon,  and  is  rarely  a  fallacious 
guide.  It  enables  animals  to  make  the  proper  selection  of  the  noxious 
from  the  innocent; — the  alimentary  from  that  which  is  devoid  of  nutri- 
ment ; — the  agreeable  from  the  disagreeable  ;  and  the  power  appears  to 
be  instinctive  or  dependent  upon  inappreciable  varieties  of  structure  in 
the  organs  concerned  in  olfaction. 

As  an  intellectual  sense,  smell  is  not  entitled  to  a  higher  rank  than 
taste.  Its  mediate  functions  are  very  limited.  It  enables  the  chemist, 
mineralogist,  and  perfumer,  to  discriminate  bodies  from  each  other. 
We  can,  likewise,  by  it  form  a  slight — but  only  a  slight — idea  regard- 
ing the  distance  and  direction  of  bodies,  owing  to  the  greater  intensity 
of  odours  near  an  odorous  body,  than  at  a  distance  from  it.  Under 
ordinary  circumstances,  the  information  of  this  kind  derived  by  olfac- 
tion is  inconsiderable;  but  in  the  blind;  and  in  the  savage,  who  is 
accustomed  to  exercise  all  his  external  senses  more  than  the  civilized, 
its  sphere  of  utility  and  accuracy  is  largely  augmented.  Of  this  we 
shall  have  to  speak  presently.  We  find  it,  too,  surprisingly  developed 
in  certain  animals;  in  which  it  is  considered,  by  the  eloquent  Buffon,  as 
an  eye  that  sees  objects  not  only  where  they  are,  but  where  they  have 
been, — as  an  organ  of  gustation,  by  which  the  animal  tastes  not  only 
what  it  can  touch  and  seize,  but  even  what  is  remote,  and  cannot  be 
attained;  and  he  esteems  it  a  universal  organ  of  sensation,  by  which 
animals  are  most  readily  and  most  frequently  impressed ;  by  which  they 
act  and  determine,  and  recognise  whatever  is  in  accordance  with,  or  in 


172  SENSE  OF  SMELL. 

opposition  to,  their  nature.  The  hound  amongst  quadrupeds  affords  us 
a  familiar  example  of  the  extreme  delicacy  of  this  sense.  For  hours 
after  the  passage  of  game,  it  is  capable  of  detecting  its  traces;  and  the 
bloodhound  can  be  trained  to  indicate  the  human  footsteps  with  unerr- 
ing certainty. 

Until  of  late  years,  it  was  almost  universally  believed,  that  many  of 
the  birds  of  prey  possess  an  astonishingly  acute  sense  of  smell.  Hum- 
boldt1  relates,  that  in  Peru,  Quito,  and  in  the  province  of  Popayan, 
when  they  are  desirous  of  taking  the  gigantic  condor —  Vultur  gryphus 
of  Linnaeus — they  kill  a  cow,  or  horse,  and  in  a  short  time,  the  odour 
of  the  dead  animal  attracts  those  birds  in  numbers,  and  in  places  where 
they  were  scarcely  known  to  exist.  It  is  asserted,  too,  that  vultures 
went  from  Asia  to  the  field  of  battle  at  Pharsalia,  a  distance  of  several 
hundred  miles,  attracted  thither  by  the  smell  of  the  killed!2  Pliny,3 
however,  exceeds  almost  all  his  contemporaries  in  his  assertions  on  this 
matter.  He  affirms,  that  the  vulture  and  the  raven  have  the  sense  of 
smell  so  delicate,  that  they  can  foretell  the  death  of  a  man  three  days 
beforehand,  and  in  order  not  to  lose  their  prey  they  arrive  upon  the 
spot  the  night  before  his  dissolution!  The  turkey-buzzard  of  the 
United  States  is  a  bird  of  this  class,  and  it  is  surprising  to  see  how 
soon  they  collect  from  immense  distances  after  an  animal  has  died  in 
the  forests.  The  observations  and  experiments  of  the  ornithologist 
Audubon4  would  seem,  however,  to  show  that  this  bird  possesses  the 
sense  of  smell  in  a  less  degree  than  the  carnivorous  quadruped.  He 
stuffed  the  skin  of  a  deer  with  hay,  and  after  the  whole  had  become 
perfectly  dry  and  hard,  placed  it  in  an  open  field  on  its  back,  and  in 
the  attitude  of  a  dead  animal.  In  the  course  of  a  few  minutes  a  vul- 
ture was  observed  flying  towards  it,  which  alighted  near,  and  began  to 
attack  it;  tearing  open  the  seams,  and  pulling  out  the  hay;  but  finding 
that  it  could  obtain  nothing  congenial  to  its  taste,  it  took  flight.  It 
was  found,  too,  that  when  animals  in  an  advanced  state  of  putridity 
were  lightly  covered  over  so  as  to  prevent  vultures  from  seeing  them, 
they  remained  undisturbed  and  undiscovered,  although  the  birds  re- 
peatedly flew  over  them.  In  some  other  experiments  it  was  found, 
that  birds  of  prey  were  attracted  by  well-executed  representations  of 
dead  animals  painted  on  canvass  and  exposed  in  the  fields, — and  in 
others,  that  young  vultures,  enclosed  in  a  cage,  exhibited  no  tokens  of 
their  perceiving  food,  when  it  could  not  be  seen  by  them,  however  near 
them  it  was  brought.  These  results — which  were  obtained,  also,  by 
Dr.  Bachman  in  the  presence  of  a  number  of  scientific  gentlemen  of 
Charleston,  South  Carolina — are  strange,  inasmuch  as  the  olfactory 
apparatus  of  the  turkey-buzzard,  when  examined  by  the  comparative 
anatomist,  exhibits  great  development,  and  admirable  adaptation  for 
acuteness  of  smell.  They  are  confirmed,  however,  by  more  recent  expe- 
riments on  the  condor  by  Mr.  Charles  Darwin,5  a  distinguished  natu- 

1  Rec.  de  Zoolog.  ejt  d'Anat.  Comp.,  2de  livr.,  p.  73,  Paris,  1807. 

9  Haller,  edit,  cit.,  torn,  v.  lib.  xiv.  p.  158.     a  Hist.  Nat.,  lib.  x.  cap.  6,  p.  230,  Lugd.  1587. 
4  Ornithological  Biography,  p.  33,  Boston,  1835;  London's  Mag.  of  Nat.  Hist.,  vii.  167. 
s  Journal  of  Researches  into  the  Natural  History  and  Geography  of  the  countries  visited 
during  the  voyage  of  H.  M.  S.  Beagle  round  the  World.     Amer.  edit.,  New  York,  1846. 


IMPROVED  BY  EDUCATION.  173 

ralist.  He  tied  several  condors  by  ropes  in  a  long  row  at  the  bottom 
of  a  wall;  and  having  folded  up  a  piece  of  meat  in  white  paper,  he 
walked  backwards  and  forwards  carrying  it  in  his  hand  at  the  distance 
of  about  three  yards  from  them;  but  no  notice  whatever  was  taken  of 
it.  He  then  threw  it  on  the  ground  within  one  yard  of  an  old  male 
bird,  which  looked  at  it  for  a  moment  with  attention,  but  regarded  it 
no  more.  With  a  stick  he  pushed  it  closer  and  closer,  until  at  last  the 
bird  touched  it  with  its  beak :  the  paper  was  then  instantly  torn  off 
with  fury,  and  at  the  same  moment  every  condor  in  the  long  row  began 
struggling,  and  flapping  its  wings.  "Under  the  same  circumstances, 
it  would  have  been  quite  impossible  to  have  deceived  a  dog." 

As  the  organ  of  smell,  in  all  animals  that  respire  air,  is  situate  at 
the  entrance  of  the  organs  of  respiration,  it  is  probable  that  its  seat,  in 
insects,  is  in  the  mouth  of  the  air  tubes.  This  sense  appears  to  guide 
them  to  the  proper  kinds  of  food,  and  to  the  execution  of  most  of  the 
few  offices  they  perform  during  their  transient  existence.  Occasionally, 
however,  they  are  deceived  by  the  resemblance  between  odours  of  sub- 
stances very  different  in  other  qualities.  Certain  plants,  for  example, 
emit  a  cadaverous  odour  similar  to  putrid  flesh,  by  which  the  flesh-fly 
is  attracted,  and  led  to  deposit  its  ova  in  places  that  can  furnish  no 
food  to  its  future  progeny. 

As  regards  the  extent  of  the  organ  of  smell,  man  is  undoubtedly 
worse  situate  than  most  animals ;  and  all  things  being,  in  other  respects, 
equal,  it  may  be  fair  to  presume,  that  those,  in  which  the  olfactory 
membrane  is  most  extensive,  possess  the  sense  of  smell  most  acutely. 
It  is  curious,  however,  that  certain  animals,  which  have  the  sense*  of 
smell  in  the  highest  degree,  feed  on  the  most  fetid  substances.  The 
dog,  for  instance,  riots  in  putridity;  and  the  birds  of  prey,  to  which 
reference  has  been  made,  but  whose  acuteness  of  smell,  we  have  seen, 
has  been  contested,  have  similar  enjoyment.  The  turkey-buzzard  is  so 
fetid  and  loathsome,  that  his  captors  are  glad  to  loosen  him  from  bond- 
age; and  it  is  affirmed,  that  if  his  ordinary  foetor  be  insufficient  to 
produce  his  release,  he  affords  an  irresistible  incentive,  by  ejecting  the 
putrid  contents  of  his  stomach  upon  them  I1 

One  inference  may,  perhaps,  be  drawn  from  this  penchant  of  animals 
with  exquisite  olfactories  for  putrid  substances ; — that  the  taste  of  the 
epicure  for  game,  kept  until  it  has  attained  the  requisite  fumet,  is  not 
so  unnatural  as  might  at  first  sight  appear. 

Like  the  senses  already  described,  that  of  smell  is  to  a  certain  extent 
under  the  influence  of  volition : — in  other  words,  it  can  be  exerted 
actively,  and  passively.  Its  active  exercise — as  when  we  smell  any 
substance  to  enjoy  its  sweets,  orx  test  its  odorous  qualities — generally 
requires  prehension,  the  proper  direction  of  the  head  towards  the  object, 
and  more  or  less  contraction  of  certain  muscles  of  the  alse  nasi.  Doubt- 
less, here  again,  the  papillae  are  capable  of  being  erected  under  atten- 
tion, as  in  the  senses  of  taste  and  touch.  On  the  other  hand,  we  can 
throw  obstacles  in  the  way  of  the  reception  of  disagreeable  odours; 
and,  if  necessary,  prevent  their  ingress  altogether,  by  compressing  the 
nostrils  with  the  upper  extremity. 

1  Wilson's  American  Ornithology,  by  Geo.  Ord,  Plrilad.,  1803-1814. 


174  SENSE  OF  HEARING. 

Lastly: — like  the  other  senses,  smell  is  capable  of  great  improvement 
by  education.  The  perfumer  arrives,  by  habit,  at  an  accurate  discri- 
mination of  the  nicest  shades  of  odours ;  and  the  chemist  and  the 
apothecary  employ  it  to  aid  them  in  distinguishing  bodies  from  each 
other ;  and  in  pointing  out  the  changes  that  take  place  in  them,  under 
the  influence  of  heat,  light,  moisture,  &c.  In  this  way,  it  becomes  a 
useful  chemical  test.  The  effect  of  education  is  likewise  shown,  by  the 
difference  between  a  dog  kept  regularly  accustomed  to  the  chase,  and 
one  that  has  not  been  trained.  For  the  same  reason,  in  man,  the  sense 
is  more  exquisite  in  the  savage  than  in  the  civilized  state.  In  the  latter, 
he  can  have  recourse  to  a  variety  of  means  for  discriminating  the  proper- 
ties of  bodies  ;  and  hence  has  less  occasion  for  acuteness  of  smell  than 
in  the  former ;  whilst,  again,  in  the  latter  state,  numbers  destroy  the 
sense  to  procure  pleasure.  The  use  of  snuff  is  one  of  the  most  common 
of  these  destructive  influences. 

Of  the  acuteness  of  the  sense  of  smell  in  the  savage  we  have  an 
example  on  the  authority  of  Humboldt :  he  affirms,  that  the  Peruvian 
Indians  in  the  middle  of  the  night  can  distinguish  the  different  races 
by  their  smell, — whether  they  are  European,  American,  Indian,  or 
negro.  To  the  same  cause  must  be  ascribed  the  delicacy  of  olfaction 
generally  observed  in  the  blind.  The  boy  Mitchell,1  who  was  born 
blind  and  deaf,  and  whose  case  will  have  to  be  referred  to  hereafter, 
was  able  to  distinguish  the  entrance  of  a  stranger  into  the  room  by 
smell  alone.  A  gentleman,  blind  from  birth,  from  some  unaccountable 
impression  of  dread  or  antipathy,  could  never  endure  the  presence  of 
a  cat  in  the  apartment.  One  day,  in  company,  he  suddenly  leaped 
up ;  got  upon  an  elevated  seat ;  and  exclaimed,  that  a  cat  was  in  the 
room,  begging  them  to  remove  it.  It  was  in  vain  that  the  company, 
after  careful  inspection,  assured  him  he  was  under  an  illusion.  He 
persisted  in  his  assertion  and  state  of  agitation ;  when,  on  opening  the 
door  of  a  small  closet,  it  was  found  that  a  cat  had  been  accidentally 
shut  up  in  it. 

SENSE  OF  HEARING  OR  AUDITION. 

Audition  makes  known  to  us  the  peculiar  vibrations  of  sonorous 
bodies,  that  constitute  sounds.  It  differs  from  the  senses  which  have 
already  been  described,  in  the  fact,  that  contact  is  not  required  between 
the  organ  of  sense  and  the  sonorous  body;  or  between  it  and  any 
emanation  from  the  body.  It  is,  however,  a  variety  of  touch,  but  pro- 
duced by  a  medium  acted  upon  by  the  vibratory  body. 

1.  ANATOMY  OF  THE  ORGAN  OF  HEARING. 

The  auditory  apparatus  is  a  subject  of  intricate  study  to  the  young 
anatomist ;  and  unfortunately  when  he  has  become  acquainted  with  the 
numerous  minute  portions  to  which  distinct  and  difficult  appellations 
have  been  appropriated,  he  has,  as  in  many  other  cases,  attained  a 
tedious  detail  of  names,  without  having  added  to  his  stock  of  physio- 

1  Wardrop's  History  of  James  Mitchell,  Lond.,  1813;  and  Dugald  Stewart's  Elements  of 
the  Philosophy  of  the  Human  Mind,  iii.  401,  3d  edit.,  Lond.,  180S. 


ORGAN  OF  HEARING. 


175 


Those  of   audi-    View  of  the  Left  Ear  in  its  Natural 


logical    information.     Happily,   it   is  not  Fig.  63. 

necessary  for  our  purpose  to  go  so  minutely 
into  the  description  of  the  organ  of  hear- 
ing. According  to  the  plan  hitherto  pur- 
sued, allusion  will  be  made  to  those  portions 
only  that  concern  the  physiological  in- 
quirer. 

In  the  ear,  as  well  as  in  the  eye,  we  have 
the  distinction  between  the  physical  and 
nervous  portions  of  the  organ  more  clearly 
exhibited  than  in  the  skin,  mouth,  or  nose. 
The  nervous  portion  is  situate  deeply 
within  the  organ;  and  the  parts  between 
it  and  the  exterior  act  physically — on  so- 
norous vibrations,  in  the  case  of  the  ear ; 
and  on  light,  in  that  of  the  eye. 

The  organs  of  the  senses  hitherto  con- 
sidered are  symmetrical. 

tion  are  two  in  number,  distinct  but  bar-     V2  Origin  and  termination  of  the 
monious,  and  situate  at  the  sides  of  the  |Lelix-  3  Antheiix.  4  Antitragus.  5. 

,         ,     .    '  c     -i  11  Tragus.    6    Lobus  of  the  external  ear. 

nead,  in  a  part  ot  the  temporal  bone,  ge-  7.  Points  to  the  scapha,  and  is_on  the 
nerally  called,  from  its  hardness,  pars  pe-  9™Meau! 
trosa,    and     by     the 

French   and   German  Fig.  64. 

anatomists  regarded 
as  a  distinct  bone, 
under  similar  appella- 
tions— Le  Hocher^aud 
F  e  1  s  e  n  b  e  i  n,  ( "  rock- 
bone.")  This  bone  is 
seated  at  the  base  of 
the  skull,  so  that  the 
internal  parts  of  the 
auditory  organ  are 
deeply  and  securely 
lodged. 

For  facility  of  de- 
scription, the  ear  may 
be.  divided  into  three 
portions: — 1.  Exter- 
nal ear  or  that  exte- 
rior to  the  membrana 

tympani  *     2.    Middle    General  View  of  the  External,  Middle,  and  Internal  Ear,  as  seen 

in  a  Prepared  Section.     (From  Scarpa.) 

ear — the    space    con- 

11                          ,1  a.  The  auditory  canal,    b.  The  tympanum  or  middle  ear.     e.  Eus- 

)6tWeen       tne  tachian  tube,  leading  to  the  pharynx,     d.  Cochlea;  ande.  Semicir- 

momV»v?»r»Q         f  Tr-mi-var*!  cular  canals  and  vestibule,  seen  on  their  exterior,  as  brought  into 

lid,         tympani  yiew  fay  dissecting.  away  the  surrounding  petrous  bone.     The  styloid 

and  internal  ear;  and  process  projects  below  ;  and  the  inner  surface  of  the  carotid  canal  is 

0       rjll         .     ,  seen  above  the  Eustachian  tube. 

3.   The   internal   ear 

in  which  the  auditory  nerve  is  distributed. 

1.  External  Ear.     This  portion  of  the  auditory  apparatus  is  com- 


176 


SENSE  OF  HEARING. 


monly  looked  upon  as  an  acoustic  instrument,  for  collecting  the  so- 
norous rays  or  vibrations,  and  directing  them,  in  a  concentrated  state, 
to  the  parts  within.  It  is  composed  of  the  pavilion,  and  meatus  audi- 
torium externus. 

The  pavilion  varies  in  size  and  position  in  different  individuals.  It 
is  the  fibro-cartilaginous,  thin,  expanded  portion,  which  is  an  append- 
age, as  it  were,  to  the  head.  It  is  irregular  on  its  anterior  surface  ; 
presenting  several  eminences  and  depressions.  The  eminences  are  five 
in  number;  and  have  been  called,  by  anatomists,  helix,  anthelix,  tragus, 
antitragus,  and  lobe.  The  helix  forms  the  rim  of  the  pavilion:  the 
tragus  is  the  small  nipple-like  projection  on  the  facial  side  of  the 
meatus  auditorius;  the  antitragus  is  the  projection  opposite  to  this,  — 
forming  the  lower  portion  of  the  anthelix;  and  the  lobule  is  the  fatty, 
pendulous  portion,  to  which  ear-rings  are  attached.  The  depressions 
are  three  in  number  —  the  groove  of  the  helix  or  cavitas  innominata  ; 
the  fossa  navicularis  or  scapha  ;  and  the  concha.  The  name  of  the 
first  sufficiently  indicates  its  situation;  the  second  is  nearer  the  meatus 
auditorius;  and  the  third  is  the  expanded  portion,  which  joins  the  com- 
mencement of  the  meatus,  and  is  bounded  by  the  anthelix,  tragus,  and 
antitragus.  The  pavilion  is  supple  and  elastic  ;  and,  beneath  the  skin 
are  numerous  sebaceous  follicles,  which  are  distinctly  perceptible,  and 
give  the  skin  its  polish,  and  probably  a  portion  of  its  suppleness.  On 
the  different  eminences,  some  muscular  fibres  are  perceptible,  which  it 
is  not  necessary,  for  our  purpose,  to  distinguish  ;  for  in  man  at  least 
they  are  but  vestiges  —  as  the  French  term  them  —  to  indicate  the  uni- 
form plan  that  appears  to  have  prevailed  in  the  formation  of  verte- 
brated  animals  :  if  they  have  any  office  it  must  be  unimportant.  Nu- 

merous vascular  and  nervous  ramifications 
are  distributed  on  the  pavilion.  It  is  at- 
tached to  the  head  by  different  ligaments, 
called  —  from  their  situation  or  attachments 
—  zygomato-auricular  or  anterior-auricu- 
lar :  —  temporo-auricular  or  superior-au- 
ricular, and  mastoido-auricular  or  posteri- 
or-auricular ;  all  of  which  terminate  on 
the  convex  part  of  the  concha.  Three 
muscles,  in  animals  at  least,  are  attached 
to  the  ear  to  move  the  pavilion.  These 
occupy  the  same  position  as  the  ligaments 
described;  and  have  similar  names.  In 
man,  they,  again,  are  mere  vestiges;  but  in 
many  animals  —  as  the  horse  —  they  are 
largely  developed,  and  capable  of  moving 
the  pavilion  in  various  directions;  and 
there  are  persons,  who  possess  a  degree  of 

Voluntary  pOWCr  OVCr  it. 

The  mecttus  auditorius  externus  extends 


Fig.  65. 


Anterior  View  of  the  External  Ear, 
as  well  as  of  the  Meatus  Audito- 
rius, Labyrinth,  &c. 

1.  The  opening  into  the  ear  at  the 
bottom  of  the  concha.  2.  Meatus  au- 
ditorius externus  or  cartilaginous  ca-  _  .. 

3.  Membrana  tympani  stretched  from  the  inner  extremity  of  the  concha  to 

4.  Malleus.    5.  Stapes.    ^rt    rv™l_™    ^ „„;         Jn    the   a(Jult,  it 


the  membrana  tympani. 


ORGAN  OF  HEARING.  177 

is  about  an  inch  long;  narrower  in  its  middle  than  extremities;  longer 
inferiorly  than  superiorly,  owing  to  the  obliquity  of  the  membrana 
tympani;  and  slightly  curved  upwards  about  its  middle.  The  outer 
orifice  is  furnished  with  down  or  hairs — vibrissse — like  the  orifices  of 
certain  other  canals.  The  meatus  is  osseous,  for  the  space  of  half  an 
inch,  and  penetrates  the  temporal  bone.  More  externally,  it  is  formed 
of  fibro-cartilage, — a  prolongation  of  that  of  the  concha.  It  is  lined  by 
an  extension  of  the  skin,  which  becomes  gradually  thinner  as  it  proceeds 
inwards,  and  is  ultimately  reflected  over -the  outer  surface  of  the  mem- 
brana tympani.  Beneath  this  skin,  numerous  sebaceous  glands  or  folli- 
cles are  situate,  which  secrete  the  bitter  humour,  called  cerumen.  This 
humour  occasionally  becomes  inspissated;  obstructs  the  canal ;  prevents 
sonorous  vibrations  from  reaching  the  membrana  tympani,  and  is  thus 
the  cause  of  deafness.  Softening  it,  by  means  of  warm  water  or  oil, 
or  soap  and  water  dropped  into  the  meatus,  and  removing  it  by  means 
of  the  syringe,  restores  the  hearing. 

The  portion  of  the  auditory  apparatus  arbitrarily  termed  the  exter- 
ternal  ear,  is  a  complete  cul-de-sac,  formed  by  a  prolongation  of  the 
common  integument.  There  is  no  opening  communicating  with  the 
next  portion — the  middle  ear  ; — the  membrana  tympani,  with  its  der- 
moid  envelopes,  forming  at  once  the 
medium  of  union  and  separation  Fis- 66- 

between  the  two.     A  knowledge  of  A  B 

this  fact  would  somewhat  diminish 
the  alarm  in  cases  where  insects  or 
other  extraneous  bodies  get  into  the 
meatus.  The  pain  is  excruciating, 
owing  to  the  great  general  sensibi- 
lity of  this  portion  of  the  auditory 
apparatus ;  but  the  chief  dread  en- 
tertained is,  that  the  irritating  sub- 
stance  may  pass  into  the  head.  It 

*    *      »     •       ,  T  !•   Membrana  tympani.     2.  Malleus.    3.  Sta- 

cannot   proceed  further    than   the  pes.  4.  incus. 

membrana  tympani,  and  even  if  it 

were  able  to  clear  this  obstacle,  insuperable  impediments  would  exist 

to  its  farther  progress  inwardly. 

2.  The  middle  ear  includes  the  cavity  of  the  tympanum,  the  small 
bones  contained  in  the  cavity,  the  mastoid  cells,  Eustachian  tube,  &c. 
Like  the  last,  it  belongs  to  the  physical  portion  of  the  ear.  The 
cavity  of  the  tympanum  or  drum  of  the  ear  has  the  shape  of  a  portion 
of  an  irregular  cylinder.  Its  name  is,  indeed,  not  inappropriate.  It 
bears  some  resemblance  to  a  drum  ;  not  only  in  form,  but,  as  will  be 
seen,  in  function.  The  outer  extremity  is  closed,  as  in  a  drum,  by  the 
membrana  tympani.  This  membrane  is  not  situate  vertically  in  the 
meatus;  but  obliquely  downwards  and  inwards;  so  that  the  cavity  is 
broader  above  than  below.  It  is  very  thin  and  transparent,  and  con- 
sists of  three  layers,  the  outermost  formed  by  the  membrane  lining 
the  meatus  auditorius  externus ;  the  innermost  belonging  to  the  mem- 
brane of  the  cavity  of  the  tympanum ;  and  the  middle  the  membrane 
proper.  On  its  inner  side  passes  the  nerve  called  chorda  tympani; 

VOL.  I. — 12 


178 


SENSE  OF  HEARING. 


and  its  centre  affords  attachment  to  one  extremity  of  the  chain  of 
small  bones,  —  to  the  handle  of  the  malleus.  The  proper  tissue  of  the 
membrane  is  dry,  and  it  is  generally  esteemed  to  be  devoid  of  fibres, 
vessels,  and  nerves.  Sir  Everard  Home,1  however,  asserts,  that  it  is 
muscular;  that  its  fibres  run  from  the  circumference  towards  the  cen- 
tre, and  are  attached  to  the  malleus  ;  and  that  if  the  membrane  of  the 
human  ear  be  completely  exposed  on  both  sides  by  removing  the  con- 
tiguous parts,  the  cuticular  covering  be  washed  off  from  its  external 
surface,  and  it  be  placed  in  a  clear  light,  the  radiated  direction  of  its 
fibres  may  be  easily  detected.  This  fibrous  arrangement,  Sir  Everard 
conceives  to  be  muscular,  and  on  this  he  founds  some  ingenious  specu- 
lations, to  be  hereafter  noticed,  regarding  the  appreciation  of  sounds. 
The  discovery  of  a  fibrous  structure  would,  however,  by  no  means 
prove,  that  the  membrane  is  capable  of  contracting;  or  that  it  is 
formed  of  muscular  tissue.  Many  ligaments,  which  consist  of  gelatin, 
and  are,  consequently,  not  contractile  like  muscles,  are  distinctly 
fibrous  in  their  arrangement.  The  same  may  be  said  of  tendons,  whose 
utility,  as  conductors  of  force  developed  by  muscle,  would  be  mate- 
rially interfered  with,  were  they  possessed  of  contractility.  Again  :  — 
Messrs.  Ruysch,2  Sir  Everard  Home,  and  Sir  Charles  Bell,3  affirm, 
that  the  membrana  tympani  is  vascular,  —  Sir  Everard  asserting,  that 
the  vessels,  in  their  distribution,  resemble  those  of  the  iris,  and  are 
nearly  half  as  numerous  ;  —  their  general  direction  being  from  the  cir- 
cumference to  the  handle  of  the  malleus.  It  is  not  easy  to  account 

for  this  discrepancy  amongst  practical  ana- 
tomists as  to  the  structure  of  the  membrana 
tympani.  A  part  of  it  is  probably  refer- 
able to  some  having  directed  their  attention 
to  the  membrane  proper;  and  others  to  the 
membrane  with  its  dermoid  coverings,  .which 
are  highly  vascular. 

The  inner  extremity  of  the  drum  is 
partly  osseous,  partly  membranous.  Nearly 
opposite  the  centre  of  the  membrana  tym- 
pani is  the  foramen  ovale  seu  vestibulare, 
called,  also,  ihefenestra  ovalis  seu  vestibu- 
laris,  situate  vertically,  and  forming  a  com- 
munication  between  the  middle  and  internal 

T,    .       ,         ,  ,  r 

ear.     It  is  closed  by  a  membrane  —  consist- 

m  Head  of  the  malleus  below  ™g,  like  the  membrana  tympani,  of  three 

layers-to  which  is  attached  the  base  of  the 
stapes,  the  inner  extremity  of  the  chain  of 

vi  ,         .1  .    i  ,  i 

ossides   that   stretches   across   the    cavity. 

"h/ilnw  t>iA  fnvampn  nvnlp  i<3  thp 

Deiow  tne  loramen  ovaie 


Ossicies  of  the  left  Ear  articulated, 

and  seen  from  the  outside  and  be- 

iow. 


the  root  of  which  is  the  short  process, 

h.  Manubrium,  or  handle,    sc.  Short 

cms;  and  ic,  long  crus  of  the  incus, 

The  body  of  this  bone  is  seen  articu- 

lating  with  the  malleus,  and  its  long 

crus,  through  the  medium  of  the  orbi-   D0ny  projection  called  the  promontory  ;  and 

cular  process,  here  partly  concealed,  *>    *       *>    .  .  -t  .  n    j 

Base  of  the   beneath  this,  again,  a  second  opening,  called 


with  the  stapes,   s. 

"* 


,  , 

foramen  rotundum  seu  cochleare,  and  fenes- 


1823. 


i  Philos.  Transact,  for  1800,  P.  i.  p.  1,  and  Lectures  on  Comp.  Anat.,iii.  262,  Lond 

9  Epist.  Anat.  octava,  p.  10.     Amstel.,  1724. 

8  Anat.  and  Physiol.,  edited  by  J.  D.  Godman,  5th  Amer.  edit.,  ii.  253,  New  York,  1827 


ORGAN  OF  HEARING.  179 

tra  rotunda  sen  cocJtlearis,  which  forms  a  communication  between  the 
middle  ear  and  the  external  scala  of  the  cochlea.  This  foramen  is 
closed  by  a  membrane,  similar  to  that  of  the  foramen  ovale ;  not,  like 
it,  parallel,  or  nearly  so,  to  that  of  the  tympanum, — but  situate  ob- 
liquely. There  is  no  communication  by  a  chain  of  bones  between  it  and 
the  membrana  tympani. 

The  small  bones  or  ossicles  are  four  in  number,  so  connected  with 
each  other  as  to  form  a  bent  lever ;  one  extremity  of  which  is  attached 
to  the  tympanic  surface  of  the  membrana  tympani, — the  other  to  the 
membrane  of  the  foramen  ovale.  These  bones  are  usually  termed, 
from  their  shape — beginning  with  the  most  external,  and  following  their 
order — malleus,  incus,  os  orbiculare,  (by  some  not  considered  a  distinct 
bone,  but  a  process  of  the  incus,)  and  stapes.  A  small  muscular  appa- 
ratus,— consisting  of  three  muscles,  anterior  muscle  of  the  malleus; 
internal  muscle  of  the  same  bone;  and  muscle  of  the  stapes, — is  attached 
to  the  chain,  which  it  can  stretch  or  relax ;  and,  of  course,  it  produces 
a  similar  effect  upon  the  membranes  to  which  the  chain  is  attached. 

Bellingeri1  thinks,  that  the  fifth  pair  regulates  altogether  the  invo- 
luntary motions  of  the  middle  ear. 

At  the  anterior  and  inferior  part  of  the  cavity  is  the  tympanic  ex- 
tremity of  a  canal,  through  which  the  drum  receives  the  air  it  contains. 
This  canal,  called  Eustachian  tube,  is  about  two  inches  long,  and  pro- 
ceeds obliquely  forwards  and  inwards  from  the  middle  ear  to  the  lateral 
and  superior  part  of  the  pharynx,  into  which  it  opens  behind  the  pos- 
terior nares.  It  is  partly  osseous,  partly  fibro-cartilaginous  and  mem- 
branous; and,  towards  its  pharyngeal  extremity,  expands,  terminating 
by  an  oval  aperture  resembling  a  cleft.  Throughout  its  course  it  is 
lined  by  a  mucous  membrane,  which  appears  to  be  a  prolongation  of 
that  of  the  nasal  fossse,  and  is  capable  of  being  more  or  less  contracted 
and  expanded  by  the  muscles,  which  compose  and  move  the  velum  palati. 
The  cavity  of  the  tympanum  communicates,  by  a  short  and  ragged 
canal,  with  numerous  cells  contained  in  the  mastoid  process.  These 
cells  open  into  each  other,  and  vary  in  number,  size,  and  arrangement 
in  different  individuals,  and  animals.  They  are  called  mastoid  cells. 
The  cavity  of  the  tympanum  is  larger  in  animals  whose  sense  of  hear- 
ing is  most  acute.  In  man,  it  is  about  a  quarter  of  an  inch  deep,  and 
half  an  inch  broad,  and  is  lined  by  a  prolongation  of  the  same  mem- 
brane as  that  which  lines  the  Eustachian  tube.  This  membrane,  as  we 
have  seen,  covers  the  membrana  tympani,  and  the  membranes  of  the 
foramen  ovale,  and  foramen  rotundum.  It  likewise  lines  the  mastoid 
cells,  and  is  reflected  over  the  small  bones. 

The  middle  ear  does  not  exist  in  every  animal  endowed  with  hearing. 
It  does  not  begin  to  appear  lower  in  the  scale  than  reptiles ;  and  is  by 
no  means  equally  complex  in  all.  Frequently,  the  chain  of  bones  is 
entirely  wanting;  and  at  other  times  we  find  one  bone  only. 

8,  The  internal  ear  or  labyrinth  is  the  most  important  part  of  the 
apparatus.  It  consists  of  several  irregular  cavities  in  the  pars  petrosa 
of  the  temporal  bone,  in  which  the  nerve  of  audition  is  distributed.  It  is, 

1  Edinb.  Medical  and  Surgical  Journal,  July,  1834,  p.  128. 


180 


SENSE  OF  HEARING. 


consequently,  here  that  the  physical  part  of 
audition  terminates,  and  the  nervous  begins. 
The  labyrinth  comprises  the  vestibule,  semi- 
circular canals,  and  cochlea.  The  vestibule  — 
as  its  name  imports  —  is  the  hall,  that  com- 
municates with  all  the  other  cavities  of  the 
labyrinth.  It  would  appear  to  be  the  most 
essential  part  of  the  organ,  as  it  often  exists 
alone.  At  its  inner  surface  are  numerous 
small  foramina,  which  communicate  with  the 
bottom  of  the  meatus  auditorius  internus,  and 
through  which  the  filaments  of  the  auditory 
nerve  reach  the  labyrinth.  Externally,  it 
communicates  with  the  cavity  of  the  tympa- 

Labyrinth^tedfrom  the  solid  num  bJ  the  foramen  ovale.     Posteriorly,  it 

bone  in  which  it  lies  embedded,  opens  into  the  semicircular  canals  by  five  fora- 

v.  vestibule,  x,  Y,  z.  Semicir-  mina;  and  anteriorly,  by  a  single  foramen, 

R.  ta&totaSC  into  the  internal  scala  of  the  cochlea.    There 


Fig.  69. 


is,  also,  posteriorly  and  inferiorly,  near  the 

common  orifice  of  the  two  vertical  semicircular  canals,  the  opening  of  a 
small,  bony  duct,  which  terminates  internally  at  the  posterior  surface  of 

the  petrous  portion  of  the  temporal  bone. 
This  duct  is  called  aquseductus  seu  diver- 
ticulum  vestibuli.  The  semicircular  ca- 
nals are  three  in  number,  and  occupy  the 
hinder  part  of  the  labyrinth.  They  are 
called  superior  vertical,  posterior  verti- 
cal, and  horizontal.  They  are  cylindrical 
cavities,  curved  semicircularly,  and  are 
more  expanded  at  their  vestibular  origin, 
which  has  been,  therefore,  called  ampulla. 
They  are  constituted  of  a  plate  of  bone, 

Cochlea  divided  parallel  with  its  axis,    situate  in  thf  Spongy  tissue   of  the  pars 

through  the  centre  of  the  modioius.   petrosa,  and  all  of  them  communicate 

w«tn  t^e  vestibule.  The  cochlea  is  the 
most  anterior  portion  of  the  labyrinth. 

nerve,  sending  its  filaments  through  centre    Jfc  jg  go  called  in    COnSCQUCnCC  of   its    YQ- 
of  modioius.    4,  4.  Scala  tympani  of  first  .  .  .  ,*  ,. 

turn  of  cochlea.  5,  5.  Scala  vestibuli  of  semblance  —  in  man  and  mammalia  —  to  a 

first  turn.    6.  Section  of  lamina   spiralis,  ___•!»_  cl^ll  .   V,AT1«A    nl«A    ife  "FVonnli  anrl 

its  zonula  ossea  ;  one  of  the  filaments  of  the  Snail  S  SHCll  ,  nenCC,  aiSO,  US 

cochlear  nerve  is  seen  passing  between  the  GermannameS,  UmaCOH.  and  S  chn  6  eke. 

two  layers  of  the  lamina  spiralis  to  be  dis-  JT    .                             .'        .    y 

tributed  upon  the  membrane  which  invests  J.t  IS  tilC  mOSt  intricate  part  01  the  Organ 

the  lamina.    7.  Membranous  portion  of  the  /,-.           .                   vj                          j*j.r> 

lamina  spiralis.    8.  Loops  formed  by  fila-  01    hearing,   and  (IOCS  not    admit  01    easy 

ments  of  cochlear  nerve.    9,  9.  Scala  tym-  ^oc,,,.:^/^        Tf  i<a  n    nnnmrlnl   r>Qr»al     cm 

pani  of  second  turn  of  cochlea.  10,  10.   description,    it  is  a  conoidai  canal,  spi- 

Scala  vestibuli  of  second  turn  ;  the  septum    rally  convoluted,  making  tWO  tumS  UDOn 

between  the  two  is  the  lamina  spiralis.    11.     .        ^  ,  .    ' 

Scala  tympani  of  remaining  half  turn.     12.    itselt,   and  resting  On  a    DOny  nUClCUS  Or 

cu!  pillar,  called  modiolui.     The  base  of  the 
™  nucleus  is  concav«;  corresponds  to  the 

rally  around  to  constitute  the  infundibu-    bottom   of   the    meatllS    auditorius 
lum   (2).      14.    The    helicotrema  through  .     .          .  1    .  -1-1 

which  a  bristle  is  passed;  its  lower  extre-     nUS,  and    IS    pierced    by  Small 

through  which  the  filaments  of  the  an- 


(Breschet.) 


ORGAN  OP  HEARING. 


181 


ditory  nerve  reach  the  cochlea.  The  spiral  canal  is  divided,  in  its 
whole  length,  by  a  partition,  half  osseous  and  half  membranous,  called 
lamina  spiralis;  so  that  two  distinct  tubes  are  thus  formed.  These  are 
the  scalse  of  the  cochlea.  At  the  apex  of  the  cochlea  they  run  into 
each  other,  by  an  opening  termed  by  M.  Breschet  helicotrema;  and  at 
the  base,  one  turns  into  the  vestibule,  and  is  hence  called  superior  or 
vestibular  or  internal  scala;  the  other  communicates  with  the  cavity 
of  the  tympanum  by  the  foramen  rotundum,  and  is  called  inferior, 
tympanic,  or  external  scala.  At  this  scala,  near  the  foramen  rotun- 
dum, a  bony  canal  begins,  which  proceeds  towards  the  posterior  sur- 
face of  the  pars  petrosa,  on  which  it  opens.  It  is  aquseductus  seu 
divertieulum  cochlese.  The  cochlea  does  not  exist  in  all  animals  that 
hear.  It  is  not,  therefore,  of  essential  importance.  It  varies,  too, 
greatly,  in  complication,  in  different  animals.  In  birds,  whose  hear- 
ing is  extremely  delicate,  it  merely  consists  of  a  short,  hollow,  bony 
process,  divided  into  two  scalae  but  without  any  spiral  arrangement.  In 
reptiles,  it  is  still  more  imperfect;  and  in  many  species  can  scarcely  be 
said  to  exist.  In  fishes  there  is  no  trace  of  it. 


Fig.  70. 


Osseous  Labyrinth  laid  open  to  show  especially  the  Membranous  Labyrinth. 

X,  Y.  Z.  Semicircular  canals.  A,  A,  A.  Ampullae.  P.  Perilymph  between  the  osseous  and  mem- 
branous labyrinth.  U.  Utricle.  S.  Sacculus.  O,  O.  Cretaceous  bodies.  G,  N.  Auditory  nerve.  " 
Branch  going  to  the  cochlea.  L.  Lamina  spiralis.  M.  Apex  of  modiolus.  D.  Portio  dura. 


K. 


The  different  cavities  of  the  internal  ear  are  lined  by  an  extremely 
delicate  membrane.     In  many  animals  this  membrane  exists  alone, 


182 


SENSE  OF  HEARING. 


Fig.  71. 


without  any  bony  parietes.  It  exhales  at  its  inner  surface  a  limpid 
fluid,  called  liquor  or  lymph  of  Cotugno  or  Cotunnius,  perilymph  of 
Breschet,  which,  under  special  circumstances,  can  reflow  into  the  aquse- 
ductus  vestibuli  and  aquseductus  cochleae.  This  fluid  is  contained  in  all 
the  cavities  of  the  internal  ear.  Within  that  of  the  osseous  labyrinth 

are  contained  membranes 
having  nearly  the  shape  of 
the  vestibule  and  semicir- 
cular canals,  but  not  ex- 
tending into  the  cochlea. 
These  membranes,  which 
compose  what  has  been 
called  the  membranous 
labyrinth,  form  a  continu- 
ous but  close  sac,  contain- 
ing a  fluid,  endolymph, — 
termed  by  M.  De  Blainville 
vitrine  auditive,  from  its 
supposed  analogy  to  the 
vitreous  humour  of  the  eye. 
It  is  similar  in  appearance 


Auditory  Nerve. 


t0     the 


which 


1.  Corpora  quadrigemina.    2,  2.  Processus  6  cerebello  ad  -     .     -       - 
testes.    3,  3.  Corpora  restiformia.    4.  Fourth  ventricle.    5.  SUrrOUnuS    it    On    the    Outer 
Iter  a  tertio  ad  quartum  ventriculum.  6.  Calamus  scriptorius.  -i  •» 
7.  Posterior  median  columns  of  spinal  cord  forming  by  their  81(16,      and      intervenes     De- 
divergence  the  point  of  the  calamus,  also  called  ventricle  of  f-TTpppn    it    nnrl    tViA    QiflpQ    rvf 
Arantius.    8.  Lines  of  origin  of  4th  ventricle,  and  of  auditory  L"tJtJll    11    dllU    Lilt 
nerve.    9.  Anterior  branch  distributed  to  cochlea.     10.  Poste-  the  OSSCOUS  labvrinth  SO  aS 
rior  or  vestibular  branch.   11.  Utriculus  communis  concealing                                          w 
sacculus  proprius  from  view.     12.  Ampulla  of  oblique  semi-  tO      prevent      any     COtttaCt. 
circular  canal.    13.  Ampullae  of  perpendicular  and  horizontal  rpu         f                ^     *l» 

semicircular  canals.  I  he    form   of    the    mem- 

branous  vestibule  requires 

special  notice,  as  it  is  not  an  exact  imitation  of  the  osseous  cavity, 
being  composed  of  two  distinct  sacs  which  open  into  each  other;  one 
of  these  is  termed  utricle,  sinus  seu  alveus  utriculosus,  sacculus  vesti- 
buli,   and   median    sinus; 

Fig.  72.  the  other,  sacculus.     Each 

sac  contains  in  its  interior 
a  small  mass  of  white  cal- 
careous matter  resembling 
powdered  chalk,  which 
seems  to  be  suspended  in 
the  fluid  of  the  sacs,  by 
means  of  nervous  filaments 
proceeding  from  the  audi- 
tory nerves,  G,  N,  Fig.  70. 
From  the  universal  pre- 
sence of  these  substances 
in  the  labyrinth  of  all  the 
mammalia,  and  from  their 


Ampulla  of  the  External  Semicircular  Membranous  Canal, 


showing  the  mode  of  termination  of  its  Nerve. 

much  greater  size  and  hard- 
ness in  aquatic  animals,  it  is  presumable,  that  they  perform  some  office 
of  importance  in  audition.  They  are  termed  by  M.  Breschet,  otolithes 


ORGAN  OF  HEARING. 


183 


and  otoconieSj  according  as  they  are  of  a  hard  or  a  soft  consistence. 
The  small  square  figures  (Fig.  70),  represent  their  size  and  appearance 
in  the  dog  and  the  hare. 


Fig.  73. 


Fig.  74. 


Auditory  Nerve  taken  out  of  the  Cochlea. 

1,  1,  1.  Trunk  of  the  nerve.  2,  2.  Its  filaments  in  the 
zona  ossea  of  the  lamina  spiralis.  3,  3.  Its  anastomoses 
in  the  zona  vesicularis. 


Papillae  of  the  Auditory  Nerve,  on  a 
segment  of  the  spiral  lamina  of  the 
cochlea  of  a  young  Mouse. 

The  lower  portion  is  the  osseous,  and 
the  higher  the  membranous  part  of  the 
lamina. — Magnified  300  times. 


It  is  in  the  cavities  of  the  internal  ear,  and  on  the  different  parts  of 
the  membranous  labyrinth,  that  the  auditory  or  acoustic  nerve  is  dis- 
tributed. This  nerve  is  the  portio  mollis  of  the  seventh  pair,  of  most 
anatomists.  It  arises,  like  other  nerves  of  the  senses,  from  the  medulla 
oblongata ;  and  near  the  anterior  paries  of  the  fourth  ventricle.  Thence 
it  passes  obliquely  outwards,  forwards,  and  upwards,  and  enters  the 
meatus  auditorius  internus,  the  foramen  of  which  is  situate  on  the  pos- 
terior surface  of  the  pars  petrosa.  The  base  of  this  meatus  corresponds 
to  the  inner  surface  of  the  vestibule,  and  to  the  base  of  the  cochlea. 
Through  the  first  foramen,  near  the  base  of  the  meatus,  the  portio  dura 
of  the  seventh  pair  or  facial  nerve  passes  to  gain  the  aqueduct  of 
Fallopius;  along  which  it  proceeds,  giving  off  filaments  to  different 
parts  of  the  middle  ear,  and  ultimately  issuing  by  the  stylo-mastoid 
foramen  to  be  lost  on  the  muscles  of  the  face.  Below  the  part  of  the 
meatus,  where  the  facial  nerve  emerges,  are  several  other  foramina, 
through  which  filaments  of  the  auditory  nerve  attain  the  labyrinth. 
These  are  distributed  to  the  vestibule,  semicircular  canals,  and  cochlea; 
and  terminate,  by  very  delicate  ramifications,  in  the  tissue  and  at  the 
surface  of  the  membrane  that  lines  the  labyrinth.  The  precise  mode 
in  which  the  ramifications  terminate  has  been  a  matter  of  dispute  : 
some  affirming,  that  they  end  in  papillae,  as  in  the  marginal  figure  from 
Treviranus  (Fig.  74) ;  others,  that  the  fibres  return  by  loops.  The 
arrangement  is  probably  analogous  to  that  which  prevails  in  the  retina.1 

Such  is  the  apparatus  concerned  in  the  function  of  audition.  Before 
proceeding  to  the  physiology  of  these  different  parts,  and  the  assistance 

1  Carpenter's  Human  Physiology,  §  352,  Lond.,  1842. 


184  SENSE  OF  HEARING. 

afforded  to  the  mind  by  this  sense,  it  is  necessary  to  enter  into  a  brief 
physical  disquisition  on  sound. 

2.  SOUND. 

If  a  body,  by  percussion  or  otherwise,  be  thrown  into  vibration, 
every  vibration  excites  a  corresponding  wave  in  the  air ;  and  these 
oscillations  are  propagated  in  all  directions,  until  gradually  lost  in  dis- 
tance; but  if  they  strike  on  the  organ  of  hearing  with  the  necessary 
force,  a  sensation  is  produced,  which  is  called  sound  or  noise.  The 
term,  however,  is  frequently  used  to  signify,  not  only  the  sensation, 
but  the  affection  of  the  air,  or  of  the  sonorous  body  by  which  the 
sensation  is  effected. 

That  bodies  move  or  oscillate  when  they  produce  sound  admits  of 
easy  detection.  We  can  see  it  in  drums,  bells,  musical  strings,  &c., 
whose  vibrations  are  extensive ;  and  can  arrest  them,  and  with  them 
the  sound,  by  putting  the  hand  upon  the  body,  or  muffling  it.  When- 
ever a  sonorous  body  is  struck,  a  change  in  the  relative  position  of  its 
molecules  is  produced.  These,  by  virtue  of  their  elasticity,  tend  to 
return  to  their  former  place.  This  is  done  by  a  series  of  oscillations, 
which  are,  at  first,  more  extensive;  but  become  gradually  less,  until 
they  finally  cease.  The  rapidity  of  these  oscillations  is  greater  in  bodies 
that  are  hard  and  elastic ;  and  hence  it  has  been  concluded,  that  these 
two  qualities  render  a  body  sonorous.  It  is  not,  however,  a  matter  of 
facility  to  say,  what  is  the  precise  cause  of  the  difference  of  sound  in 
analogous  bodies.  It  must  be  dependent  upon  intimate  composition,  but 
of  what  nature  is  not  intelligible  to  us.  There  are  but  one  or  two 
individuals  in  Great  Britain,  who  have  been  celebrated  for  the  fabrica- 
tion of  the  larger  order  of  bells  for  churches,  colleges,  &c.,  and  in 
certain  countries  the  art  is  comparatively  unknown.  Resonance  is 
entirely  owing  to  the  intimate  composition  of  the  body,  and  is  beauti- 
fully and  singularly  exhibited  in  the  Chinese  gong,  the  sound  of  which 
continues  to  rise  for  some  time  after  a  succession  of  rapid  and  forcible 
blows  has  been  inflicted. 

But,  in  order  that  sonorous  oscillations  may  affect  the  organ  of  sense, 
an  intermediate  body  is  necessary  to  repeat  and  transmit  them.  This 
body  is  called  the  vehicle  of  sound,  and  it  is  usually  air.  M.  De  Lamarck 
supposes  the  existence,  in  the  atmosphere,  of  a  vibrative  fluid  of  great 
subtilty,  which  pervades  the  globe  as  well  as  the  bodies  on  its  surface ; 
and  Geoffroy  St.  Hilaire  affirms,  that  sound  "  is  a  matter  resulting  from 
the  combination  of  the  external  air,  with  the  polarized  air  of  the  sono- 
rous body!" — but  these  are  topics  that  belong  to  works  on  higher 
physics-. 

Air,  by  virtue  of  its  elasticity,  is  admirably  adapted  as  a  vehicle  for 
sound ;  and  the  loudness  of  the  sound  conveyed  by  it  is  greatly  de- 
pendent upon  its  density.  If  we  put  a  bell  under  the  receiver  of  an 
air-pump,  and  exhaust  the  air,  the  sound  becomes  gradually  more  and 
more  faint,  and  when  the  air  is  exhausted  is  not  heard  at  all.  For  the 
same  reason  a  pistol  fired  on  the  top  of  the  Himala  Mountains  gives  a 
much  feebler  report  than  in  the  valleys  beneath. 

Sympathetic  sounds  afford  additional  evidences  of  the  carrying  power 


SOUND.  185 

of  air.  Every  sonorous,  elastic  body  can  be  thrown  into  oscillations, 
if  the  air  surrounding  it  be  made  to  tremble.  Thus,  if  we  sound  a 
note  near  a  piano-forte,  whose  dampers  are  raised  so  as  to  admit  of 
free  vibration,  the  string,  that  is  in  unison  with  the  tone  produced,  will 
vibrate  by  reciprocation ;  and  a  wine-glass  or  goblet  may,  according  to 
Dr.  Arnott,  be  made  to  tremble,  and  even  to  fall  from  a  table,  by 
sounding  on  a  violoncello  near  it  the  note  that  accords  with  its  own. 
The  strata  of  air,  in  proximity  with  the  sonorous  body,  receive  the  first 
impulses ;  and  from  these  they  are  successively  propagated  to  others ; 
much  in  the  same  manner  as  the  undulations  extend  from  the  place  in 
which  a  stone  is  cast  on  a  surface  of  smooth  water ;  except  that  the 
aerial  undulations  extend  in  every  direction,  whilst  the  aqueous  proceed 
only  horizontally.  In  this  propagation  from  stratum  to  stratum  a  por- 
tion of  the  sound  is  necessarily  lost ;  so  that  the  loudest  sound  is  heard 
only  within  certain  limits ;  and,  in  all  cases,  its  intensity  is  inversely 
as  the  square  of  the  distance  from  the  sonorous  body. 

By  causing  the  sonorous  undulations  to  proceed  entirely  in  one  di- 
rection, and  preventing  their  escape  in  every  other,  sound  may  be  ren- 
dered audible  at  a  much  greater  distance.  M.  Biot  found,  that  when 
he  spoke  in  a  whisper  at  one  extremity  of  a  cylinder  upwards  of  one 
thousand  yards  long,  he  was  distinctly  heard  at  the  other.  In  many 
large  manufactories  the  knowledge  of  this  fact  is  turned  to  good  ac- 
count. By  having  numerous  tubes  communicating  with  the  different 
rooms  of  the  establishment,  and  terminating  in  the  office  of  the  princi- 
pal, he  is  enabled  to  have  his  directions  readily  conveyed,  and  to  receive 
information  without  the  slightest  inconvenience. 

The  velocity  with  which  sound  proceeds  admits  of  easy  calculation. 
Light  passes  with  such  rapidity,  that  it  may  be  regarded  as  proceeding 
instantaneously  from  objects  on  the  earth  to  the  eye.  The  velocity  of 
sound  is  incomparably  less.  We  see  the  flash  of  a  gun  at  a  distance ; 
and,  some  time  afterwards,  hear  the  report.  Considering  the  light 
then  to  have  reached  the  eye  instantaneously,  if  we  know  the  distance 
of  the  gun,  and  note  the  time  that  elapsed  between  the  appearance  of 
the  flash  and  the  report,  we  can  calculate  accurately  the  rapidity  of 
sound.  This  is  found  to  be  about  eleven  hundred  and  forty-two  feet 
in  a  second.  We  can,  in  this  manner,  estimate  the  distance  of  a 
thunder-cloud,  by  noting  the  time  of  the  flash,  and  the  interval  that 
elapses  before  hearing  the  clap.  If  it  be  thirty-seconds,  the  cloud  is  at 
a  distance  of  thirty  times  eleven  hundred  and  forty-two  feet,  or  six 
miles  and  a  half.  The  velocity  is  the  same  for  all  kinds  of  sounds. 
M.  Biot  found,  on  playing  a  flute  at  the  end  of  the  tube,  above  referred 
to,  that  the  tones  arrived  at  the  ear  placed  at  the  other  extremity  in 
due  succession;  so  that  their  velocity  must  have  been  uniform. 

When  aerial  oscillations  meet  with  a  resisting  body  of  a  regular  sur- 
face, as  A  B,  Fig.  75,  they  are  reflected  at  an  angle  equal  to  the  angle 
of  incidence:  consequently,  an  ear,  placed  in  the  course  of  the  reflected 
waves  as  at  C,  will  refer  the  sound  to  a  distance  as  far  behind  the  point 
of  reflection,  and  in  the  direction  of  the  reflected  ray,  as  the  sonorous 
body  is  from  the  point  of  reflection.  It  will  seem  to  be  at  E.  The  ear 
at  C  will,  however,  receive  the  direct  oscillations  from  the  bell  D,  as 


186  SENSE  OF  HEARING. 

well  as  those  that  proceed  along  the  lines  D  F  and  F  C ;  or  in  other 
words,  it  will  hear  both  the  sound  and  its  echo ;  and,  if  the  surfaces  on 

which  the  sonorous    undula- 

Fis-  75-  tions  impinge  be  favourably 

disposed,  the  echoes  may  be 
very  numerous.  The  utility 
of  the  ear  trumpet,  and 
speaking  trumpet,  is  to  be 
explained  by  this  law  of  the 
reflection  of  the  aerial  undu- 
lations; and  some  physiolo- 
gists are  of  opinion,  that  the 
external  ear  is  inservient  to 
audition  on  similar  principles. 

K     /  The  ear  trumpet  is  a  tube, 

narrow  at  one  extremity,  so 

E  as  to  enter  the  concha;  and 

Reflection  of  Sound.  expanded  at  the  other  like  a 

trumpet.     It  is  also  curved, 

so  that  it  may  be  easily  directed  to  objects.  All  the  sonorous  rays, 
that  enter  the  expanded  extremity,  are  brought  after  various  reflections 
to  a  focus  in  the  auricular  end;  and  the  intensity  of  the  sound  is,  in 
this  way,  so  much  augmented,  that  a  person  who,  without  it,  is  entirely 
deaf  to  common  conversation,  may  enjoy  it.  A  sheet  of  paper,  folded 
like  a  cone,  the  apex  of  which  is  placed  in  the  concha,  and,  to  a  less 
extent,  the  hand  held  concavely  behind  the  ear,  serve  a  like  purpose. 

Air  is  not  the  only,  nor  the  most  perfect,  vehicle  of  sound.  The 
personal  experiments  of  divers  show,  that  it  can  be  conveyed  through 
water.  The  blows  of  workmen  around  a  diving  bell  are  distinctly 
heard  above;  and  fish  have  manifestly  an  acute  sense  of  hearing, 
although  this  was  at  one  time  denied.  Aiy  experiment,  made  by  the 
Abbd  Nollet,  and  repeated  by  Dr.  Franklin,  proves,  that  water  trans- 
mits a  much  stronger  vibration  than  air.  When  two  stones  were  struck 
together  under  water,  a  shock  was  given  to  the  ear,  which  was  almost 
insupportable.  The  latter  philosopher  found  by  experiment,  that 
sound,  after  travelling  above  a  mile  through  water,  loses  but  little  of 
its  intensity.  According  to  Chladni,  its  rate  of  progression  in  water  is 
about  4900  feet  in  a  second,  or  between  four  and  five  times  as  great  as 
in  air.  Solids,  too,  are  much  better  conductors  of  sound  than  air.  If 
we  scratch  one  end  of  a  wooden  rod,  the  sound  is  distinctly  heard  by 
the  ear  applied  to  the  other;  although  it  may  be  inaudible  through  the 
air.  Savage  tribes  are  in  the  habit  of  discovering  the  advance  of 
enemies,  or  of  their  prey,  by  applying  the  ear  to  the  ground ;  and 
watchmen,  in  some  towns,  instead  of  springing  a  rattle,  and  alarming 
offenders,  strike  the  pavement  with  a  staff,  the  sound  of  which  is  heard 
by  their  fellow-watchmen  at  a  considerable  distance.  It  is  a  common 
practice  to  ascertain,  whether  a  kettle  boils,  by  putting  one  end  of  a 
poker  on  the  lid,  and  the  other  to  the  ear.  The  difference  between 
simmering  and  boiling  is  in  this  way  detected.  A  knowledge  of  the 
ready  communication  of  sound  through  solids,  has  given  rise  to  a  valu- 


SOUND.  187 

able  suggestion  for  the  discrimination  of  diseases  of  the  chest,  and  of 
various  healthy  and  morbid  conditions.  By  putting  the  ear  to  the 
chest  we  can  hear  the  rush  of  air  along  the  bronchial  tubes,  the  pulsa- 
tions of  the  heart,  &c.,  and  can  discover  any  aberration  in  the  execu- 
tion of  their  functions.  This  is  what  was  called  by  the  late  distin- 
guished Laennec,  of  Paris — the  proposer  of  the  method — immediate 
auscultation.  The  direct  application  of  the  ear  to  the  chest  is,  how- 
ever, frequently  inadmissible.  In  these  cases  he  used  a  hollow  cylinder 
called  a  stethoscope,  one  end  of  which  he  applied  to  the  chest — the 
other  to  the  ear.  This  plan  he  termed  mediate  auscultation.  The 
suggestion  has  led  to  valuable  improvements  in  diagnosis. 

MM.  Hassenfratz  and  Biot  have  made  some  accurate  experiments  on 
the  comparative  rapidity  of  the  progress  of  sound  through  air  and  solid 
bodies.  The  latter  found,  in  the  aqueducts  of  Paris,  that  a  blow, 
struck  upon  a  pipe  nine  hundred  and  fifty-one  metres,  or  about  ten 
hundred  and  forty  yards,  in  length,  was  heard  two  seconds  and  a  half 
sooner  through  the  sides  of  the  pipe  than  through  the  air  within;  but 
the  sound  did  not  extend  so  far.  Ice  conveys  sound  even  better  than 
water;  for  if  a  cannon  be  fired  from  a  distant  post — a  frozen  river 
intervening — each  flash  is  followed  by  two  distinct  reports,  the  first 
conveyed  by  the  ice, — the  second  by  the  air. 

It  has  been  already  stated,  that  the  vibrations  of  air,  caused  by  a 
sonorous  body,  are  capable  of  exciting  corresponding  or  sympathetic 
vibrations  in  solid  bodies  within  their  sphere  of  action.  It  was  an  old 
observation,  that  such  vibrations  are  excited  only  in  bodies  that  are  in 
unison  with  the  sonorous  body;  in  other  words,  in  those  that  are  capa- 
ble of  producing  the  same  tone.  Unison,  however,  is  not  necessary. 
When  a  sound  is  produced  in  air,  every  body  receives  a  vibration,  which 
is  a  repetition  of  the  one  that  occasioned  the  sound.  This  M.  Savart 
proved  by  using  small  membranes  on  which  he  placed  fine  sand.  They 
were  agitated ;  and  the  sand  assumed  various  regular  arrangements, 
whenever  a  sound  was  produced  in  their  vicinity.  In  other  words,  the 
membrane  was  thrown  into  vibration,  not  as  a  whole,  unless  its  funda- 
mental note  was  in  unison  with  the  one  sounded;  but  in  distinct  seg- 
ments, every  one  of  which  reciprocated  the  sound.  This  law  of  physics 
is  important  in  its  physiological  relations.  The  apparatus  of  audition 
consists  of  several  membranous  structures,  which  are  thrown  into  oscilla- 
tion, whenever  the  ear  receives  the  impressions  of  sound. 

The  vibrations,  which  produce  sound,  differ  much  as  regards  their 
extent  and  rapidity ;  and  on  these  differences  two  of  the  qualities  of 
sound — strength  and  tone — are  dependent.  Strength  or  intensity  de- 
pends on  the  extent  of  the  vibrations  of  a  sonorous  body.  This  is  seen 
in  a  musical  string,  the  sound  of  which  becomes  weaker  as  the  extent 
of  the  oscillations  diminishes.  The  tone,  on  the  other  hand,  is  depend- 
ent on  the  rapidity  of  the  oscillations ; — on  their  number  in  a  given 
time.  The  tone,  produced  by  .a  string  or  other  sonorous  body  that 
vibrates  quickly,  is  termed  acute  or  sharp,  when  compared  with  that  of 
one  which  vibrates  more  slowly.  The  latter  is  called  grave,  when  com- 
pared with  the  former.  The  gravest  sound  that  the  ear  can  appreciate 
is  considered  to  result  from  thirty-two  vibrations  per  second;  the  most 


1S8  SENSE  OF  HEARING. 

acute,  from  eight  thousand  one  hundred  and  ninety-two  vibrations,  ac- 
cording to  some; — twelve  thousand,  according  to  others.  Some  well- 
devised  experiments,  however,  made  by  M.  Savart,  largely  extend  these 
limits,  and  appear  to  indicate  that  they  cannot  be  esteemed  rigidly 
fixed.  In  his  experiments,  the  ear  distinctly  appreciated  fourteen  or 
sixteen  vibrations,  or  seven  or  eight  impulses  per  second;  and  the  acutest 
note  that  was  audible  proceeded  from  upwards  of  forty  thousand  vibra- 
tions, or  more  than  twenty  thousand  impulses  per  second.  Recently, 
M.  Despretz1  has  determined,  that  classifiable  sounds  are  comprised 
between  the  limits  of  32  simple  vibrations  for  the  lowest  tone,  and 
73,000  for  the  highest. 

The  duration  of  the  impression  of  a  sonorous  vibration  on  the  ear 
has  been  estimated  at  about  the  sixteenth  part  of  a  second;  but  it  is 
difficult  to  determine  it  exactly. 

If  a  sonorous  body  be  struck,  and  the  vibrations  excited  be  all  per- 
formed in  equal  times,  a  simple  and  uniform  sensation  is  produced  on 
the  auditory  nerve,  and  one  musical  tone  is  heard.  But  if  the  vibrations 
be  various  and  irregular,  they  fall  scatteringly  on  the  organ  of  hearing, 
and  excite  a  harsh  impression,  as  if  various  sounds  were  heard  together. 
In  other  words  a  noise  or  discord  is  produced.  If  two  notes,  sounded 
together,  afford  pleasure,  they  produce  harmony  or  concord.  This  arises 
from  the  agreement  of  the  vibrations,  so  that  some  of  them  strike  upon 
the  ear  at  the  same  time.  If,  for  example,  the  vibrations  of  one  sono- 
rous body  take  place  in  double  the  time  of  another,  the  second  vibration 
of  the  latter  will  strike  upon  the  ear  at  the  same  instant  as  the  first 
vibration  of  the  former.  This  is  the  concord  or  harmony  of  an  octave. 
Between  a  note  and  its  octave,  there  are  six  intermediate  notes,  consti- 
tuting the  diatonic  -scale  or  gamut.  If  the  vibrations  of  two  strings  are 
as  two  to  three,  the  second  vibration  of  the  former  will  correspond  with 
the  third  vibration  of  the  latter,  producing  the  harmony  called  a  fifth. 
There  are  other  tones,  which,  although  they  cannot  be  struck  together 
without  producing  discord,  if  produced  in  succession,  give  the  pleasure 
called  melody.  Melody  is,  in  truth,  nothing  more  than  the  effect  pro- 
duced on  the  brain  by  pleasing  musical  tones  sounded  in  succession. 

There  is  another  quality  of  sound  whieh  the  French  call  timbre. 
By  some  of  the  translators  of  the  works  of  the  French  physiologists 
and  physicists  this  word  has  been  rendered  note.  It  is  essentially  dif- 
ferent from  note  or  tone;  and  is  peculiar.  By  English  philosophers  it 
is  termed  quality  of  sound.  It  is  this  quality  that  enables  us  to  recog- 
nise various  instruments,  when  giving  forth  the  same  note  or  tone; 
and  to  distinguish  the  voices  of  individuals  from  each  other.  Its  cause 
is  not  evident,  but  is  conceived  to  depend  upon  the  nature  of  the  sono- 
rous body,  if  it  be  a  surface, — and  at  the  same  time  on  its  shape,  if  a 
tube.  M.  Biot  conjectures,  that  it  is  owing  to  the  series  of  harmonic 
sounds  that  form  part  of  every  appreciable  sound.  When  any  sonorous 
body  is  made  to  vibrate,  a  distinct  sound  is  heard,  which  is  the  funda- 
mental; but,  if  attention  be  paid,  others  are  heard  at  the  same  time. 
These  are  called  harmonics;  and  it  is  not  improbable  that  timbre  or 

1  Comptes  Rendus,  xx.  1214,  cited  by  Longet,  Traite  de  Physiologic,  ii.  136,  Paris,  1850. 


PHYSIOLOGY  OF  THE  EXTERNAL  EAR.  189 

quality  may  be  dependent  as  well  upon  the  nature  of  the  sonorous  body, 
as  upon  the  greater  or  less  number  of  harmonics,  that  accompany  the 
fundamental  sound.1 

3.    PHYSIOLOGY  OF  AUDITION. 

In  tracing  the  progress  of  sonorous  vibrations  to  the  internal  ear, 
we  shall  follow  the  order  of  parts  described  in  the  anatomical  sketch  of 
the  auditory  apparatus ; — commencing  with  the  external  ear.  The 
meatus  auditorius  externus  being  always  open,  sonorous  vibrations  can 
readily  reach  the  membrana  tympani.  Some  of  these  pass  directly  to 
the  membrane  without  experiencing  reflection,  and  communicate  their 
oscillations  to  it.  The  pavilion  has  been  regarded,  by  most  physio- 
logists, as  a  kind  of  ear-trumpet,  for  collecting  aerial  undulations,  and 
directing  them,  after  various  reflections,  to  the  bottom  of  the  auditory 
canal.  In  the  horse,  and  in  those  animals  which  have  the  power  of 
pricking  the  ears,  or  of  moving  them  in  various  directions,  this  is 
doubtless  the  case;  but  in  man  we  cannot  expect  any  great  effect  of 
the  kind,  if  we  regard  its  arrangement,  and  the  incapability  of  moving 
it  from  its  fixed  direction,  which  is  nearly  parallel  to  the  head.  Boer- 
haave,2  indeed,  pretended  to  have  proved  by  calculation,  that  every 
sonorous  ray,  which  falls  upon  the  pavilion,  is  ultimately  directed  to- 
wards the  meatus  auditorius  externus.  Simple  inspection  of  the  pavil- 
ion shows  that  this  cannot  be  universally  true.  Some  part  of  the  an- 
thelix  is,  in  almost  every  individual,  more  prominent  than  the  helix; 
and  it  is  therefore  impossible  for  the  undulations,  that  fall  upon  the 
posterior  surface  of  the  former,  to  be  reflected  towards  the  concha. 
M.  Itard,3  a  distinguished  physiologist  and  aurist  of  Paris,  asserts,  that 
he  has  never  seen  the  loss  of  the  pavilion  affect  the  hearing;  and  many 
animals,  whose  sense  of  hearing  is  acute, — the  mole  and  birds,  for 
example, — are  devoid  of  it.  Hence  he  concludes,  that  it  is,  perhaps, 
rather  injurious  than  favourable  to  audition;  and  is  more  inservient  to 
the  expression  than  to  the  hearing  of  the  animal. 

M.  Itard's  view  is  doubtless  too  exclusive.  The  pavilion  may  have 
but  little  agency  as  an  ear-trumpet,  but  it  must  have  some.  The 
concha,  being  the  expanded  extremity  of  the  meatus  auditorius,  must 
receive  more  sonorous  vibrations  than  could  be  admitted  by  the  meatus 
itself.  These  are  reflected  towards  the  membrana  tympani,  and  reach 
it  in  a  state  of  concentration — but,  to  no  great  amount,  it  is  true.  In 
this  way,  and  perhaps  in  that  suggested  by  M.  Savart,4  the  pavilion  is 
useful  in  audition.  That  gentleman  is  of  opinion,  that  the  whole  of 
the  external  ear,  the  elasticity  of  which  he  considers  to  be  capable  of 
slight  modification  by  the  action  of  its  proper  muscles,  is  an  apparatus 
for  repeating  sonorous  vibrations,  and  transmitting  or  conducting  them 
along  its  own  parietes  to  the  membrane  of  the  tympanum.  According 
to  this  view,  the  different  inequalities  of  surface  of  the  pavilion  admit 

1  On  sonorous  undulations  in  general,  see  Muller's  Elements  of  Physiology,  by  Baly,  Pt.  v. 
p.  1215,  Lond.,  1839. 

2  Praelect.,  torn.  iv.  p.  317. 

»  Traite  des  Maladies  de  1'Oreille  et  de  1'Andition,  i.  131,  Paris,  1821. 

*  Annales  de  Chimie,  xxvi.  5;  and  Journal  de  Physiologie,  iv.  183,  and  v.  367. 


190 


SENSE  OF  HEARING. 


of  explanation.  When  the  membrane  is  stretched  in  a  direction  paral- 
lel to  a  sonorous  surface,  the  oscillations,  impressed  upon  it,  are  most 
marked;  and,  accordingly,  as  sounds  impinge  upon  the  pavilion  from 
various  quarters,  the  inequalities  of  surface  always  admit  of  some  being 
disposed  in  the  most  favourable  way  for  the  reception  of  vibrations. 
It  is  true  that  the  pavilion  is  not  essential  to  audition ;  the  hearing  not 
suffering  by  its  removal  for  more  than  a  few  days ;  so  that  its  physio- 
logical influence  is  much  more  limited  than  might  be  conceived.  It 
probably  contributes  to  a  knowledge  of  the  direction  of  sounds,  and  is 
certainly  calculated  to  protect  the  membrana  tympani. 

The  meatus  auditorius  externus  conducts  the  sonorous  vibrations 
directly,  and  by  reflection,  as  well  as  by  its  parietes,  to  the  membrana 
tympani.  It  is  probable,  too,  that  it  is  useful  in  protecting  the  mem- 
brane from  the  direct  action  of  air  and  extraneous  bodies.  This  is, 
perhaps,  the  cause  of  its  tortuous  character.  If  too  much  so,  hearing 
becomes  impaired, — the  sonorous  oscillations  not  being  properly  di- 
rected towards  the  membrane.  Baron  Larrey  has  published  cases  of 
deafness  produced  in  this  manner,  which  were  removed  by  wearing  an 
artificial  concha  and  meatus  of  the  natural  curvature  made  of  gum 
elastic.  The  down  or  hairs,  at  the  entrance  of  the  meatus,  have  been 
regarded  as  protecting  agents  against  the  intrusion  of  extraneous  bodies; 
whilst  the  cerumen  has  been  looked  upon  as  a  fit  material  for  entrap- 
ping insects  in  the  slough  formed  by  it,  or  for  destroying  them  by  its 
poisonous  influence.  It  is  probable,  however,  that  the  most  important 
function  of  the  cerumen  is  to  keep  the  lining  membrane  of  the  meatus 
in  a  physical  condition  adapted  for  the  proper  fulfilment  of  its  func- 
tions. 

Middle  Ear. — In  the  mode  described,  the  vibrations  of  a  sonorous 
body  attain  the  membrana  tympani.  An  experiment  by  M.  Savart 
•would  seem  to  show,  that  the  membrane  is  thrown  into  vibrations  chiefly 
by  the  air  contained  in  the  meatus.  He  made  a  small  truncated  cone 
of  pasteboard,  and  closed  the  narrow  extremity  by  a  tense  mem- 
brane, nearly  as  the  membrana  tympani  closes  the  inner  extremity  of 
the  meatus  auditorius ;  and  he  found,  that  when  sounds  were  produced 
near  the  parietes  of  the  cone,  the  membrane  vibrated  but  little;  whilst 
if  they  were  occasioned  opposite  the  base  of  the  cone,  so  that  they 
could  be  transmitted  to  the  membrane  by  the  air  within  the  canal,  the 
vibrations  were  distinct,  even  at  a  distance  of  thirty  yards  and  upwards. 

The  membrane  of  the  tympanum,  then,  receives  and  repeats  the 
sonorous  vibrations.  It  has,  however,  been  supposed  to  be  pos- 
sessed of  other  functions.  M.  Dumas1  conceived  it  to  be  composed 
of  numerous  cords,  each  corresponding  to  some  particular  tone.  But 
of  this  arrangement  we  have  no  evidence  from  observation  or  analogy. 
By  others,  it  has  been  supposed,  and  with  probability,  that  the  mem- 
brane is  capable  of  being  rendered  tense,  or  the  contrary,  by  the  bent 
lever,  formed  by  the  chain  of  ossicles.  They  have  farther  presumed, 
that  this  tension  or  relaxation  is  adapted  to  the  sounds,  which  the  mem- 
brane has  to  transmit.  The  ancients  believed,  that  the  adaptation  was 

1  Principes  de  Physiologic,  2de  6dit.,  Paris,  1806. 


PHYSIOLOGY  OF  THE  MIDDLE  EAR.  191 

produced  by  the  stretching  of  the  membrane,  so  as  to  put  it  in  unison 
with  the  sound  produced.  Independently,  however,  of  the  experiments 
of  M.  Savart,  which  show,  that  unison  is  not  necessary  for  the  produc- 
tion of  vibrations,  the  fact,  that  we  are  capable  of  distinguishing  several 
sounds  at  the  same  time,  would  seem  to  negative  the  supposition.  Nor 
can  we  easily  conceive,  that  the  membrane  could  admit  of  as  many 
distinct  vibrations  as  the  ear  is  capable  of  accurately  appreciating 
tones,  amounting  to  about  eight  octaves.  Bichat  thought,  that  the 
degree  of  tension  of  the  membrane  corresponded  with  the  intensity  of 
sounds;  and  that  by  it  the  sonorous  vibrations  attained  the  internal 
ear  in  a  degree  sufficiently  strong  to  excite  the  appropriate  impression, 
but  not  so  strong  as  to  cause  pain, — the  membrane  becoming  more  tense 
for  a  feeble  sound,  and  relaxed  for  one  too  strong.  In  support  of  this 
view,  Bichat  cites  the  case  of  several  persons,  who  could  not  hear  ordi- 
nary sounds,  until  the  ear  had  been  impressed  by  louder,  which,  accord- 
ing to  him,  roused  the. membrane  to  tension.  M.  Savart,  on  the  other 
hand,  from  the  fact  that  every  membrane  vibrates  with  more  difficulty, 
and  less  extensively,  according  to  its  tension,  conjectures  that  the  mem- 
brane is  relaxed  in  the  case  of  very  feeble  or  agreeable  sounds,  and  is 
rendered  tense  to  transmit  the  too  powerful  or  disagreeable. 

Again,  it  has  been  conceived  that  the  tension  varies  with  the  tone 
of  the  sound, — being  augmented  according  to  some  physiologists,  in 
acute,  according  to  others,  in  grave  sounds.  Sir  Everard  Home,1  it 
has  been  remarked,  esteems  the  membrane  to  be  muscular:  and  he 
affirms,  that  it  is  chiefly  by  means  of  this  muscle,  that  accurate  per- 
ceptions of  sound  are  made  by  the  internal  organ ;  and  that  the  mem- 
brane can  alter  its  degree  of  tension.  It  has  been  before  observed, 
that  the  muscles,  attached  to  the  small  bones,  are  capable  of  varying 
this  tension ;  that  the  internal  muscle  of  the  malleus  or  tensor  tympani, 
for  example,  by  its  contraction,  renders  it  more  tense.  Sir  Everard 
admits,  "  that  the  membrana  tympani  is  relaxed  by  the  muscle  of  the 
malleus,  but  not  for  the  purpose  alleged  in  the  commonly  received 
theory.  It  is  stretched  in  order  to  bring  the  radiated  muscle  of  the 
membrane  itself  into  a  state  capable  of  acting,  and  of  giving  those 
different  degrees  of  tension  to  the  membrane,  which  empower  it  to  cor- 
respond with  the  variety  of  external  tremors:  when  the  membrane  is 
relaxed,  the  radiated  muscle  cannot  act  with  any  effect,  and  external 
tremors  make  less  accurate  impressions."  The  reader  is  referred  to  the 
remarks  already  made  on  the  views  of  Sir  Everard  in  their  anatomical 
relations.  His  speculations  do  not,  however,  end  here.  He  employs 
the  discovery  to  account  for  the  difference  between  a  "musical  ear,"  as 
it  is  usually  termed,  and  one  which  is  incapable  of  discriminating,  or 
feeling  pleasure  from,  the  succession  of  musical  tones, — with  what  suc- 
cess we  shall  inquire  presently.  The  truth  is,  that  none  of  the  conjec- 
tures, which  have  been  proposed  regarding  the  precise  effects  of  tension 
or  relaxation  of  this  membrane,  can  be  looked  upon  in  any  other  light 
than  as  ingenious  speculations,  based,  generally,  upon  the  fact,  that  the 
membrane  seems  certainly  capable  of  being  varied  in  its  tension  by  the 

1  Lect.  on  Comp.  Anat.,  iii.  265. 


192  SENSE  OF  HEARING. 

movements  of  the  chain  of  bones,  but  leading  to  no  certain  knowledge 
of  the  precise  effect  on  audition  of  such  tension  or  relaxation.1  In  fact, 
although  the  integrity  of  the  membrane  is  necessary  for  perfect  hear- 
ing, its  perforation  or  destruction  does  not  induce  deafness.  We  have 
numerous  cases  of  perforation  from  accident  and  otherwise,  related  by 
Messrs.  Valsalva,2  Willis,3  Riolan,4  Flourens,  and  others,  in  which  the 
hearing  continued ;  and,  in  certain  cases  of  deafness,  the  membrane  is 
actually  punctured  for  the  purpose  of  restoring  the  hearing. 

The  communication  of  sonorous  oscillations  from  the  membrana  tym- 
pani  across  the  cavity  of  the  tympanum  to  the  internal  ear  is  effected 
in  three  ways:  1st,  by  the  air  contained  in  the  cavity  of  the  tympanum; 
2dly,  by  the  chain  of  bones  to  the  membrane  of  the  foramen  ovale;  and 
3dly,  by  the  parietes  of  the  tympanum.  So  that,  if  the  membrana  tym- 
pani  should  be  punctured  or  destroyed,  the  aerial  undulations,  caused  by 
a  sonorous  body,  which  enter  the  meatus  auditorius,  may  extend  into 
the  cavity  of  the  tympanum,  and  excite  corresponding  oscillations  in 
the  membranes  of  the  foramen  ovale,  and  foramen  rotundum.  The 
chorda  tympani — composed,  perhaps,  wholly  of  a  branch  of  the  fifth 
pair,  and  distributed  on  the  interior  of  the  membrana  tympani — pro- 
bably conveys  no  acoustic  impression  to  the  brain.  To  it  is  owing  the 
excessive  pain,  which  is  caused  by  the  contact  of  an  extraneous  body 
•with  the  membrane;  and  that  occasioned  by  a  loud  noise,  or  by  com- 
pressing the  air  forcibly  in  the  meatus  by  passing  the  finger  suddenly 
and  strongly  into  the  concha. 

The  uses  of  the  mastoid  cells,  which  communicate  with  the  middle 
ear,  are  not  known.  It  would  seem,  that  the  strength  of  audition  is 
in  a  ratio  with  their  extent.  In  no  animals  are  they  more  ample  than 
in  birds,  which  are  possessed  of  great  delicacy  of  hearing.  This  effect 
may  be  induced  either  by  their  enlarging  the  cavity  of  the  tympanum, 
and  allowing  the  sonorous  oscillations  to  come  in  contact  with  a  larger 
surface ;  or  by  the  plates  which  compose  them  being  thrown  into  vibra- 
tion. It  has  been  conceived,  too,  that  they  may  serve  as  a  diverticulum 
for  the  air  in  the  middle  ear,  when  it  is  subjected  by  the  membrana 
tympani  to  unusual  compression. 

Sir  Charles  Bell,5  with  more  warmth  than  is  judicious  or  courteous, 
combats  the  idea  of  the  foramen  rotundum  receiving  the  undulations 
of  air.  The  oblique  position  of  the  membrane  of  the  foramen  with 
regard  to  the  membrana  tympani  satisfactorily,  he  thinks,  opposes 
this  doctrine.  The  function  which,  with  M.  Savart,  he  assigns  to  it — 
if  not  accurately,  at  least  ingeniously — is  the  following.  As  the  mem- 
brane of  the  foramen  ovale  receives  the  vibrations  from  the  chain  of 
ossicles,  these  vibrations  circulate  through  the  intricate  windings  of  the 
labyrinth,  and  are  again  transmitted  to  the  air  in  the  tympanum  by 
the  foramen  rotundum.  The  different  cavities  of  the  labyrinth  being 
filled  with  incompressible  fluid,  no  such  circulation,  he  insists,  would 
occur,  provided  the  parts  were  entirely  osseous.  As  it  is,  the  mem- 

1  For  the  fancied  uses  of  this  membrane,  see  Haller,  Element.  Physio!.,  v.  198,  Lausan.,  1769. 
3  Op.  Anat.  de  Aure  Humana,  &c.,  Ed.  J.  A.  Morgagni,  Venet.,  1740. 
3  Oper.  Ornn.     Venet.,  1720.  4  Enchirid.  Anat.,  1.  iv.  c.  4,  Lugd.  Bat.,  1649. 

*  Op.  chat.,  i.  269. 


PHYSIOLOGY  OP  THE  MIDDLE  EAR.  193 

brane  of  the  foramen  rotundum  gives  way,  "and  this  leads  the  course 
of  the  undulations  of  the  fluid  in  the  labyrinth  in  a  certain  unchange- 
able direction."  The  explanation  of  Sir  C.  Bell  is  not  as  convincing  to 
us  as  it  seems  to  be  to  himself.  The  membrane  of  the  foramen  rotun- 
dum does  not  appear  to  be  required  for  the  undulation  in  the  cavities 
of  the  labyrinth,  which  he  describes ;  as  the  liquor  of  Cotunnius  can 
readily  reflow  into  the  aqueducts  of  the  vestibule  and  cochlea.  The 
principal  use  of  these  canals  would  seem,  indeed,  to  be,  to  form  diver- 
ticula  for  the  liquor  when  it  receives  the  aerial  impulses.  Sir  C.  Bell 
cites  the  case — often  quoted  from  Riolan — of  an  individual  who  was 
deaf  from  birth,  and  was  restored  to  hearing  by  accidentally  rupturing 
the  mernbrana  tympani,  and  breaking  the  ossicles  with  an  ear-pick: — 
"disrupit  tympanum,  fregitque  ossicula,  et  audivit."  In  these  and 
other  cases,  in  which  the  membrana  tympani  and  ossicles  have  been 
destroyed,  and  the  hearing  has  persisted,  the  vibrations  must  have  been 
conveyed  to  the  parietes  of  the  internal  ear  through  the  air  in  the  cavity 
of  the  tympanum ;  and,  notwithstanding  the  charge  of  "  absolute  con- 
fusion of  ideas,"  brought  against  such  individuals  as  Scarpa,1  Magendie, 
Adelon,  and  others,  who  believe  that  the  foramen  rotundum  receives 
the  undulations  of  air,  we  must  confess,  that  the  idea  of  the  communi- 
cation of  vibrations  through  that  medium,  as  well  as  through  the  mem- 
brane of  the  foramen  ovale,  and  the  osseous  parietes  of  the  labyrinth, 
appears  to  us  most  solid  and  satisfactory. 

The  ossicles  or  small  bones  have  given  occasion  to  the  wildest  specu- 
lations. At  the  present  day,  they  are  considered  to  fulfil  one  of  two 
functions ; — to  conduct  the  vibrations  from  the  membrana  tympani, — 
or  to  stretch  the  membranes  to  which  the  extremities  of  the  chain  are 
attached.  Both  these  offices  are  probably  executed  by  them ;  the 
malleus  receiving  the  vibrations  from  the  membrana  tympani,  and  con- 
veying them  to  the  incus, — the  incus  to  the  os  orbiculare, — the  os 
orbiculare  to  the  stapes,  and  the  stapes  to  the  membrane  of  the  foramen 
ovale,  by  which  they  are  transmitted  to  the  liquor  of  Cotunnius.  M. 
Savart  conceives,  that  the  chain  of  ossicles  is  to  the  ear  what  the  bridge 
is  to  the  violin.  It  has  been  already  observed,  that  the  ossicles  are 
not  essential  to  hearing,  although  they  may  be  required  to  perfect  it ; 
and  that  they  may  be  destroyed  without  deafness  being  produced, 
provided  the  membrane  of  the  foramen  ovale  remains  entire,  and  the 
parts  within  the  labyrinth  retain  their  integrity  k  If,  in  the  removal  of 
the  stapes  by  ulceration  or  otherwise,  the  membrane  of  the  foramen 
should  be  ruptured,  the  liquor  of  Cotunnius  would  of  course  escape, 
and  partial  or  total  deafness  result.  In  some  experiments  instituted 
by  M.  Flourens  on  pigeons,  he  found,  that  the  removal  of  the  malleus 
and  incus  did  not  have  much  effect  upon  the  hearing ;  but  when  the 
stapes  was  taken  away  it  was  greatly  impaired,  and  still  more  so  when 
the  membranes  of  the  fenestra  ovalis  and  fenestra  rotunda  were 
destroyed. 

The  JEustachian  tube  is  an  important  part  of  the  auditory  apparatus, 

*  Anat.  Disqnis.  de  Auditu  et  Olfactu.,  Ticin,  1789;  and  De  Structure.  Fenestrae  Rotundse 
Auris,  &c.,  Mutin.,  1772. 
VOL.  I. — 13 


194 


SENSE  OF  HEARING. 


and  an  invariable  accompaniment  of  the  membrana  tympani,  in  animals. 

Without  the  tube,  the  mem- 
brane would  be  almost  devoid 
of  function.  Pathology  shows 
us,  in  the  clearest  manner, 
that  its  integrity  is  necessary 
to  audition ;  and  that  deaf- 
ness is  the  consequence  of 
its  closure.  Dr.  Bostock1 
thinks,  "it  is  perhaps  not 
very  easy  to  ascertain  in 
what  mode  it  acts,  but  it  may 
be  concluded  that  the  proper 
vibration  of  the  membrana 
tympani  is,  in  some  way, 
connected  with  the  state  of 
the  air  in  the  tube."  The 
name  of  the  cavity  to  which 
the  tube  forms  a  communi- 
cation with  the  external  air 
suggests  an  easy  and  sufficient 
explanation  of  its  use.  The 

Vertical  Section  of  the  Head  and  Neck  through  the  drum  of  the  ear,  like  every 

Mesial  Line,  to  show  the  opening  of  the  Eustachian    drum,    requires    an    aperture 
Tube  and  its  relations  '«  th^  Pha^m-.-  .  -   . 


in  some  part  of  its  parietes, 

1.  Section  of  the  os  frontis.    2.  Section  of  the  os  occipi-  •  i         ,1      ,    •,  r 

tis.    3.  Muscles  on  the  back  of  the  neck.    4.  Integuments  "*  Order   tliat  its    membranes 

onthechin.    5.  Frontal  sinus.    6.  Middle  spongy  bone.    7.  rnov     vilirofp       -fYpAlv  TVia 

Inferior  spongy  bone.    8.  Middle  meatus  of  the  nose.    9.  ^^J      \10raiC       ir  ,6iy.          J.IH 

Inferior  meatus  of  the  nose.     10.  Thickness  of  the  roof  of  Eustachian     tube    SCrVCS    this 
the  mouth  and  floor  of  the  nostril.     11.  Opening  of  the  Eus-  j    .,         •• 

tachian  tube.    A  catheter  is  introduced  in  the  nostril  and  purpose,   and   its  ClOSUre  prO- 

about  to  enter  the  tube.     12.  Cartilaginous  nasal  septum,  Jllppa    *},«    ~xrn(*    oflf^f    nr»nn 

13.  Genio-glossus  muscle.    14.  Soft  palate.  QUCCS    tne    Same    CffCCt    Upon 

the   membrana    tympani   at 

one  end  of  the  cylinder,  and  on  the  membrane  of  the  foramen  ovale  at 
the  other,  as  would  be  produced  on  the  parchments  of  the  ordinary 
drum  by  the  closure  of  its  lateral  aperture.  We  can,  in  this  way, 
account  for  the  temporary  deafness,  which  accompanies  severe  cases  of 
inflammation  of  the  throat : — the  swelling  obstructs  the  Eustachian 
tube.  Dr.  Carpenter,2  however,  thinks  that  the  effect  of  the  hole  in 
the  side  of  a  drum  seems  rather  to  be  the  communication  of  the  sono- 
rous vibrations  of  the  contained  air  to  the  ear  of  the  observer,  which 
are  thus  transmitted  directly  through  the  atmosphere,  instead  of  being 
weakened  by  transmission  through  the  walls  of  the  instrument ;  and 
hence  he  concludes,  that  there  is  no  real  analogy  between  the  two  cases. 
During  the  constant  efforts  of  deglutition  the  air  is  renewed  in  the 
cavity  of  the  tympanum ;  and,  as  the  extremities  of  the  Eustachian 
tube  terminate  in  the  pharynx,  it  enters  at  a  modified  temperature. 
The  writer  last  cited  thinks  the  principal  object  of  the  tube  seems  to 
be  maintenance  of  the  equilibrium  between  the  air  within  the  tympanum 


Physiology,  3d  edit.,  p.  721,  London,  1836. 
Human  Physiology,  §  357,  London,  1842. 


PHYSIOLOGY  OF  THE  INTERNAL  EAR.  195 

and  that  without,  so  as  to  prevent  the  inordinate  tension  of  the  mem- 
brane, that  would  be  produced  by  too  great  or  too  little  pressure  on 
either  side ;  the  effect  of  which  would  be  impaired  hearing. 

By  closing  the  nose  and  mouth,  and  forcing  air  from  the  lungs,  we 
can  feel  a  sensation  of  fulness  in  the  ear,  produced  by  the  pressure  of 
the  air  against  the  internal  surface  of  the  membrana  tympani;  and 
they,  who  have  the  membrane  perforated,  can  send  tobacco  smoke 
copiously  out  of  the  external  ear. 

Besides  this  necessary  function,  the  Eustachian  tube  has  been  sup- 
posed to  possess  another, — that  of  serving  as  a  second  meatus  auditorius, 
by  permitting  sonorous  vibrations  to  enter  the  pharyngeal  extremity, 
and,  in  this  way,  attain  the  middle  ear.  A  simple  experiment,  first 
described  by  M.  Pdrolle,1  exhibits  the  fallacy  of  this  notion.  If  we 
carry  a  watch  far  back  into  the  mouth,  taking  care  not  to  touch  the 
teeth,  little  or  no  sound  will  be  heard ;  but  if  we  draw  the  watch  for- 
ward, so  as  to  touch  the  teeth,  the  ticking  becomes  distinctly  audible. 
If  the  pharyngeal  extremity  acted  as  a  second  meatus,  the  sound  ought 
to  be  heard  better  when  the  watch  is  placed  nearer  to  it;  but  such  is 
not  the  case.  On  the  contrary,  it  is  not  until  the  sonorous  body  is  put 
in  contact  with  the  teeth,  that  the  sound  is  appreciated.  This  is  effected 
by  the  vibrations  of  the  watch  being  conveyed  along  the  bony  parietes 
until  they  reach  the  auditory  nerve.  Again  ;  if  the  meatus  auditorius 
externus  be  completely  closed,  we  cannot  hear  the  voice  of  one  who 
speaks  into  the  mouth;  and  can  hear  but  imperfectly  our  own.  The 
fact  of  our  gaping,  when  desirous  of  hearing  accurately,  has  partly  led 
to  the  belief,  that  the  tube  acts  as  a  second  meatus.  It  has  been  pro- 
perly remarked,  however,  that  this  may  be  merely  an  act  of  expression; 
and,  also,  that  the  meatus  auditorius  is  rendered  more  open,  when  we 
depress  the  lower  jaw,  than  when  it  is  raised,  as  may  be  perceived  by 
inserting  the  little  finger  into  the  meatus,  when  the  jaw  is  in  either 
situation. 

In  addition  to  these  functions,  it  is  probable,  that  the  tube  acts  as  a 
diverticulum  for  the  air  in  the  cavity  of  the  tympanum,  when  the  mem- 
brane is  agitated  by  too  powerful  sounds.  The  closure  of  the  tube  is 
the  cause  of  that  form  of  deafness,  which  is  relieved  by  injection  of 
air  or  other  fluids  into  it — a  fact,  the  knowledge  of  which  has  been  the 
foundation  of  much  empiricism.  It  likewise  conveys  into  the  pharynx 
the  mucus  secreted  by  the  lining  membrane  of  the  tympanum,  probably 
by  means  of  the  vibratile  cilia  on  its  mucous  surface. 

Internal  Ear. — In  the  various  ways  mentioned,  the  vibrations  of  a 
sonorous  body  reach  the  internal  ear.  The  membranes  of  the  foramen 
ovale  and  foramen  rotundum  resemble  the  membrana  tympani  in  their 
physical  characteristics;  and  when  thrown  into  vibrations  communicate 
the  impression  to  the  liquor  of  Cotunnius  contained  in  the  cavities  of 
the  internal  ear.  By  this  medium,  the  vibrations  are  conducted  to  the 
auditory  nerve,  which  conveys  the  impression  to  the  brain. 

Almost  all  the  views  entertained  regarding  the  sympathetic  vibrations 
of  the  membrana  tympani  have  been  applied  to  the  membrane  of  the 

1  Hist,  et  Mem.  de  la  Societe  Royale  de  Medecine,  torn.  iii. 


196  SENSE  OF  HEARING. 

foramen  ovale :  our  knowledge,  however,  is  restricted  to  the  fact,  that 
its  tension  can  be  varied  by  the  chain  of  ossicles,  without  our  being 
able  to  specify  the  circumstances  under  which  this  takes  place.  M. 
Adelon  asserts,  that  the  membrane  may  be  torn,  and  yet  the  sense  of 
hearing  not  be  destroyed.  This  seems  scarcely  possible,  as  the  liquor 
of  Cotunnius  must  necessarily  escape,  and  so  much  morbid  action  be 
induced  as  to  render  audition  impracticable. 

The  membrane  of  the  foramen  rotundum,  which  forms  the  medium 
of  communication  between  the  cavity  of  the  tympanum  and  the  cochlea, 
has  no  chain  of  bones  to  modify  its  tension.  The  vibrations  into  which 
it  is  thrown,  as  well  as  those  of  the  vestibular  membrane,  are  imparted, 
as  we  have  seen,  to  the  liquor  of  Cotunnius,  which  is  present  in  every 
ear,  and  appears  essential  to  audition. 

Of  the  precise  use  of  the  vestibule,  semicircular  canals,  and  cochlea, 
we  have  very  limited  notions.  The  beauty  and  complexity  of  their 
arrangement  has  given  rise  to  various  conjectures.  M.  Le  Cat1  con- 
sidered the  lamina  spiralis  to  consist  of  numerous  minute  cords,  stretched 
along  it,  and  capable  of  responding  to  every  tone.  M.  Magendie2 
affirms,  that  no  one  admits  the  hypothesis  regarding  the  use  of  this 
osseo-membranous  septum ;  but  he  is  in  error.  Sir  C.  Bell3  asserts, 
that  the  cochlea  is  the  most  important  part  of  the  organ  of  hearing ; 
or  rather,  that  it  is  "the  refined  and  higher  part  of  the  apparatus;" 
and  he  considers  the  lamina  spiralis  as  the  only  part  adapted  to  the 
curious  and  admirable  powers  of  the  human  ear  for  the  enjoyment  of 
melody  and  harmony.  The  subject  of  the  musical  ear  will  engage  us 
presently.  It  may  be  sufficient  to  remark,  that  there  is  no  ratio  in 
animals,  between  their  delicacy  of  hearing  arid  the  degree  of  compli- 
cation of  the  cochlea.  The  cochlea  of  the  Guinea  pig  is  more  convoluted 
than  that  of  man ;  yet  we  can  hardly  conceive  it  to  have  a  better  ap- 
preciation of  musical  tones ;  whilst  in  birds,  whose  hearing  is  delicate, 
the  organ  is,  as  we  have  remarked,  simple,  and  has  no  spiral  arrange- 
ment. 

Again;  the  semicircular  canals  have  been  compared  to  organ  pipes, 
adapted  for  producing  numerous  tones ;  and  Dr.  Young4  supposes  them 
to  be  "  very  capable  of  assisting  in  the  estimation  of  the  acuteness  or 
pitch  of  a  sound,  by  receiving  its  impression  at  their  opposite  ends ; 
and  occasioning  a  recurrence  of  similar  effects  at  different  points  of 
their  length  according  to  the  different  character  of  the  sound ;  while 
the  greater  or  less  pressure  of  the  stapes  must  serve  to  moderate  the 
tension  of  the  fluid  within  the  vestibule,  which  serves  to  convey  the 
impression."  "  The  cochlea,"  he  adds,  "  seems  to  be  pretty  evidently 
a  micrometer  of  sound."  Another  view — to  be  remarked  upon  here- 
after— is,  that  their  peculiar  function  is  the  reception  of  the  impressions 
by  which  we  distinguish  the  direction  of  sounds.  All  these  are  mere 
hypotheses ;  ingenious,  it  is  true,  but  still  hypotheses  ;  and,  in  candour, 
it  must  be  admitted,  that  we  have  no  positive  knowledge  of  the  precise 
functions  of  either  vestibule,  cochlea,  or  semicircular  canals.  Our 

1  Traite  des  Sens,  Paris,  1767,  or  English  translation,  London,  1750. 

3  Precis,  &c.,  i.  121.  3  Op.  citat.,  ii.  273.  •«  Med.  Literature,  p.  98,  London,  1813. 


PHYSIOLOGY  OF  THE  INTERNAL  EAR.  197 

acquaintance  with  them  is  limited  to  this ; — that  they  contain  the  final 
expansions  of  the  auditory  nerve ;  and  that  it  is  within  them,  that  the 
nerve  receives  its  impressions  from  the  oscillations  of  sonorous  bodies. 

It  has  been  observed,  that  sonorous  vibrations  may  reach  the  nerve 
by  the  bony  parietes,  and  that  the  ticking  of  a  watch  held  between  the 
teeth  is,  in  this  way,  heard.  A  blow  upon  the  head  is  distinctly  aud- 
ible; and  Ingrassias1  relates  the  case  of  a  person,  who  had  become 
deaf  in  consequence  of  obstruction  of  the  meatus  auditorius  externus, 
and  yet  could  hear  the  sound  of  a  guitar  by  placing  the  handle  between 
his  teeth,  or  by  making  a  communication  between  his  teeth  and  the 
instrument  by  means  of  a  metallic  or  other  rod.  The  physician  has 
recourse  to  a  plan  of  this  kind  for  detecting  if  a  case  of  deafness  be 
dependent  upon  obstructed  Eustachian  tube;  upon  some  affection  of  the 
meatus  auditorius  externus ;  or  upon  insensibility  of  the  auditory  nerve, 
or  of  the  part  of  the  brain  where  the  sensation  is  accomplished.  If  the 
latter  be  the  fact,  the  ticking  of  a  watch,  applied  to  the  teeth,  will  not 
be  audible,  and  the  case  will  necessarily  be  of  a  hopeless  character. 
If,  on  the  other  hand,  the  sound  be  perceived,  the  attention  of  the 
physician  may  be  directed,  with  well-founded  expectation  of  success,  to 
the  physical  parts  of  the  organ,  or  to  those  concerned  in  the  transmis- 
sion of  vibrations.  Frequently,  it  will  happen,  in  such  cases,  that  the 
Eustachian  tube  is  impervious,  and  properly  directed  efforts  may  succeed 
in  removing  the  obstruction;  or,  if  this  be  impracticable,  temporary,  if 
not  permanent,  relief  may  be  obtained  by  puncturing  the  membrana 
tympani,  and  allowing  the  aerial  undulations,  in  this  way,  to  reach  the 
middle  and  internal  ear. 

Lastly; — as  regards  the  precise  nerve  ofliearing.  In  this  sense,  we 
have  the  distinction  between  the  nerve  of  general,  and  that  of  special 
sensibility,  more  clearly  perceptible.  The  experiments  of  M.  Magendie2 
have  shown,  that  the  portio  mollis  of  the  seventh  pair  is  a  nerve  of 
special  sensibility; — that  it  may  be  cut,  pricked,  or  torn,  without  ex- 
hibiting any  general  sensibility,  and  is  inservient  to  the  sense  of 
hearing  only.  The  same  experiments  demonstrate,  that  it  cannot  act 
unless  the  fifth  or  nerve  of  general  sensibility  be  in  a  state  of  integrity. 
If  the  latter  be  divided  within  the  cranium,  hearing  is  always  enfeebled, 
and  frequently  destroyed.  The  experiments  of  M.  Flourens,3  to  which 
allusion  has  been  made,  led  him  to  infer  that  the  rupture  of  the  cochlea 
was  of  less  consequence  than  that  of  the  semicircular  canals.  Lacera- 
tion of  the  nerve,  distributed  to  the  vestibule,  enfeebled  the  hearing, 
and  its  total  destruction  was  followed  by  irreparable  deafness.  For 
these,  and  other  reasons  afforded  by  comparative  anatomy,  M.  Lepelle- 
tier4  infers,  that,  in  the  higher  organisms,  the  vestibule  and  its  nerve 
constitute  the  essential  organ  of  impression;  the  other  parts  being  super- 
added  to  perfect  the  apparatus. 

An  interesting  case  of  malformation  has  been  related  by  Professor 

1  De  Ossibus,  p.  7.     Also,  Boerhaave,  Praelectiones,  iv.  415,  and  Haller,  Element.  Physiol. 
torn.  v.  p.  253,  Lausann.,  1763. 
a  Precis,  &c.,  2de  edit.,  i.  114. 

3  Experiences  sur  le  Systeme  Nerveux,  p.  42,  Paris,  1825,  or  2de  edit.,  Paris,  1842. 

4  Traite  de  Physiologic  Medicale  et  Philosophique,  iii.  143,  Paris,  1832. 


198  SENSE  OF  HEARING. 

Mussey,1  of  Cincinnati,  which  shows,  that  other  nerves  besides  the 
portio  mollis  of  the  seventh  pair  may,  under  unusual  circumstances,  be 
inservient  to  audition.  In  this  case  there  was  no  appearance  of  meatus 
auditorius  externus  in  either  ear,  and  yet  the  man,  twenty-seven  years 
of  age,  although  his  sense  of  hearing  was  too  obtuse  for  low  conversa- 
tion, could  hear  sufficiently  well  to  prosecute  his  business — that  of  a 
bookseller — without  material  inconvenience.  By  covering  the  head 
with  layers  of  cloth,  the  hearing  was  manifestly  obscured.  On  speak- 
ing to  him  with  one  end  of  a  stick  in  the  speaker's  mouth,  whilst  the 
other  end  was  applied  in  succession  to  different  parts  of  the  head  and 
face,  it  was  found,  that  the  part  over  the  mastoid  process  conducted 
sound  most  readily;  and  that  the  parts  corresponding  with  the  upper 
two-thirds  of  the  occipital,  the  mastoid  plate  of  the  temporal,  and  the 
posterior  half  of  the  parietal  bone,  transmitted  sounds  more  readily  than 
the  anterior  half  of  the  scalp,  the  forehead,  temples,  or  any  other  part 
of  the  face.  Professor  Mussey  infers,  from  the  results  of  his  observa- 
tions on  this  case,  that  the  nerves,  derived  from  the  spinal  cord  below 
the  foramen  magnum  of  the  occipital  bone,  and  reflected  in  profusion 
over  the  scalp,  were  concerned  in  this  unusual  function,  and  that  the 
branches  of  the  fifth  nerves  were  probably  the  seat  of  the  peculiar 
faculty  on  the  face.2  A  case  also  was  communicated  to  the  author  by 
the  Rev.  Dr.  Parker,  of  Macao,  in  which  there  was  no  evidence  of  ex- 
ternal ear.  The  hearing  was  very  indistinct.  Under  the  idea,  that  the 
internal  organs  were  perfect,  and  that,  to  render  the  hearing  so,  it  was 
only  necessary  to  perforate  the  integument  so  as  to  admit  the  air  to  the 
tympanum,  Dr.  Parker,  at  the  request  of  the  youth  and  his  parents, 
determined  to  perforate  one  ear.  In  accordance  with  Chinese  prejudice 
in  favour  of  the  cautery,  caustic  potassa  was  applied,  and  "  as  soon  as 
the  slough  from  the  first  applications  was  removed,  the  hearing  was 
surprisingly  improved."  No  cavity,  however,  could  be  discovered. 
After  different  operations,  he  was  able  to  hear  a  whisper.3 

The  immediate  function  of  the  sense  of  hearing  is  to  appreciate 
sound;  and  we  may  apply  to  it  what  has  been  said  of  the  other  senses; 
that,  in  this  respect,  it  cannot  be  supplied  by  any  other;  is  instinctive;' 
requires  no  education;  and  is  exerted  as  soon  as  the  parts  have  attained 
a  due  degree  of  development. 

Amongst  the  advantages  afforded  by  the  possession  of  this  sense, 
which  has  been  well  termed  intellectual,  are  two  of  the  highest  gratifi- 
cations we  enjoy, — the  appreciation  of  music,  and  the  pleasures  of  con- 
versation. To  it  we  are  indirectly  indebted  for  the  use  of  verbal  lan- 
guage— the  happiest  of  all  inventions — as  it  has  been  properly  termed; 
and  to  which  we  shall  have  to  advert  in  the  course  of  our  inquiry  into 
the  animal  functions. 

Metaphysicians  and  physiologists  have  differed  widely  in  their  views 
regarding  the  organs  more  immediately  concerned  in  the  appreciations 
in  question.  Many,  for  example,  have  referred  the  faculty  of  music  to 
the  ear;  and  hence,  in  common  language,  we  speak  of  an  individual, 

1  American  Journal  of  the  Medical  Sciences,  Feb.,  1838,  p.  378. 

3  A  similar  case  by  Mr.  Swan  is  in  Medico-Chirurgical  Transactions,  vol.  xi. 

3  First  JReport  of  the  Ophthalmic  Hospital,  Canton,  Feb.,  1826. 


MUSICAL  EAK.  199 

•who  has  a  "musical  ear"  or  the  contrary.  Others,  more  philosophi- 
cally, have  considered,  that  the  faculty  is  encephalic ;  that  the  ear  is 
merely  the  instrument  for  conveying  the  sonorous  undulations,  which, 
in  due  order,  constitute  melody;  but  that  the  appreciation  is  ultimately 
effected  in  the  brain.  "That  it,"  (the  power  of  distinguishing  the  mu- 
sical relations  of  sounds,)  says  Dr.  Brown,1  "depends  chiefly,  or  per- 
haps entirely,  on  the  structure  or  state  of  the  mere  corporeal  organ  of 
hearing,  which  is  of  a  kind,  it  must  be  remembered,  peculiarly  compli- 
cated, and  therefore  susceptible  of  great  original  diversity  in  the  parts, 
and  relations  of  the  parts  that  form  it,  is  very  probable;  though  the 
difference  of  the  separate  parts  themselves,  or  of  their  relations  to  each 
other,  may,  to  the  mere  eye,  be  so  minute,  as  never  to  be  discovered 
by  dissection."  Many  physiologists  of  eminence  have  regarded  the 
complex  internal  ear  as  the  seat  of  the  faculty ;  some  looking  to  the 
cochlea ;  others  to  the  semicircular  canals ;  and  but  few  referring  it  to 
the  brain.  Sir  C.  Bell,  indeed,  asserts,  that  "we  are  not  perhaps  war- 
ranted in  concluding,  that  any  one  part  of  the  organ  of  hearing 
bestows  the  pleasures  of  melody  and  harmony,  since  the  musical  ear, 
though  so  termed,  is  rather  a  faculty  depending  on  the  mind."  Yet 
afterwards  he  adds: — "We  think  that  we  find  in  the  lamina  spiralis  (of 
the  cochlea)  the  only  part  adapted  to  the  curious  and  admirable  powers 
of  the  human  ear  for  the  enjoyment  of  melody  and  harmony.  It  is  in 
vain  to  say,  that  these  capacities  are  in  the  mind  and  not  in  the  out- 
ward organ.  It  is  true,  the  capacity  for  enjoyment  or  genius  for  music 
is  in  the  mind.  All  we  contend  for  is,  that  those  curious  varieties  of 
sound,  which  constitute  the  source  of  this  enjoyment,  are  communicated 
through  the  ear,  and  that  the  ear  has  mechanical  provisions  for  every 
change  of  sensation."2  A  cherished  opinion  of  Sir  Everard  Home3  on 
this  subject  has  been  given  before.  Conceiving  the  membrane  of  the 
tympanum  to  be  muscular,  he  considers  the  membrana  tympani,  with 
its  tensor  and  radiated  muscles,  to  resemble  a  monochord,  "  of  which 
the  membrana  tympani  is  the  string ;  the  tensor  muscles  the  screw, 
giving  the  necessary  tension  to  make  the  string  perform  its  proper 
scale  of  vibrations;  and  the  radiated  muscle,  acting  upon  the  membrane, 
like  the  movable  bridge  of  the  monochord,  adjusting  it  to  the  vibrations 
required  to  be  produced;"  and  he  adds:  "the  difference  between  a  mu- 
sixjal  ear  and  one  which  is  too  imperfect  to  distinguish  the  different 
notes  in  music  will  appear  to  arise  entirely  from  the  greater  or  less 
nicety  with  which  the  muscle  of  the  malleus  renders  the  membrane 
capable  of  being  truly  adjusted.  If  the  tension  be  perfect,  all  the  va- 
riations produced  by  the  action  of  the  radiated  muscle  will  be  equally 
correct,  and  the  ear  truly  musical."  In  this  view, — as  unsatisfactory 
in  its  basis  as  it  is  in  some  of  the  details, — Sir  Everard  completely 
excludes,  from  all  participation  in  the  function,  the  internal  ear,  to 
which  the  attention  of  physiologists,  who  consider  the  faculty  to  be 
seated  in  the  ear,  has  been  almost  exclusively  directed. 

1  Lectures  on  the  Philosophy,  of  the  Human  Mind,  Edinb.,  1820  ;  or  Amer.  edit.,  vol.  i. 
p.  207.     Boston,  1826. 

a  Anat.  and  PhysioL,  5th  Amer.  edit.,  by  Godman,  ii.  273.     New  York,  1829. 
3  Lect.  on  Comp.  Anat.,  iii.  268. 


200  SENSE  OF  HEARING. 

A  single  case,  detailed  by  Sir  Astley  Cooper,1  prostrates  the  whole 
of  the  ingenious  fabric  erected  by  Sir  Everard.  Allusion  has  already 
been  made  to  the  old  established  fact,  that  the  membrane  of  the  tym- 
panum may  be  destroyed  without  loss  of  hearing  necessarily  following. 
Sir  Astley  was  consulted  by  a  gentleman,  who  had  been  attacked,  at 
the  age  of  ten  years,  with  inflammation  and  suppuration  in  his  left  ear, 
which  continued  discharging  matter  for  several  weeks.  In  the  space 
of  about  twelve  months  after  the  first  attack,  symptoms  of  a  similar 
kind  took  place  in  the  right  ear,  from  which  matter  issued  for  a  con- 
siderable time.  The  discharge,  in  each  instance,  was  thin,  and 
extremely  offensive ;  and  in  it,  bones  or  pieces  of  bones  were  observable. 
In  consequence  of  these  attacks  he  became  deaf,  and  remained  so  for 
three  months.  The  hearing  then  began  to  return ;  and  in  about  ten 
months  from  the  last  attack,  he  was  restored  to  the  state  he  was  in 
when  the  case  was  published.  Having  filled  his  mouth  with  air,  he 
closed  his  nostrils  and  contracted  the  cheeks;  the  air,  thus  compressed, 
was  heard  to  rush  through  the  meatus  auditorius  with  a  whistling  noise, 
and  the  hair,  hanging  from  the  temples,  became  agitated  by  the  cur- 
rent of  air  that  issued  from  the  ear.  When  a  candle  was  applied,  the 
flame  was  agitated  in  a  similar  manner.  Sir  Astley  passed  a  probe 
into  each  ear,  and  thought  the  membrane  of  the  left  side  was  totally 
destroyed,  as  the  probe  struck  against  the\  petrous  portion  of  the  tem- 
poral bone.  The  space,  usually  occupied  by  the  membrana  tympani, 
was  found  to  be  an  aperture  without  one  trace  of  membrane  remaining. 
On  the  right  side,  also,  a  probe  could  be  passed  into  the  cavity  of  the 
tympanum ;  but,  on  this  side,  some  remains  of  the  circumference  of  the 
membrane  could  be  discovered,  with  a  circular  opening  in  the  centre, 
about  a  quarter  of  an  inch  in  diameter.  Yet  this  gentleman  was  not 
only  capable  of  hearing  everything  that  was  said  in  company,  but  was 
nicely  susceptible  to  musical  tones ;  "  he  played  well  on  the  flute,  and 
had  frequently  borne  a  part  in  a  concert ;  and  he  sang  with  much  taste 
and  perfectly  in  tune." 

But,  independently  of  these  partial  objections,  the  views  which  assign 
musical  ear  and  acquired  language  to  the  auditory  apparatus,  appear 
liable  to  others  that  are  insuperable.  The  man  who  is  totally  devoid 
of  musical  ear  hears  the  sound  distinctly.  His  sense  of  hearing  may 
be  as  acute  as  that  of  the  best  musician.  It  is  his  appreciation  that 
is  defective.  He  hears  the  sound;  but  is  incapable  of  communicating 
it  to  others.  The  organ  of  appreciation  is — in  this,  as  in  every  other 
sense — the  brain.  The  physical  part  of  the  organ  may  modify  the 
impression  that  has  to  be  made  upon  the  nerve  of  sense ;  the  latter 
is  compelled  to  transmit  the  impression  as  it  receives  it;  and  it  is  not 
until  the  brain  has  acted,  that  perception  takes  place,  or  that  any  idea 
of  the  physical  cause  of  the  impression  is  excited  in  the  mind.  If, 
from  faulty  organization,  such  idea  be  not  formed  in  the  case  of  mu- 
sical tones,  the  individual  is  said  not  to  possess  a  musical  ear ;  but  the 
fault  lies  in  his  cerebral  conformation.  We  do  not  observe  the  slight- 
est relation  between  musical  talent  and  delicacy  of  hearing.  The  best 

1  Philosoph.  Transact,  for  1800,  p.  151,  and  for  1801,  p.  435. 


MUSICAL  EAR.  201 

musicians  have  not  necessarily  the  most  delicate  sense ;  and,  for  the 
reasons  already  assigned,  it  will  be  manifest,  why  the  idiot,  whose  hear- 
ing may  be  acute,  is  incapable  of  singing,  as  well  as  of  speaking. 
Again,  we  do  not  see  the  least  ratio  in  animals  between  the  extent  and 
character  of  their  music  and  the  condition  of  their  auditory  sense. 
We  are  compelled,  then,  to  admit,  that  the  faculties  of  music  and 
speech  are  dependent  upon  organization  of  the  brain;  that  they 
require  the  ear  as  an  instrument ;  but  that  their  degree  of  perfection 
is  by  no  means  in  proportion  to  the  delicacy  of  the  sense  of  hear- 
ing. In  these  opinions,  MM.  Gall,1  Broussais,2  Adelon,3  and  other 
distinguished  physiologists  concur.  "  Speech,"  says  M.  Broussais, 
"  is  heard  and  repeated  by  all  men,  who  are  not  deprived  of  the  audi- 
tory sense  ;  because  they  are  all  endowed  with  cerebral  organization 
fit  to  procure  for  them  distinct  ideas  on  the  subject.  Music,  when 
viewed  as  a  mere  noise,  is  also  heard  by  every  one ;  but  it  furnishes 
ideas,  sufficiently  clear  to  be  reproduced,  to  those  individuals  only 
whose  frames  are  organized  in  a  manner  adapted  to  this  kind  of  sensa- 
tion." 

Yet,  although  we  must  regard  the  musical  faculty  to  be  intellectual, 
and  consequently  elevated  in  the  scale,  it  is  hardly  necessary  to  say, 
that  the  want  of  it  is  no  evidence  of  that  mental  and  moral  degrada- 
tion, which  has  been  depicted  by  poets  and  others. 

"The  man  that  hath  no  music  in  himself, 
Nor  is  not  moved  with  concord  of  sweet  sounds, 
Is  fit  for  treasons,  stratagems,  and  spoils  ; 
The  motions  of  his  spirit  are  dull  as  night, 
And  his  affections  dark  as  Erebus : 
Let  no  such  man  be  trusted." 

SHAKSPEAUE,  u Merchant  of  Venice"  v.  i. 

"  Is  there  a  heart  that  music  cannot  melt? 
Alas  !  how  is  that  rugged  heart  forlorn  ! 
Is  there,  who  ne'er  those  mystic  transports  felt 
Of  solitude  and  melancholy  born  ! 
He  needs  not  woo  the  muse  ;  he  is  her  scorn. 
The  sophist's  rope  of  cobweb  he  shall  twine ; 
Mope  o'er  the  schoolman's  peevish  page  ;  or  mourn, 
And  delve  for  life  in  mammon's  dirty  mine; 
Sneak  with  the  scoundrel  fox,  or  grunt  with  glutton  swine." 

BEATTIE,  "  Minstrel." 

In  the  classification  of  the  objects  of  human  knowledge,  music  has 
been  ranked  with  poetry;  but  we  meet  with  striking  evidences  of  their 
wide  separation.  Whilst  the  professed  musician  is  frequently  devoid 
of  all  poetical  talent,  many  excellent  poets  have  no  musical  ear.  Nei- 
ther does  the  power  of  discriminating  musical  tones  indicate,  that  the 
possessor  is  favoured  with  the  finer  sensibilities  of  the  mind ;  nor  the 
want  of  it  prove  their  deficiency.  It  has  been  a  common  remark,  that 
amongst  professed  musicians,  the  intellectual  manifestations  have  been 
singularly  and  generally  feeble;  a  result  partly  occasioned  by  their 
attention  having  been  almost  entirely  engrossed  from  childhood  by  their 

1  Sur  les  Fonctions  du  Cerveau,  v.  96.     Paris,  1825. 

a  Traite  de  Physiologic,  translated  by  Drs.  Bell  and  La  Roche,  p.  84,  3d  Amer.  edit., 
Philad.,  1832.  a  Op.  citat.,  i.  383. 


202  SENSE  OF  HEARING. 

one  favourite  pursuit,  but  not  perhaps  to  be  wholly  explained  by  this 
circumstance;  and,  whilst  we  find  them  often  unmarked  by  any  of  the 
kindlier  sympathies,  we  see  those,  that  are  "  not  moved  with  concord 
of  sweet  sounds,"  alike  distinguished  as  philosophers  and  philanthro- 
pists. 

The  defect,  in  these  cases,  differs  probably,  in  an  essential  manner, 
from  one  to  which  attention  has  been  drawn  by  the  late  Dr.  Wollas- 
ton,1  who  has  detailed  many  curious  facts,  regarding  what  he  terms  a 
peculiarity  in  certain  ears,  which  seem  to  have  no  defect  in  their  gene- 
ral capacity  for  being  impressed  by  sound,  or  in  the  perception  of  mu- 
sical tones ;  but  are  insensible  to  very  acute  sounds.  This  insensibility 
commences  when  the  vibrations  have  attained  a  certain  degree  of  rapi- 
dity ;  beyond  which  all  sounds  are  inaudible  to  ears  thus  constituted. 
Thus,  according  to  Dr.  Wollaston,  certain  persons  cannot  hear  the  chirp 
of  the  grasshopper ;  others,  the  cry  of  the  bat ;  and  he  refers  to  one 
case,  in  which  the  note  of  the  sparrow  was  inaudible.  He  himself  was 
incapable  of  hearing  any  sound  higher  than  six  octaves  above  the  mid- 
dle E  of  the  piano  forte.  The  defect  would,  at  first  sight,  appear  to 
be  referable  to  the  physical  part  of  the  ear,  rather  than  to  the  auditory 
nerve,  or  to  the  part  of  the  brain  concerned  in  the  appreciation  of 
sounds; — the  vibrations  that  are  performed  with J  great  rapidity  not 
being  responded  to  by  the  parts  of  the  organ  destined  for  that  purpose; 
and,  consequently,  never  reaching  the  auditory  nerve.  Researches, 
however,  by  M.  Savart,2 — a  most  dexterous  and  ingenious  experimenter, 
— seem  to  show  that  the  defect  in  the  appreciation  of  acute  sounds,  in 
such  cases,  is  not  owing  to  their  acuteness  but  to  their  feebleness;  that 
if  the  sound  can  be  made  sufficiently  intense,  the  ear  is  capable  of 
hearing  a  note  of  upwards  of  forty  thousand  simple  oscillations  in  a 
second;  and  that  the  cases  referred  to  by  Dr.  Wollaston  are,  conse- 
quently, owing  to  defective  hearing,  rather  than  to  insensibility  to  very 
acute  sounds. 

Another  acquired  perception  of  the  ear  is  that  of  forming  a  judg- 
ment of  the  distance  of  bodies.  This  we  do  by  attending  to  the  loud- 
ness  of  the  sound ;  for  we  instinctively  believe,  that  a  loud  sound  pro- 
ceeds from  a  body  near  us,  and  a  feeble  sound  from  one  more  remote. 
This  is  the  cause  of  numerous  acoustic  errors,  in  spite  of  all  reason  and 
experience.  In  the  theatres,  the  deception  is  often  admirably  managed, 
when  the  object  is  to  give  the  idea  of  bodies  approaching.  The  sound 
— that  of  martial  music,  for  example — is  rendered  faint  and  subdued ; 
and,  under  such  circumstances,  appears  to  proceed  from  remote  dis- 
tance ;  and,  by  adding  gradually  and  skilfully  to  its  intensity,  we  are 
irresistibly  led  to  the  belief  that  the  army  is  approaching;  and  the 
illusion  is  completed  by  the  appearance  of  the  military  band  on  the 
stage,  allowing  its  soul-inspiring  strains  to  vibrate  freely  in  the  air.  In 
like  manner,  we  are  deceived  by  the  ventriloquist.  He  is  aware  of  the 
law  that  guides  us  in  our  estimation  of  distance ;  and,  by  skilfully 
modifying  the  intensity  of  his  voice,  according  as  he  wishes  to  make 

1  Philosophical  Transactions  for  1820,  p.  306. 

2  Journal  de  Physiologic  de  Magendie,  v.  367. 


JUDGMENT  OF  DISTANCE,  ETC.,  BY  SOUND.  203 

the  sound  appear  to  proceed  from  a  near  or  a  distant  object,  he  irre- 
sistibly leads  us  into  acoustic  error. 

Education  or  experience  is  required  to  enable  us  to  appreciate  dis- 
tances accurately  by  this  sense;  as  well  as  to  judge  of  their  position. 
In  the  case,  detailed  by  M.  Magendie,1  of  a  boy,  who,  after  having  been 
entirely  deaf  until  the  age  of  nine,  was  restored  to  hearing  by  M. 
Deleau,  by  means  of  injections  thrown  into  the  cavity  of  the  tympanum 
through  the  pharyngeal  extremity  of  the  Eustachian  tube,  one  of  the 
most  remarkable  points  was  his  difficulty  in  acquiring  a  knowledge  of 
the  position  of  sonorous  bodies.  In  forming  an  accurate  judgment  on 
this  subject  we  seem  to  require  the  use  of  both  ears.  In  all  other  cases 
an  impression  made  upon  one  only  would  perhaps  be  sufficient.  The 
common  opinion  is,  that  to  judge  of  the  direction  of  a  sound  we  com- 
pare the  intensity  of  the  impression  on  each  ear,  and  form  our  deduc- 
tions accordingly;  and  that  if  we  close  one  ear  we  are  led  into  errors, 
which  are  speedily  dissipated  by  employing  both.  Still  we  are  often 
deceived  even  under  these  last  circumstances,  and  are  compelled  to  call 
in  the  aid  of  sight.  The  blind  afford  us  striking  examples  of  accuracy, 
in  their  perceptions  by  the  ear.  In  the  Belisar  of  Zeune,  the  case  of  a 
blind  man  is  cited  from  Diderot;  who,  guided  by  the  direction  of  the 
voice,  struck  his  brother  in  a  quarrel  on  the  forehead,  with  a  missile, 
which  brought  him  to  the  ground.2 

Mr.  Wheatstone  supposes,  that  the  perception  we  have  of  the  direc- 
tion of  sounds  arises  solely  from  the  portion  transmitted  through  the 
solid  parts  of  the  head,  which,  by  affecting  the  three  semicircular 
canals,  situate  in  planes  at  right  angles  with  each  other,  with  different 
degrees  of  intensity,  according  to  the  direction  in  which  the  sound  is 
transmitted,  suggests  to  the  mind  the  corresponding  direction.  If  the 
sound  be  transmitted  in  the  plane  of  either  of  the  semicircular  canals, 
the  nervous  matter  in  that  canal  will  be  more  strongly  acted  on  than 
that  in  either  of  the  other  two;  and  if  in  any  plane  intermediate  be- 
tween two  of  the  rectangular  planes,  the  relative  .intensities  in  these 
two  canals  corresponding  therewith  will  vary  with  the  direction  of  the 
intermediate  plane;3  and  it  has  been  regarded  by  Dr.  Carpenter4  as  a 
powerful  argument  in  support  of  this  view,  that  in  almost  every  instance 
in  which  these  canals  exist  at  all,  they  hold  the  same  relative  position 
to  each  other  as  in  man;  their  three  planes  being  nearly  at  right  angles 
to  one  another.  He  properly,  however,  adds,  that  the  idea  must  be 
regarded  as  a  mere  speculation,  the  value  of  which  cannot  be  decided 
without  an  increased  knowledge  of  the  laws  according  to  which  sonorous 
vibrations  are  transmitted. 

If  these  vibrations,  before  reaching  the  ear,  be  deflected  from  their 
course,  we  are  liable  to  deception,  mistaking  the  echo  for  the  direct  or 
radiant  sound. 

The  ideas  of  magnitude  acquired  by  the  ear  are  few,  and  to  a  trifling 
extent  only.  They  occasionally  enable  the  blind  to  judge  of  the  size 

1  Journal  de  Physiologie,  v.  223. 

2  Rudolphi,  Grundriss  der  Physiologie,  s.  149,  Berlin,  1823. 

3  Journal  of  Science,  New  Series,  ii.  67,  London,  1827. 

4  Human  Physiology,  §  359,  London,  1842. 


204  SENSE  OF  HEARING. 

of  apartments,  and  this  they  sometimes  do  with  much  accuracy.  It  is 
well  known,  that  if  a  sound  be  confined  within  a  small  space,  it  appears 
louder  than  when  the  sonorous  undulations  can  extend  farther;  hence 
the  greater  noise  caused  directly  by  a  pistol  fired  in  a  room  than  in  the 
open  air.  The  sound  indirectly  produced  will  necessarily  be  modified 
by  the  different  reflections  or  echoes,  that  may  be  excited.  By  attend- 
ing to  these  circumstances — to  the  loudness  of  the  voice  and  the  inten- 
sity of  the  reverberations  occasioned  by  the  walls,  and  calling  into  aid 
experience  under  similar  circumstances, — in  other  words,  by  effecting 
a  strictly  intellectual  process, — the  blind  attain  the  knowledge  in 
question. 

The  velocity  of  a  body  is  indicated  by  the  rapid  succession  of  the 
vibrations  that  impress  the  ear,  as  well  as  by  the  change  in  their  inten- 
sity, if  the  body  be  moving  along  a  surface  or  through  the  air.  A  car- 
riage, approaching  with  great  velocity,  is  detected  by  the  ear,  from  the 
rapidity  with  which  the  wheels  strike  against  intervening  obstacles; 
and  by  the  gradual  augmentation  in  the  intensity  of  the  sound  produced. 
When  opposite  to  us  the  intensity  is  greatest ;  and  a  declension  gradu- 
ally takes  place  until  the  sound  is  ultimately  lost  in  distance. 

Lastly ; — by  audition  we  form  some  judgment  of  the  nature  of  bodies 
by  the  difference  in  the  sounds  emitted.  It  has  been  already  remarked, 
that  the  timbre  or  quality  of  sound  can  be  accurately  appreciated.  By 
this  quality  we  distinguish  between  the  sound  of  wood  or  metal;  of 
hollow  or  solid  bodies,  &c. ;  but  in  all  these  cases  we  are  compelled  to 
call  into  aid  our  experience — without  which  we  should  be  completely  at 
a  loss — and  to  execute  a  rapid,  but  often  very  complicated,  intellectual 
operation. 

Audition  may  be  exercised  passively  as  well  as  actively ;  hence  the 
difference  between  simply  hearing,  and  listening.  We  cannot  appre- 
ciate, in  man,  the  precise  effects  produced  on  the  different  portions  of 
the  ear  by  volition ; — whether,  for  example,  the  advantage  be  limited 
to  the  better  direction  given  to  the  ear,  as  regards  the  sonorous  body, 
and  to  avoiding  all  distraction  by  confining  the  attention  to  the  im- 
pressions made  on  the  sense;  or  whether,  by  it,  the  pavilion  may  not 
be  made  somewhat  more  tense  by  the  contraction  of  its  intrinsic  and 
extrinsic  muscles ; — whether  the  membrana  tympani,  and  the  membrane 
of  the  foramen  ovale  may  be  modified  by  the  contraction  of  the  muscles 
of  the  ossicles;  or,  in  fine,  the  auditory  nerve  be  rendered  better  adapt- 
ed for  the  reception  of  the  impression,  and  the  brain  for  its  apprecia- 
tion. All  these  points  are  unsusceptible  of  direct  observation  and 
experiment;  and  are,  therefore,  enveloped  in  uncertainty.  In  some 
animals — as  the  horse — the  outer  ear  becomes  an  acoustic  instrument 
under  the  guidance  of  volition;  and  is  capable  of  being  turned  in  every 
direction  in  which  a  sonorous  body  may  be  placed. 

Like  other  senses,  that  of  hearing  is  largely  improved  by  education 
or  cultivation.  The  savage,  accustomed,  in  the  stillness  of  the  forest, 
to  listen  to  the  approach  of  enemies  or  his  prey,  has  the  sense  so  deli- 
cate as  to  hear  sounds,  that  are  inaudible  to  one  brought  up  in  the  din 
of  the  busy  world.  The  blind,  for  reasons  more  than  once  assigned, 


SENSE  OF  SIGHT.  205 

afford  examples  of  extreme  delicacy  of  this  as  well  as  of  their  other 
senses.  They  are  necessarily  compelled  to  cultivate  it  more ;  and, 
lastly,  the  musician,  by  education,  attains  the  perception  of  the  nicest 
shades  of  musical  tones.  The  aptitude  is  laid  in  cerebral  organiza- 
tion, and  is  developed  by  the  education  of  the  instrument — the  ear — 
as  well  as  of  the  encephalic  or  intellectual  organ,  without  which,  as  we 
have  seen,  no  such  appreciation  could  be  accomplished. 

SENSE  OF  SIGHT  OR  VISION. 

The  immediate  function  of  the  sense  of  sight  is  to  give  us  the  notion 
of  light  and  colours.  Like  the  other  senses,  it  is  a  modification  of  that 
of  touch,  whether  we  regard  the  special  irritant — light — as  an  emana- 
tion from  luminous  bodies,  or  as  the  vibration  of  a  subtile,  ethereal 
fluid,  pervading  all  space.  Under  the  latter  theory  it  would  most 
strongly  resemble  the  sense  last  considered. 

The  pleasures  and  advantages  derived  by  the  mind  through  this 
inlet,  are  of  so  signal  a  kind  as  to  render  the  organ  of  vision  a  subject 
of  universal  interest.  Every  one,  who  lays  the  slightest  claims  to  a 
general  education,  has  made  it  more  or  less  a  subject  of  study,  and 
is  not  unfrequently  better  acquainted  with  its  structure  and  properties 
than  the  medical  practitioner.  Complicated  as  its  organization  may 
seem,  it  is,  in  action,  characterized  by  extreme  simplicity ;  yet,  "  in 
its  simplicity,"  as  Dr.  Arnott1  has  remarked,  "  so  perfect,  so  unspeak- 
ably perfect,  that  the  searchers  after  tangible  evidences  of  an  all- wise 
and  good  Creator  have  declared  their  willingness  to  be  limited  to  it 
alone,  in  the  midst  of  millions,  as  their  one  triumphant  proof."  Into 
this  structure  we  shall  inquire,  so  far  as  is  necessary  for  our  pur- 
pose, after  having  described  the  general  properties  of  light;  and  then 
detail  the  mode  in  which  its  various  functions  are  accomplished,  and  the 
knowledge  derived  by  the  mind  through  its  agency. 

The  eye  is  the  organ  of  vision.  It  varies  materially  in  different 
animals; — in  some,  consisting  of  a  simple  capsule,  with  the  final  expan- 
sion-of  the  nerve  of  sight  distributed  on  its  interior,  and  communi- 
cating externally  by  means  of  the  transparent  cornea,  which  admits 
the  light.  It  is  in  this  simple  state  that  M.  de  Blainville2  assimilates 
it  to  a  bulb  of  hair,  modified  for  the  new  function  it  has  to  execute. 
In  man,  and  the  upper  classes  of  animals,  the  organ  is  much  more  com- 
plicated in  its  structure;  and  in  it  we  have  a  still  clearer  example  of 
the  distinction  between  the  physical,  and  the  nervous  or  vital  part  of 
the  apparatus,  than  in  any  of  the  other  organs  of  sense, — the  former 
consisting  of  transparent  tunics,  and  humours,  which  modify  the  light 
according  to  the  laws  of  optics ; — the  latter  being  a  production  or  ex- 
pansion of  nervous  structure,  for  the  reception  of  the  impression  of 
light,  and  for  conveying  such  impression  to  the  proper  part  of  the 
encephalon.  There  is,  besides,  attached  to  the  organ,  a  number  of 
accessory  parts  or  tutamina,  which  are  more  or  less  concerned  in  the 
proper  performance  of  the  function.  It  will  be  necessary,  therefore,  to 

1  Elements  of  Physics,  2d  Amer.  edit.,  vol.  ii.  P.  i.  p.  1(51,  Pliilad.,  1836. 

2  De  ('Organization  ties  Animaux,  Paris,  1825. 


206  SENSE  OF  SIGHT. 

give  a  succinct  view,  not  only  of  the  eye,  properly  so  called,  but  also 
of  these  accessory  organs,  which  serve  to  lodge,  move,  protect,  and 
lubricate  it.  The  description  will  not,  however,  be  clearly  understood, 
•without  premising  some  general  observations  on  the  properties  of  light, 
especially  as  regards  its  refraction,  on  which  the  phenomena  of  vision 
are  greatly  dependent. 

1.    LIGHT. 

The  sun  and  the  fixed  stars  are  the  great  sources  of  light.  It  is 
given  off,  also,  from  substances  in  a  state  of  combustion,  and  from  phos- 
phorescent bodies ;  and,  by  entering  the  eye  directly,  or  after  various 
reflections  or  refractions,  impinges  on  the  optic  nerve,  and  gives  the 
sensation  of  light. 

Two  main  opinions  have  been  entertained  regarding  the  nature  of 
light;  the  one,  propounded  by  Newton — that  it  consists  of  extremely 
minute  particles,  emanating  from  luminous  bodies ;  the  other — that 
of  Des  Cartes,  Hook,  Huygens,  Euler,  and  others, — that  it  is  a  sub- 
tile, eminently  elastic  fluid — an  ether — pervading  all  space ;  the  elastic 
molecules  of  which,  when  put  in  motion  by  the  oscillations  of  bodies, 
impress  the  eye  as  sonorous  vibrations  affect  the  ear.  It  is  not  for 
us  to  discuss  this  question  of  higher  physics.  We  may  merely  re- 
mark, that  difficulties  attend  both  hypotheses.  According  to  that 
of  Des  Cartes,  it  is  not  easy  to  explain,  why  an  opaque  body  should 
prevent  the  undulations  from  reaching  the  eye, — or  the  change  of 
direction,  which  light  experiences  in  passing  from  one  medium  into 
another ;  whilst,  according  to  that  of  Newton,  it  is  difficult  to  con- 
ceive, how  a  luminous  body,  as  the  sun,  can  shed  its  immense  tor- 
rents of  light  incessantly,  without  undergoing  rapid  diminution ;  and 
how,  with  the  extreme  velocity  of  light,  these  particles  should  not  be 
possessed  of  sensible  momentum ;  for  it  has  been  found  that  a  large 
sunbeam,  collected  by  a  burning-glass,  and  thrown  upon  the  scale  of 
a  balance  of  extreme  delicacy,  is  insufficient  to  disturb  the  equili- 
brium. To  the  hypothesis  of  Newton  it  has  been  objected,  that  the 
particles  being  reflected  by  thousands  of  bodies,  and  in  innumer- 
able directions,  would  necessarily  jostle  and  interfere  with  each  other. 
This  objection  is  not,  however,  as  valid  as  it  appears  at  first  sight.  It 
•will  be  seen  hereafter,  that  the  impression  of  a  luminous  object  remains 
upon  the  retina  for  the  sixth  part  of  a  second.  Admitting  it,  however, 
to  impress  the  eye  for  the  3  J^th  part,  three  hundred  particles,  per 
second,  would  be  sufficient  to  excite  a  constant  and  uniform  sensation 
of  the  presence  of  light;  and  since,  as  we  shall  find,  it  traverses  sixty- 
seven  thousand  leagues  in  a  second  of  time,  if  we  divide  this  by  three 
hundred,  we  shall  find  a  space  of  six  hundred  and  seventy  miles  be- 
tween each  particle ;  a  distance  equal  to  that — in  a  straight  line — be- 
tween New  York  and  Savannah;  and  if  we  suppose  six  particles  to  be 
sufficient  per  second,  each  will  be  separated  from  the  other  by  a  space 
of  thirty-three  thousand  five  hundred  miles ! 

Without  deciding  in  favour  of  either  of  the  great  theories,  that  of 
Newton  admits  of  more  easy  application  to  our  subject,  and  will,  there- 
fore, be  employed  in  the  various  explanations  that  may  be  required. 


LIGHT.  207 

Light,  then,  proceeding  from  a  luminous  body,  impinges  on  the  sub- 
stances that  are  within  its  sphere ;  and  these,  by  reflecting  the  whole 
or  a  part  of  it  to  the  eye,  become  visible  to  us.  In  its  course,  direct 
or  reflected,  its  velocity  is  almost  inconceivable.  From  observations 
made  on  the  eclipses  of  Jupiter's  satellites,  by  Homer,  Cassini,  and 
other  astronomers,  it  has  been  calculated,  that  the  light  of  the  sun  is 
eight  minutes  and  thirteen  seconds  in  its  passage  from  that  luminary  to 
the  earth.  The  distance  between  the  earth  and  the  sun  is  thirty-three 
millions  of  leagues,  so  that  the  velocity  of  light  is  sixty-seven  thousand 
leagues,  or  two  hundred  thousand  miles  per  second;  in  other  words,  in 
the  lapse  of  a  single  second  it  could  pass  between  Washington  and 
Albany — supposing  the  distance  to  be  three  hundred  miles — seven  hun- 
dred times;  and  could  make  the  tour  of  the  globe  in  the  time  it  takes 
us  to  wink.  In  consequence  of  this  extreme  velocity, — in  all  calcula- 
tions, regarding  the  light  from  bodies  on  the  surface  of  the  globe,  it  is 
presumed  to  reach  the  eye  instantaneously;  for,  granting  that  a  lumi- 
nous body  at  Albany  could  be  seen  at  Washington,  the  light  from  it 
would  reach  the  eye  in  the  ^jjth  part  of  a  second.  Inconceivable  as 
this  velocity  is,  it  is  far  surpassed  by  that  of  the  attractive  force  ex- 
erted between  the  heavenly  bodies.  "I  have  ascertained,"  says  M.  La 
Place,  "that  between  the  heavenly  bodies  all  attractions  are  transmitted 
with  a  velocity,  which,  if  it  be  not  infinite,  surpasses  several  thousand 
times  the  velocity  of  light;  and  we  know  that  the  light  of  the  moon 
reaches  the  earth  in  less  than  two  seconds."  An  annotator  on  the 
works  of  this  distinguished  mathematician  is  more  definite ;  affirming, 
"that  the  gravific  fluid  passes  over  one  million  of  the  earth's  semi- 
diameters  in  a  minute  of  time."  Its  velocity  is  eight  millions  of  times 
greater  than  that  of  light. 

A  series  of  particles,  succeeding  each  other  in  a  straight  line,  is 
called  a  ray  of  light.  Light  which  proceeds  from  a  radiant  point,  forms 
diverging  cones,  which  would  be  prolonged  indefinitely  did  they  not 
meet  with  obstacles.  In  its  course,  it  loses  its  intensity  according  to  a 
law,  which  seems  applicable  to  all  influences  radiating  from  a  centre. 
If  a  taper  be  placed  in  the  middle  of  a  box,  each  one  of  whose  sides  is 
a  foot  square,  all  the  light  must  impinge  upon  the  sides  of  the  box;  if 
it  be  placed  in  a  box,  whose  sides  are  two  feet  square,  the  light  will 
shine  upon  them  from  double  the  distance,  but  it  will  be  distributed 
over  four  times  the  surface.  The  intensity  of  the  light,  then,  in  this 
case,  as  in  every  other,  diminishes  according  to  the  square  of  the  dis- 
tance from  the  luminous  body.  According  to  this  rule,  those  planets 
which  are  nearer  the  sun  than  ours  must  receive  the  light  and  also  the 
heat — for  the  same  law  applies  to  caloric — in  much  greater  intensity; 
whilst  the  more  distant  luminaries  can  receive  but  little  caloric,  or  light, 
in  comparison  with  the  earth;  hence,  perhaps,  the  necessity  for  the 
satellites  by  which  they  are  accompanied,  and  by  whose  agency  the  light 
of  the  sun  is  reflected  to  the  planet,  and  the  deficiency  in  some  measure 
compensated. 

In  proceeding  from  a  luminous  body,  rays,  cones,  or  pencils  of  light 
must  traverse  intermediate  bodies,  in  order  to  reach  the  eye.  These 
bodies  are  called  media.  Air  is  the  common  medium;  and  when,  in 


208 


SENSE  OF  SIGHT. 


Reflection  and  Refraction  of  Light. 


this  way,  the  light  has  attained  the  exterior  of  the  organ,  the  farther 
transmission  is  effected  through  different  transparent  humours,  which 
consequently  form  so  many  media.  In  its  course  through  media,  light 
may  remain  unmodified:  it  may  proceed  in  the  same  straight  line;  or 

it  may  meet  with  an  ob- 

Fig.  77.  stacle  which   arrests  it 

altogether,  or  reflects  it ; 
or,  again,  it  may  tra- 
verse media  of  different 
natures  and  densities, 
and  be  made  to  deviate 
from  its  original  course, 
or  be  refracted. 

When  a  ray  of  light 
falls  upon  an  opaque 
body,  as  upon  a  bright 
metallic  or  other  mirror, 
it  is  reflected  from  the 
mirror,  in  such  a  man- 
ner, that  the  angle  made 
by  the  incident  ray  with 
a  perpendicular  to  the 
surface  of  the  medium 
at  the  point  of  incidence, 
is  exactly  equal  to  that 
made  by  the  reflected  ray  with  the  same  perpendicular.  Suppose  I  J 
to  represent  a  plate  of  polished  metal,  or  glass,  rendered  opaque  by  a 
metal  spread  upon  its  posterior  surface,  as  in  the  common  looking-glass. 
The  rays,  proceeding  from  an  observer  at  K,  will  be  reflected  back  to 
him  in  the  same  line  K  C ;  that  is,  in  a  line  perpendicular  to  C,  the 
point  of  incidence.  The  observer  will,  therefore,  see  his  own  image; 
but,  for  reasons  to  be  mentioned  hereafter,  under  optical  illusions,  he 
will  seem  to  be  as  far  behind  the  mirror  as  he  really  is  before  it,  or 
at  E.  Suppose,  on  the  other  hand,  that  the  observer  is  at  A,  and  that 
a  luminous  body  is  placed  at  B;  in  order  that  the  rays,  proceeding  from 
it,  shall  impinge  upon  the  eye  at  A,  it  is  necessary  that  the  latter  be 
directed  to  that  point  of  the  mirror  from  which  a  line,  drawn  to  the  eye, 
atid  another  to  the  object,  will  form  equal  angles  with  the  perpendicu- 
lar; in  other  words,  the  angle  B  C  K,  or  angle  of  incidence,  must  be 
equal  to  the  angle  of  reflection,  A  C  K.  In  this  case,  again,  the  object 
will  not  appear  to  be  at  B,  but  in  the  prolongation  of  the  line  A  C,  at 
H,  as  far  from  the  point  of  incidence  C  as  B  is. 

Except  in  the  case  of  illusions,  the  study  of  the  reflection  of  light 
or  catoptrics  does  not  concern  vision  materially.  It  is  on  the  princi- 
ples of  dioptrics,  that  the  chief  modifications  are  effected  on  the  pro- 
gress of  the  light  through  the  physical  part  of  the  organ ;  and,  with- 
out a  knowledge  of  these  principles,  the  subject  would  be  totally 
unintelligible.  It  is  necessary,  therefore,  to  dwell  at  some  length  on 
this  topic. 

Whenever  a  ray  of  light  passes  through  diaphanous  or  transparent 


LIGHT.  209 

i 

bodies  of  different  densities  it  is  bent  or  made  to  deviate  from  its 
course ;  and  such  deviation  is  called  refraction  ;  the  ray  is  said  to  be 
refracted;  and,  owing  to  its  being  susceptible  of  such  refraction,  is 
held  to  be  refrangible.  The  point,  at  which  a  ray  enters  the  medium, 
is  called  the  point  of  immersion ;  and  that,  by  which  it  issues  from 
such  medium,  the  point  of  emergence.  Instead  of  considering  the  me- 
dium I  J  opaque,  let  it  be  regarded  as  transparent.  C,  in  this  case, 
will  be  the  point  of  immersion  for  the  incident  rays  that  meet  there ; 
and  L  and  F  will  be  the  points  of  emergence  for  the  rays  K  E  and  A 
C  F  G,  respectively.  If  a  ray  of  light,  as  K  C,  falls  perpendicularly 
on  the  surface  of  any  medium,  it  continues  its  course  through  it  with- 
out experiencing  any  modification,  and  emerges  in  the  same  straight 
line.  Hence  a.  body  at  L  will  appear  in  its  true  direction  and  distance 
to  an  observer  at  K  looking  directly  downwards  on  a  pool  of  water,  I  J. 
If,  on  the  other  hand,  a  ray,  as  A  C,  after  having  passed  through  air, 
falls  obliquely  upon  the  surface  of  the  water  B ; — by  entering  a  medium 
of  different  density,  it  is  deflected  from  its  course ;  and,  instead  of  pro- 
ceeding in  the  direction  C  H,  it  is  refracted,  at  the  point  of  immersion, 
in  the  direction  C  F — that  is,  towards  the  perpendicular  K  E.  If, 
again,  the  ray  emerges  at  F  into  a  medium  of  the  same  density  as  that 
through  which  it  passed  in  the  course  A  C,  it  will  proceed  in  a  line 
parallel  to  A  C,  or  in  the  direction  F  G,  or  will  wander  from  the  per- 
pendicular. The  cause  of  this  difference  in  the  deflections  produced 
by  different  media  is  not  easy  of  explanation.  The  fact  alone  is  known 
to  us,  that  bodies  refract  light  differently  according  to  their  densities 
and  nature.  If  the  light  proceeds  from  a  rarer  to  a  denser  medium,  it 
is  attracted  or  refracted  towards  the  perpendicular ;  if,  on  the  contrary, 
it  passes  from  a  denser  to  a  rarer  medium,  it  is  refracted  from  the  per- 
pendicular. The  ray  A  C  proceeded  from  a  rarer  medium, — the  air, — 
into  a  denser,  I  J — water;  it  was  refracted  in  the  direction  C  F, 
towards  the  perpendicular  K  E.  On  emerging  at  F,  circumstances 
were  reversed ;  it  wandered  from  the  perpendicular  M  N,  and  in  the 
direction  F  G,  parallel  to  A  C,  because  the  media,  above  and  below  I 
J,  were  identical.  We  can  now  understand,  why  water,  saline  solutions, 
glass,  rock-crystal,  &c.,  have  higher  refractive  powers  than  air.  They 
are  more  dense. 

The  nature  or  character  of  bodies  greatly  influences  their  refractive 
powers.  Newton  observed  this  in  his  experiments,  and  has  furnished 
science  with  one  of  its  proudest  trophies,  by  his  prognostic,  in  the  then 
infant  state  of  chemistry,  that  water  and  the  diamond  would  be  found 
to  contain  combustible  ingredients.  The  diamond  or  brilliant  is  one  of 
the  most  refractive  of  known  substances,  and  this  is  one  of  the  sources 
of  its  brilliancy.  The  opinion  of  Newton,  it  is  hardly  necessary  to 
say,  has  been  triumphantly  confirmed. 

This  refraction  of  rays,  that  fall  obliquely  upon  a  medium,  gives  rise 
to  numerous  optical  illusions.  The  ray  proceeding  from  F,  in  the  bent 
course  F  C  A,  will  impinge  on  an  eye  at  A ;  and  the  object  F  will  ap- 
pear to  be  at/.  The  pool  will  consequently  seem  shallower.  In  like 
manner,  an  object  0  in  the  air  would  not  be  perceptible  to  an  eye  in 
the  water  at  F,  in  the  direction  0  C  F ;  whilst  one  at  A  would  be  dis- 

VOL.  I.— 14 


210  SENSE  OF  SIGHT. 

tinctly  visible, — the  ray  from  it  proceeding  in  the  direction  A  C  F,  but 
appearing  to  come  straight  to  the  eye  in  the  direction  0  C  F. 

All  transparent  bodies,  at  the  same  time  that  they  refract  light,  re- 
flect a  portion  of  it.  This  is  the  cause  of  the  reflections  we  notice  in 
the  glass  of  windows,  and  of  the  image  perceptible  in  the  eye.  The  same 
substance  has  always  the  same  refractive  power,  whatever  may  be  its 
shape: — in  all  cases,  the  sine  of  the  angle  of  refraction  holding  the 
same  ratio  to  the  sine  of  the  angle  of  incidence,  whatever  may  be  the 
incidence.  The  angle  of  incidence  is  the  angle  formed  by  the  incident 
ray  with  a  perpendicular  raised  from  the  point  of  immersion  ;  the 
angle  of  refraction  that  formed  by  the  refracted  portion  of  the  ray 
with  the  same  perpendicular.  In  Fig.  77,  A  C  K  is  the  angle  of  in- 
cidence of  the  ray  A  C ;  and  L  C  F  the  angle  of  refraction.  The 
sines  of  these  angles  respectively  are  the  lines  P  Q  and  L  F.  But 
although  media  may  refract  the  rays  of  light  equally,  the  form  of  the 
refracting  body  materially  modifies  their  arrangement.  The  perpen- 
diculars to  the  surface  may  approach  or  recede  from  each  other ;  and 
if  this  be  the  case  the  refracted  rays  will  approach  or  recede  from  each 
other  likewise. 

Where  the  body  has  plane  and  parallel  surfaces,  as  the  glass  of  our 
windows,  the  refraction,  experienced  by  the  ray  on  entering  the  glass, 
is  corrected  by  that  which  occurs  on  its  emergence ;  the  light  does  not, 
therefore,  proceed  in  one  straight  line,  but  in  parallel  lines  separated 
by  a  space  dependent  upon  the  thickness  of  the  refracting  body,  and 
the  obliquity  of  the  incident  ray.  If  the  medium  be  thin  as  in  a  pane 
of  glass,  the  rays  do  not  appear  deflected  from  their  original  direction. 
In  Fig.  77,  the  interval  between  the  direct  ray  and  the  ray  A  C  F  after 

its    emergence   is   that 

Fig.  78.  between  G  and  H.     If 

the  surfaces  of  the  dia- 
phanous body  be  plane, 
but  inclined  towards 
each  other,  as  in  the 
common  prism  ;  the  re- 
fraction experienced  by 
the  ray,  on  emerging, 
instead  of  correcting 
Prism.  that  experienced  during 

its  passage  through  the 

body,  is  added  to  it ;  and  the  rays  are  deflected  from  their  course  to  an 
extent  equal  to  the  sum  of  the  two  refractions.  The  ray  A  B,  Fig.  78, 
after  impinging  upon  the  side  D  L  of  the  prism  at  B,  instead  of  con- 
tinuing its  course  in  the  direction  B  J,  is  refracted  toivards  the  perpen- 
dicular C  B  F, — the  medium  being  denser  than  air.  and  on  emerging 
into  the  rarer  medium,  instead  of  continuing  its  course  in  the  direction 
G  I,  it  is  refracted  in  the  line  G  H,  or  from  the  perpendicular  K  J. 
Again,  if  the  surfaces  of  the  medium  be  convex,  the  rays  are  so  situate, 
after  refraction,  as  to  converge  behind  the  refracting  body  into  a  point 
called  the  focus,  which  is  nearer  to  the  medium  the  less  the  divergence 
of  the  rays,  or  in  other  words,  the  more  distant  the  luminous  object. 


LIGHT. 


211 


Double  Convex  Lens. 


Fig.  79  exhibits  a  pencil  of 
rays,  proceeding  from  a  ra- 
diant point  at  A,  and  meet- 
ing at  a  focus  at  B;  the 
dotted  lines  being  the  per- 
pendiculars drawn  to  the 
surface  at  the  points  of 
immersion  and  emergence. 
Lastly;  if  the  surfaces  of 
the  medium  be  concave,  as 
in  Fig.  80,  the  luminous 

rays,  proceeding  from  a  radiant  point  as  at  A,  are  rendered  so  divergent, 
that  if  we  look  for  a  focus  here  it  must  be  anterior  to  the  medium  or 
at  Gr. 

A  knowledge  of  these  facts  has  given  occasion  to  the  construction 
of  numerous  invaluable  optical  instruments,  adapted  to  modify  the 
luminous  rays  so  as  to  change  the  situation  in  which  bodies  are  seen ; 
to  augment  their  dimensions;  and  to  render  them  more  luminous  and 
visible,  when  remote  and  minute.  It  is  to  this  branch  of  science  that 
we  are  indebted  for  some  of  the  most  important  information  and  ad- 
vantages, that  we 

possess   in   the  do-  Fis-  80- 

mains  of  science  and 
art.  The  simplest 
of  these  instruments 
are  bodies  shaped 
like  a  lentil,  and 
hence  called  lenses. 
They  are  composed 
of  two  segments  of 
a  sphere.  The  me- 
dium in  Fig.  7  9  is  a 
double  convex;  that 
in  Fig.  80,  a  double 
concave  lens.  The 
manner  in  which 
they  modify  the 
course  of  the  lumi- 


Double  Concave  Lens. 


nous  rays  passing  through  them  has  been  sufficiently  described. 

The  study  of  the  refraction  of  light  leads  to  the  knowledge  of  an 
extremely  important  fact ;  which,  when  it  was  first  made  known  by 
Newton,  excited  universal  astonishment ;— that  a  ray  of  light  is  itself 
composed  of  several  coloured  rays  differing  from  each  other  in  their 
refrangibility.  If  a  beam  of  the  sun's  light  be  admitted  through  the 
hole  of  a  window-shutter,  E  F,  Fig.  81,  into  a  dark  chamber,  it  will 
proceed  in  a  direct  line  to  P,  and  form  a  white  spot  upon  the  wall,  or 
on  a  whitened  screen  placed  there  for  the  purpose.  But  if  a  glass 
prism,  B  A  C,  be  placed,  so  that  the  light  may  fall  upon  its  surface, 
C  A,  and  emerge  at  the  same  angle  from  its  second  surface,  B  A,  in 


212 


SENSE  OF  SIGHT. 


Violet 

Indigo 

Blue 

Green 

Yellow 

Orange 

Red 


White 


the  direction  g  G,  the  beam  will  expand ;  and  if,  after  having  emerged, 

it  be  received  on  the 
whitened  screen,  M 
N,  it  will  be  found  to 
occupy  a  considera- 
ble space ;  and,  in- 
stead of  the  white 
spot,  there  will  be  an 
oblong  image  of  the 
sun,  K  L,  consisting 
of  seven  colours  ; — 
red,  orange,  yellow, 
green,  blue,  indigo, 

•;'.'•••''  and  violet.     Each  of 

these  colours  admits 
of  no  farther  decom- 

Prismatic  Spectrum.  position  when    again 

passed    through    the 

prism ;  and  the  whole  lengthened  image  of  the  sun  is  called  the  pris- 
matic or  solar  spectrum.  In  this  dispersion  of  the  coloured  rays,  it 
will  be  observed  that  the  red  ray  is  the  least  turned  from  its  course ; 
and  is  hence  said  to  be  the  least  refrangible ;  whilst  the  violet  is  most  so. 
Such  is  the  spectrum,  as  depicted  by  Newton:  since  his  time,  it  has,  by 
some,  been  reduced  to  three  colours, — red,  yellow,  and  blue;  as  certain 
of  the  colours  can  be  composed  from  others, — the  green,  for  example,  from 
the  blue  and  yellow.  Wollaston  made  it  to  consist  of  four;  red,  green, 
blue,  and  violet;  Sir  J.  Herschel  of  four;  red,  yellow,  blue,  and  violet: 
and,  more  recently,  Sir  David  Brewster  has  restricted  it  to  three;  red, 
yellow,  and  blue.  The  causes  which  have  led  to  these  various  divisions, 
it  is  not  our  province  to  explain. 

Each  of  the  rays,  of  which  the  spectrum  is  composed,  appears  to 
have  a  different  calorific  and  chemical  action ;  but  this  also  is  a  subject, 
that  nowise  concerns  the  function  under  consideration. 

The  decomposition  of  light  into  its  constituent  rays  enables  us  to 
explain  the  cause  of  the  colour  of  different  substances.  When  white 
light  impinges  upon  a  body,  the  body  either  absorbs  all  the  rays  that 
compose  it ;  reflects  all ;  or  absorbs  some,  and  reflects  others.  If  it 
reflects  the  whole  of  the  light  to  the  eye,  it  is  of  a  white  colour;  if  it 
absorbs  all,  or  reflects  none,  it  is  black;  if  it  reflects  only  the  red  ray, 
and  absorbs  all  the  rest,  it  is  red;  and  so  of  the  other  colours.  The 
cause,  why  one  body  reflects  one  ray,  or  set  of  rays,  and  absorbs 
others,  is  unknown.  It  is  conceived  to  be  owing  to  the  nature  and 
particular  arrangement  of  its  molecules;  which  is  probable.  But  we 
are  still  as  much  in  the  dark  as  ever.  It  is  accounting  for  the  ignotum 
per  ignotius. 

Two  other  points  require  a  brief  notice,  being  intimately  concerned 
in  vision ; — the  aberration  of  sphericity,  and  aberration  of  refrangibility. 
It  has  been  remarked,  that  rays  of  light — after  passing  through  a  con- 
vex lens,  or  medium  whose  surfaces  are  convex — converge,  and  are 
brought  to  a  focus  behind  it.  The  whole  of  the  rays  do  not,  however, 


LIGHT.  213 

meet  in  this  focus.  Those  that  are  nearest  the  axis,  R"  F  of  the  lens, 
Fig.  82,  are  refract- 
ed to  a  focus  more  Fis-  8'2- 
remote  from  the  lens, 
than  those  that  fall 
on  the  lens  at  a  dis- 
tance from  the  axis. 
The  rays  R',R",  and 
E/",  are  brought  to  a 
focus  at  F,  whilst  the 
rays  R  L,  and  R"", 
I/  converge  at  the 

point  I,  much  nearer  Aberration  of  Sphericity. 

the   lens.      In   like 

manner,  rays  which  fall  upon  the  lens  intermediate  between  the  rays  R 
and  R',  will  have  their  foci  intermediate  between  I  and  F.  This  diver- 
sity of  focal  distances  is  called  spherical  aberration  or  aberration  of 
sphericity:  the  distance  I  F  is  the  longitudinal  spherical  aberration; 
and  B  A  the  lateral  spherical  aberration,  of  the  lens.  This  aberration 
is  the  source  of  confusion  in  common  lenses ;  and  as  it  is  dependent 
upon  the  shape  of  the  lens,  it  has  been  obviated  by  forming  these  instru- 
ments, of  such  degrees  of  curvature,  that  the  rays,  falling  upon  the 
centre  or  margins  of  the  lens,  may  be  refracted  to  the  same  focus. 
This  is  effectually  accomplished  by  lenses,  whose  sections  are  ellipses 
or  hyperbolas.  In  a  common  lens,  the  inconvenience  is  obviated  by 
employing  lenses  of  a  small  number  of  degrees,  or  by  interposing  an 
opaque  body — called,  by  the  opticians,  a  diaphragm — anterior  to  the 
lens,  so  that  the  rays  of  light  can  only  impinge  upon  the  central  part, 
and  consequently  be  refracted  to  the  same  focus.  This  diaphragm  is 

S:esent  in  all  telescopes,  and  occupies  the  situation  of  the  curves  D  and 
',  so  as  only  to  admit  the  rays  R',  R",  and  Rw,  to  fall  upon  the  lens. 
Such  an  apparatus,  we  shall  find,  exists  in  the  human  eye. 

Lastly, — it  has  been  already  observed,  that  the  different  rays,  con- 
stituting the  solar  spectrum,  are  unequally  refrangible, — the  red  being 
the  least,  the  violet  the  most  so;  hence  the  cause  of  their  dispersion  in 
the  spectrum.  It  follows  from  this  fact,  that,  whenever  light  expe- 
riences refraction,  there  must  be  more  or  less  dispersion  of  its  consti- 
tuent rays;  and  the  object,  seen  by  the  refracted  ray,  will  appear 
coloured.  This  must,  of  course,  occur  more  particularly  near  the 
margins  of  the  lens,  where  the  surfaces  become  less  and  less  parallel 
until  they  meet.  The  inconvenience  resulting  from  this  dispersion  is 
called  the  aberration  of  refrangibility  or  chromatic  aberration,  and  it 
has  been  attempted  to  be  obviated  by  glasses,  which  have  been  termed, 
in  consequence,  achromatic.  These  are  made  by  combining  transparent 
bodies  of  different  dispersive  powers,  in  such  sort,  that  they  may  com- 
pensate each  other;  and  thus  the  object  be  seen  in  its  proper  colours, 
notwithstanding  the  refraction.  Dr.  Blair  found,  for  example,  that 
by  enclosing  chloride  of  antimony,  B  E,  between  two  convex  lenses  of 
crown  glass,  A  D  and  C  F,  the  parallel  rays  R  R,  and  R  were  refracted 
to  a  single  focus  at  P  without  the  slightest  trace  of  secondary  colour. 


214 


SENSE  OF  SIGHT. 


Fjg-  83- 


ABC 


DEF 


Aberration  of  Refrangibility. 


Newton  was  of  opinion, 
that  the  light,  in  travers- 
ing a  refracting  medium, 
always  experiences  a  dis- 
persion of  its  rays,  pro- 
portional to  its  refraction. 
He  therefore  believed, 
that  it  would  be  impos- 
sible to  fabricate  an 
achromatic  glass.  This 
is  one  of  the  rare  cases 
in  which  that  illustrious 
philosopher  erred.  Since 
his  time  —  and  chiefly  by 
the  labours  of  Mr.  Dollond  —  instruments  have  been  formed  on  the  prin- 
ciples above  mentioned,  so  as  to  greatly  diminish  the  inconveniences 
sustained  from  the  use  of  common  lenses;  although  they  may  still  not 
be  perfectly  achromatic.  The  inconvenience  is  farther  obviated  by  the 
diaphragm  in  telescopes,  already  referred  to.  As  the  dispersion  is  most 
experienced  near  the  margin  of  the  lens,  it  shuts  off  the  rays,  which 
would  otherwise  fall  upon  that  portion,  and  diminishes  the  extent  of 
aberration.  The  human  eye  is  achromatic.  It  is  obviously  essential 
that  it  should  be  so;  and  this  result  is  owing  to  a  combination  of  causes. 
It  is  formed  of  media  of  different  dispersive  powers.  Its  lens  is  con- 
stituted of  layers  of  different  densities,  and  it  is  provided  with  a  dia- 
phragm of  singularly  valuable  construction. 

Such  are  the  prominent  points  of  the  beautiful  science  of  optics,  that 
chiefly  concern  the  physiologist  as  an  introduction  to  vision.  Others 
will  have  to  be  adverted  to,  as  we  consider  the  eye  in  action. 

2.   ANATOMY  OF  THE  ORGAN  OF  VISION. 

The  human  eye  is  almost  spherical,  except  for  the  prominence  at  its 
anterior  and  transparent  part  —  the  cornea.  It  has  been  compared  to 
a  telescope,  and  with  much  propriety  ;  as  many  of  the  parts  of  that 

instrument  have  been  added  to  exe- 
cute special  offices,  which  are  admi- 
rably performed  by  the  eye  —  the  most 
perfect  of  all  optical  instruments. 
Every  telescope  consists,  in  part, 
of  a  tube,  which  always  comprises 
pieces,  capable  of  readily  entering 
into  each  other.  Within  this  cylinder 
are  glasses  or  lenses,  placed  in  suc- 
cession from  one  extremity  to  the 
other.  These  are  intended  to  re- 
Front  View  of  the  Left  Eye-moderately  fract  the  rays  of  light,  and  to  bring 
opened.  them  to  determinate  foci.  Within 

i.  Superciiia.    s.  cilia  of  each  eyelid     3.  the  telescope  is  a  kind  of  partition 

Inferior  palpebra.    4.  Internal  canthus.    5.  Kx-        „  ,     .  , 

ternal  canthus.    6.   Caruncula  lachrymalis.    7.    01    paper    Or    metal,   having    a    round 
Plica  semilunaris.    8.  Eyeball.    9.  Pupil.  ftnd  usually  placed 


Fig.  84. 


ORGAN  OF  VISION. 


215 


Fig.  85. 


near  a  convex  glass,  for  the  purpose  of  diminishing  the  surface  of  the 
lens  accessible  to  the  rays  of  light,  and  thus  of  obviating  spherical 
aberration.  The  interior  of  the  tube  and  of  the  diaphragm  is  coloured 
black,  to  absorb  the  oblique  rays,  which  are  not  inservient  to  vision ; 
and  thus  to  prevent  them  from  causing  confusion.  This  arrangement 
is  nearly  a  counterpart  of  that  which  exists  in  the  eye.  The  tube  of 
the  instrument  is  represented  by  three  membranes  in  superposition, — 
the  sclerotic,  choroid,  and  retina;  the  last  receiving  the  impression  of 
light.  Within,  are  four  refracting  bodies,  situate  one  behind  the  other  ; 
and  intended  to  bring  the  rays  of  light  to  determinate  foci, — the  cornea, 
aqueous  humour,  crystalline  lens,  and  vitreous  humour.  Lastly,  in  the 
interior  of  the  eye,  near  the  anterior  surface  of  the  crystalline,  is  a 
diaphragm — the  iris,  having  an  aperture  in  its  centre — the  pupil. 
These  different  parts  demand  a  more  detailed  notice. 

1.  Coats  of  the  Eye. — Before  describing  the  coats  of  the  eye  it  may 
be  remarked,  that  the  eyeball  is  invested  with 
a  membranous  tunic,  which  separates  it  from 
the  other  structures  of  the  orbit ;  and  forms 
a  smooth,  hollow  surface  by  which  its  motions 
are  facilitated.  This  investment  has  been 
variously  called,  cellular  capsule  of  the  eye, 
ocular  capsule,  tunica  vaginalis  oculi,  and 
submuscular  fascia. 

The  sclerotic  is  the  outermost  proper  coat. 
It  is  that  which  gives  shape  to  the  organ,  and 
which  constitutes  the  white  of  the  eye.  It  is 

of  a  dense,  resisting,  fibrous  nature,  belonging  Side  View  of  the  same  Eye>  as 
to  what  M.  Chaussier  calls  alougineous  tissue. 
Behind,  it  is  penetrated  by  the  optic  nerve  ; 
and  before,  the  cornea  is  dovetailed  into  it. 
It  has,  by  some  anatomists,  been  considered 
a  prolongation  of  the  dura  mater,  accompany- 
ing the  optic  nerve  ;  whilst  the 
choroid  has  been  regarded  as 
an  extension  of  the  pia  mater ; 
and  the  retina  of  the  pulp  of 
the  nerve.     The  sclerotic  is  the 
place  of  insertion  for  the  various 
muscles  that  move  the  eyeball, 
and  is  manifestly  intended  for 
the  protection  of  the  internal 
parts  of  the  organ. 

Immediately  within  the  scle- 
rotica,  and  feebly  united  with  it 


in  Fig.  84,  showing  that  the 
Cilia  of  the  Upper  Lid  are  con- 
cave upwards,  and  those  of  the 
Lower  Lid  concave  down- 
wards. The  general  Convexity 
of  the  Eyeball  is  seen. 

Fig.  86. 


Choroid  Coat  of  the  Eye. 

Curved  lines  marking  the  arrangement  of  venae 
vorticosce.    2,  2.  Ciliary  nerves.    3.  A  long  ciliary  ar- 


by  vessels,  nerves,  and  areolar 
tissue,1  is  the  choroid  coat; — a 

n,       ,1   •  i  ,  vui  iiuusue.     -&.-&,   Binary  nerves,     o.  A  mug  umaiy  ctr- 

SOlt,  tiim,  VaSCUlar,  and  nerVOUS    tery  and  nerve.    4.  Ciliary  ligament.    5.  Iris.    6.  Pupil. 

1  In  the  situation  of  this  areolar  tissue,  Arnold  describes  a  serous  membrane,  Spinnwebenhaut 
JLrachnoidea  oculi,  Lamina  fusca  sderotica — Arnold  uber  das  Auge,  Tab.  iii.,  Fig.  2,  and  Weber's 
Hildebrandt's  Haridbuch  der  Anatomic,  iv.  68,  Braunschweig,  1832. 


216 


SENSE  OF  SIGHT. 


membrane.  It  completely  lines  the  sclerotic ;  and  has,  consequently, 
the  same  shape  and  extent.  Behind,  it  is  perforated  by  the  optic  nerve ; 
before,  it  has  the  iris  united  with  it ;  and  within,  it  is  lined  by  the 
retina,  which  does  not,  however,  adhere  to  it, — the  black  pigment  sepa- 
rating them  from  each  other.  It  is  chiefly  composed  of  the  ciliary 
vessels  and  nerves,  and  consists  of  two  distinct  laminae,  to  the  innermost 
of  which  Ruysch — the  son — gave  the  name  membrana  Ruyschiana. 
In  fishes  these  laminse  are  very  perceptible,  being  separated  from  each 
other  by  a  substance,  which  M.  Cuvier  considers  to  be  glandular.  The 
choroid  is  impregnated  and  lined  by  a  dark-coloured  mucous  pigment, 
stratum  pigmenti,  pigmentum  nigrum.  In  some  cases,  as  in  the  albino, 
Fig  87  this  substance,  which  is  exhaled  from 

the  choroid,  is  light-coloured,  ap- 
proximating to  white.  Leopold 
Gmelin1  conceives  that  it  approaches 
the  nature  of  indigo ;  Dr.  Young,2 
regards  it  as  a  mucous  substance, 
united  to  a  quantity  of  carbonaceous 
matter,  upon  which  its  colour  de- 
pends ;  and  Berzelius,3  from  his 
chemical  investigations,  considers  it 
to  consist  chiefly  of  carbon  and  iron ; 
Pigmentum  Nigmm.  but  Professor  Jacob  thinks  it  obvi- 

A.  choroid  epithelium,  with  the  ceils  filled  ouslv  an  animal  principle  sui  generis, 

with  pigment,  except  at  a.  where  the  nuclei  are  ••        V              ,     -,     •                              r      j 

visible     The  irregularity  of  the  pigment-cells  its  elements  being  OXygen,  hydrogen, 

is  seen.     b.  Grains  of  pigment.  ^QV^ATI     or>rl    •m+mrron          "Hv      ArkinVm 

B.  Pigment-cells  from  the  substance  of  the  Carbon,  ana    nitrogen.       UY.   ADJOnn 
choroid.  A  detached  nucleus  is  seen.— Magnified  found  100  DartS.  in  a  dry  State,  leave, 
320  diameters.  .                    .^          '  .        .     .£        ,,    ' 

when   incinerated,   4-46    of  a    calx 

consisting  of  chloride  of  calcium,  carbonate  of  lime,  phosphate  of  lime, 
and  peroxide  of  iron.  Mr.  Thomas  Wharton  Jones  has  examined  the 
layer  of  black  pigment  on  the  inner  surface  of  the  choroid  microscopi- 
cally. He  states  that  it  possesses 
organization,  and  constitutes  a 
real  membrane — pigmental  mem- 
brane— consisting  of  very  minute 
flat  bodies  of  an  hexagonal  form, 
joined  together  at  their  edges.4 
It  is  generally  considered  to  con- 
sist of  pigment  cells,  which  form  a 
kind  of  pavement,  and  are  some- 
what of  a  polyhedral  shape; 
lying  in  a  very  regular  manner, 
with  some  intercellular  substance 
between  them. 

On  the  outer  side  of  the  bottom 


1.  Terminatins 
2.  Foramen  of  S 
Crystalline  lens. 


Retina. 

anteriorly   in  a  scalloped  border, 
immering.    3.  Zonula  ciliaris.    4. 


1  Dissert.  Sistens  Indagationem  Chemicam  Pigment!  Nigri  Oculorum  Taurorum,  Getting., 
1812. 

2  Medical  Literature,  p.  521,  Lond.,  1813.  3  Medico-Chirurg.  Trans.,  iii.  225. 

*  Art.  Eye,  by  Dr.  Jacob,  in  Cyclop,  of  Anat.  and  Physiol.,  Part  x.  p.  181,  for  June,  1837. 


ORGAN  OF  VISION. 


217 


a  small  shining  space,  destitute  of  pigment,  through  which  the  colours 
of  the  membrana  Ruyschiana  appear.  This  is  termed  tapetum.  It  is 
met  with  only  in  quadrupeds. 

The  retina  is  the  last  coat,  if  we  except  a  highly  delicate  serous 
membrane  —  discovered    by 

Dr.  Jacob,1  of  Dublin,   and  Fis-  89- 

called  after  him  Tunica  Ja- 
cobi, — which  is  interposed  be- 
tween the  retina  and  the  cho- 
roid  coat.2  It  appears  to  be 
composed  of  cylindrical,  trans- 
parent, and  highly  refractive 
bodies,  which  are  arranged 
perpendicularly  to  the  surface 
of  the  retina, — their  outer  ex- 
tremities imbedded,  to  a  great- 
er or  less  depth,  in  a  layer 
of  the  pigmentum  nigrum. 
The  only  plausible  suggestion, 
which,  according  to  Messrs. 
Kirkes  and  Paget3,  has  been 
offered,  concerning  the  use  of 
these  bodies,  is  that  of  Brticke, 
who  thinks  it  not  unlikely, 


Fig.  A.  An  Enlarged  Plan  of  the  Retina,  in  section. 


rg 
-mrrmcmf  nm  rn       side  of  the  figure,  where  the  objects  are  disturbed,  t 

pigmentum  m-    win  cones  pr»ject  'likepapill£e;  a^  ff)  the  small  rods  b'eing 


he 


in  a  great  measure  lost  at  this  place.     And  these  (small 

f    TT    -,1  4    -,  ,v>  i      bodies)  are  seen  to  become  horizontal  towards  the  extre- 

01     ±lUll,      liaS    affirmed,    mity  of  the  object,  h,  where  some  are  in  disorder. 


1.  The  nervous  structure,  viz.,  the  nerve-fibres  (&)  be- 
that  they  may  Serve  tO  COn-  twcennerve-oella  («,«).  2.  Jacob's  membrane.  3.  Inner 
T  i  i  ,  ,1  •••  surface  of  choroid.  d.  One  of  the  small  pointed  bodies  of 

duct      back     tO     the      Sensitive    Jacob's  membrane. 

portion   of  the   retina  those  Fig  B   The  Outer  Surface  of  Jacob,s  Membrane. 

rays  of  light  which  have  tra-  (From  Hannover.) 

Versed     that     membrane,  and  Opposite  e,  the  twin  cones  are  obscurely  seen,  not  being 

,      r  i  in  focus,  while,  at  the  lower  part  of  the  figure,  near/,  the 

not     been     entirely  ab-  same  bodies  are  clearly  discernible.     Towards  the  riht 
\\\r 

by 

Mr.  GreOrge  H.   Field- 
ing, 

that  immediately  behind  the 
retina,  and  in  connexion  with  it,  there  is  a  peculiar  membrane,  separable 
into  distinct  layers  from  the  choroid,  and  supplied  with  bloodvessels, 
which  he  proposes  to  name  membrana  versicolor.  He  presumes,  that 
it  receives  the  vibrations  of  light,  and  communicates  them  to  the  retina: 
the  eyes,  used  for  experiment,  were  those  of  the  ox  and  sheep. 

The  retina  lines  the  choroid,  and  is  a  soft,  thin,  pulpy,  and  grayish 
membrane,  formed  chiefly,  if  not  wholly,  by  the  final  expansion  of  the 
optic  nerve.  M.  Kibes,5  indeed,  esteems  it  a  distinct  membrane,  on 
which  the  optic  nerve  is  distributed;  —  a  structure  more  consistent 

1  Philosoph.  Transact,  for  1819;  Medico-Chimrg.  Transactions,  xii.,  Lond.,  1823,  and  Art. 
Eye,  in  Cyclop,  of  Anat.  and  Phys.,  p.  186. 

2  Philosophical  Transactions  for  1829,  p.  300. 

3  Manual  of  Physiology,  American  edition,  p.  405,  Philadelphia,  1849. 

4  Second  Report  of  the  British  Association  for  the  Advancement  of  Science;  or  Amer. 
Journal  of  the  Med.  Sciences,  Nov.,  1833,  p.  220. 

s  Memoir,  de  la  Societe  Medicale  d'Emulation,  vii.  86. 


218 


SENSE  OF  SIGHT. 


with  analogy.  On  its  inner  surface  it  is 
in  contact  with  the  membrane  of  the  vitre- 
ous humour;  but  they  are  not  adherent. 
Anteriorly,  it  terminates  near  the  ante- 
rior extremity  of  the  choroid,  forming  a 
kind  of  ring,  from  which  an  extremely 
delicate  lamina  is  given  off.  This  is  re- 
flected upon  the  ciliary  processes;  dips  into 
the  intervals  separating  them,  and,  accord- 
ing to  some  anatomists,  passes  forward 
as  far  as  the  crystalline.  Modern  ob- 
^  servers — Messrs.  B.  C.  R.  Langenbeck, 

Part  of  the  Retina  of  a  Frog  seen    m  >->,    .        ,          TT  n  -r\      TT 

from  the  outer  surface?          Treviranus,    Gottsche,    Volkmann,   E.    H. 
Magnified  300  times.   (Treviranus.)  Weber,    Michaelis,    and    others,    have    ex- 
amined minutely  into  the  anatomy  of  the 

retina,  and  have  shown  that  it  consists  of  several  layers : — Langenbeck 
says  three;  Michaelis,  four.  The  outer  layer  of  the  true  retina  is  con- 
sidered to  be  formed  by  the  optic  nerve,  which,  at  its  entrance  into  the 
eye,  divides  into  numerous  small  fasciculi  of  ultimate  fibrils,  that 
spread  themselves  out,  and  inosculate  with  each  other  by  an  inter- 
Fig.  91. 


Vertical  Section  of  the  Human  Retina  and  Hyaloid  Membrane. 

h.  Hyaloid  membrane,  h' .  Nuclei  on  its  inner  surface,  c.  Layer  of  transparent  cells,  connecting 
the  hyaloid  and  retina,  c'.  Separate  cell  enlarged  by  imbibition  of  water,  n.  Gray  nervous  layer, 
with  its  capillaries.  1.  Its  fibrous  lamina.  2.  Its  vesicular  lamina.  1'.  Shred  of  fibrous  lamina  de- 
tached. 2'.  Vesicle  and  nucleus  detached,  g.  Granular  layer.  3.  Light  lamina  frequently  seen,  g' . 
Detached  nucleated  particle  of  the  granular  layer,  m.  Jacob's  membrane,  m1 .  Appearance  of  its  par- 
ticles, when  detached,  in" .  Its  outer  surface. — Magnified  320  diameters. 

change  of  fibrils,  so  as  to  form  a  net-like  plexus.  From  this  plexus,  the 
fibres  of  which  lie  in  the  plane  of  the  surface  of  the  vitreous  humour, 
a  very  large  number  of  fibrils  arises  in  a  direction  perpendicular  to 
the  surface,  so  as  to  be  all  directed  towards  the  centre  of  the  eye. 
These  pass  through  a  delicate  layer  of  areolar  tissue,  containing  a 
minute  plexus  of  bloodvessels,  and  from  this  every  fibril  receives  a 
sheath,  which  envelopes  its  extremity,  and  thus  forms  a  minute  papilla. 
The  surface  of  the  retina,  in  contact  with  the  vitreous  humour,  is 
wholly  composed  of  these  papillae,  which  are  closely  set  together.  Dr. 


ORGAN  OF  VISION. 


219 


Frog,  seen  from 
the  side  turned  to- 
wards the  vitreous 
humour. 

The  four  higher    rows 


Fig.  93. 


Carpenter1  thinks  there  can  be  little  doubt  that  Fig.  92. 

they  are  identical  with  the  globules  of  the  retina  of 
Weber.  The  diameter  of  these  globules  in  man, 
according  to  Weber,  is  from  the  s^^th  to  s^Tjth 
of  an  inch. 

About  a  sixth  of  an  inch  on  the  outside  of  the 
optic  nerve,  and  in  the  direction  of  the  axis  of  the 
eye,  or  of  a  line  drawn  perpendicularly  through  the  Pa£e 
centre  of  the  cornea,  is  a  yellow  spot,  about  a  line 
in  extent,  having  a  depression  in  its  centre.     This 
spot  and  depression  are  the  limbus  luteus  or  ma- 
cula lutea,   and  foramen  centrale  of  Sommering.2 
The  yellow  spot  does  not  exist  in  the  foetus;3  and 
the  folds,  described  by  Sommering  as  surrounding 
the  yellow  spot,  would  appear  to  be  a  post  mortem  appearance.     In 
the  examination  of  two  convicts,  three  hours  after  execution,  the  fora- 
men was  not  seen  satisfactorily.4 

The  retina  receives  many  blood-vessels, 
which  proceed  from  the  central  artery  of 
the  retina,  or  of  Zinn.  This  vessel  —  it 
is  important  to  observe  —  enters  the  eye 
through  the  centre  of  the  optic  nerve,  the 
porus  options,  and,  before  passing  directly 
through  the  vitreous  humour,  sends  off  late- 
ral branches  to  the  retina. 

2.  Diaphanous  parts  of  the  Eye.  —  The 
parts  that  act  as  refracting  bodies,  are 
either  transparent  membranes,  or  fluids  con- 
tained in  capsules,  which  give  them  a  fixed 
shape.  These  parts  are  the  cornea,  aqueous 
humour,  crystalline,  and  vitreous  humour. 

The  cornea  is  the  convex  transparent 
part  of  the  eye,  advancing  in  front  of  the 
rest  of  the  organ,  as  a  watch-glass  does 
before  the  case  ;  and  appearing  like  the 
segment  of  a  smaller  sphere  superadded 
to  a  larger.  It  was,  for  a  long  time,  con- 

sidered  tO   be    a   prolongation   of  the  Scle-    Plan  of  the  Structures  in  the  Fore  Part 
•i  ,-,        L  .,,     ,,        ,.     . 

rotic  ;    but   they  are   manifestly  distinct 


of  the  Eye,  seen  in  section. 


r                     •,                                  iii  1-    Conjunctiva.      2.    Sclerotica.      3. 

membranes,   being   separable   by  macera-  cornea.  4.  choroid.  5. 

tion.      The   posterior  surface  is  concaye,  ^fl/S^ 

and,  between  it  and  the  iris,  is  the  small  %*$>y-f&$£8?£?%g$:  {?; 

Space     OCCUpied     by    the     aQUeOUS     humOUr,  Membrane  of  the  aqueous  humour  (too 

11     j            .       •           77             j?    ,^                     mi  thick),     a.  Aqueous  humour:   anterior 

called  anterior  chamber  of  the  eye.    The  chamber  and  fa)  posterior  chamber,  b 

cornea  is  generally  considered  to  be  com-  Crystalline  lens-  c-  vitreous  humour- 

1  Human  Physiology,  p.  262,  Lond.,  1842. 

2  Sommering,  in  Comment.  Societ.  Getting.,  torn.  xiii.  1795-98;  A.  ab  Ammon,  de  Genesi 
et  Usu  Maculae  Lutese,  &c.,  Vinar.,  1830. 

3  Rudolphi,  Grundriss  der  Physiologic,  B.  ii.  Abtheil,  1,  s.  176,  Berlin,  1823. 

<  W.  E.  Homer,  Special  and  General  Anatomy,  5th  edit.,  p.  426,  Philad.,  1839,  and  J. 
Pancoast,  in  Wistar's  Anatomy,  8th  edit.,  Philad.,  1842. 


220 


SENSE  OF  SIGHT. 


Fig.  94. 


Posterior  Segment  of  Transverse  Sec- 
tion of  the  Globe  of  the  Eye  seen 
from  within. 

1.  Divided  edge  of  three  tunics.  The 
membrane  covering  the  whole  internal 
surface  is  the  retina.  2.  Entrance  of 
optic  nerve  with  arteria  centralis  retina 
piercing  its  centre.  3,  3.  Ramifications 
of  arteria  centralis.  4.  Foramen  of 
Sommering,  in  centre  of  axis  of  eye  ; 
the  shade  from  sides  of  the  section  ob- 
scures the  limbus  luteus  which  sur- 
rounds it.  5.  A  fold  of  the  retina,  which 
generally  obscures  the  foramen  of  Som- 
mering after  the  eye  has  been  opened. 


posed  of  several  thin  laminae  in  superposi- 
tion, which  have  been  compared  to  horn  ; 
and  hence  the  name  of  the  membrane  : 
but  Mr.  T.  Wharton  Jones1  denies  this,' and 
describes  it  as  consisting  merely  of  inter- 
weaving bundles  of  fibres.  Like  corneous 
tissue  in  general,  it  possesses  neither  blood- 
vessels nor  nerves.  In  animals,  the  dens- 
ity and  convexity  of  the  cornea  vary  with 
the  media  in  which  they  live,  and  with 
the  condition  of  the  other  refractive  parts 
of  the  eye.  In  old  age,  the  membrane 
is  harder,  tougher,  and  less  transparent 
than  in  youth  ;  and  it  frequently  becomes 
completely  opaque  in  its  circumference, 
presenting  the  appearance  called  arcus 
senilis, — in  German,  Crreisenbogen. 
Nerves  have  been  traced  into  the  sub- 
stance of  the  cornea.  They  are  ramifica- 
tions of  the  ciliary.2 

The  aqueous  humour  is  a  slightly  viscid 
fluid,  which  occupies  the  whole  of  the  space 
between  the  posterior  surface  of  the  cornea 

Fig.  95. 


Vertical  Section  of  the  Sclerotic  and  Cornea,  showing  the  continuity  of  their  tissue  between  the 

dotted  lines. 

a.  Cornea,  b.  Sclerotic.  In  the  cornea,  the  tubular  spaces  are  seen  cut  through,  and  in  the  sclero- 
tic, the  irregular  areolse.  Cell-nuclei,  as  at  c,  are  seen  scattered  throughout,  rendered  more  plain  by 
acetic  acid. — Magnified  320  diameters. 

and  the  anterior  surface  of  the  crystalline.  This  space  is  divided  by 
the  iris  into  two  chambers — an  anterior  and  a  posterior — the  latter 
being  the  small  interval  between  the  hinder  surface  of  the  iris,  and 
the  anterior  surface  of  the  crystalline.  Sir  David  Brewster3  erro- 
neously asserts  that  the  posterior  chamber  contains  the  crystalline  and 

1  Introduction  toW.  Mackenzie's  Practical  Treatise  on  Diseases  of  the  Eye,  Lond.,  1840. 

2  Lond.  Med.  Gaz.,  Oct.,  1845,  cited  from  Miiller's  Archiv. 

3  A  Treatise  on  Optics,  edit,  cit.,  p.  241. 


ORGAN  OF  VISION. 


221 


vitreous  humours  ;  and  Dr.  Fis-  96> 

Arnott,1  that  the  anterior 
and  posterior  chambers  of 
the  eye  are  the  compart- 
ments before  and  behind 
the  crystalline.  Anato- 
mists are  not  agreed,  whe- 
ther the  aqueous  humour 
have  a  proper  membrane, 
which  secretes  it  5  or  whe- 
ther it  be  not  an  exhalation 
from  the  vessels  of  the  iris 
and  ciliary  processes.  M. 
Kibes  derives  it  from  the 
vitreous  humour.  Howso- 
ever secreted,  it  is  very 
rapidly  regenerated  when 
evacuated  ;  as  it  must  be 
in  every  operation  for  cata- 
ract by  extraction.  It  is 
not  lodged  in  cells ;  and 
hence  readily  flows  out 
when  the  cornea  is  punc- 
tured. The  quantity  of 
aqueous  humour,  in  the 
adult,  is  about  five  or  six 
grains.  Its  specific  gravity  is  not  rigorously  determined,  but  it  differs 
slightly  from  that  of  water,  being  a  little  greater.  According  to  Berze- 
lius,  it  is  composed  of  water,  98'10;  a  little  albumen;  chlorides  and 
lactates,  1*1.5 ;  soda,  with  a  substance  soluble  in  water,  0*75. 

The  crystalline  lens  is  a  small  body,  of  a  crystalline  appearance,  and 
lenticular  shape, — whence  its  name.  It  measures,  in  the  adult,  about 
1*33  of  an  inch  in  its  greatest  circumference;  and  is  about  2J  lines 
thick  at  the  centre.  It  is  situate  between  the  aqueous  and  vitreous 
humours  ;  and  at  about  one-third  of  the  antero-posterior  diameter  of  the 
organ.  A  depression  at  the  anterior  surface  of  the  vitreous  humour 
receives  it ;  and  a  reflection  of  the  proper  membrane  of  the  humour 
passes  over  it.  The  crystalline  is  surrounded  by  its  capsule,  the  inte- 
rior of  which  is  bathed  by  a  slightly  viscid  and  transparent  secretion, 
called  liquor  Morgagnii.  The  lens  is  more  convex  behind  than  before ; 
the  radius  of  its  anterior  surface  being,  according  to  Sir  David  Brews- 
ter,2  0*30  ;  and  that  of  its  posterior  surface  0*22  of  an  inch.  It  con- 
sists of  a  number  of  concentric  ellipsoid  laminae,  increasing  in  density 
from  the  circumference  to  the  centre.  Some  fibres  detach  themselves 
from  the  different  laminae;  pass  to  those  immediately  beneath,  and  consti- 
tute the  sole  bond  of  union  that  exists  between  them.  Of  old  it  was  be- 
lieved that  the  crystalline  was  of  a  muscular  structure,  and  capable  of 


Longitudinal  Section  of  the  Globe  of  the  Eye. 

1.  Sclerotic,  thicker  behind  than  in  front.  2.  Cornea,  re- 
ceived within  anterior  margin  of  sclerotic,  and  connected  with 
it  by  means  of  a  bevelled  edge.  3.  Choroid,  connected  ante- 
riorly with  (4)  ciliary  ligament,  and  (5)  ciliary  processes.  6. 
Iris.  7.  Pupil.  8.  Third  layer  of  eye,  retina  terminating  an- 
teriorly by  abrupt  border  at  commencement  of  ciliary  pro- 
cesses. 9.  Canal  of  Petit,  encircles  the  lens  (12);  the  thin 
layer  in  front  of  this  canal  is  the  zonula  ciliaris,  a  prolonga- 
tion of  vascular  layer  of  retina  to  the  lens.  10.  Anterior  cham- 
ber of  eye  containing  aqueous  humour ;  the  lining  membrane,  by 
which  the  humour  is  secreted,  is  represented  in  diagram.  11. 
Posterior  chamber.  12.  Lens,  more  convex  behind  than  be- 
fore, enclosed  in  its  proper  capsule.  13.  Vitreous  humour  en- 
closed in  hyaloid  membrane,  and  in  cells  formed  in  its  interior 
by  that  membrane.  14.  Tubular  sheath  of  hyaloid  membrane, 
which  serves  for  the  passage  of  the  artery  of  capsule  of  the 
lens.  15.  Neurilemma  of  optic  nerve.  16.  Arteria  centralis 
retinae,  embedded  in  the  centre. 


1  Elements  of  Physics,  &c.,-2d  Amer.  edit.,  vol.  ii.  P.  i.  p.  162,  Philad.,  1836. 
*  Op.  citat.,  p.  242.     See,  also,  Plulos.  Transact,  for  1835,  p.  3GO.J 


222  SENSE  OF  SIGHT. 

modifying  its  own  convexity,  so  as  to  adapt  the  eye  to  different  dis- 
tances.    This  was  the  opinion  of  Des  Cartes ;  and  it  has  more  recently 

Fig.  97.  Fig.  98.  Fig.  99. 


Lens,  hardened  in  spirit  and  par-          Front  View  of  the  Crys-    Side  View  of  the  Adult 
tially  divided  along  the  three  interior     talline  Humour  or  Lens,  in  Lens, 

planes,  as  well  as  into  lamellae. — Mag-      the  Adult. 

nified  3*  diameters.    (After  Arnold.)  a/'lt^posSr    get 

3,  3.  Its  circumference. 

been  received,  with  modifications,  by  Dr.  Young.1  Its  muscularity  is, 
however,  by  no  means  established,  although  its  fibrous  character  is  un- 
questionable. 

The  specific  gravity  of  the  human  crystalline  is  said  by  Chenevix2  to 
be  1*0790.  He  considered  it  to  be  composed  chiefly  of  albumen.  Ac- 
cording to  an  analysis,  however,  of  Berzelius,3  it  would  appear  to  con- 
tain 35*9  parts  in  the  hundred  of  a  matter  analogous  to  the  colouring 
matter  of  the  blood. 

The  vitreous  humour,  so  called  in  consequence  of  its  resemblance  to 
glass,  occupies  the  whole  of  the  cavity  of  the  eye  behind  the  crystal- 
line. It  is  convex  behind;  concave  before;  and  is  invested  by  a  deli- 
cate, thin,  transparent  membrane,  called  tunica  hyaloidea,  which  fur- 
nishes prolongations  internally,  that  divide  it  into  cells.  It  is  owing  to 
this  arrangement  of  the  membrane,  and  not  to  the  density  of  the 
humour,  that  it  has  the  tenacity  of  the  white  of  egg.  Its  density  does 
not  differ  materially  from  that  of  the  aqueous  humour ; — their  specific 
gravities  being  stated  at  1-0009,  and  1-0003  respectively.  The  cells, 
formed  by  the  hyaloid  membrane,  are  not  all  of  the  same  shape  and 
size.  They  communicate  freely  with  each  other,  and  are  well  repre- 
sented in  Fig.  96.  At  the  anterior  part,  where  the  hyaloid  membrane 
reaches  the  margin  of  the  crystalline,  it  is  separable  into  two  laminae; 
one  of  which  is  reflected  over  the  anterior;  the  other  over  the  posterior 
surface  of  the  lens.  Between  these  laminae,  and  at  their  junction 
round  the  crystalline,  a  canal  exists,  into  which  air  may  be  introduced : 
when  it  exhibits  a  plaited  arrangement,  and  has  been  called  bullular 
canal  of  Petit;4'  and,  by  the  French  writers,  canal  godronne,  or  simply 
canal  of  Petit.  This  canal  is  generally  conceived  to  be  devoid  of 
aperture;  but  Jacobson  affirms,  that  it  has,  in  its  sides,  a  number  of 

'  Philos.  Transact,  for  1793,  p.  169  ;  and  Med.  Literature,  p.  521,  Lond.,  1813. 
2  Philos.  Transact,  for  1803,  p.  195.  3  Medico-Chirurgical  Transact,  iii.  253. 

4  Mernoires  de  PAcademie  des  Sciences,  Paris,  1723  and  1728;  and  Haller.  Element. 
Physiol.,  xvi.  2,  18. 


ORGAN  OF  VISION.  223 

minute  foramina,  which  admit  the  entrance  and  exit  of  the  aqueous 
humour. 

The  composition  of  the  vitreous  humour,  according  to  Berzelius,1  is 
as  follows: — Water,  98-40;  albumen,  0*16 ;  chlorides  and  lactates,  142; 
soda,  with  an  animal  matter,  soluble  only  in  water,  0'02.  Its  absolute 
weight  is  fifteen  or  twenty  times  greater  than  that  of  the  aqueous 
humour. 

3.  It  was  remarked,  in  the  comparison  drawn  between  the  eye  and 
a  telescope,  that  a  diaphragm  exists  in  the  former,  called  iris,  and 
sometimes  uvea.  Generally,  however,  the  latter  term  is  appropriated 
to  the  posterior  lamina  of  the  iris.  By  some  anatomists,  the  iris  is 
conceived  to  be  a  prolongation  of  the  choroid;  by  others,  to  consist  of 
a  proper  membrane,  of  a  muscular  character;  and,  by  others,  again,  to 
be  essentially  vascular  and  nervous; — the  vessels  and  nerves  being  dis- 
tributed on  an  erectile  tissue.2  There  is,  in  the  views  of  anatomists 
and  physiologists,  much  discrepancy  regarding  the  structure  and  func- 
tions of  this  portion  of  the  eye.  M.  Edwards,3  of  Paris,  affirms,  that 
it  consists  of  four  laminae,  two  of  which  are  extensions  of  laminae, 
composing  the  choroid ;  a  third  belongs  to  the  membrane  of  the  aqueous 
humour,  and  is  reflected  over  its  anterior  surface;  the  fourth  is  the 
proper  tissue  of  the  iris.  M.  Magendie4  asserts,  that  the  most  recent 
anatomical  investigations  prove  the  iris  to  be  muscular,  and  composed 
of  two  sets  of  fibres; — the  outermost  radiating,  whose  office  is  to  dilate 
the  pupil ;  the  innermost  circular  and  concentric,  for  the  purpose  of 

Fig.  100.  Fig.  101. 


Internal  View  of  the  Iris.  External  View  of  the  Iris. 

contracting  it.  The  arrangement  of  these  fibres  is  represented  in  Fig. 
100,  which  is  an  internal  view  of  the  human  iris  magnified  three  diame- 
ters; and  Fig.  101,  an  external  view,  exhibiting  the  surface  to  consist 
essentially  of  a  plexus  of  bloodvessels.  Both  are  taken  from  the  mi- 
croscopic investigations  of  Mr.  Bauer,  and  Sir  Everard  Home.5  These 
vessels  and  nerves  are  ramifications  of  the  ciliary, — the  nerves  arising 
from  the  ophthalmic  ganglion  and  nasal  branch  of  the  fifth  pair. 

1  Medico-Chirurgical  Transactions,  iii.  253. 

2  Lepelletier,  Physiologie  Medicale  et  Philosophique,  torn.  iii.  p.  158,  Paris,  1832. 

3  Bullet,  de  la  Societe  Philom.,  etc.,  1814,  p.  81.  4  Op.  citat.,  i.  61. 

6  Lectures  on  Comparative  Anatomy,  Lond.,  1814-1828;  and  Mr.  Bauer,  Philosophical 
Transactions  for  1822,  p.  78 


224 


SENSE  OF  SIGHT. 


Fig.  102. 


Fig.  103. 


A  representation  of  some  of  the  Nerves  of  the 
Orbit,  especially  to  show  the  Lenticular  Ganglion. 
(Arnold.) 

1.  Ganglion  of  the  fifth.  2.  Ophthalmic  nerve.  3. 
Upper  maxillary.  4.  Lower  maxillary.  5.  Nasal 
branch,  giving  the  long  root  to  the  lenticular  ganglion. 
6.  Third  nerve.  7.  Inferior  oblique  branch  of  the  third 
connected  with  the  ganglion  by  the  short  root.  8.  Optic 
nerve.  9.  Sixth  nerve.  10.  Sympathetic  on  the  caro 
tid  artery. 


Fig.  104. 


Segment  of  the  Anterior  Face  of  the 
Iris  with  its  Vessels  injected. — Magnified 
25  diameters. 

1,  1.  Portion  of  the  pupillary  circumfer- 
ence of  the  iris.  2,2.  Part  of  its  greater  cir- 
cumference surrounded  by  a  branch  of  the 
long  ciliary  artery.  3.  Part  of  the  lesser  circle 
of  the  iris.  4,  4.  Part  of  its  greater  circle. 
5,  5.  Three  arteries  which  are  larger  than  the 
others,  and  coming  from  the  greater  circle  are 
lost  in  the  iris.  6.  Smaller  arteries  arising 
from  these.  7.  Branches  of  the  larger  arte- 
ries, which  are  lost  in  the  smaller  circle  of 
the  iris.  An  outline  of  the  natural  size  of 
this  piece  is  seen  on  the  left  side  of  the  figure 
between  3  and  7. 

Berzelius,1  too,  affirms,  that 
the  iris  has  all  the  chemical 
characters  of  muscle. 

The  iris  is  the  coloured  part 
of  the  eye  seen  through  the 
transparent  cornea;  and,  ac- 
cording to  the  particular  co- 
lours reflected  from  it,  the  eye 
is  said  to  be  blue,  gray,  hazel, 
&c.  In  its  centre  is  an  open- 
ing, called  pupil,  through 
which  alone  the  rays  of  light 
can  reach  the  lens.  This  open- 
ing can  be  enlarged  or  con- 

An  enlarged  View  of  the  Arteries  of  the  Iris.    (From    tracted  by  the    Contraction  Or 

dilatation  of  the  iris;  and  in 

a.  Optic  nerve,  b.  Sclerotic,  c.  Ciliary  ligament,  d.  Iris.       -  .  .       .  -.-, 

1.  Posterior   ciliary  arteries  perforating    the    sclerotic.  thlS    rCSpCCt   it    IS    perpetually 

2.  Long  (external)  ciliary  artery.     3.    Anterior  (short)  varv;T1o.     «PPnr(lino-  to 
ciliary  arteries.  (The  figure  is  larger  than  natural.)  varying,  according  IO 

1  View  of  the  Progress  of  Animal  Chemistry,  p.  86,  Lond.,  1843. 


ORGAN  OF  VISION.  225 

stances.  In  man,  the  pupil  is  circular;  but  it  differs  greatly  in  its 
dimensions  and  shape  in  different  animals.  On  the  posterior  surface 
of  the  iris,  the  uvea,  pigmentum  nigrum  exists,  as  on  the  choroid. 
This  layer  has  likewise  some  effect  in  giving  colour  to  the  eye;  in  blue 
eyes,  for  instance,  the  tissue  of  the  iris  is  nearly  white, — the  pigmentum 
which  appears  through  it,  being  the  chief  cause  of  the  coloration. 

At  the  point  of  junction  between  the  iris  and  choroid  coat,  they  are 
united  to  the  sclerotica  by  a  band  of  cellular  substance,  called  ciliary 
ligament;  and,  from  the  anterior  margin  of  the  choroid,  where  it  unites 
with  the  base  of  the  iris,  numerous  vasculo-membranous  appendages 
arise,  which  appear  to  be  prolongations  of  the  anterior  margin  of  the 
choroid,  turning  inwards  towards  the  margin  of  the  crystalline  lens,  and 
terminating  abruptly,  without  being  attached  to  that  body.  They  are 
the  ciliary  processes.  These  beautiful  appendages  are  from  sixty  to 
eighty  in  number ;  and  resemble  the  disk  of  a  radiated  flower — corpus 
ciliare.  On  their  posterior  surface,  they  are  covered  by  the  same  kind 
of  pigment  as  that  on  the  choroid  and  uvea;  and  they  impart  a  stain 
to  the  membranes  of  the  crystalline  and  vitreous  humours.  The  great- 
est diversity  of  opinion,  here  again,  exists  regarding  both  structure  and 
function.  By  some,  the  processes  have  been  esteemed  nervous;  by 
others,  muscular;1  glandular ;  and  vascular.  Sir  Everard  Home  asserts, 
on  the  authority  of  microscopic  observations  by  Mr.  Bauer,2  that  be- 
tween the  processes  are  bundles  of  muscular  fibres  of  considerable 

Fig.  105.  Fig.  106. 


Anterior  Segment  of  a  Transverse  Choroid  and  Iris,  exposed  by  turning  aside  ihe 

Section  of  the  Globe  of  the  Eye  seen  Sclerotica. 

from  within. 

c,  c.  Ciliary  nerves  branching   in  the  iris.    d.  Smaller 

1.  Divided  edge  of  the  three   tunics;  ciliary  nerve,     e,  e.  Vasa  vorticosa.     h.  Ciliary  ligament 

sclerotic,  choroid  (the  dark  layer),  and  and  muscle,    k.  Converging  fibres  of  the  greater  circle  of 

retina.    2.   Pupil.    3.   Iris,   the   surface  the  iris.     I.  Looped   and   knotted   form  of  these  near   the 

presented  to  view  in  this  section  being  the  pupil ,  with  the  converging  fibres  of  the  lesser  circle  of  the 

uvea.    4.  Ciliary  processes.    5.  Scalloped  iris  within  them.     o.  The  optic  nerve.     (From  Zinn.) 
anterior  border  of  the  retina. 

1  Hyrtl,  Lehrbuch  der  Anatomic  des  Menschen,  &<-•.,  s.  408,  Prag.,  1846. 
a  Op.  citat,  and  Philosoph.  Transact,  for  Ib32,  p.  78. 
VOL.  I. — 15 


226  SENSE  OF  SIGHT. 

length,  which  originate  all  around  from  the  capsule  of  the  vitreous  hu- 
mour ;  pass  forward  over  the  edge  of  the  lens ;  are  attached  firmly  to 
its  capsule,  and  there  terminate.  They  are  unconnected  with  the  ciliary 
processes,  or  iris,  and  he  conceives  that  their  contraction  will  pull  the 
lens  towards  the  retina.  The  existence  of  unstriped  muscular  fibres  in 
them  is  confirmed  by  the  observations  of  Wagner,  Todd  and  Bowman 
and  others.1 

Of  late,  the  ciliary  muscle  has  been  described  as  a  grayish  semi- 
transparent  ring  of  non-striated  muscular  fibres,  which  covers  the  out- 
side of  the  corpus  ciliare ;  and,  by  its  contraction,  can  draw  the  ciliary 
processes  forwards,  and  advance  the  lens.  Dr.  Clay  Wallace,2  of  New 
York,  who  was  one  of  the  early  describers  of  this  muscle,  and  did  the 
author  the  favour  to  demonstrate  it  to  him,  is  of  opinion,  that  its  fibres 
when  they  contract  compress  the  ciliary  veins,  and  thus  produce  tur- 
gescence  of  the  ciliary  processes  which  occasions  the  movement  of  the 
lens.  It  appears  to  be  the  same  muscle  as  the  -tensor  muscle  of  the 
choroid — tensor  choroidese — of  some  anatomists.3 

Such  is  an  anatomical  view  of  the  physical  part  of  the  eye  proper, 
so  far  as  is  necessary  for  the  physiological  inquirer.  We  have  yet  to 
consider  the  most  important  part  of  the  organ; — that  which  is  essen- 
tially nervous  and  vital  in  its  action ;  and  which,  as  we  have  seen,  goes 
to  constitute  one  of  the  membranes  of  the  eyeball — the  retina. 

The  optic  nerves — second  pair  of  Willis — arise  from  the  anterior  part 
of  the  optic  lobes — corpora  quadrigemina4 — and  not,  as  was  at  one  time 
universally  believed,  from  the  thalami  nervorum  opticorum.  Setting 
out  from  this  point,  they  proceed  forwards  towards  the  thalami,  to  which 
they  adhere ;  receiving  filaments  from  the  corpus  geniculatum  externum, 
an  eminence  a  little  anterior  to,  and  on  the  outside  of,  the  corpora ;  and 
from  a  layer  of  cineritious  substance,  situate  between  the  point  of  junc- 
tion of  the  nerve  of  each  side  and  the  eminentise  mammillares — called 
tuber  cinereum.5  Proceeding  forward  towards  the  eye,  the  nerves  ap- 
proach, and  form  a  junction  at  the  sella  turcica,  or  on  the  upper  surface 
of  the  sphenoid  bone.  Anterior  to  this  point,  they  diverge, — each  pass- 
ing through  the  optic  foramen  to  the  corresponding  eye;  piercing  the 
sclerotic  and  choroid  at  a  point  about  one-tenth  of  an  inch  from  the 
axis  of  the  eye  on  the  side  next  the  nose,  where  it  has  a  button-like 
appearance;  and  expanding  to  form  the  whole,  or  a  part  of  the  retina 
(see  page  215).  When  the  optic  nerve  is  regarded  from  the  inside, 
after  removing  the  retina  and  choroid,  it  appears  in  the  form  of  a  cir- 
cular spot,  perforated  with  small  holes,  from  which  medullary  matter 
may  be  expressed.  This  is  the  lamina  cribrosa  of  Albinus.  M.  Las- 

1  Baly  and  Kirkes,  Recent  Advances  in  the  Physiology  of  Motion,  the  Senses,  Generation 
and  Developement,  p.  25,  Lond.,  1848. 

2  A  Treatise  on  the  Eye,  p.  53,  3d  edit.,  New  York,  1841,  and  The  Accommodation  of  the 
Eye  to  Distances,  p.  14,  New  York,  1850. 

3  Ruete,  in  Wagner's  Handworterbuch  der  Physiologic,  16te  Lieferung,  s.  297,  Braunsch- 
weig, 1847. 

4  A  Pathological  case  illustrating  this  origin,  by  G.  Kennion,  M.  D.,  is  in  Lond.  Med.  Gaz., 
Sept.,  1838. 

fi  Solly,  Lond.  Med.  Gazette,  Sept.  24,  1838. 


ORGAN  OF  VISION. 


227 


saigne  has  examined  the  chemical  Fi*-  107- 

composition  of  the  optic  nerve  and 
retina;  and  concludes,  from  his  ex- 
periments, that  the  retina  is  formed 
of  the  same  elements  as  the  cere- 
bral and  nervous  substance;  differ- 
ing only  in  the  proportion  of  con- 
stituents. 

It  is  a  question  that  has  often  been 
agitated,  whether  the  optic  nerves, 
at  their  junction  on  the  sella  turcica, 
simply  lie  alongside  each  other,  or 
decussate  so  that  the  root  of  the 
nerve  of  the  left  eye  is  on  the  right 
side,  and  that  of  the  right  on  the  left. 
Anatomical  investigations  have, 
hitherto,  left  the  question  unsettled; 
and  pathology  appears^  to  have  fur- 
nished proofs  on  both  sides.  Thus,  AT 

r       .    ,  L  ,        ,  ,      ,  „   '    Optic  Nerves,  with  the  origin  of  seven  other 

where  the  right  eye  has  been  lost  for  Pairs  of  Nerves. 

a  Considerable  time,  the  Optic  nerve  1,  I.  Globe  of  the  eye  ;  the  one  on  the  left  hand 
rif  flio  onvno  airta  Vine  hpon  fminrl  in  *  is  perfect,  but  that  on  the  right  has  the  sclerotic 

ol  the  same  side  nas  Deen  round  in  a  an^  choro'id  coats  rem0ved  m  order  to  show  the 

State  Of   atrophy  through    itS    Whole  retina.    2.  Chiasm  of  the  optic  nerves.      3.  Cor- 

-.-     L     •',  „        ,  pora  albicantia.     4.  Infundibulum.    5.  Pons  Va- 

extent.         In     Other     Cases      Of     the  rolU.    6.  Medulla  oblongata.     ~.  Third  pair.    8. 

i  •      i      ,  r  .  ,•  _/•    .1  Fourth  pair.     9.  Fifth  pair.     10.  Sixth  pair.     11. 

kind,    the    posterior    portion    OI    the  Seventh  pair.    12.  Eighth  pair.    13.  Ninth  pair, 

left   nerve  has  been  found  in  this 

condition.1  Fishes  have  the  nerve  arising  from  one  side  of  the  brain, 
and  passing  to  the  eye  of  the  other  side ;  hence  crossing,  but  not 
uniting.  On  the  other  hand,  Vesalius2  gives  a  plate  of  a  case  in  which 
he  found  the  optic  nerves  passing  to  the  eye  of  the  same  side  from  which 
they  originate,  without  touching  at  all;  and  yet  without  disturbance  of 
vision.  It  is  not  necessary,  however,  to  adduce  the  numerous  cases  that 
have  been  published  in  favour  of  the  one  view  or  the  other.  It  is  impos- 
sible to  sift  those  that  are  entitled  to  implicit  confidence  from  those  that 
are  not.  It  may  merely  be  remarked  that  certain  observations  of  Val- 
salva,  Cheselden,3  and  Petit4  appear  to  show,  that  where  the  brain  is 
injured,  it  is  the  eye  of  the  opposite  side  that  is  affected;  and,  in  cases 
of  hemiplegia  or  paralysis  of  one  side  of  the  body,  we  certainly  have 
many  instances  for  testing  the  accuracy  of  this  opinion.  Sommering5 — 
whose  correctness  as  an  observing  anatomist  has  never  been  disputed — 
affirms,  that  he  had  an  opportunity  of  examining  seven  blind  persons, 
in  all  of  whom  the  atrophy  of  the  nerve  was  on  the  side  or  root  oppo- 
site to  the  eye  affected.6 

1  Rudolphi,  Grundriss  der  Physiologic,  B.  ii,  Abth.  1,  s.  203,  Berlin,  1823. 

2  De  Corp.  Human.  Fabric.,  lib.  iv.  c.  4. 

3  Anatomy  of  the  Human  Body,  13th  edit.,  Lond.,  1792. 

4  Memoir,  de  1'Acad.,  1723  and  1728. 

6  Bltimenbach,  Med.  Bibl.,  ii.  2,  s.  368;  and  De  Decussatione  Nervorum  Opticorum, 
Mogunt.,  1786. 

«  A  case  elucidative  of  this  point  in  Lallemand,  Sur  Les  Pertes  Seminales,  or  in  Dr.  Wood's 
Translation  in  Dunglison's  American  Med.  Library  for  1839,  p.  30. 


228  SENSE  OF  SIGHT. 

Some,  again,  have  advanced  an  opinion,  that  the  decussation  is  par- 
tial, and  concerns  only  the  internal  filaments ;  that  the  other  filaments 
pass  directly  on  to  half  the  corresponding  eye ;  so  that  one-half  of  each 
eye  is  supplied  by  straight  fibres  proceeding  directly  from  the  root  of 
the  same  side;  the  other  half  by  those  resulting  from  the  decussation 
of  the  internal  fibres.  Messrs.  Wollaston,1  Berard,  Pravaz,2  Gall  and 
Spurzheim,  Cuvier,  Serres,  Vicq-d' Azyr,  Caldani,  Ackermann,  the  bro- 
thers Wenzel,  G.  R.  Treviranus,  J.  Muller,  Ruete,3  and  others,4  em- 
brace this  opinion  for  the  purpose  of  explaining  the  anomaly  of  vision 
called  hemiopia,  in  which  only  one-half  the  object  is  seen.  MM.  Cu- 
vier, Serres,  and  Caldani  assert,  that  they  have  noticed  the  above 
arrangement  in  the  nerves  of  the  horse,  when  subjected  to  appropriate 
maceration.  More  recently,  Mr.  H.  Mayo5  has  stated  that  the  optic 
nerve  consists  in  man  of  three  tracts  ;  the  innermost  of  which  is  wholly 
commissural,  connecting  the  two  retinae  anteriorly,  and  the  optic  gan- 
glia posteriorly.  The  middle  tract  decussates,  and  is  considered  by  him 
to  supply  the  part  of  the  retina  that  lies  on  the  inner  side  of  each  eye- 
ball, between  its  anterior  border  and  the  entrance  of  the  optic  nerve. 
The  external  tract,  he  affirms,  does  not  decussate,  but  passes  on  to 
supply  the  outer  portion  of  the  retina  of  the  same  side.  Hence,  the 
right  optic  nerve,  in  Mr.  Mayo's  view,  supplies  the  right  side  of  each 
eyeball ;  and  the  left  the  left.  Dr.  Wollaston  himself  was  affected  with 
hemiopia ;  and,  in  his  case,  the  loss  of  vision  was  sometimes  on  one 
side,  and  sometimes  on  the  other ;  and  he  thought,  that  the  phenomena 
might  be  explained  by  partial  decussation  of  the  optic  nerves ;  but 
Messrs.  Solly6  and  Mayo  have  known  instances  of  a  like  affection  in- 
volving alternately  the  centre  and  circumference  of  the  retina,  and 
therefore  not  attributable  to  any  such  structural  arrangement. 

These  views  are  opposed,  also,  by  the  direct  experiments  of  M.  Ma- 
gendie.7  He  divided,  in  a  rabbit,  the  right  optic  nerve,  behind  the  point 
of  decussation,  or  what  has  been  called  the  chiasm  of  the  nerves  : — 
the  sight  of  the  left  eye  was  destroyed.  On  cutting  the  left  root,  the 
sight  of  the  right  eye  was  equally  destroyed ;  and  on  dividing  the  bond 
of  union,  in  another  rabbit,  by  a  longitudinal  incision,  made  between 
the  nerves,  vision  was  entirely  abolished  in  both  eyes  ; — a  result,  which, 
as  he  properly  remarks,  proves  not  only  the  existence  of  decussation, 
but  also  that  it  is  total,  and  not  partial  as  Wollaston  had  supposed. 
Another  experiment,  which  he  instituted,  led  to  a  similar  result.  Fif- 
teen days  before  examining  a  pigeon  he  destroyed  one  eye.  The  nerve 
of  the  same  side,  as  far  as  the  chiasm,  was  wasted ;  and,  behind  the 

•  Philosophical  Transact.,  1 824,  p.  222. 

2  Archives  Generates  de  Medecine,  Mai,  p.  59,  Paris,  1825. 

3  Wagner's    Handworterbuch  der    Physiologic,   16te    Lieferung,    s.    297,  Braunschweig, 
1847. 

4  Hildebrandt's  Handbuch  der  Anatomie,  von  E.  H.  Weber,  Band.  iii.  s.  438,  Braunsch- 
weig, 1832  ;  Blumenbach,  op.  citat. ;  Sir  D.  Brewster's  Natural  Magic,  Amer.  edit.,  p.  36, 
New  York,  1833  ;  and.  Pouillet,  Elemens  de  Physique,  iii.  338,  Paris,  1832. 

6  London  Medical  Gazette,  Nov.  5,  1841. 

6  The  Human  Brain,  its  Configuration,  &e.,  p.  263,  London,  1836;  and  Carpenter's  Hu- 
man Physiology,  Amer.  edit.,  p.  246,  Philada.,  1843. 

7  Precis,  &c.,  edit.  cit..  i.  64. 


ORGAN  OP  VISION.  229 

chiasm,  the  root  of  the  opposite  side.  MM.  Rolando  and  Flourens,1 
too,  found  in  their  experiments,  that  when  one  cerebral  hemisphere  was 
removed,  the  sight  of  the  opposite  eye  was  lost.  We  may  conclude, 
then,  in  the  present  state  of  our  knowledge,  that  there  is  not  simply  a 
junction,  or  what  the  French  call  adossement,  of  the  optic  nerves ;  but 
that  they  decussate  at  the  sella  turcica.2 

The  eye  proper  receives  numerous  vessels, — ciliary  arteries  and  veins 
— and  several  nervous  ramifications, — ciliary  nerves — the  greater  part 
of  which  proceed  from  the  ophthalmic  ganglion  of  the  fifth  pair.  The 
following  are  the  dimensions,  &c.,  of  the  organ,  on  the  authority  of 
Petit,  Young,  Gordon,  and  Brewster. 

Eng.  inch. 
Length  of  the  antero -posterior  diameter  of  the  eye  •  0'9 1 


Vertical  chord  of  the  cornea   - 

Versed  sine  of  the  cornea 

Horizontal  chord  of  the  cornea 

Size  of  pupil  seen  through  the  cornea 

Size  of  pupil  diminished  by  magnifying  power  of  cornea 

Radius  of  the  anterior  surface  of  the  crystalline 

Radius  of  posterior  surface 


0-45 
0-11 
0-47 

-  027  to  0-13 

-  0-25  to  0-12 

0-30 
022 

Principal  focal  distance  of  lens        - 1*73 

Distance  of  the  centre  of  the  optic  nerve  from  the  foramen  centrale  of  * 

Sommering     ........         ...         0'11 

Distance  of  the  iris  from  the  cornea 0-10 

Distance  of  the  iris  from  the  anterior  surface  of  the  crystalline          -         -         002 


Field  of  vision  above  a  horizontal  line 
Field  of  vision  below  a  horizontal  line 
Field  of  vision  in  a  horizontal  plane 
Diameter  of  the  crystalline  in  a  woman 
Diameter  of  the  cornea 
Thickness  of  the  crystalline    -         -    ^ 
Thickness  of  the  cornea 


50°) 

70°  I  L*"~ 
150°' 

above  fifty  years  of  age       -         -         0'378 

0-400 
0-172 
0-0424 


It  is  proper  to  remark,  that  all  these  measurements  were  necessarily 
taken  on  the  dead  organ,  in  which  the  parts  are  by  no  means  in  the 
same  relative  situation  as  when  alive ;  and  this  is  a  cause  why  many 
of  the  phenomena  of  vision  can  never  be  determined  with  mathematical 
accuracy. 

3.   ACCESSORY  ORGANS. 

The  visual  organs  being  of  an  extremely  delicate  texture,  it  was  of 
obvious  importance,  that  they  should  be  guarded  against  deranging 
influences.  They  are  accordingly  provided  with  numerous  parts  that 
afford  them  protection,  and  enable  them  to  execute  the  functions  for 
which  they  are  destined.  They  are,  in  the  first  place,  securely  lodged 
in  the  bony  cavities  called  orbits,  which  are  of  a  conical  figure,  with 
the  apices  directed  inwards.  In  the  truncated  apex  the  foramen  opti- 
cum  is  situate,  by  which  the  optic  nerve  enters  the  orbit.  Here  are, 

'  Recherches  Experimental  sur  le  Systeme  Nerveux,  2de  e"dit.,  Paris,  1842. 

*  See,  on  this  subject,  Adelon,  Physiologic  de  1'Homme,  i.  402,  2de  edit.,  Paris,  1829,  and 
Bostock's  Physiology,  edit,  cit.,  p.  709. 

a  According  to  Young,  Philos.  Transact.,  P.  i.  p.  46,  Lond.,  1801,  the  field  of  vision  inter- 
nally is  60°,  externally  90°;  according  to  Purkinje,  (Rust's  Magazine,  B.  xx.  Berlin,  1825,) 
internally  60°,  externally  100°. 

<  For  the  dimensions  of  different  parts  of  the  eye  see  Krause,  in  Meckel's  Archiv  ftir 
Anatomie  und  Physiologic  "fur  1832;  and  Longet,  Traite  de  Physiologie,  ii.  41,  Paris,  1850. 


230  SENSE  OF  SIGHT. 

also,  superior  orbitar  and  spTieno-maxillary  fissures ,  through  which  many 
vessels  and  nerves  proceed  to  the  eye  and  its  appendages.  The  base 
of  the  orbits  is  not  directly  opposite  the  apices,  but  tends  outwards;  so 
that  the  axes  of  these  cavities,  forming  an  angle  of  about  90°  with 
each  other,  if  prolonged,  would  meet  at  the  sella  turcica.  The  eye, 
however,  is  not  placed  in  the  direction  of  the  axis  of  the  orbit,  but 
straight  forward ;  and  as  it  is  nearly  spherical,  it  is  obvious  that  it 
cannot  completely  fill  the  conical  cavity.  In  Fig.  108,  muscles  9  and 
13  indicate  the  shape  of  the  upper  and  lower  surfaces  of  the  cavities; — 
the  whole  of  the  space  between  the  posterior  part  of  the  orbit  and  the 
muscles,  which  is  not  occupied  by  the  optic  nerve,  being  occupied  by 
an  adipous,  areolar  tissue,  on  which  the  eye  is  placed  as  it  were  on  a 
cushion.  Under  special  morbid  circumstances,  this  deposit  becomes 
greatly  augmented,  so  as  to  cause  the  eye  to  start  from  its  socket, — 
constituting  the  disease  called  exophthalmos. 

The  parts,  however,  that  are  more  immediately  reckoned  amongst 
the  protectors  of  the  organ — tutamina  oculi — are  the  eyebrows,  eyelids, 
and  lachrymal  apparatus.  The  eyebrows  or  supercilia  are  situate  im- 
mediately on  the  superciliary  ridge  of  the  frontal  bone.  They  con- 
sist of  hair,  varying  in  colour  according  to  the  individual,  and  turned 
towards  the  outer  angle  of  the  eye;  of  common  integument;  sebaceous 
follicles,  situate  at  the  root  of  each  hair ;  and  muscles  to  move  them, — 
namely,  the  frontal  portion  of  the  occipito-frontalis,  the  upper  edge  of 
the  orbicularis  palpebrarum,  and  the  corrugator  supercilii.  The  pal- 
pebr&  or  eyelids  are,  in  man,  two  in  number,  an  upper  and  a  lower, 
or  a  greater  and  a  less, — palpebra  major  vel  superior,  and  palpebra 
minor  vel  inferior, — the  former  covering  three-fourths  of  the  eye;  hence 
the  transverse  diameter  of  the  organ  is  not  represented  by  their  union, — 
the  latter  being  much  below  it,  and  therefore  improperly  termed,  by 
Haller,  sequator  oculi.  By  the  separation  of  the  eyelids,  we  judge, 
but  inaccurately,  of  the  size  of  the  eye, — one,  who  is  capable  of  sepa- 
rating them  largely  from  each  other,  appearing  to  have  a  large  eye ; — 
and  conversely. 

The  edge  of  the  eyelids  is  thick;  rounded;  and  furnished  with  hairs, 
which  resemble  generally,  in  colour,  those  of  the  head.  These  are  the 
eyelashes  or  cilia.  On  the  upper  eyelid  they  are  curved  upwards ;  on 
the  lower  downwards.  The  eyelids  are  formed  of  four  membranous 
layers  in  superposition;  and  of  a  fibro-cartilage,  which  extends  along 
the  whole  edge,  and  keeps  them  tense.  The  outermost  of  these  layers 
is  the  common  integument,  the  skin  of  which  is  delicate  and  semitrans- 
parent,  yielding  readily  to  the  motions  of  the  eyelids,  and  having  nu- 
merous transverse  folds.  The  areolar  tissue  beneath  the  skin  is  very 
loose;  and,  under  particular  circumstances,  is  infiltrated  by  a  serous 
fluid,  which  gives  the  eyelids,  especially  the  lower,  a  dark  appearance ; 
but  they  never  contain  fat.  Beneath  the  common  integument  is  the 
muscular  stratum,  formed,  in  the  lower  eyelid,  by  the  orbicularis  palpe- 
brarum; in  the  upper,  by  the  same  muscle,  and  the  levator  palpebrse 
superioris,  (Fig.  108,)  which  arises  from  above  the  foramen  opticum, 
and  is  inserted  into  the  superior  edge  of  the  fibro-cartilage  of  the 
tarsus.  Beneath  the  orbicularis  palpebrarum,  again,  is  a  fibrous  layer, 


ACCESSORY  ORGANS  OP  VISION. 


231 


which  occupies  the  whole  of  the  eyelids,  passing  from  the  edge  of  the 
orbit  to  the  tarsal  margin,  and  seeming  intended  to  limit  the  motion 
of  the  eyelids,  when  they  approximate  each  other.  The  last  layer, 
and  that  which  forms  the  posterior  surface  of  the  eyelids,  is  a  fine, 
delicate,  transparent,  mucous  membrane,  called  tunica  conjunctiva  or 
tunica  adnata;  so  named  because  it  joins  the  eyelids  to  the  globe  of 
the  eye.  It  lines,  in  fact,  the  eyelids,  and  is  reflected  over  the  ball ; 
but  it  has  been  a  matter  of  contention  whether  it  passes  over  the  trans- 
parent cornea.  The  generality  of  anatomists  say  it  does;  M.  Ribes,1 
however,  maintains  the  opinion,  that  it  extends  only  as  far  as  the  cir- 
cumference of  the  cornea,  and  that  the  cornea  itself  is  covered  by  a 
proper  membrane.  Physiologically,  this  dispute  is  of  no  moment.  At 
its  outer  surface,  a  humour  is  constantly  exhaled,  which  keeps  it  moist, 
and  facilitates  the  motions  of  the  eyelids  over  the  eyeball.  Its  loose 
state  also  favours  these  motions. 

Both  eyelids  are  kept  tense  by  the  aid  of  a  fibro-cartilage,  situate 
along  the  edge  of  each,  and  called  tarsus.  That  of  the  upper  is  much 
more  extensive  than  that  of  the  lower;  and  both  seem  as  if  cut  obliquely 
at  the  expense  of  their  inner  surface ;  so  that,  in  the  opinion  of  most 
anatomists,  when  the  eyelids  are  brought  together,  a  triangular  canal 


Fig.  108. 


Fig.  109. 


Muscles  of  the  Eyeball. 

1.  A  small  fragment  of  the  sphenoid  bone 
around  entrance  of  optic  nerve  into  orbit.  2. 
Optic  nerve.  3.  Globe  of  eye.  4.  Levator 
palpebrae  muscle.  5.  Superior  oblique  muscle. 
6.  Its  cartilaginous  pulley.  7.  Its  reflected 
tendon.  8.  Inferior  oblique  muscle  ;  the  small 
square  knob  at  its  commencement  is  a  piece  of 
its  bony  origin  broken  off.  9.  Superior  rectus. 
10.  Internal  rectus  almost  concealed  by  optic 
nerve.  11.  Part  of  external  rectus,  showing  its 
two  heads  of  origin.  12.  Extremity  of  external 
rectus  at  its  insertion ;  the  intermediate  portion 
of  muscle  having  been  removed.  13.  Inferior 
rectus.  14.  Tunica  albuginea  formed  by  ex- 
pansion of  tendons  of  four  recti. 


Meibomian  Glands  seen  from  the  Inner  or  Ocular 
Surface  of  the  Eyelids,  with  the  Lachrymal 
Gland— the  Right  Side. 

a.  Palpebral  conjunctiva.  1.  Lachrymal  gland. 
2.  Openings  of  lachrymal  ducts.  3.  Lachrymal 
puncta.  6.  Meibomian  glands. 


is  formed  between  them  and  the  ball  of  the  eye,  which  has  been  con- 
ceived useful  in  conducting  the  tears  towards  the  lachrymal  puncta. 
M.  Magendie2  denies  that  any  such  canal  exists ;  and  there  seems  little 

1  Memoires  de  la  Societe  Medicale  d'Emulation,  vol.  vii.,  Paris,  1817. 

2  Precis  Elementaire,  i.  52. 


232 


SENSE  OF  SIGHT. 


evidence  of  it,  when  we  examine  how  the  tarsal  cartilages  come  in  con- 
tact. Such  a  canal,  destined  for  the  purposes  mentioned,  would  seem 
superfluous.  Besides  the  eyelashes,  certain  compound  glands  or  follicles, 
called  Meibomian,  are  situate  in  the  substance  of  the  tarsal  cartilages. 
They  are  thirty  or  forty  in  number  in  the  upper  eyelid  ;  and  twenty- 
five  or  thirty  in  the  lower,  are  in  particular  furrows  between  the  tarsal 
fibro-cartilages  and  the  conjunctiva,  and  secrete  a  sebaceous  fluid,  called 
by  the  French  chassie,  when  in  the  dry  state  ;  by  the  Germans 
Augenbutter,  ("eyebutter,")  and  by  us,  gum  of  the  eye.  It 
serves  the  purposes  of  follicular  secretions  in  general. 

The  arrangement  of  the  eyelids  differs  in  different  animals.  In 
several,  both  move;  but,  in  others,  only  one;  either  the  lower  rising 
to  join  the  upper,  or  the  upper  descending  to  meet  the  lower.  In  the 
sunfish  —  tetraodon  mola  —  the  eyelid  is  single  and  circular,  with  a  per- 
foration in  the  centre,  which  can  be  contracted  or  enlarged,  according 
to  circumstances.  In  many  animals  there  is  a  third  eyelid,  called 
nictitating  membrane,  which  is  of  a  more  delicate  texture  and  more 
largely  supplied  with  bloodvessels  ;  and  in  some  animals  is  transparent. 
In  birds  it  exists,  and  is  well  seen  in  the  owl.  It  is  at  the  inner  angle 
of  the  eye  ;  arid  is  capable  of  being  drawn  over  the  ball  like  a  curtain 
by  two  special  muscles,  and  of  thus  freeing  the  surface  of  the  eye  from 
extraneous  substances.  In  man,  it  is  only  a  vestige,  destined  to  no 
apparent  use.  It  is  called  valvula  or  plica  semilunaris. 

The  eye  has  its  proper  muscles,  capable  of  moving  it  in  various 

directions.  Their  arrangement  is 
readily  understood.  They  are  six 
in  number:  —  four  recti  or  straight 
muscles;  and  two  oblique.  1.  Rectus 
superior  or  levator.  2.  Rectus  in- 
ferior or  depressor.  3.  Rectus  ex- 
ternus  or  adductor;  and  4.  Rectus 
externus  or  abductor.  All  arise 
from  the  base  of  the  orbit,  around 
the  optic  foramen;  pass  forward  to 
vanish  on  the  sclerotica;  and,  ac- 
cording to  some  anatomists,  extend 
over,  and  form  a  layer  to,  the  cor- 
nea. 

The  oblique  muscles  are  —  1. 
G-reater  oblique,  obliquus  superior, 
patheticus  or  trochlearis,  which 

r  .          _  .  .  ,  '       .     . 

arises  from  the  inner  side  of  the 

1.  Ball  of  the  eye  and  rectus  externus  muscle,    foramen    Opticum  ;     paSSCS    forwards 
2.  Superior  maxilla.    3.  Third  pair,  distributed  ,  ,          •  *.  n. 

to  all  the  muscles  of  the  eye  except  the  superior    tO    the    internal    OrDltar    prOCCSS    Ot 

,1  frrmt«l  hnnp  wViPrp  it«  fpnrlnn 
tn6  J  I  DOne,  Wnei 

Jg  reflected  OVCr  a  pulley  Or  trOchUa* 
r  ,       J  , 

and  CrOSSCS  the    Orbit  to  be  inserted 

into  the  upper,  posterior,  and  outer 

third  pair.  part    Qf   tne    g^g    Qf    tne    eye.       2. 

Lesser  oblique  or  obliquus  inferior,  whose  fibres  arise  from  the  anterior 


110- 


,  -D  . 

View  of  the  Third,  Fourth,  and  Sixth  Pairs 

of  Nerves. 


oblique  and  external  rectus.  4.  Fourth  pair 
going  to  the  superior  oblique  muscle.  5.  One  of 
the  branches  of  the  seventh  pair.  6.  Sixth  pair, 
distributed  to  the  external  rectus  muscle.  7. 
Spheno-palatine  ganglion  and  branches.  8.  Cili- 


ACCESSORY  ORGANS  OF  VISION. 


233 


and  inner  part  of  the  floor  of  the  orbit,  near  the  lachrymal  groove ; 
pass  under  the  eyeball,  and  are  inserted  between  the  entrance  of  the 
optic  nerve  and  insertion  of  the  abductor  oculi,  and  opposite  the  inser- 
tion of  the  obliquus  superior.  These  muscles  have  their  proper  nerves. 
The  third  pair — motores  oculorum — or  common  oculo-muscular,  are  dis- 
tributed to  all  the  muscles  except  the  trochlearis  and  abductor;  the 
fourth  pair  or  pathetic  or  internal  oculo-muscular,  to  the  trochlearis 
singly ;  and  the  sixth  pair  or  external  oculo-muscular,  to  the  abductor. 


Fig.  ill. 


Fig.  112. 


Posterior  View  of  the  Eyelids  and  Lachrymal  Gland. 

1,1.  Orbicularis  palpebrarum  muscle.  2.  Borders  of 
the  lids.  3.  Lachrymal  gland.  4.  Its  ducts  opening  in 
the  upper  lid.  5.  Conjunctiva  covering  the  lids.  6. 
Puncta  lachrymalia.  7.  Lachrymal  caruncle  as  seen 
from  behind. 


Lachrymal  Canals. 

1.  Puncta  lachrymalia.  2.  Cul-de-sac 
at  the  orbital  end  of  the  canal.  3.  Course 
of  each  canal  to  the  saccus  lachrymalis. 
4,5.  Saccus  lachrymalis.  6.  Lower  part 
of  the  ductus  ad  nasum. 


The  office  of  tutamina  oculi  is  not  wholly  engrossed  by  the  parts 
that  have  been  mentioned.  The  apparatus  for  the  secretion  of  the 
tears  participates  in  it,  by  furnishing  a  fluid,  which  lubricates  the  sur- 
face of  the  eye,  and  keeps  it  in  the  necessary  degree  of  humidity  for  the 
proper  performance  of  its  functions.  It  is  a  beautiful,  and  ingenious 
little  apparatus ;  the  structure  of  which  can  easily  be  made  intelligible. 
It  consists  of  the  lachrymal  gland;  the  excretory  ducts  of  the  gland;  the 
caruncula  lachrymalis;  the  lachrymal  ducts;  and  the  nasal  duct;  in 
other  words,  of  two  sets  of  parts, — one,  forming  the  fluid  and  pouring 
it  on  the  anterior  surface  of  the  eye;  the  other  comprising  the  organs 
for  its  excretion.  The  lachrymal  gland  is  situate  in  a  small  fossa  or 
depression  at  the  upper,  anterior,  and  outer  part  of  the  orbit.  It  is  an 
oval  body  of  the  size  of  a  small  almond;  of  a  grayish  colour;  and  com- 
posed of  small,  whitish,  granular  bodies  collected  into  lobes.  From 
these,  six  or  seven  excretory  ducts  arise,  which  run  nearly  parallel  to 
each  other,  and  open  on  the  inner  side  of  the  upper  eyelid,  near  the 
outer  angle  of  the  eye  and  the  tarsal  cartilage.  Through  these  ducts, 
the  tears,  secreted  by  the  lachrymal  gland,  are  spread  over  the  tunica 
conjunctiva.  They  are  not  secreted  by  animals  that  live  in  water. 

At  the  inner  angle  of  the  eye  is  the  caruncula  lachrymalis.     It  is  a 


234  SENSE  OF  SIGHT. 

collection  of  small  mucous  follicles,  which  secrete  a  thick,  whitish 
humour,  to  fulfil  a  similar  office  with  the  secretion  of  the  Meibomian 
follicles.  It  completes  the  circle  formed  by  those  follicles  around  the 
eyelids.  The  rosy  or  pale  colour  of  the  body  is  supposed  to  indicate 
strength  or  debility.  This  it  does,  like  other  vascular  parts  of  the  sys- 
tem, and  in  a  similar  manner.  The  puncta  lachry media  are  two  small 
orifices,  situate  near  the  inner  angle  of  the  eye;  the  one  in  the  upper; 
the  other  in  the  lower  eyelid,  at  the  part  where  the  eyelids  quit  the 
globe  to  pass  round  the  caruncula  lachrymalis.  They  are  continually 
open,  and  directed  towards  the  eye.  Each  punctum  is  the  commence- 
ment of  a  lachrymal  duct,  which  passes  towards  the  nose  in  the  sub- 
stance of  the  eyelids,  between  the  orbicularis  palpebrarum  and  tunica 
conjunctiva.  These  open,  as  represented  in  Fig.  112,  into  the  lachry- 
mal sac,  which  is  nothing  more  than  the  commencement  of  the  nasal 
duct  or  ductus  ad  nasum.  The  bony  canal  is  formed  by  the  anterior 
half  of  the  os  unguis,  and  by  the  superior  maxillary  bone,  and  opens 
into  the  nose  behind  the  os  spongiosum  inferius.  Through  these  ex- 
cretory ducts,  all  of  which  are  lined  by  a  prolongation  of  mucous  mem- 
brane, the  tears  pass  into  the  nasal  fossae. 

Dr.  Horner,1  professor  of  anatomy  in  the  University  of  Pennsylva- 
nia, has  best  described  a  small  muscle,  which  is  evidently  a  part  of  the 
lachrymal  apparatus,  and  to  which  he  gives  the  name  tensor  tarsi.  It 
is  on  the  orbital  face  of  the  lachrymal  sac ;  arises  from  the  superior 
posterior  part  of  the  os  unguis;  and,  after  having  advanced  a  quarter 
of  an  inch,  bifurcates;  one  fork  being  inserted  along  each  lachrymal 
duct,  and  terminating  at  or  near  the  punctum.  It  is  probable,  that 
the  function  of  this  muscle  is  to  keep  the  punctum  properly  directed 
towards  the  eyeball;  or,  as  Dr.  Physick  suggested,  to  keep  the  lids 
in  contact  with  the  globe.  The  office,  assigned  to  it  by  Dr.  Horner,  of 
enlarging,  by  its  contraction,  the  cavity  of  the  lachrymal  sac,  and  thus 
producing  a  tendency  to  a  vacuum — which  vacuum  can  be  more  readily 
filled  through  the  puncta  than  through  the  nose,  owing  to  the  valves 
or  folds  of  the  internal  membrane  of  the  sac — is  ingenious,  but 
apocryphal.  The  tensor  tarsi  muscle  is  now  commonly  associated  with 
the  name  of  Horner2 — "muscle  of  Horner." 

4.    PHYSIOLOGY  OF  VISION. 

The  preceding  anatomical  sketch  will  enable  the  reader  to  compre- 
hend this  important  organ  in  action.  In  describing  the  office  executed 
by  its  various  components,  we  shall  follow  the  order  there  observed, 
premising  some  general  considerations  on  the  mechanism  of  vision ;  and 
afterwards  depict  the  protecting  and  modifying  influences  exerted  by 
the  various  accessory  parts: — the  different  phenomena  of  vision  will 
next  be  explained;  and,  lastly,  the  information  conveyed  to  the  mind 
by  this  sense. 

In  tracing  the  progress  of  luminous  rays  through  the  purely  physical 

1  Lessons  in  Practical  Anatomy,  3d  edit.,  p.  116,  Philad.,  1836;  and  General  Anatomy  and 
Histology,  6th  edit.,  ii.  425,  Philad.,  1843.     Also.  Rosenmxiller's  Handbuch   der  Anatomie, 
dritte  Auflage,  Leipz.,  1819. 

2  T.  W.  Jones,  art.  Lachrymal  Organs,  Cyclop,  of  Anat.  and  Physiol.,  July,  1840. 


PHYSIOLOGY  OF  VISION. 


235 


part  of  the  organ,  we  shall,  in  the  first  instance,  suppose  a  single  cone 
to  proceed  from  a  radiant  point  in  the  direction  of  the  axis  of  the  eye ; 
or,  in  other  words,  of  the  antero-posterior  diameter  of  the  organ,  B  b. 


Progress  of  Luminous  Rays  through  the  Eye. 

It  is  obvious,  that  the  rays  which  fall  upon  the  transparent  cornea 
can  alone  be  inservient  to  vision.  Those  that  impinge  upon  the  scle- 
rotica  are  reflected ;  as  well  as  a  part  of  those  that  fall  upon  the  cornea, 
giving  occasion,  in  the  latter  case,  to  the  image  observed  in  the  eye, 
and  to  the  brilliancy  of  the  organ.  Nor  does  the  whole  of  the  cornea 
admit  rays,  for  it  is  commonly  more  or  less  covered,  above  and  below, 
by  the  free  edge  of  the  eyelids.  Again :  the  whole  of  the  light,  that 
enters  the  cornea,  does  not  impinge  upon  the  retina.  A  portion  falls 
upon  the  iris,  and  is  reflected  back  to  the  eye,  in  such  manner  as  to 
give  us  the  notion  of  the  colour  of  the  organ.  It  is,  consequently, 
the  light,  which  passes  through  the  pupil,  that  can  alone  attain  the 
retina. 

Some  interesting  points  of  diagnosis  are  connected  with  the  reflection 
which  takes  place  from  the  humours  of  the  eye.  If  a  lighted  candle 
be  held  before  an  eye  the  pupil  of  which  has  been  dilated  by  belladonna, 
and  in  which  there  is  no  obscurity  in  the  humours  or  their  capsules, 
three  distinct  images  of  the  flame  are  perceptible — situated  one  behind 
the  other.  Of  these  images  the  anterior  and  the  posterior  are  erect ; 
the  middle  inverted.  The  anterior  is  the  brightest  and  most  distinct ; 
the  posterior  the  least  so.  The  middle  one  is  the  smallest,  but  it  is 
bright.  The  anterior  erect  image  is  produced  by  the  cornea  ;  the  pos- 
terior by  the  anterior  surface  of  the  lens ;  and  the  middle  or  inverted 
image  by  the  concave  surface  of  the  capsule  of  the  crystalline.  M. 
Sanson  proposed  this  catoptric  method  of  examining  the  eye  as  a  means 
of  diagnosis  between  cataract  and  amaurosis, — in  the  latter  all  the 
images  being  seen :  and  experience  has  shown  it  to  be  a  valuable  mode 
of  investigating  various  conditions  of  the  eye,  which  might  not  be 
readily  understood  without  its  agency.1 

1  Gazette  Medicate  de  Paris,  27  Janvier,  1844.  See,  also,  T.  Wharton  Jones,  The  Princi- 
ples and  Practice  of  Ophthalmic  Medicine  and  Surgery,  Amer.  edit,  by  Dr.  Hays,  p.  39, 
Philad..  1847. 


236 


SENSE  OF  SIGHT. 


If  we  suppose  a  luminous  cone  to  proceed  from  a  radiant  point  B, 
Fig.  113,  directly  in  the  prolongation  of  the  antero-posterior  diameter 
of  the  eye,  the  axis  of  this  cone  will  also  be  the  axis  of  the  organ ;  so 
that  a  ray  of  light,  impinging  upon  the  humours  in  the  direction  of  the 
axis,  as  in  the  case  of  the  lenses  previously  referred  to,  will  pass  through 
the  humours  without  undergoing  deflection,  and  will  fall  upon  the  retina 
at  b.  This,  however,  is  not  the  case  with  the  other  rays  composing  the 
cone.  They  do  not  fall  perpendicularly  upon  the  cornea ;  and  are, 
consequently,  variously  refracted  in  their  passage  through  the  cornea, 
aqueous  humour,  crystalline,  and  vitreous  humour  ;  but  in  such  a  man- 
ner that  they  join  their  axis  in  a  focus  at  a  point  where  it  strikes  the 
retina. 

The  transparent  parts  of  the  eye,  as  has  been  seen,  are  of  different 
densities,  and  consequently  possessed  of  different  refractive  powers. 
These  powers  it  has  been  attempted  to  estimate ;  and  the  following  is 
the  result  of  the  somewhat  discordant  evaluations  of  different  experi- 
menters;— the  power  of  air  being  1-000295. 


CRYSTALLINE  LENS. 

Cornea. 

Aqueous 
Humour. 

Capsule. 

Outer 

Centre. 

Mean. 

Vitreous 
Humour. 

Layers. 

Hawksbee 

1-33595 

1-33595 

Jurin          -     - 

1-3333 

Rochon      -     - 

1-329 

1-332 

Young        -     - 

1-3333 

Chossat      •    - 

1-339 

1-338 

1-339 

1-338 

1  393 

1-384 

1-339 

Brewster   -     - 

1-3366 

1-3767 

1-3990 

1-3839 

1-3394* 

A  ray  of  light  impinging  obliquely  on  the  surface  of  the  transparent 
cornea  passes  from  a  rarer  to  a  denser  medium.  It  will,  consequently, 
be  refracted  towards  a  perpendicular  raised  from  the  point  of  impact. 
From  this  cause,  as  well  as  from  the  convexity  of  the  cornea,  it  will 
be  rendered  more  convergent ;  or,  in  other  words,  approach  the  axis  of 
the  cone.  In  proceeding  through  the  aqueous  humour,  little  variation 
will  be  produced,  as  the  densities  of  it  and  the  cornea  differ  but  little ; 
the  latter  is  slightly  more  refractive,  according  to  the  table  ;  and  there- 
fore the  tendency  will  be  to  render  the  ray  less  convergent.  This 
convergence  gives  occasion  to  the  passage  of  a  greater  number  of  rays 
through  the  pupil ;  and  necessarily  adds  to  the  intensity  of  the  light 
that  impinges  on  the  crystalline.  Pursuing  the  ray  through  the  two 
chambers  of  the  eye,  we  find  it  next  impinging  on  the  surface  of  the 
crystalline,  which  possesses  a  much  higher  refractive  power  than  the 
cornea  or  aqueous  humour;  in  the  ratio  of  1-384  to  1-336.  From  this 
cause,  and  from  the  convexity  of  the  anterior  surface  of  the  lens,  the 
ray  is  rendered  still  more  convergent  or  approaches  still  more  the  axis 
of  the  cone.  It  is  probable,  however,  that  even  here  some  of  the  light 
is  reflected  back ;  and  goes  towards  the  formation  of  the  image  in  the 


1  For  the  measurements  of  M.  Vallee,  see  his  Theorie  de  1'CEil,  p.  20,  Paris,  1843;  or 
Longet,  Traite  de  Physiologic,  ii.  42,  Paris,  1850. 


PHYSIOLOGY  OF  VISION — INVERTED  IMAGE.  237 

eye,  and  the  brilliancy  of  the  organ:  other  reflected  rays  perhaps 
impinge  upon  the  pigmentum  nigrum  lining  the  posterior  surface  of 
the  iris,  and  are  absorbed  by  it.  From  the  crystalline  the  ray  emerges 
into  a  medium  possessing  less  refractive  power ;  and,  therefore,  it  is 
deflected  from  the  perpendicular.  The  shape,  however,  of  the  posterior 
surface  of  the  lens  so  modifies  the  perpendiculars,  as  to  occasion  such 
a  degree  of  convergence,  that  the  oblique  ray  meets  the  axis  at  a  focus 
on  the  retina.  (See  Figs.  79  and  113.)  In  this  manner  two  cones  are 
formed ;  one  having  its  apex  at  the  radiant  point,  and  its  base  on  the 
cornea — the  objective  cone; — the  other  having  its  apex  on  the  retina, 
and  termed  the  ocular  cone. 

These  remarks  apply  chiefly  to  the  cone  proceeding  in  the  direc- 
tion of  the  axis  of  the  different  humours,  from  a  single  radiant  point. 
It  is  easy  to  understand,  that  every  portion  of  the  object  ABC,  Fig. 
113,  must  be  a  radiant  point,  and  project  so  many  cones  in  an  analo- 
gous manner,  which,  by  impinging  upon  the  retina,  form  a  picture  of 
the  object  upon  that  expansion,  at  g  b  h.  It  is  important,  however, 
to  observe,  that  the  rays  proceeding  from  the  upper  part  of  the  object 
fall,  after  refraction,  upon  the  lower  part  of  the  retina;  and  those  from 
the  lower  part  of  the  object  upon  the  upper ;  so  that  the  picture  or 
representation  of  the  object  on  the  retina  must  be  inverted.  How  the 
idea  of  an  erect  object  is  excited  in  the  mind  will  be  the  subject  of  after 
inquiry. 

When  rays,  as  A  g  and  C  A,  fall  obliquely  on  a  lens,  and  pass 
through  its  centre,  they  suffer  refraction  at  each  of  its  surfaces  ;  but 
as  the  two  refractions  are  equal,  and  in  opposite  directions,  they  may 
be  esteemed  to  pursue  their  course  in  a  straight  line.  The  point  #,  at 
which  these  various  rays  cross,  is  called  the  optic  centre  of  the  crys- 
talline. Each  of  the  straight  rays  proceeding  from  a  radiant  point 
may  be  assumed  as  the  axis  of  all  the  rays  proceeding  obliquely  from 
the  same  point;  and  the  common  focus  must  fall  on  some  part  of  this 
axis.  In  this  way  the  object  is  represented  in  miniature,  and  inverted, 
on  the  retina.  As,  however,  the  oblique  ray  has  to  pass  through  the 
cornea  and  aqueous  humour,  before  it  impinges  on  the  crystalline,  it 
undergoes  considerable  deflection ;  and  consequently  it  is  not  accurate 
to  represent  it  as  pursuing  a  straight  course  through  the  different  hu- 
mours on  its  way  to  the  retina.  The  main  deflection — as  in  the  case  of 
the  rays  D  t  s,  and  E  t  r,  Fig.  113 — occurs  at  the  entrance  of  the  rays 
into  the  cornea. 

That  an  inverted  representation  of  external  objects  is  formed  within 
the  eye  is  in  accordance  with  sound  theory ;  and  is  supported  not 
only  by  indirect,  but  by  direct  experiment.  If  a  double  convex  lens 
be  fitted  into  an  opening  made  in  the  window-shutter  of  a  darkened 
chamber,  luminous  cones  will  proceed  from  the  different  objects  on  the 
outside  of  the  house,  and  converge  within ;  so  that  if  they  be  received 
on  a  sheet  of  paper,  a  beautiful  and  distinct  image  of  the  object  will 
be  apparent.  This  is  the  well-known  instrument,  the  camera  obscura, 
of  which  the  organ  of  sight  may  be  regarded  as  a  modification.  Mak- 
ing abstraction,  indeed,  of  the  cornea,  and  of  the  aqueous  and  vitreous 
humours,  the  representation  of  the  eye  in  Fig.  113,  with  the  object, 


238  SENSE  OF  SIGHT. 

ABC  and  its  image  on  the  retina,  is  the  common  camera  obscura.    The 
eye  is,  therefore,  more  complicated  and  more  perfect  than  this  simple 

Fig.  114. 


Camera  Obscura. 

instrument :  the  cornea,  with  the  aqueous  and  vitreous  humours,  is 
added  for  the  purpose  of  concentrating  the  light  on  the  retina;  the  lat- 
ter, in  addition,  affording  a  large  space  for  the  expansion  of  the  retina, 
and  preventing  the  organ  from  collapsing.  In  the  operation  for  cata- 
ract by  extraction,  which  consists  in  removing  the  lens  through  an 
opening  made  in  the  lower  part  of  the  cornea,  the  aqueous  humour 
escapes,  but  is  subsequently  regenerated.  If,  however,  too  much  pres- 
sure be  exerted  on  the  ball,  to  force  the  crystalline  through  the  pupil 
and  the  opening  in  the  cornea,  the  vitreous  humour  is  sometimes 
pressed  out,  when  the  eye  collapses,  and  is  irretrievably  lost. 

Experiments  have  been  instituted  on  this  subject,  the  results  of 
which  are  even  more  satisfactory  than  the  facts  just  mentioned. 
These  have  been  of  different  kinds.  Some  experimenters  have  formed 
artificial  eyes  of  glass,  to  represent  the  cornea  and  crystalline,  with 
water  in  place  of  the  aqueous  and  vitreous  humours.  Another  mode 
has  been  to  place  the  eye  of  an  ox  or  a  sheep  in  a  hole  in  the  shutter 
of  a  dark  chamber,  having  previously  removed  the  posterior  part  of 
the  sclerotica  so  as  to  permit  the  images  of  objects  on  the  retina  to  be 
distinctly  seen.  Malpighi  and  Haller  employed  a  more  easy  method. 
They  selected  the  eyes  of  the  rabbit,  pigeon,  puppy,  &c.,  the  choroid 
of  which  is  nearly  transparent ;  and,  directing  the  cornea  towards 
luminous  objects,  they  saw  them  distinctly  depicted  on  the  retina.  M. 
Magendie1  repeated  these  experiments  by  employing  the  eyes  of  albino 
animals,  as  those  of  the  white  rabbit,  white  pigeon,  white  mouse,  &c., 
which  afford  great  facilities, — the  sclerotica  being  thin,  and  almost 
transparent ;  the  choroid,  also,  thin,  and  when  the  blood,  which  gives 
it  colour,  has  disappeared  after  the  death  of  the  animal,  offering  no 
sensible  obstacle  to  the  passage  of  light.  In  every  one  of  these  ex- 
periments, external  objects  were  found  to  be  represented  on  the  natu- 
ral or  artificial  retina  in  an  inverted  position ;  the  image  being  clearly 
defined,  and  with  all  the  colours  of  the  original.  Yet  how  minute 
must  these  representations  be  in  the  living  eye ;  and  how  accurate  the 
mental  appreciation, — seeing,  that  each  impression  from  myriads  of 
luminous  points  is  transmitted  by  the  retina  to  the  encephalon,  and 
perceived  with  unerring  certainty ! 

1  Precis  Elementaire,  i.  70. 


PHYSIOLOGY  OF  VISION — EYE  ACHROMATIC.  239 

In  the  prosecution  of  his  experiments — in  some  of  which  he  was 
assisted  by  M.  Biot — M.  Magendie  found,  as  might  have  been  expected, 
that  any  alteration  in  the  relative  proportion  or  situation  of  the  dif- 
ferent humours  had  a  manifest  effect  upon  vision.  When  a  minute 
opening  was  made  in  the  transparent  cornea,  and  a  small  quantity  of 
the  aqueous  humour  permitted  to  escape,  the  image  had  no  longer  the 
same  distinctness.  The  same  thing  occurred  when  a  little  of  the 
vitreous  humour  was  discharged  by  a  small  incision  made  through  the 
sclerotica.  He  farther  found,  that  the  size  of  the  image  on  the  retina 
was  proportionate  to  the  distance  of  the  object  from  the  eye.  When 
the  whole  of  the  aqueous  humour  was  evacuated,  the  image  seemed  to 
occupy  a  greater  space  on  the  retina,  and  to  be  less  distinct  and  lumi- 
nous; and  the  removal  of  the  cornea  was  attended  with  similar  results. 
When  the  crystalline  was  either  depressed  or  extracted,  as  in  the  ope- 
ration for  cataract,  the  image  was  still  formed  at  the  bottom  of  the 
eye;  but  it  was  badly  denned;  slightly  illuminated,  and  at  least  four 
times  the  usual  size.  Lastly, — when  the  cornea,  aqueous  humour,  and 
crystalline  were  removed,  leaving  only  the  capsule  of  the  crystalline 
and  the  vitreous  humour,  an  image  was  no  longer  formed  upon  the 
retina :  the  light  from  the  luminous  body  reached  it,  but  it  assumed  no 
shape  similar  to  that  of  the  body  from  which  it  emanated. 

Most  of  the  results — as  M.  Magendie1  remarks — accord  well  with 
the  theory  of  vision.  Not  so,  the  distinctness  of  the  image  under  these 
deranging  circumstances.  According  to  the  commonly  received  notions 
on  this  subject,  it  is  necessary,  in  order  to  have  the  object  depicted  with 
distinctness  on  the  retina,  that  the  eye  should  accommodate  itself  to 
the  distance  at  which  the  object  is  placed.  This  is  a  subject,  however, 
that  will  be  discussed  presently. 

Such  are  the  general  considerations  relating  to  the  progress  of 
luminous  rays  from  an  object  through  the  dioptrical  part  of  the  organ 
of  sight  to  the  nervous  portion — the  retina.  We  shall  now  inquire  into 
the  offices  executed  by  such  of  the  separate  parts  that  enter  into  its 
composition  as  have  not  already  engaged  attention. 

We  have  shown,  that  the  cornea,  aqueous  humour,  crystalline,  and 
vitreous  humour,  are  a  series  of  refractive  bodies,  to  concentrate  the 
luminous  rays  on  the  retina ;  to  keep  the  parietes  of  the  eye  distended ; 
and  to  afford  surface  for  the  expansion  of  the  retina; — thus  enlarging 
the  field  of  vision.  It  is  probably  owing  to  their  different  refractive 
powers,  that  the  eye  is  achromatic;  or,  in  other  words,  that  the  rays, 
impinging  upon  the  retina,  are  not  decomposed  into  their  constituent 
colours, — an  inconvenience  which  appertains  to  the  common  lens  (Fig. 
82).  The  eye  is  strictly  achromatic;  and  it  has  been  an  object  of 
earnest  inquiry  amongst  philosophers  to  determine  how  the  aberration 
of  refrangibility  is  corrected  in  it.  Euler,2  first  perhaps,  asserted,  that 
it  is  owing  to  the  different  refractive  powers  of  the  humours;  and  he 
conceived,  that,  by  imitating  this  structure  in  the  fabrication  of  lenses, 

1  Precis  Elementaire,  i.  73. 

a  Mem.  Berlin,  p.  279,  pour  1747;  and  Letters  of  Euler,  by  Sir  D.  Brewster,  Amer. 
edit.,  i.  163,  New  York,  1833. 


240  SENSE  OF  SIGHT. 

they  might  be  rendered  achromatic.  Experience  has  shown  the  accu- 
racy of  this  opinion  (Fig.  83).  Others  have  believed,  that  the  effect  is 
produced  by  certain  of  the  humours — as  the  aqueous  and  vitreous — 
which  they  have  considered  capable  of  correcting  the  dispersion  pro- 
duced by  the  cornea  and  crystalline.  Others,  again,  have  placed  it  in 
the  crystalline,  the  layers  of  which  being  of  different  dispersive  powers 
may  correct  each  other.  Lastly; — some  have  denied  altogether  the 
necessity  for  the  eye's  being  achromatic;  asserting,  that  the  depth  of 
the  organ  is  so  inconsiderable,  that  the  dispersion  of  the  rays,  by  the 
time  they  reach  the  retina,  ought  to  be  inappreciable.  This  was  the 
opinion  of  M.  D'Alembert.  Dr.  Maskelyne1  calculated  the  amount  of 
the  aberration,  that  must  necessarily  take  place  in  the  eye,  and  con- 
cluded that  it  would  be  fourteen  or  fifteen  times  less  than  in  a  common 
refracting  telescope;  and  therefore  imperceptible.  Uncertainty  still 
rests  on  this  subject;  and  it  cannot  be  removed  until  the  dispersive 
and  refractive  powers  of  the  transparent  parts  of  the  organ  as  well  as 
their  exact  curvatures  shall  have  been  mathematically  determined.  It 
has  been  already  shown,  that  the  data  we  possess  on  this  subject  from 
different  observers  are  sufficiently  imprecise. 

Our  knowledge,  then,  is  restricted  to  the  fact,  that  the  eye  is  per- 
fectly achromatic;  and  that,  in  this  respect,  it  exceeds  any  instrument 
of  human  construction.  The  views  of  Euler  are  the  most  probable; 
and  the  effect  doubtless  is  much  aided  by  the  iris  or  diaphragm,  which 
prevents  the  rays  from  falling  upon  the  margins  of  the  lens,  where,  by 
the  surfaces  meeting  at  an  angle,  the  aberration  must  necessarily  be 
greatest. 

Of  the  coats  of  the  eye, — the  sclerotic  gives  form  to,  and  protects  the 
organ. 

The  choroid  is  chiefly  useful  by  the  black  pigment,  which  lines  and 
penetrates  it.  It  will  be  seen  that  some  individuals,  on  insufficient 
grounds,  have  esteemed  it  the  seat  of  vision.  Leaving  this  question  for 
the  moment,  and  granting,  as  we  shall  endeavour  to  establish,  that  the 
impression  is  received  upon  the  expansion  of  the  optic  nerve — the 
retina, — the  use  of  the  choroid  would  seem  to  be,  in  ordinary  circum- 
stances, to  afford  surface  for  the  pigmentum  nigrum,  whose  function  it 
is  to  absorb  the  rays  after  they  have  passed  through  the  retina;  and 
thus  to  obviate  the  confusion,  that  would  arise  from  varied  reflections, 
we're  the  choroid  devoid  of  such  dark  covering.  In  albinos  or  white 
animals,  in  which  the  pigment  is  wanting,  this  inconvenience  is  really 
experienced;  so  that  they  become  nyctalopes,  or,  at  least,  see  but  im- 
perfectly during  the  day.  In  the  night,  or  when  the  light  is  feeble, 
their  vision  is  unimpaired;  hence  the  albinos  of  our  species  have  been 
called  by  the  Germans  and  Dutch,  Kakerlaken  or  cockroaches.  Sir 
Everard  Home2  is  of  opinion,  that  the  pigmentum  nigrum  is  provided 
as  a  defence  against  strong  light;  and  that,  hence,  it  is  lightest  in  those 
countries  least  exposed  to  the  scorching  effects  of  the  sun.  In  con- 

1  Philosoph.  Transactions  for  1789,  Ixix.  256. 

2  Lectures  on  Comparative  Anatomy,  iii.  220,  Lond.,  1823. 


PHYSIOLOGY  OP  THE  COATS  OF  THE  EYE.  241 

firmation  of  this,  he  remarks,  that  it  is  dark  in  the  monkey,  and  in  all 
animals  that  look  upwards,  and  in  all  birds  exposed  to  the  sun's  rays; 
whilst  the  owl,  that  never  sees  the  sun,  has  no  black  pigment.  It 
doubtless  possesses  the  function  assigned  to  it  by  Sir  Everard. 

The  use  of  the  shining  spot  on  the  outside  of  the  optic  nerves  of  quad- 
rupeds, called  tapetum.)  has  been  an  interesting  theme  of  speculation  ; 
and  has  given  rise  to  much  ingenious,  and  to  not  a  little  ridiculous, 
hypothesis  amongst  naturalists.  The  absence  of  the  black  pigment  ne- 
cessarily occasions  the  reflection  of  a  portion  of  the  rays  from  the  mem- 
brana  Ruyschiana  ;  and  it  has  been  presumed,  that  these  reflected  rays, 
in  their  passage  back  through  the  retina,  may  cause  a  double  impres- 
sion, and  thus  add  to  the  intensity  of  vision.  Another  view  has  been, 
that  the  reflected  rays  may  pass  outwards  through  the  retina  without 
exciting  any  action,  to  be  thrown  on  the  object  in  order  to  increase  the 
distinctness  of  the  image  on  the  retina,  by  an  increase  of  its  light.  Dr. 
Fleming,1  who  usually  exhibits  much  philosophical  acumen,  and  phy- 
siological accuracy,  thinks  it  not  probable,  that  both  surfaces  of  the 
retina  are  equally  adapted  for  receiving  impressions  of  external  objects, 
and  is  of  opinion,  that  the  rays,  in  their  passage  inwards,  alone  produce 
the  image.  M.  Desmoulins2  has,  however,  adduced  many  facts  and 
arguments  to  show,  that  the  tapetum  really  does  act  the  part  of  a  mir- 
ror; and,  by  returning  the  rays  through  the  retina,  subjects  it  to  a  dou- 
ble contact.  He  affirms,  that  in  nocturnal  animals,  and  in  many  fishes 
and  birds,  which  require  certain  advantages  to  compensate  for  the  con- 
ditions of  the  media  in  which  they  are  situate,  the  tapetum  is  of  great 
extent,  and  always  corresponds  to  the  polar  segment  of  the  eyeball  or 
to  the  visual  axis ; — that  in  many  animals,  as  in  the  cat,  the  pigment 
is  wholly  wanting ;  and  that  it  is  only  necessary  for  the  vision  of  diur- 
nal animals.  He  farther  remarks,  that,  in  man,  it  diminishes  accord- 
ing to  age,  and  in  advanced  life  becomes  white;  and  he  ingeniously 
presumes,  that  this  is  a  means  employed  by  nature  to  compensate,  in 
some  measure,  for  the  gradual  diminution  of  the  sensibility  of  the  re- 
tina,— the  choroid  beneath  reflecting  more  and  more  of  the  rays  in  pro- 
portion as  the  pigment  is  removed  from  its  surface. 

The  views  of  M.  Desmoulins  are  the  most  satisfactory  of  any  that 
have  been  propounded,  and  they  are  corroborated  by  the  experiments 
of  Gruithuisen,  Esser,  and  Tiedemann,3  which  show,  that  the  luminous 
phenomena  never  occur  in  the  eyes  of  nocturnal  animals  when  light  is 
totally  excluded.  Gruithuisen  observed  it  in  the  dead  as  well  as  the 
living  Animal.  Tiedemann  perceived  it  in  a  cat,  which  had  been  de- 
capitated for  twenty  hours ;  and  it  did  not  cease  until  the  humours  had 
become  turbid.  The  views  of  these  observers  impress  us  the  more 
forcibly,  when  we  compare  them  with  certain  fanciful  speculations, — 
as  that  of  M.  Richerand,4  who  supposes,  that  the  use  of  the  tapetum  is 
to  cause  animals  to  have  an  exaggerated  opinion  of  man !  As  if  the 

1  Philosophy  of  Zoology,  i.  192,  Edinb.,  1822. 
9  Magendie's  Journal  de  Physiologie,  iv.  89. 

3  Traite  Complet  de  Physiologie  de  1'Homtne,  &c.,  traduit  par  A.  J.  L.  Jourdan,  p.  550. 
«  Adelon,  Physiologie  de  1'Homme,  2de  edit.,  i.  443.     See,  also,  Sir  E.  Home's  Lectures  on 
Comp.  Anat.,  iii.  243. 
VOL.  I. — 16 


242  SENSE  OF  SIGHT. 

same  exaggerated  opinion  would  not  be  produced  whatever  were  the 
object  that  impressed  the  organ. 

The  iris  has  been  compared,  more  than  once,  to  the  diaphragm  of  a 
lens  or  telescope.  Its  function  consequently  must  be, — to  correct  the 
aberration  of  sphericity ',  which  would  otherwise  take  place.  This  it 
does  by  diminishing  the  surface  of  the  lens  on  which  the  rays  impinge, 
so  that  they  meet  at  the  same  focus  on  the  retina.  M.  Biot  has  re- 
marked, that  this  diaphragm  is  situate  in  the  eye  precisely  at  the  place 
where  it  can  best  fulfil  the  office,  and  yet  admit  the  greatest  possible 
quantity  of  light. 

The  iris  is  capable  of  contracting  or  dilating,  so  as  to  contract  or 
dilate  the  pupil.  It  has  been  already  observed,  that  the  views  of  anato- 
mists regarding  the  muscular  structure  of  the  iris  have  been  discrepant ; 
and  that  some  esteem  it  to  be  essentially  vascular  and  nervous,  the  ves- 
sels and  nerves  being  distributed  on  an  erectile  tissue.  The  partisans 
of  each  opinion  explain  the  motions  of  the  iris  differently.  They  who 
admit  it  to  consist  of  muscular  fibres  affirm,  that  the  pupil  is  contracted 
by  the  action  of  the  circular  fibres,  and  dilated  by  that  of  the  radiated. 
Those,  again,  that  deny  the  muscularity  of  the  organ  say,  that  contrac- 
tion of  the  pupil  is  caused  by  the  afflux  of  blood  into  the  vessels,  or  by 
a  sort  of  turgescence  similar  to  what  occurs  in  erectile  parts  in  general ; 
and  dilatation,  by  the  withdrawal  of  the  surplus  fluid. 

Admitting — and  we  think  this  must  be  conceded — that  the  iris  is 
really  muscular,  we  meet  with  the  singular  anomaly  in  its  physiology — 
that  no  ordinary  stimulus,  applied  directly  to  it,  has  any  effect  in  excit- 
ing it  to  contraction.  It  may  be  pricked  with  the  point  of  a  cataract 
needle  without  the  slightest  motion  being  excited ;  and,  from  the  expe- 
riments of  Fontana1  and  Caldani,2  it  seems  equally  insensible  when 
luminous  rays  are  made  to  impinge  upon  it ;  yet  MM.  Fowler,  Rinhold, 
and  Nysten3  have  proved,  that  it  contracts  like  other  muscular  parts  on 
the  application  of  the  galvanic  stimulus.  Like  them,  too,  it  is  under 
the  nervous  influence, — its  movements  being  generally  involuntary ; 
but,  there  is  some  reason  to  believe,  occasionally  voluntary.  Dr.  Roget 
asserts,  that  this  is  the  case  with  his  own  eye.4  In  the  parrot,  and 
certain  nocturnal  birds,  its  motions  are  manifestly  influenced  by  voli- 
tion ;5  and  when  the  cat  is  roused  to  attention,  the  pupil  dilates,  so  as 
to  allow  a  greater  quantity  of  light  to  reach  the  retina.  M.  Magendie6 
affirms,  that  the  attention  and  effort  required  to  see  minute  objects' dis- 
tinctly occasion  contraction  of  the  human  pupil.  He  selected  an  indi- 
vidual whose  pupil  was  very  movable ;  and  placing  a  sheet  of  paper  in 
a  fixed  direction  as  regarded  the  eye  and  light  he  marked  the  state  of 
the  pupil.  He  then  directed  the  person  to  endeavour,  without  moving 
the  head  or  eyes,  to  read  very  minute  characters  traced  on  the  paper. 
The  pupil  immediately  contracted,  and  continued  so,  as  long  as  the 
effort  was  maintained. 

'  Dei  Moti  dell'  Iride,  cap.  i.  p.  7,  Lucca,  1765. 

2  Institutiones  Physiologicse,  &c.,  Lips.,  1785.  3  Magendie,  Ibid.,  i.  75. 

4  Outlines  of  Physiology,  Amer.  edit.,  by  the  Author,  p.  286,  Philad.,  1839. 

5  Mayo,  Outlines  of  Physiology,  4th  edit.,  p.  286,  Lond.,  1837. 
e  Precis  Elementaire,  2de  edit.,  i.  74. 


ACTION  OF  THE  IKIS.  243 

Many  experiments  have  been  made  to  discover  the  nerve,  which  pre- 
sides over  the  movements  of  the  iris.  These  experiments  have  demon- 
strated, that  if,  instead  of  directing  a  pencil  of  rays  upon  the  iris,  we 
throw  it  on  the  retina,  or  through  the  retina  on  the  choroid,  contrac- 
tion of  the  pupil  is  immediately  induced.  The  movements  of  the  iris 
must,  then,  be  to  a  certain  extent  under  the  influence  of  the  optic  as 
an  afferent  nerve.  It  is  found,  indeed,  that  if  the  optic  nerve  be 
divided  on  a  living  animal,  the  pupil  becomes  immovable  and  ex- 
panded. Yet,  that  the  motions  of  the  iris  are  not  solely  influenced 
by  this  nerve  is  evinced  by  the  fact,  that  in  many  cases  of  complete 
amaurosis  of  both  eyes,  there  has  been  the  freest  dilatation  and 
contraction  of  the  pupil;  and  also,  that  section  of  the  nerve  of  the 
fifth  pair,  which  chiefly  supplies  the  iris,  equally  induces  immobility  of 
the  pupil.  The  same  effect  is  produced,  according  to  Mr.  Mayo,1  by 
dividing  the  third  pair.  If  the  trunk  of  that  nerve  be  irritated,  con- 
traction of  the  pupil  is  seen  to  follow ;  and,  according  to  Desmoulins,2 
in  the  eagle,  whose  iris  is  extremely  movable,  the  third  is  the  only 
nerve  distributed  to  the  organ.  The  general  remark,  made  by  M. 
Broussais3  on  the  organs  that  combine  voluntary  and  involuntary  func- 
tions, has  been  considered  applicable  here ; — that  they  will  be  found  to 
possess  both  cerebral  and  ganglionic  nerves.  Accordingly,  M.  Magen- 
die4  conjectures,  that  those  of  the  ciliary  nerves,  which  proceed  from 
the  ophthalmic  ganglion,  preside  over  the  dilatation  of  the  pupil,  or 
are  the  nerves  of  involuntary  action;  and  that  those  which  arise  from 
the  nasal  branch  of  the  fifth  pair,  preside  over  its  contraction.  We 
might  thus  understand  why,  in  apoplexy,  epilepsy,  &c.,  the  pupil 
should  be  immovably  dilated.  All  volition  and  every  cerebral  pheno- 
menon are  abolished  by  the  attack :  the  nerve  of  the  fifth  pair,  there- 
fore, loses  its  influence;  and  the  iris  is  given  up  to  the  agency  of  the 
ganglionic  nerves  or  nerves  of  involuntary  action  proceeding  from  the 
ophthalmic  ganglion. 

On  the  whole,  our  notions  regarding  the  motions  of  the  iris,  and 
the  nerves  that  preside  over  them,  must  be  esteemed  vague  and  unsatis- 
factory :  and  the  obscurity  is  not  diminished  by  a  remark  of  Bellingeri.5 
The  iris,  he  observes,  derives  its  nerves  from  the  ophthalmic  ganglion, 
which  is  formed  by  the  fifth  in  conjunction  with  the  third  pair ;  and  its 
involuntary  motions,  he  thinks,  are  regulated  by  the  fifth  pair.  In 
those  instances,  in  which  the  motions  of  the  iris  have  been  found  de- 
pendent on  the  will,  Bellingeri  argues,  that  the  ciliary  nerves  received 
no  branches  from  the  fifth — a  fact,  which  has  been  proved  by  dissec- 
tion, as  well  as  by  the  circumstance,  that  in  the  parrot,  owl,  and  the 
ray  genus  among  fishes — in  which  the  iris  is  under  the  will  of  the  ani- 
mal— there  is  no  ophthalmic  ganglion. 

1  Commentaries,  P.  ii.  p.  5,  arid  Outlines  of  Human  Physiology,  &c.,  4th  edit.,  p.  287, 
Lond.,  1837. 

3  Anatom.  des  System.lNerveux,  Paris,  1825. 

3  Traite  de  Physiologic  appliquee  a  la  Pathologic,  translated  by  Drs.  Bell  and  La  Roche, 
3d  edit.,  p.  77,  Phil,  1833. 

4  Precis,  &c.,  ed.  cit.,  i.  77. 

*  Dissert.  Inaugural.  Turin,  1823;  cited  in  Edinb.  Med.  and  Surg.  Journal  for  July,  1834. 


244  SENSE  OF  SIGHT. 

The  iris  contracts  or  dilates  according  to  the  intensity  of  the  light 
that  strikes  the  eye.  If  the  light  from  an  object  be  feeble,  the  pupil 
is  dilated  to  admit  more  of  the  luminous  rays :  on  the  contrary,  if  the 
light  be  powerful,  it  contracts.  We  see  this  very  manifestly  on  open- 
ing the  eyes,  after  they  have  been  for  some  time  closed,  and  bringing 
a  candle  suddenly  near  them.  It  is  one  of  the  means  frequently  em- 
ployed in  cerebral  disease  to  judge  of  the  degree  of  insensibility. 

We  shall  presently  inquire  into  the  effect  of  contraction  or  dilatation 
of  the  pupil  on  distinct  vision ;  and  show,  that  they  are  actions  for  ac- 
commodating the  eye  to  vision  at  different  distances. 

We  may  conclude,  then,  that  the  iris  is  one  of  the  most  important 
parts  of  the  visual  apparatus ;  that  its  functions  are  multiple : — that 
it  is  partly  the  cause  of  the  achromatism  of  the  organ,  by  preventing 
the  rays  of  greatest  divergence  from  falling  near  the  marginal  parts 
of  the  crystalline; — that  it  corrects  the  aberration  of  sphericity;  regu- 
lates the  quantity  of  light  admitted  through  the  pupil,  and  accommodates 
the  eye,  to  a  certain  extent,  to  vision  at  different  distances. 

An  enumeration  of  the  multiform  sentiments  regarding  the  functions 
of  the  ciliary  processes,  will  show  how  little  we  know,  that  is  precise, 
on  this  matter  also.  They  have  often  been  considered  contractile; 
some  believing  them  connected  with  the  motions  of  the  iris,  others  to 
vary  the  distance  of  the  crystalline  from  the  retina.  Jacobson1  makes 
them  dilate  the  apertures,  which  he  conceives  to  exist  in  the  canal 
godronne,  so  as  to  cause  the  admission  of  a  portion  of  the  aqueous 
humour  into  the  canal ;  and  thus  to  change  the  situation  of  the  crys- 
talline. Others  believe,  that  they  secrete  the  pigmentum  nigrum;  and 
others — the  aqueous  humour.  But  the  processes  are  wanting  in  ani- 
mals, in  which  the  humours,  notwithstanding,  exist ;  and  in  our  igno- 
rance of  their  precise  function,  it  has  been  considered  that  there  is  no 
opinion,  perhaps,  more  probable  than  that  of  Haller  ;2 — that  they  are 
destined  to  assist  mechanically  in  the  constitution  of  the  eye ;  and  have 
no  farther  use. 

The  function  of  the  retina  remains  to  be  considered.  It  is  the  part 
that  receives  the  impression  from  the  luminous  rays,  which  impression 
is  conveyed  by  the  optic  nerve  to  the  brain.  It  was,  at  one  time, 
universally  believed  to  be  the  most  delicately  sensible  membrane  of 
the  frame.  It  has  been  shown  by  the  experiments  of  M.  Magendie,3 
that  the  sensibility  of  both  it  and  the  optic  nerve  is  almost  entirely 
special,  and  limited  to  the  appreciation  of  light; — that  the  general 
sensibility  is  exclusively  possessed  by  the  fifth  encephalic  pair ;  and 
that  the  nerve  of  special  sensibility  is  incapable  of  executing  its  func- 
tions, unless  that  of  general  sensibility  is  in  a  state  of  integrity.  That 
distinguished  physiologist  found,  when  a  couching  needle  was  passed 
into  the  eye  at  its  posterior  part,  that  the  retina  might  be  punctured 
and  lacerated  without  the  animal  exhibiting  evidences  of  pain.  The 
same  result  attended  his  experiments  on  the  onj;ic  nerves.  These 
nerves,  both  anterior  and  posterior  to  their  decussation,  as  well  as  the 
thalami  nervorum  opticorum,  the  superficial  layer  of  the  tubercula 

i  Magendie,  Precis,  edit,  cit,  i.  78.  2  Element.  Physiol.,  xvi.  4,  20. 

»  Op.  cit.,  i.  83. 


ACTION  OF  THE  RETINA.  245 

quadrigemina,  and  the  three  pairs  of  motor  nerves  of  the  eye,  gave  no 
signs  of  general  sensibility.  On  the  other  hand,  the  general  sensi- 
bility of  the  conjunctiva  is  well  known.  It  is  such,  that  the  smallest 
particle  of  even  the  softest  substance  excites  intense  irritation.  This 
general  sensibility  M.  Magendie1  found  to  be  totally  annihilated  by  the 
division  of  the  fifth  pair  of  nerves  within  the  cranium;  after  which, 
hard-pointed  bodies  and  even  liquid  ammonia  made  no  painful  impres- 
sion on  the  conjunctiva.  Nictation  was  arrested ;  and  the  eye  remained 
dry  and  fixed  like  an  artificial  eye  behind  the  paralysed  eyelids.  The 
sight,  in  this  case  also,  was  almost  wholly  lost ;  but  by  making  the  eye 
pass  rapidly  from  obscurity  into  the  vivid  light  of  the  sun,  the  eyelids 
approximated;  and,  consequently,  slight  sensibility  to  light  remained; 
but  it  was  slight. 

In  this  sense,  then,  as  in  the  senses  of  hearing  and  smell,  we  have 
the  distinction  between  a  special  nerve  of  sense,  and  one  of  general 
sensibility :  without  the  latter,  the  former  is  incapable  of  executing  its 
elevated  functions. 

The  expansion  of  the  retina  occupies  at  least  two-thirds  of  the  cir- 
cumference of  the  eyeball.  It  is  of  obvious  importance,  that  it  should 
have  as  much  space  as  possible;  and,  in  certain  animals,  in  which  the 
sense  is  very  acute,  the  membrane  is  plaited  so  as  to  have  a  much 
larger  surface  than  the  interior  of  the  eyeball;  and  thus  to  allow  the 
same  luminous  ray  to  impinge  upon  more  than  one  point  of  the  mem- 
brane. This  is  seen  in  the  eyes  of  the  eagle  and  vulture,  and  in  noc- 
turnal animals.  The  inconceivable  acuteness  of  the  sense  of  sight  in 
birds  of  prey  has  been  already  referred  to  under  the  sense  of  smell. 
It  was  then  stated,  that  the  strange  facts  regarding  the  condor,  vulture, 
turkey-buzzard,  &c.,  which  meet  in  numbers  in  the  forest,  when  an 
animal  is  killed,  ought  rather,  perhaps,  to  be  referred  to  acuteness  of 
the  sense  of  sight  than  of  smell.  Sir  Everard  Home2  affords  an  addi- 
tional illustration  of  this  subject.  In  the  year  1778,  Mr.  Baber,  and 
several  other  gentlemen  were  on  a  hunting  party  in  the  island  of  Cas- 
simbusar,  in  Bengal,  about  fifteen  miles  north  of  the  city  of  Marshe- 
dabad:  they  killed  a  wild  hog  of  uncommon  size,  and  left  it  on  the 
ground  near  the  tent.  An  hour  after,  walking  near  the  spot  where  it 
lay,  the  sky  being  perfectly  clear,  a  dark  spot  in  the  air,  at  a  great 
distance,  attracted  their  attention;  it  appeared  to  increase  in  size, 
and  move  directly  towards  them ;  as  it  advanced  it  proved  to  be  a 
vulture  flying  in  a  direct  line  to  the  dead  hog.  In  an  hour,  seventy 
others  came  in  all  directions,  which  induced  Sir.  Baber  to  remark, — 
"this  cannot  be  smell." 

How  inconceivably  sensible  to  its  special  irritant  must  this  mem- 
brane be  in  the  human  eye,  when  we  consider  that  every  part  of  an 
extensive  landscape  is  depicted  upon  its  minute  surface ;  not  only  in  its 
proper  situation,  but  with  all  its  varied  tints !  and  how  impracticable 
for  us  to  comprehend,  how  the  infinitely  wider  range  of  country  can  be 
so  vividly  depicted  on  the  diminutive  eye  of  the  vulture,  as  to  enable  it 
to  see  its  prey  from  such  remote  distances. 

1  Op.  cit.,  i.  494.  *  Lectures  on  Comparative  Anatomy,  Lond.,  1814-1828. 


246  SENSE  OF  SIGHT. 

If  pressure  be  made  on  the  eyeball,  behind  the  cornea,  so  as  to  affect 
the  retina,  concentric  luminous  circles  are  seen,  opposite  to  the  part  on 
which  the  pressure  is  applied ;  and,  if  the  pressure  be  continued  for 
twenty  or  thirty  seconds,  a  broad  undefined  light,  which  increases  in 
intensity  every  moment,  rises  immediately  before  the  eye.  If  the  eye- 
lids be  open,  and  light  be  present — on  the  repetition  of  the  last  experi- 
ment, a  dense  cloud  arises,  instead  of  the  broad  undefined  light ;  and 
the  eye  becomes,  in  a  few  seconds,  perfectly  blind;  but  in  the  course 
of  three  or  four  seconds  after  the  finger  is  removed,  the  cloud  appears 
to  roll  away  from  before  the  eye.  From  this,  it  seems,  that  sensations 
of  light  may  be  produced  by  mechanical  pressure  made  on  the  retina ; 
in  other  words,  the  retina  becomes  phosphorescent  by  pressure.  The 
same  thing  is  observed  if  a  sudden  blow  be  given  on  the  eye,  or  if  we 
place  a  piece  of  zinc  under  the  upper  lip,  and  a  piece  of  copper  above 
the  eye.  A  flash  of  light  is  seen  ;  produced,  doubtless,  by  the  galvanic 
fluid  impressing  directly,  or  indirectly,  the  optic  nerve.  The  same 
thing  occurs  in  the  act  of  sneezing,  and  in  forcing  air  violently  through 
the  nostrils.  On  repeating  the  experiment  of  pressing  the  eyeball,  Sir 
David  Brewster1  observed,  that  when  a  gentle  pressure  is  first  applied, 
so  as  to  compress  slightly  the  fine  pulpy  substance  of  the  retina,  a 
circular  spot  of  colourless  light  is  produced,  though  the  eye  be  in 
total  darkness,  and  has  not  been  exposed  to  light  for  many  hours ;  but 
if  light  be  now  admitted  to  the  eye,  the  compressed  part  of  the  retina 
is  found  to  be  more  sensible  to  the  light  than  any  other  part ;  and, 
consequently,  it  appears  more  luminous.  If  the  pressure  be  increased, 
beyond  the  point  mentioned  above,  the  circular  spot  of  light  gradually 
becomes  darker,  and,  at  length,  black,  and  is  surrounded  with  a  bright 
ring  of  light.  By  augmenting  the  pressure  still  more,  a  luminous  spot 
appears  in  the  middle  of  the  central  dark  one,  and  another  luminous 
spot  diametrically  opposite,  and  beneath  the  point  of  pressure.  "  Con- 
sidering the  eye,"  says  Sir  David,  "  as  an  elastic  sphere,  filled  with 
incompressible  fluids,  it  is  obvious,  that  a  ring  of  fluids  will  rise  round 
the  point  depressed  by  the  finger ;  and  that  the  eyeball  will  protrude 
all  round  the  point  of  pressure ;  and  consequently  the  retina,  at  the 
protruded  part,  will  be  compressed  by  the  outward  pressure  of  the  con- 
tained fluid,  while  the  retina  on  each  side, — that  is,  under  the  point  of 
pressure,  and  beyond  the  protruded  part, — will  be  drawn  towards  the 
protruded  part  or  be  dilated.  Hence  the  part  under  the  finger,  which 
was  originally  compressed,  is  now  dilated,  the  adjacent  parts  are  com- 
pressed, and  the  more  remote  parts,  immediately  without  this,  dilated 
also."  "Now,"  continues  Sir  David,  "we  have  observed,  that  when 
the  eye  is,  under  these  circumstances,  exposed  to  light,  there  is  a  bright 
luminous  circle  shading  off  externally  and  internally  into  total  darkness. 
We  are  led  therefore  to  the  important  conclusions,  that  when  the  retina 
is  compressed  in  total  darkness  it  gives  out  light ;  that  when  it  is  com- 
pressed, when  exposed  to  light,  its  sensibility  to  light  is  increased  ; 
and  that  when  it  is  dilated  under  exposure  to  light,  it  becomes  abso- 
lutely blind  or  insensible  to  all  luminous  impressions." 

1  Letters  on  Natural  Magic,  Amer.  edit.,  p.  27,  New  York,  1832. 


ACTION  OF  THE  ACCESSORY  ORGANS.  247 

Having  traced  the  mode  in  which  the  general  physiology  of  vision  is 
effected,  and  the  part  performed  by  each  of  the  constituents  of  the  eye 
proper,  we  shall  briefly  consider  the  functions  of  the  rest  of  the  visual 
apparatus,  the  anatomical  sketch  of  which  has  been  given  under  the 
head  of  accessory  organs;  and  afterwards  inquire  into  the  various  in- 
teresting and  important  phenomena  exhibited  by  this  sense.  These 
organs  perform  but  a  secondary  part  in  vision.  The  orbit  shelters  the 
eye,  and  protects  it  from  external  violence.  The  eyebrows  have  a 
similar  effect;  and,  in  addition  to  this,  the  hair,  with  which  they  are 
furnished,  by  virtue  of  its  oblique  direction  towards  the  temple,  and  by 
the  sebaceous  secretion  that  covers  it,  prevents  the  perspiration  from 
flowing  into  the  eye,  and  directs  it  towards  the  temple  or  root  of  the 
nose.  By  contracting  the  eyebrows,  they  can  be  thrown  forwards  and 
downwards  in  wrinkles;  and  can  thus  protect  the  eye  from  too  strong 
a  light,  especially  when  coming  from  above. 

The  eyelids  cover  the  eye  during  sleep,  and  preserve  it  from  the 
contact  of  extraneous  bodies.  During  the  waking  state,  this  protection 
is  afforded  by  the  instantaneous  occlusion  of  the  eyelids,  on  the  antici- 
pation of  danger  to  the  ball.  The  incessant  nictation  likewise  spreads 
the  lachrymal  secretion  over  the  surface  of  the  conjunctiva,  and  cleanses 
it;  whilst  the  movement,  at  the  same  time,  probably  excites  the  gland 
to  augmented  secretion.  The  chief  part  of  the  movement  of  nictation 
is  performed  by  the  upper  eyelid ;  the  difference  in  the  action  of  the 
eyelids  being  estimated,  by  some  physiologists,  as  four  to  one.  Under 
ordinary  circumstances,  according  to  M.  Adelon,1  it  is  the  levator 
palpebrae  superioris,  which,  by  its  contraction  or  relaxation,  opens  or 
closes  the  eye ;  the  orbicularis  palpebrarum  not  acting.  If  the  levator 
be  contracted,  the  eyelid  is  raised  and  folded  between  the  eye  and 
orbit,  and  the  eye  is  open ;  if,  on  the  other  hand,  the  levator  be  relaxed, 
or  spread  passively  over  the  surface  of  the  organ,  the  eye  is  closed.  In 
this  view,  the  orbicularis  muscle  is  not  contracted,  except  in  extraordi- 
nary cases,  and  under  the  influence  of  volition;  whilst  the  closure  of 
the  eye  during  sleep  is  dependent  upon  simple  relaxation  of  the  levator. 
The  views  of  M.  Broussais2  on  this  subject  are  more  satisfactory.  He 
considers,  that  the  open  state  of  the  eye,  in  the  waking  condition, 
requires  no  effort;  because  the  two  muscles  of  the  eyelids  are  so  ar- 
ranged, that  the  action  of  the  levator  is  much  more  powerful  than  that 
of  the  orbicularis ;  and  he  adduces,  in  proof  of  this,  that  the  eyelids,  at 
the  time  of  death,  are  half  open.  On  the  other  hand,  the  closure  of 
the  eye  in  sleep  he  conceives  to  be  owing  to  the  contraction  of  the 
orbicularis  muscle,  which  acts  whilst  the  others  rest.  If  the  opening 
of  the  eye  were  wholly  dependent  upon  the  action  of  the  levator  pal- 
pebrae  superioris,  its  relaxation  during  insensibility  and  death  ought 
to  be  sufficient  to  close  the  eye  completely;  and  the  orbicularis  palpe- 
brarum would  be  comparatively  devoid  of  function ;  being  only  necessary 
for  the  closure  of  the  organ  under  the  influence  of  volition. 

It  has  been  found  by  experiments  instituted  by  Sir  Charles  Bell,3 

1  Physiologie  de  1'Homme,  2de  edit,  i.  419,  Paris,  1829.  2  Op.  citat.,  p.  188. 

3  The  Nervous  System  of  the  Human  Body,  Amer.  edit.,  p.  48,  Washington,  1833. 


248  SENSE  OP  SIGHT. 

and  by  M.  Magendie,1  that  nictation  is  effected  under  the  influence 
chiefly  of  the  portio  dura  of  the  seventh  pair  or  facial  nerve, — one  of 
the  respiratory  nerves  of  Sir  Charles  Bell's  system— the  respiratory 
of  the  face.  When  this  nerve  is  cut,  nictation  is  completely  arrested ; 
and  when  the  nerve  of  the  fifth  pair,  also  distributed  to  these  parts,  is 
divided,  it  ceases  likewise,  but  less  thoroughly;  a  very  vivid  light 
exciting  it,  but  only  at  considerable  intervals,  and  imperfectly.  We 
see  here  something  very  analogous  to  the  partition  of  the  nerves  of  the 
senses  into  those  possessing  general,  and  special  sensibility.  Like  the 
latter  functionaries,  the  nerve  of  the  seventh  pair  appears  to  be  specially 
concerned  in  nictation,  and  not  to  be  capable  of  executing  its  office, 
unless  the  fifth  pair — the  nerve  of  general  sensibility — be  in  a  state  of 
integrity.  The  explanation  of  Dr.  Marshall  Hall  is  different.  It  has 
been  before  remarked,  that  if  the  functions  of  the  brain  be  suspended 
or  destroyed,  the  true  spinal  system  being  uninjured,  the  orbicularis 
palpebrarum  still  contracts  so  as  to  close  the  eyelids,  when  the  tarsus 
is  touched  with  any  solid  body.  In  this  case,  neither  sensation  nor 
volition  can  be  concerned.  It  is  a  reflex  action;  the  excito*  nerves 
being  probably  branches  of  the  fifth,  and  the  motor,  branches  of  the 
seventh  pair.  Hence,  when  the  will  ceases  to  act,  as  in  sleep,  or  in 
apoplexy,  the  lids  close  over  the  eye  to  protect  it.  In  the  waking 
state,  the  levator  palpebrae,  under  the  influence  of  the  will,  acts  as  an 
antagonist  to  the  orbicularis  and  keeps  the  eye  open;  but  there  is  an 
almost  irresistible  tendency  to  close  the  eye;  and,  as  in  the  case  of 
respiration,  the  muscular  contraction  can  only  be  restrained  to  a  cer- 
tain degree :  it  takes  place,  whenever  the  condition  of  the  conjunctiva 
is  such  as  to  occasion  an  impression  to  be  conveyed  along  the  excitor 
nerve  which  demands  a  reflex  movement  to  modify  it ;  for  example, 
when  particles  of  dust  collect  upon  it ;  or  the  surface  becomes  dry.2 

The  eyelids,  by  their  approximation,  can  regulate  the  quantity  of 
light  that  enters  the  pupil,  when  it  is  injuriously  powerful ;  when  feeble, 
they  are  widely  separated,  to  allow  as  much  light  as  possible  to  pene- 
trate the  organ.  By  their  agency,  again,  the  most  diverging  rays  from 
an  object  can  be  prevented  from  falling  upon  the  cornea;  and  the  vision 
of  the  myopic  or  short-sighted  can  be  assisted.  It  is  a  means  of  which 
they  often  avail  themselves.  The  cilia  or  eyelashes,  it  is  probable,  are 
of  similar  advantage  as  regards  the  admission  of  light  into  the  eye,  and, 
probably,  have  some  part  in  preventing  extraneous  bodies,  borne  about 
in  the  air,  from  reaching  the  sensible  conjunctiva. 

The  muscles  of  the  eyeball  have  acquired  the  chief  portion  of  their 
interest  in  recent  times,  and  largely  through  the  investigations  of  the 
eminent  physiologist — of  whose  labours  we  have  so  frequently  had 
occasion  to  speak — Sir  Charles  Bell.3  The  arrangement  of  the  four 
straight  muscles,  and  especially  their  names,  sufficiently  indicate  the 
direction  in  which  they  are  capable  of  moving  the  organ,  when  acting 
singly.  If  any  two  of  them  contract  together,  the  eyeball  will,  of 

1  Precis  Elementaire,  i.  309. 

a  Carpenter,  Human  Physiology,  p.  154,  London,  1842. 

3  Op.  chat.,  p.  102,  and  Anatomy  and  Physiology,  5th  Amer.  edit,  ii.  213,  New  York, 
1827. 


ACTION  OF  THE  MUSCLES  OF  THE  EYEBALL.  249 

course,  be  moved  in  the  direction  of  the  diagonal  between  the  two 
forces;  and  if  each  muscle  contracts  rapidly  after  the  other,  the 
organ  will  execute  a  movement  of  circumduction.  The  oblique  mus- 
cles are  in  some  respects  antagonists  to  each  other,  and  roll  the  eye  in 
opposite  directions;  the  superior  oblique  directing  the  pupil  down- 
wards and  inwards ;  the  inferior  upwards  and  inwards.  But  as  the 
different  straight  muscles  are  capable  of  carrying  the  eye  in  these  di- 
rections, were  we  to  regard  the  two  sets  of  muscles  as  possessing  ana- 
logous functions,  the  oblique  would  appear  to  be  superfluous.  This, 
along  with  other  reasons,  attracted  the  attention  of  Sir  Charles  Bell 
to  the  subject;  and  the  result  of  his  experiments  and  reflections  was  ;— • 
that  the  straight  muscles  are  concerned  in  the  motions  of  the  eye 
excited  by  volition  :  and  that  the  oblique  muscles  are  the  organs  of  its 
involuntary  motions.  In  this  manner,  he  accounts  for  several  pheno- 
mena, connected  with  the  play  of  the  organs  in  health  and  disease. 
Whilst  the  power  of  volition  can  be  exerted  over  the  recti  muscles,  the 
eye  is  moved  about,  in  the  waking  state,  by  their  agency;  but,  as  soon 
as  volition  fails  from  any  cause,  the  straight  muscles  cease  to  act,  and 
the  eye  is  turned  up  under  the  upper  eyelid.  Hence  this  happens  at 
the  approach  of,  and  during  sleep;  and  whenever  insensibility  occurs 
from  any  cause,  as  in  faintness,  or  on  the  approach  of  dissolution;  and 
the  turning  up  of  the  eyeball,  which  we  have  been  accustomed  to  re- 
gard as  the  expression  of  agony,  is  but  the  indication  of  a  state  of  in- 
cipient or  total  insensibility.  Whenever,  too,  the  eyelids  are  closed, 
the  eyeball  is  moved,  so  that  the  cornea  is  raised  under  the  upper  eye- 
lid. If  one  eye  be  fixed  upon  an  object,  and  the  other  be  closed  with 
the  finger  so  placed  as  to  feel  the  convexity  of  the  cornea  through  the 
upper  eyelid,  and  the  open  eye  be  shut,  the  cornea  of  the  other  eye 
will  be  found  to  be  elevated.  This  change  takes  place  during  the  most 
rapid  winking  motions  of  the  eyelids ;  and  is  obviously  inservient  to 
the  protection  of  the  eye ;  to  the  clearing  of  the  eyeball  of  everything 
that  could  obscure  vision,  and  perhaps,  as  Sir  Charles  Bell  presumes, 
to  procure  the  discharge  from  the  Bluets  of  the  lachrymal  gland.  Dur- 
ing sleep,  when  the  closure  of  the  eye  is  prolonged,  the  transparent 
cornea  is,  by  this  action,  turned  up  under  the  upper  eyelid,  where  it  is 
securely  lodged  and  kept  moist  by  the  secretions  of  the  lachrymal 
gland,  follicles,  and  conjunctiva. 

The  different  distributions  of  the  motor  nerves  of  the  eye  have  been 
described  in  the  anatomical  sketch.  It  was  there  stated,  that  the  supe- 
rior oblique  muscle  receives  one  whole  pair  of  nerves, — the  fourth. 
This  nerve,  then,  it  seemed  to  Sir  Charles  Bell,  must  be  concerned  in 
the  functions  we  have  described;  and,  as  the  various  involuntary 
motions  of  the  eyeball  are  intimately  concerned  in  expression,  as  in 
bodily  pain,  and  in  mental  agony, — in  which  the  action  of  the  direct 
muscles  seems,  for  a  time,  to  be  suspended, — he  was  led  to  consider 
the  fourth  as  a  nerve  of  expression, — a  respiratory  nerve;  and, 
hence,  intimately  connected  with  the  facial  of  the  seventh  pair,  which, 
as  has  been  already  remarked,  is  the  great  nervous  agent  in  the 
twinkling  of  the  eyelids.  Anatomical  examination  confirmed  this 
view: — the  roots  of  the  nerve  being  found  to  arise  from  the  same  co- 


250  SENSE  OF  SIGHT. 

lumn  as  other  respiratory  nerves.  The  coincidence  of  this  twinkling, 
and  of  the  motion  of  the  eyeball  upwards,  was,  therefore,  easily  under- 
stood. 

There  is  a  difficulty,  however,  here,  which  has  doubtless  already  sug- 
gested itself  to  the  reader.  The  fourth  pair  is  distributed  to  the  supe- 
rior oblique  only;  the  lesser  oblique  receives  none  of  its  ramifications. 
They  cannot,  therefore,  be  identically  situate  in  this  respect.  Yet 
they  are  both  considered  by  Sir  Charles  Bell  as  involuntary  muscles. 
The  action,  indeed,  of  the  lesser  oblique  would  appear  to  be  even  more 
important  than  that  of  the  greater  oblique,  as  the  function  of  the 
former,  when  acting  singly,  is  to  carry  the  eye  upwards  and  inwards  ; 
and,  when  the  action  of  its  antagonist  is  abolished,  this  is  more  clearly 
manifested.  Sir  Charles  found,  that  the  effect  of  dividing  the  supe- 
rior oblique  was  to  cause  the  eye  to  roll  more  forcibly  upwards ; — in 
other  words,  it  was  given  up,  uncontrolled,  to  the  action  of  the  anta- 
gonist muscle.  This  difficulty,  although  it  is  not  openly  stated  by  Sir 
Charles,  must  have  impressed  him ;  for,  after  having  referred  to  the 
effect  of  the  division  of  the  superior  oblique,  he  is  constrained  to 
suggest  an  influence  to  the  fourth  pair,  which  would,  we  think,  be 
anomalous: — that  it  may,  on  certain  occasions,  cause  a  relaxation  of 
the  muscle  to  which  it  goes,  and,  in  such  case,  the  eyeball  must  be 
rolled  upwards!  In  addition  to  this,  too,  as  Mr.  Mayo1  has  observed, 
the  distribution  of  the  muscular  nerves  of  the  eye  is  not  such  as 
to  allow  of  our  opposing  the  straight  muscles  to  the  oblique;  and  one 
cogent  reason  is,  that  the  third  pair  supplies  part  of  each  class. 

We  have  still,  therefore,  much  to  learn  regarding  this  subject,  into 
which  so  much  interest,  and,  at  the  same  time,  so  much  uncertainty 
has  been  infused.  In  some  experiments  on  the  fresh  subject,  made  by 
the  author  with  Professor  Pancoast,  who  carefully  separated  the  differ- 
ent muscles,  with  the  view  of  discovering  their  precise  action,  it  was 
clearly  apparent,  that  the  oblique  muscles  act  in  the  manner  above 
mentioned;  the  superior  oblique  directing  the  eye  slightly  inwards  and 
downwards;  and  the  inferior,  rolling  it  upwards  and  inwards,  when 
they  acted  singly :  when  the  two  were  brought  into  action,  simultane- 
ously, they  appeared  to  antagonize  each  other  as  rotators,  but  pro- 
jected the  eye  forward.  It  would  seem,  indeed,  that  an  important  use 
of  these  muscles  is  to  keep  the  eye  prominent  during  the  action  of  the 
straight  muscles. 

These  results  harmonize  greatly  with  the  deductions  from  experi- 
ments on  living  animals  by  Mr.  Bransby  Cooper.2  He  divided  the 
superior  and  inferior  oblique  muscles  on  the  eyes  of  several  living 
rabbits;  and  inferred,  that  the  oblique  muscles,  when  acting  together, 
suspend  the  eyeball  in  a  central  position  in  the  orbitar  cavity ;  moderate 
the  retracting  influence  of  the  four  straight  muscles;  and,  when  acting 
in  succession,  without  being  restricted  by  the  influence  of  the  straight 
muscles,  they  roll  the  eye  on  its  own  axis,  drawing  the  globe  forward, 
and  at  the  same  time  tending,  in  a  great  degree,  to  extend  the  sphere 
of  vision. 

1  Outlines  of  Human  Physiology,  4th  edit.,  p.  299,  London,  1837. 
9  Guy's  Hospital  Reports,  vol.  iii.,  April  and  October,  1838. 


ACTION  OF  THE  MUSCLES  OF  THE  EYEBALL.  251 

The  great  use  of  the  tears  would  seem  to  be  to  moisten  the  conjunc- 
tiva, and  to  remove  extraneous  bodies  from  its  surface, — thus  assisting 
the  motions  of  the  eyelids  and  .eyeball.  The  tears  are  secreted  by  the 
lachrymal  gland ;  and,  by  means  of  its  excretory  ducts,  are  poured  upon 
the  surface  of  the  tunica  conjunctiva,  at  the  upper  and  outer  part  of 
the  eyeball.  Their  farther  course  towards  the  puncta  lachrymalia  has 
been  the  subject  of  difference  of  sentiment.  Many  physiologists  have 
considered  that,  owing  to  the  form  of  the  tarsal  cartilages,  a  canal 
exists,  when  the  eyelids  are  closed,  of  a  triangular  shape,  formed  an- 
teriorly by  the  junction  of  the  cartilages,  and  behind  by  the  ball  of 
the  eye.  M.  Magendie,1  on  the  other  hand,  denies  the  existence  of  this 
canal;  and  asserts  that  the  tarsal  cartilages  do  not  touch  by  a  rounded 
edge,  but  by  an  inner  plane  surface.  If  we  were  to  grant  the  existence 
of  this  canal,  it  could  only  aid  us  in  our  explanation  of  the  course  of 
the  tears  during  sleep.  In  the  waking  state,  they  are  not  ordinarily 
secreted  in  such  quantity  as  to  require  that  much  should  pass  to  the 
puncta; — the  movements  of  nictation  spreading  them  over  the  surface 
of  the  eye,  whence  they  are  partly  absorbed,  and  the  rest,  perhaps, 
evaporated.  Under  extraordinary  circumstances,  however,  the  gland 
increases  its  secretion  so  much,  that  the  tears  not  only  pass  freely 
through  the  lachrymal  ducts  into  the  nose,  but  flow  over  the  lower 
eyelid.  The  epiphora  or  watery  eye,  caused  by  obstruction  of  these 
ducts,  also  proves  that  a  certain  quantity  of  the  secretion  must  always 
be  passing  into  the  puncta.  The  physical  arrangement  of  the  eyelids 
and  tunica  conjunctiva  is  doubtless  the  cause  of  their  course  in  this 
direction. 

It  has  been  gratuitously  supposed  by  some,  that  the  humour  of 
Meibomius  prevents  the  tears  from  reaching  the  outer  surface  of  the 
lower  eyelid,  by  acting  like  a  layer  of  oil  on  the  margin  of  a  vessel 
filled  with  water.  A  similar  function  has  been  assigned  to  the  secre- 
tion of  the  caruncula  lachrymalis.  Both  these  fluids,  however,  are 
probably  inservient  to  other  ends.  They  are  readily  miscible  with 
water;  become  consequently  dissolved  in  the  tears,  and,  with  the  assist- 
ance of  the  fluid  secreted  by  the  tunica  conjunctiva,  aid  the  movements 
of  the  eyelids  over  the  ball  of  the  eye,  and  keep  the  tarsal  margins 
and  their  appendages  in  the  condition  requisite  for  the  due  perform- 
ance of  their  functions. 

The  action  of  the  puncta  themselves  in  admitting  the  tears  has  re- 
ceived different  explanations.  M.  Adelon2  regards  it  as  organic  and 
vital.  We  ought,  however,  in  all  cases,  to  have  recourse  to  this  mode 
of  accounting  for  phenomena  as  the  ultima  ratio;  and  the  present  ap- 
pears to  be  a  case  in  which  it  is  singularly  unnecessary.  In  many  of 
the  results  of  absorption  We  are  compelled  to  suppose,  that  a  vital 
operation  must  have  been  concerned  in  the  process.  Where,  for 
example,  as  in  the  case  of  the  lymphatic  vessels,  we  find  the  same  fluid 
circulating,  whatever  may  have  been  the  nature  of  the  substances 
whence  it  was  obtained,  the  evidence,  that  a  vital  action  of  selection 

1  Precis,  &c  ,  edit,  cit.,  i.  52. 

a  Physiologie,  2de  edit.,  p.  421,  Paris,  1829. 


252  SENSE  OF  SIGHT. 

and  elaboration  has  been  going  on,  is  irresistible ;  but  there  is  no  such 
action  in  the  case  in  question.  The  tears  in  the  lachrymal  ducts  and 
ductus  ad  nasum  are  identical  with  those  spread  upon  the  surface  of 
the  eye.  This  is  one  of  the  few  cases  in  the  human  body,  which  admit 
of  satisfactory  explanation  on  the  physical  principles  of  capillary 
attraction.  In  vegetables,  the  whole  of  the  circulation  of  their  juices 
has  been  thus  accounted  for.  If  we  twist  together  several  threads  of 
yarn;  moisten  them;  and  put  one  extremity  of  the  roll  into  a  vessel  of 
water,  allowing  the  other  to  hang  down  on  the  outside  and  to  dip  into 
an  empty  vessel  placed  below  it, — we  find,  that  the  whole  of  the  fluid 
in  the  first  vessel  is  in  a  short  time  transferred  to  the  second.  If, 
again,  we  take  a  small  capillary  tube,  less  than  the  twentieth  part  of 
an  inch  in  diameter,  and  place  it  so  as  to  touch  the  surface  of  water, 
we  find,  that  the  water  rises  in  it  to  a  height,  which  is  greater,  the 
smaller  the  bore  of  the  tube.  If  the  diameter  of  the  tube  be  the  fiftieth 
part  of  an  inch,  the  water  will  rise  to  the  height  of  two  inches  and  a 
half;  if  the  one  hundredth  part  of  an  inch,  to  five  inches;  if  the  two 
hundredth  part  of  an  inch,  to  ten  inches ;  and  so  on.  Now,  the  punc- 
tum  lachrymale  is,  in  our  view  of  the  subject,  the  open  extremity  of  a 
capillary  tube,  which  receives  the  fluid  of  the  lachrymal  gland  and  con- 
veys it  to  the  nose, — the  punctum  being  properly  directed  towards  the 
eyeball  by  the  tensor  tarsi  muscle  of  Homer,  and  the  inspiratory 
movements  drawing  it  down  the  ductus  ad  nasum. 

Lastly, — the  tunica  conjunctiva  is  another  part  of  the  guardian  ap- 
paratus of  the  eye.  It  secretes  a  fluid,  which  readily  mixes  with  the 
tears,  and  appears  to  have  similar  uses.  Like  mucous  membranes  in 
general,  it  absorbs;  and,  in  this  way,  a  part  of  the  lachrymal  secretion 
is  removed  from  its  surface.  An  animal,  for  the  same  reason,  can  be 
readily  poisoned  by  applying  hydrocyanic  acid  to  it.  As  the  conjunc- 
tiva lines  the  eyelids,  and  is  reflected  over  the  globe,  it  supports  the 
friction,  when  the  eyeball  or  eyelids  are  moved;  but,  being  highly 
polished  and  always  moist,  this  is  insignificant. 

The  extreme  sensibility  of  the  outer  part  of  the  eye  appertains  to 
the  tunica  conjunctiva,  and  is  dependent  on  the  ophthalmic  branch  of 
the  fifth  pair.  When  this  nerve  was  divided  in  a  living  animal,  M. 
Magendie1  found,  that  the  membrane  became  entirely  insensible  to 
every  kind  of  contact,  even  of  substances  that  destroyed  it  chemically. 
In  his  experiments  on  this  subject,  he  arrived  at  singular  results,  re- 
garding the  influence  of  the  fifth  nerve  on  the  nutrition  of  the  eye. 
When  the  trunk  of  the  nerve  was  divided  within  the  cranium  a  little 
after  its  passage  over  the  petrous  portion  of  the  temporal  bone,  the 
cornea  was  found,  about  twenty-four  hours  afterwards,  to  become 
troubled;  and  a  large  spot  to  form  upon  it.  In  the  course  of  from 
forty-eight  to  sixty  hours,  the  part  was  completely  opaque;  and  the 
conjunctiva,  as  well  as  the  iris,  in  a  state  of  inflammation ;  a  turbid 
fluid  was  thrown  out  into  the  inner  chamber,  and  false  membranes  pro- 
ceeded from  the  interior  surface  of  the  iris.  The  crystalline  and 
vitreous  humours  now  began  to  lose  their  transparency;  and,  in  the 

1  Precis  Elementaire,  ii.  494. 


EXPERIMENT  OF  MARIOTTE.  253 

course  of  a  few  days,  were  entirely  opaque.  Eight  days  after  the  divi- 
sion of  the  nerve,  the  cornea  separated  from  the  sclerotica ;  and  the 
portions  of  the  humours  that  remained  fluid  escaped  at  the  opening. 
The  organ  diminished  in  size,  and  ultimately  became  a  kind  of  tubercle, 
filled  with  a  substance  of  a  caseous  appearance.  M.  Magendie  properly 
concludes  from  these  experiments,  that  the  nutrition  of  the  eye  is  under 
the  influence  of  the  fifth  pair ;  and  he  conceives,  that  the  opacity  of 
the  cornea  was  directly  owing  to  the  section  of  this  nerve,  and  not  to 
a  cessation  of  the  lachrymal  secretion,  or  to  the  prolonged  contact  of 
air,  caused  by  the  paralysis  of  the  eyelids;  inasmuch  as  when  only  the 
branches  of  the  nerve  proceeding  to  the  eyelids  were  divided,  or  when 
the  lachrymal  gland  was  taken  away,  the  opacity  did  not  supervene. 

5.    PHENOMENA   OF   VISION. 

It  has  been  more  than  once  remarked,  that  the  retina — the  expansion 
of  the  optic  nerve — is  the  part  of  the  eye  which  receives  the  impressions 
of  luminous  rays,  whence  they  are  conveyed  by  that  nerve  to  the  brain. 
Yet  this  has  been  contested. 

The  Abbe  Mariotte1  discovered  the  singular  fact,  that  when  a  ray  of 
light  falls,  as  he  conceived,  upon  the  centre  of  the  optic  nerve  it  excites 
no  sensation.  " Having  often  observed,"  he  remarks,  "on  dissections 
of  men  as  well  as  of  brutes,  that  the  optic  nerve  does  never  answer 
just  to  the  middle  of  the  bottom  of  the  eye ;  that  is,  to  the  place  where 
the  picture  of  the  object  we  look  directly  upon  is  made ;  and  that  in 
man  it  is  somewhat  higher,  and  on  the  side  towards  the  nose;  to  make 
therefore  the  rays  of  an  object  to  fall  upon  the  optic  nerve  of  my  eye, 
and  to  find  the  consequence  thereof,  I  made  this  experiment.  I  fast- 
ened on  an  obscure  wall,  about  the  height  of  my  eye,  a  small  round 
paper,  to  serve  me  for  a  fixed  point  of  vision.  I  fastened  such  another 
on  the  side  thereof-  towards  my  right  hand,  at  the  distance  of  about 
two  feet,  but  somewhat  lower  than  the  first,  to  the  end  that  I  might 
strike  the  optic  nerve  of  my  right  eye,  while  I  kept  my  left  shut.  Then 
I  placed  myself  over  against  the  first  paper,  and  drew  back  by  little  and 
little,  keeping  my  right  eye  fixed  and  very  steady  on  the  same,  and  being 
about  ten  feet  distant,  the  second  paper  totally  disappeared." 

The  experiment  of  Mariotte  can  be  readily  repeated  on  the  marginal 
representations   of  the  fleur- 
de-lis  and  arrow.     If  we  close  Fig-  H5. 
the  left  eye,  and  direct  the  axis     1  A 

Of  the   right   eye    Steadily   to-  Experiment  of  Mariotte. 

wards   the   arrow,   when   the 

page  is  held  at  the  distance  of  about  ten  inches  from  the  eye,  the  fleur- 
de-lis  vanishes.  The  distance  of  the  object  which  disappears  from  the 
eye  must  be  about  five  times  as  great  as  its  distance  from  the  other 
object.  In  this  case  the  fleur-de-lis  and  arrow  are  two  inches  asunder. 
It  is  obvious,  from  what  has  been  said,  regarding  the  axis  of  the  orbits, 
and  the  part  of  the  eyeball  at  which  the  optic  nerve  enters — that  rays 

1  Philos.  Transact ,  iii.  668,  and  Memoir  de  1'Academie  Royale  des  Sciences,  torn.  i.  pp.  68, 
and  102. 


254  SENSE  OF  SIGHT. 

of  light  from  an  object  can  never  fall,  at  the  same  time,  upon  the  in- 
sensible point  of  each  eye.  The  defect  in  vision  is,  consequently,  never 
experienced  except  in  such  experiments  as  those  performed  by  Mariotte. 
In  one  of  these  he  succeeded  in  directing  the  rays  to  the  insensible  point 
of  both  eyes  at  once.  He  put  two  round  papers  at  the  height  of  the 
eye,  and  at  the  distance  of  three  feet  from  each  other.  By  then  placing 
himself  opposite  them,  at  the  distance  of  twelve  or  thirteen  feet,  and 
holding  his  thumb  before  his  eyes,  at  the  distance  of  about  eight  inches, 
so  that  it  concealed  from  the  right  eye  the  paper  on  the  left  hand,  and 
from  the  left  eye  the  paper  on  the  right,  he  looked  at  his  thumb  steadily 
with  both  eyes,  and  both  the  papers  were  lost  sight  of.  These  experi- 
ments show,  that  there  is  a  part  of  the  retina  or  optic  nerve,  which  is, 
in  each  eye,  insensible  to  light;  and  that  this  point — punctum  csecum — 
is  on  the  nasal  side  of  the  axis.  No  sooner,  however,  had  Mariotte 
published  an  account  of  his  experiments,  than  it  was  decided  that  this 
spot  was  the  basis  of  the  optic  nerve ;  a  conclusion  was  accordingly 
drawn,  that  the  nerve  is  incapable  of  distinct  vision,  and  this  conclusion 
has  been  embraced,  without  examination,  in  many  of  the  books  on  optics 
to  the  present  time.  Although  probable,  however,  it  is  by  no  means 
certain  that  the  light,  in  these  cases,  falls  upon  the  base  of  the  nerve. 
The  direction  in  which  the  ray  proceeds  is  such  that  it  is  reasonable  to 
suppose  it  does  impinge  there:  the  suggestion  of  M.  Tillaye,1  that  it 
falls  upon  the  yellow  spot  of  Sommering,  can  only  be  explained  by 
presuming  him  to  have  been  in  utter  ignorance  of  the  situation  of  the 
yellow  spot,  which,  we  have  seen,  is  on  the  outer  side  of  the  nerve. 

But,  granting  that  the  light  falls  at  the  base  of  the  optic  nerve,  it 
by  no  means  demonstrates,  that  the  nerve  is  incapable  of  receiving  the 
impression.  It  has  been  already  shown,  that  the  central  artery  of  the 
retina  penetrates  the  eye  through  the  very  middle  of  the  nerve;  and 
that  through  the  same  opening,  the  central  vein  leaves  the  organ.  It 
is  probable,  therefore,  that,  in  these  experiments,  the  ray  falls  upon  the 
bloodvessels,  and  not  upon  the  medullary  matter  of  the  nerve;  and  if 
so,  we  could  not  expect  that  there  should  be  sensation.  That  the  in- 
sensible spot  is  of  small  magnitude  is  proved  by  the  fact,  that  if  a  candle 
be  substituted  for  the  round  paper  or  wafer,  the  candle  does  not  disap- 
pear, but  becomes  a  cloudy  mass  of  light.  Daniel  Bernouilli2 — it  is 
true — considered  the  part  of  the  nerve  insensible  to  distinct  impressions 
to  occupy  about  the  seventh  part  of  the  diameter  of  the  eye,  or  about 
the  eighth  of  an  inch;  but  there  must  have  been  some  error  in  his  cal- 
culations, for  the  optic  nerve  itself  can  rarely  equal  this  proportion. 
The  estimate  of  Le  Cat,3  who  was  himself  a  believer  in  the  views  of 
Mariotte,  that  its  size  is  about  one-third,  or  one-fourth  of  a  line,  is 
probably  still  wider  from  the  truth  in  the  opposite  direction.  Simple 
experiment,  with  two  wafers  placed  upon  a  door  at  the  height  of  the 
eye,  shows  clearly,  that  both  the  horizontal  and  vertical  diameters  of 
the  spot  must  be  larger  than  this.4 

'  Adelon,  Physiologie,  2de  edit.,  i.  448,  Paris,  1829. 

*  Haller,  Element.  Physiolog.,  xvi.  4,  4. 

a  Traite  des  Sens,  p.  166,  Paris,  1767;   or  English  translation,  Lond.,  1750. 

*  Medical  and  Physiological  Problems,  by  William  Griffin,  M.D.,  and  Daniel  Griffin,  M.  D. 
p.  113,  Lond.,  1845. 


SEAT  OF  VISION.  255 

The  fact,  observed  by  Mariotte,  was  not  suffered  to  remain  in  repose. 
A  new  hypothesis  of  vision  was  framed  upon  it ;  and,  as  he  considered 
it  demonstrated,  that  the  optic  nerve  was  insensible  to  light,  he  drew 
the  inference,  that  the  retina  is  so  likewise ;  and  as  vision  was  effected 
in  every  part  of  the  interior  of  the  eye,  except  at  the  base  of  the  optic 
nerve,  where  the  choroid  is  alone  absent,  he  inferred  that  the  choroid 
must  be  the  true  seat  of  vision.  The  controversy,  at  one  time  main- 
tained on  this  subject,  has  died  away,  and  it  is  not  our  intention  to 
disturb  its  ashes,  farther  than  to  remark,  that  De  La  Hire,1  who  en- 
gaged in  it,  entertained  the  opinion,  that  the  retina  receives  the  impres- 
sion of  the  light  in  a  secondary  way,  and  through  the  choroid  coat  as 
an  intermediate  organ ;  and  that  by  the  light  striking  the  choroid,  the 
membrane  is  agitated,  and  the  agitation  communicated  from  it  to  the 
retina.  The  views  of  De  La  Hire  are  embraced  by  Sir  David  Brewster,2 
as  well  as  by  numerous  other  philosophers. 

The  opinions  of  Mariotte  have  now  few  supporters.  The  remarks 
already  made  regarding  the  optic  nerve ;  the  effect  of  disease  of  the 
retina,  of  the  nerve  itself,  and  of  its  thalami,  compel  us  to  regard  its 
expansion  as  the  seat  of  vision ;  and  if  we  were  even  to  admit,  with 
Mariotte,  that  the  insensible  portion  is  really  a  part  of  the  medullary 
matter  of  the  nerve,  and  not  a  bloodvessel  existing  there,  we  could 
still  satisfactorily  account  for  the  phenomenon  by  the  anomalous  cir- 
cumstances in  which  the  nervous  part  of  the  organ  is  there  placed. 
The  choroid  coat,  of  great  importance  in  the  function,  as  well  as  the 
pigmentum  nigrum,  is  absent ;  and  hence  we  ought  not  to  be  surprised, 
that  the  function  is  imperfectly  executed : — we  say  imperfectly,  for  the 
experiment  with  the  candles  exhibits,  that  the  part  is  not  really  insen- 
sible to  light,  or  is  so  in  a  very  small  portion  of  its  surface  only.  It 
may  seem  at  first  sight,  that  the  fact  of  this  defect  existing  only  in  the 
centre  of  the  optic  nerve,  or  at  the  porus  options  as  it  has  been  termed, 
where  the  central  artery  of  the  retina  enters,  and  the  corresponding 
vein  leaves  the  organ,  militates  against  the  idea  of  its  being  caused  by 
the  rays  impinging  upon  these  vessels ;  as,  if  so,  we  ought  to  have 
similar  defects  in  every  part  of  the  retina,  where  the  ramifications  of 
these  vessels  exist.  Circumstances  are  not  here,  however,  identical. 
When  the  ray  falls  upon  the  porus  opticus,  it  strikes  the  vessels  in  the 
direction  of  their  length ;  but,  in  the  other  cases,  it  falls  transversely 
upon  them,  pierces  them,  and  impresses  the  retina  beneath ;  so  that, 
under  ordinary  circumstances,  little  or  no  difference  is  perceived  between 
the  parts  of  the  retina  over  which  the  vessels  creep,  and  others.  We 
can,  however,  by  an  experiment  of  Purkinje,  described  by  J.  Gr.  Stein- 
buch,3  exhibit,  that  under  particular  circumstances  such  difference  really 
does  exist,  and  renders  the  bloodvessels  of  the  organ  perceptible  to  its 
own  vision.  If,  without  closing  the  eyelids,  the  left  eye  be  covered 
with  the  hand,  or  some  other  body,  and  a  candle  or  lamp  be  held  in  the 
right  hand,  within  two  or  three  inches  of  the  right  eye,  but  rather 

1  Mem.  de  I'Academie,  torn.  ix. 

3  Treatise  on  Optics,  Amer.  edit.,  by  A.  D.  Bache,  p.  243,  Philad.,  1833. 
3  Beitrag  zur  Physiologic  der  Sinne,  Niirnberg,  1811.    J.  Miiller,  Elements  of  Physiology, 
by  Baly,  ii.  1163,  Lond.,  1839. 


256 


SENSE  OF  SIGHT. 


below  it,  (keeping  the  eye  directed  straight  forward,)  on  moving  the 
candle  slowly  from  right  to  left,  (or  if  the  candle  be  held  on  the  right 
side  of  the  eye,  it  may  be  moved  up  and  down,)  a  spectrum  appears, 
after  a  short  time,  in  which  the  bloodvessels  of  the  retina,  with  their 
various  ramifications,  are  distinctly  seen  projected,  as  it  were,  on  a 
plane  without  the  eye,  and  greatly  magnified.  They  seem  to  proceed 
from  the  optic  nerve,  and  to  consist  of  two  upper  and  two  lower 
branches,  which  ramify  towards  the  field  of  vision,  where  a  dark  spot 
is  seen,  corresponding  to  the  foramen  centrale.  The  origin  of  the 
vessels  is  a  dark  oval  spot,  with  an  areola.  This  phenomenon  must  be 
accounted  for  by  the  parts  of  the  retina,  covered  by  the  bloodvessels, 
not  being  equally  fatigued  with  those  that  are  exposed. 

It  is  by  no  means  uncommon  for  appearances  of  cobwebs,  small  tubes 
with  lateral  pores,  &c.,  to  present  themselves  before  the  eyes,  without 
changing  their  position  when  the  eyes  are  fixed  upon  an  object.  These 
appearances  are  not  owing  to  any  modification  in  the  humours,  but  are 
apparently  dependent  upon  the  physical  condition  of  the  retina.  Some 
years  ago,  a  tube  of  the  kind  mentioned,  but  apparently  terminating 
in  an  open  mouth,  was  the  occasion  of  some  uneasiness  to  the  author. 
This  is  now  no  longer  seen,  but  numerous  opacities,  somewhat  resembling 
plexuses  of  vessels  or  nerves,  are  still  apparent.  All  these  appearances 
are  usually  called  collectively  "muscse  volitantes" 

They  have  been  described  by  Mr.  T.  W.  Jones1  under  three  forms  : — 
first,  as  a  convoluted  string  of  beads,  or  a 
convoluted  transparent  tube,  containing  in 
its  interior  a  row  of  beads  smaller  than  its 
diameter,  except  here  and  there  where  one 
larger  than  the  rest  is  seen  occupying  its 
whole  diameter — the  end  of  the  string  or 
tube  sometimes  presenting  a  dark  knobbed 
extremity,  as  if  formed  by  an  aggregation 
of  the  beads  composing  the  string,  or  con- 
tained within  the  tube  (Fig.  116,  #);  se- 
condly, insulated  beads,  some  of  which — 
and  these  are  more  frequent,  have  a 
well-defined  outline  5; — others,  and  these 
are  rarer,  have  a  distinct  outline  <?;  and 
thirdly,  a  parcel  of  flexuous  round  watery- 
looking  or  spun-glass-like  filaments  with 
dark  contours,  often  divided  inferiorly  into 
truncated  branches,  d. 

The  muscae,  which  change  their  position, 

Muse®  Voiitantes.  would  appear  to  be  seated  in  the  humours 

of  the  eye ;  and  it  has  been  supposed  in 

the  vitreous  more  especially;  whence  the  term  ento-hyaloid  muscde  given 
to  them. 

It  has  been  remarked,  that  the  rays,  proceeding  from  the  upper  part 
of  an  object,  impinge  upon  the  lower  portion  of  the  retina;  and  those 


Fig.  116. 


1  The  Principles  and  Practice  of  Ophthalmic  Medicine  and  Surgery,  Amer.  edit.,  p.  323, 
Philad.,  1847. 


CAUSE  OF  ERECT  VISION.  257 

from  the  lower  part  on  the  upper;  hence  the  image  of  the  object  is 
reversed,  as  in  Fig.  113.  It  has,  accordingly,  been  asked; — how  it  is, 
that  we  see  the  object  in  its  proper  position,  as  its  image  is  inverted  on 
the  retina  ?  Buffon,1  Le  Cat,2  and  others  believed,  that,  originally, 
we  do  see  them  so  inverted ;  but  that  the  sense,  of  touch  apprises  us  of 
the  error,  and  enables  us  to  correct  it  at  so  early  a  period,  and  so 
effectually,  that  we  are  afterwards  not  aware  of  the  process.  This 
cannot  apply,  however,  to  the  lower  animals;  and,  accordingly,  the 
knot  has  been  cut  by  the  supposition — and  there  is  much  to  favour  it — 
that  in  them  it  is  innate  or  intuitive.3  Berkeley,4  again,  asserted, 
that  the  position  of  objects  is  always  judged  of,  by  comparing  them 
with  our  own ;  and  that,  as  we  see  ourselves  inverted, — and  this  view  is 
embraced  by  Muller,  Volkmann,5  and  numerous  others, — external  bodies 
are  in  the  same  relation  to  us  as  if  they  were  erect.  It  is  not  necessary 
to  reply  at  length  to  these  views.  Cases  enough  have  occurred  of  the 
blind  from  birth  having  been  restored  to  sight  to  show,  that  no  such 
inversion,  as  that  described  by  Buifon,  takes  place ;  and  the  boy,  who 
stoops  down,  and  looks  at  objects  between  his  legs,  although  he  may 
be,  at  first,  a  little  confused,  from  the  usual  position  of  the  images  on 
the  retina  being  reversed,  soon  sees  as  well  in  that  way  as  in  any  other. 
The  great  error  with  all  these  speculatists  has  been,  that  they  have 
imagined  a  true  picture  to  be  formed  on  the  retina,  which  is  regarded 
by  the  mind,  and  therefore  seen  inverted.  It  need  hardly  be  said,  that 
there  is  no  interior  eye  to  take  cognizance  of  this  image;  but  that  the 
mind  accurately  refers  the  impression,  made  upon  the  retina,  to  the 
object  producing  it;  and  if  the  lower  part  of  the  retina  be  impressed 
by  a  ray  from  the  upper  part  of  an  object,  this  impression  is  conveyed 
by  the  retina  to  the  brain  as  it  receives  it,  and  no  error  can  be  indulged. 
Professor  Alison6  offers  an  explanation,  first  suggested  to  him  by  Mr. 
Dick,  veterinary  surgeon,  which  turns  on  the  alleged  fact,  that  the 
course  of  the  optic  nerves  and  tractus  optici  is  such,  that  impressions 
on  the  upper  part  of  the  retina  are,  in  fact,  impressions  on  the  lower 
part  of  the  optic  lobes, — that  impressions  on  the  outer  part  of  the  former 
are  on  the  inner  part  of  the  latter, — and  conversely. 

When  a  cone  of  light  proceeds  from  a  radiant  point,  as  from  B,  Fig. 
113,  the  whole  of  the  rays, — whatever  maybe  their  relative  obliquity, — 
are,  as  has  been  seen,  converged  to  a  focus  upon  the  retina  at  &,  yet 
the  point  B  is  seen  only  in  one  direction,  in  that  of  the  central  ray  or 
axis  of  the  cone  B  b.  If  we  look  over  the  top  of  a  card  at  the  point  B, 
till  the  edge  of  the  card  is  just  about  to  hide  it ;  or  if,  in  other  words, 
we  obstruct  all  the  rays  that  pass  through  the  pupil,  excepting  the 
uppermost,  the  point  is  still  seen  in  the  same  direction  as  when  it  was 
viewed  by  the  whole  cone  proceeding  from  B.  If  we  look,  again,  be- 
neath the  card,  in  a  similar  manner,  so  as  to  see  the  object  by  the  low- 

i  Memoires  de  1' Academic,  1743,  p.  231.  2  Op.  citat. 

3  Carpenter,  Human  Physiology,  p.  266,  Lond.,  1842. 

4  Essay  on  Vision,  2d  edit.,  p.  60,  Dublin,  1709. 

5  Wagner's  Handworterbuch  der  Physiologic,  14te  Lieferung,  s.  342,  Braunschweig,  1846. 

6  On  Single  and  Correct  Vision,  by  means  of  Double  and  Inverted  Images  on  the  Retinae, 
in  Transact,  of  the  Royal  Society  of  Edinburgh,  vol.  xiii.,  Edinb.,  1836. 

VOL.  I. — 17 


258  SENSE  OF  SIGHT. 

est  ray  of  the  cone,  the  radiant  point  will  be  equally  seen  in  the  same 
direction.  Hence,  says  Sir  David  Brewster,1  it  is  manifest,  that  the 
line  of  visible  direction  does  not  depend  on  the  direction  of  the  ray, 
but  is  always  perpendicular  to  the  retina ;  and,  as  the  surface  of  the 
retina  is  a  portion  of  a  sphere,  those  perpendiculars  must  all  pass 
through  one  point,  "which  may  be  called  the  centre  of  visible  direction ; 
because  every  point  of  a  visible  object  will  be  seen  in  the  direction  of  a 
line  drawn  from  this  centre  to  the  visible  point." 

The  point  o,  Fig.  113,  is,  in  Sir  David's  view,  the  centre  of  visible 
direction.  Where  a  luminous  cone  proceeds  in  the  direction  of  the  axis 
of  the  eye,  the  centre  of  visible  direction  will  fall  in  that  line,  and  a 
perpendicular,  drawn  from  the  point  6,  where  the  rays  of  the  cone  meet 
at  a  focus  on  the  retina,  will  pass  through  this  centre  of  visible  direc- 
tion 0,  and  the  same  thing,  he  conceives,  will  apply  to  every  other  pen- 
cil of  rays.  Thus,  the  rays  from  D  and  E,  which  fall  upon  the  cornea 
at  tj  will  be  refracted  so  as  to  impinge  upon  the  retina  at  s  and  r  re- 
spectively ;  and  D  and  R.  will  be  seen  in  the  direction  of  lines  drawn 
from  these  points  to  the  centre  of  visible  direction,  o. 

This  "law  of  visible  direction"  removes  at  once,  Sir  David  Brewster 
thinks,  every  difficulty  that  besets  the  subject  of  the  cause  of  erect 
vision  from  an  inverted  image  on  the  retina.  The  lines  of  visible 
direction  necessarily  cross  each  other  at  the  centre  of  visible  direction, 
so  that  those  from  the  lower  part  of  the  image  go  to  the  upper  part  of 
the  object ;  and  those  from  the  upper  part  of  the  image  to  the  lower 
part  of  the  object. 

The  views  of  Sir  David  are  embraced  by  Mr.  Mayo,2  who  considers 
them  confirmed  by  the  fact — to  which  reference  has  already  been  made 
— that  any  pressure  made  upon  the  retina  through  the  eyeball  causes 
a  spectrum  to  be  seen  in  a  direction  opposite  to  the  point  compressed  ; 
as  well  as  by  the  following  experiments  of  Scheiner,  by  whom  this  law 
of  visual  direction  was  first  shown.  If  the  head  of  a  pin,  strongly 
illuminated,  be  viewed  with  one  eye  at  a  distance  of  four  inches,  that 
is,  within  the  common  limit  of  distinct  vision,  the  object  is  seen  large 
and  imperfectly  defined, — the  outermost  cones  of  rays,  which  enter  the 
pupil  from  each  point,  being  too  divergent  to  be  collected  to  a  focus 
on  the  retina.  If  a  card  pierced  with  a  pinhole  be  now  interposed  be- 
tween the  eye  and  the  object,  the  latter  may  be  seen  distinctly  defined 
through  the  pinhole  by  means  of  rays  that  have  entered  the  pupil 
nearly  parallel,  with  a  slightly  divergent  tendency.  But  the  object 
may  be  seen  by  rays  passing  either  through  the  upper  or  lower  part, 
the  right  or  left  side,  or  the  centre  of  the  pupil.  On  shifting  the 
card  for  this  purpose  the  object  appears  to  move  in  an  opposite  direc- 
tion.— Qr?  if  three  pinholes  be  made,  one  in  the  centre,  and  one  at 
either  side,  the  object  appears  tripled  ;  and  if  one  of  the  side  holes 
be  closed,  the  opposite  of  the  three  objects  disappears :  if,  for  example, 
the  left-hand  pinhole  be  closed,  the  right  object  disappears. — Again, 
if  the  head  of  a  pin,  strongly  illuminated,  be  viewed  at  the  distance  of 

1  Op.  citat.,  p.  246. 

3  Outlines  of  Human  Physiology,  3d  edit.,  p.  277. 


CAUSE  OF  ERECT  VISION. 


259 


Fig.  117. 


eighteen  inches,  its  outline  is  distinct  and  clear  ;  the  rays  passing  from 
each  point  of  the  object,  are  brought  to  a  point  on  the  retina,  but 
they  reach  the  retina  at  different  angles  ;  and,  by  interposing  a  card 
perforated  with  a  single  pinhole,  the  object  may  be  seen  by  rays, 
which  enter  the  upper  part,  or  the  lower  part,  or  the  centre  of  the 
pupil.  No  change,  however,  in  the  visual  place  of  the  object  occurs 
in  this  instance,  as  the  card  is  being  shifted  ;  nor  is  the  image  mul- 
tiplied when  seen  through  several  pinholes  in  the  card. 

The  last  experiment,  says  Mr.  Mayo,  proves,  that  the  angle  at  which 
rays  of  light  fall  upon  the  retina  does  not  affect  our  notion  of  the  place 
of  objects;  and,  taken  with  the  preceding,  estab- 
lishes as  an  inductive  law,  that  the  retina  is  so 
constituted,  that,  however  exerted,  each  point  of 
it  sees  in  one  direction  only,  that  direction  being 
a  line  vertical  to  it;  or  that  in  every  instance  of 
vision,  each  point  of  an  object  is  seen  in  the  direc- 
tion of  a  line  vertical  to  the  point  of  the  retina 
upon  which  the  rays  proceeding  from  it  are  col- 
lected. It  would  seem,  however,  to  be  a  forcible 
objection  to  this  view  of  the  subject ;  that  all  the 
objects, «,  af  and  a"  on  the  line  ca",  Fig.  117,  must 
fall  upon  exactly  the  same  point  of  the  cornea ; 
and,  therefore,  upon  the  same  point  of  the  retina; 
yet,  as  only  one  of  these  lines  b  a  is  perpendicu- 
lar to  the  point  of  the  retina  on  which  the  rays 
are  collected,  such  a  perpendicular  would  obvi- 
ously refer  the  position  of  the  object  a  alone 
correctly.  Moreover,  accurate  examination  would 
appear  to  show,  that  this  law  of  visible  direction 
cannot  be  optically  correct,  as  the  lines  of  direc- 
tion cross  each  other  at  a  point  much  anterior  to  T  • 

„     .  i     11        mi  •  i  -,     Lines  of  Visible  Direction. 

the  centre  of  the  eyeball.     This  may  be  proved 

by  making  a  diagram  of  the  eye  on  a  large  scale,  and  laying  down  the 
course  of  the  rays  entering  the  organ,  according  to  the  curvatures,  and 
refractive  powers  of  its  different  parts.  In  this  manner,  Volkmann1 
found,  that  the  lines  of  direction  cross  each  other  at  a  point  a  little 
behind  the  crystalline,  and  that  they  will  thus  fall  at  such  different 
angles  on  different  points  of  the  retina,  that  no  general  law  can  be 
deduced  respecting  them. 

A  certain  intensity  of  light  is  necessary,  in  order  that  the  retina 
may  be  duly  impressed,  and  this  varies  in  different  animals;  some  of 
which,  as  we  have  seen,  are  capable  of  exercising  the  function  of  vision 
in  the  night,  and  have  hence  been  termed  nocturnal.  In  man,  the 
degree  of  light  necessary  for  distinct  vision  varies  according  to  the 
previous  state  of  the  organ.  A  person,  passing  from  a  brilliantly 
illuminated  room  into  the  dark,  is,  for  a  time,  incapable  of  seeing  any 
thing;  but  this  effect  differs  in  individuals;  some  being  much  more  able 

1  Neue  Beitrage  zur  Physiologic  des  Gesichtsinnes,  Leipzig,  1836,  and  Muller's  Elements 
of  Physiology  by  Baly,  p.  1170,  Lond.,  1839.  See,  on  this  subject,  Medical  and  Physiological 
Problems,  &c.,  by  JX.  Griffin,  M.D.,  and  Daniel  Griffin,  M.D.,  p.  97,  Lond.,  1845. 


260  SENSE  OF  SIGHT. 

to  see  distinctly  in  obscurity  than  others.  This  is  owing  to  the  retina 
being  more  sensible;  and,  consequently,  requiring  a  less  degree  of  light 
to  impress  it.  On  the  other  hand,  a  very  powerful  light  injures  the 
retina,  and  deprives  it,  for  a  time,  of  its  function;  hence  the  unpleasant 
impression  produced  by  the  introduction  of  lights  into  a  room,  where 
the  company  have  been  previously  sitting  in  comparative  obscurity ;  or 
by  looking  at  the  sun.  The  effect  upon  the  retina,  thus  induced,  is 
called  dazzling.  If  the  light  that  falls  upon  the  eye  is  extremely 
feeble,  and  we  look  long  and  intensely  upon  any  minute  object,  the 
retina  is  fatigued ;  the  sensibility  of  its  central  portion  becomes  ex- 
hausted, or  it  is  painfully  agitated;  and  the  objects  appear  and  disappear, 
according  as  it  has  recovered  or  lost  its  sensibility;  a  kind  of  remission 
seeming  to  take  place  in  the  reception  of  the  impressions. 

These  affections  are  considered  by  Sir  David  Brewster1  as  the  source 
of  many  optical  deceptions,  which  have  been  ascribed  to  a  supernatural 
origin.  "In  a  dark  night,  where  objects  are  feebly  illuminated,  their 
disappearance  and  reappearance  must  seem  very  extraordinary  to  a 
person  whose  fear  or  curiosity  calls  forth  all  his  powers  of  observation. 
This  detect  of  the  eye  must  have  been  often  noticed  by  the  sportsman, 
in  attempting  to  mark,  upon  the  monotonous  heaths,  the  particular 
spots  where  moor-game  had  alighted.  Availing  himself  of  the  slightest 
difference  of  tint  in  the  adjacent  heaths,  he  endeavours  to  keep  his  eye 
steadily  upon  it  as  he  advances;  but,  whenever  the  contrast  of  illumi- 
nation is  feeble,  he  almost  always  loses  sight  of  his  mark,  or  if  the 
retina  does  take  it  up  a  second  time,  it  is  only  to  lose  it  again." 

In  all  the  cases,  in  which  the  eye  has  been  so  long  directed  to  a 
minute  object  that  the  retina  has  become  fatigued,  on  turning  the  axis 
slightly  away  from  the  object,  the  light  from  it  will  fall  upon  a  neigh- 
bouring part  of  the  retina,  and  the  object  be  again  perceived;  and  in 
the  mean  time  the  part,  previously  in  action,  will  have  recovered  from 
its  fatigue.  By  the  fact  of  the  retina  becoming  fatigued  by  regarding 
an  object  for  a  long  time  we  explain  many  interesting  phenomena  of 
vision.  If  the  eye  be  directed,  for  a  time,  to  a  white  wafer  laid  upon 
a  black  ground;  and  afterwards  to  a  sheet  of  white  paper,  it  will  seem 
to  have  a  black  spot  upon  it,  of  the  same  size  as  the  wafer; — the  retina 
having  become  fatigued  by  looking  at  the  white  wafer.  On  the  other 
hand,  if  the  eye  be  turned  to  a  black  wafer,  placed  upon  a  sheet  of 
white  paper;  and  afterwards  to  another  part  of  the  sheet,  a  portion  of 
the  paper,  of  the  size  of  the  wafer,  will  seem  strongly  illuminated ; — 
the  ordinary  degree  of  light  appearing  intense,  when  compared  with 
the  previous  deficiency.  It  is  on  this,  that  the  whole  theory  of  acci- 
dental colours,  as  they  are  called,  rests.  When  the  eye  has  been  for 
some  time  regarding  a  particular  colour,  the  retina  becomes  insensible 
to  this  colour;  and  if,  afterwards,  it  be  turned  to  a  sheet  of  white 
paper,  the  paper  will  not  seem  to  be  white,  but  will  be  of  the  colour 
that  arises  from  the  union  of  all  the  rays  of  the  solar  spectrum,  except 
the  one  to  which  the  retina  has  become  insensible.  Thus,  if  it  be 
directed  for  some  time  to  a  red  wafer,  the  sheet  of  paper  will  seem  to 

1  Op.  citat.,  p.  250. 


ACCIDENTAL  COLOURS. 


261 


be  of  a  bluish-green,  in  a  circular  spot  of  the  same  dimensions  as  the 
wafer.  This  bluish-green  image  is  called  an  ocular  spectrum,  because 
it  is  impressed  upon  the  eye,  and  may  be  retained  for  a  short  time; 
and  the  colour  bluish- green  is  said  to  be  the  accidental  colour  of  the 
red.  If  this  experiment  be  made  with  wafers  of  different  colours,  other 
accidental  colours  will  be  observed,  varying  with  the  colour  of  the 
wafer  employed,  as  in  the  following  table : — 


Colour  of  the 
Wafer. 

Red, 

Orange,     • 
Yellow, 
Green, 
Blue, 
Indigo, 
Violet, 
Slack,        • 
White,       - 


Accidental  Colour,  or  Colour  of  the 
Ocular  Spectrum. 

-  Bluish-green. 

-  Blue. 

-  Indigo. 

-  Violet,  with  a  little  red. 

-  Orange-red. 

-  Orange-yellow. 

-  Yellow-green. 

-  White. 

-  Black. 


Black. 


Accidental  Colours. 


If  all  the  colours  of  the  spectrum  be  ranged  in  a  circle,  in  the  pro- 
portions they  hold  in  the  spectrum  itself,  as  in  Fig.  118, — the  acci- 
dental colour  of  any  particular 
colour  will  be  found  directly  oppo- 
site. Hence  the  two  have  been 
termed  opposite  colours. 

It  will  follow,  from  what  has 
been  said,  that  if  the  primary 
colour,  or  that  to  which  the  eye 
has  been  first  directed,  be  added 
to  the  accidental  colour,  the  result 
must  be  the  same  impression  as 
that  produced  by  the  union  of  all 
the  rays  of  the  spectrum — of  white 
light.  The  accidental  colour,  in 
other  words,  is  what  the  primitive 
colour  requires  to  make  it  white 

light.  The  primitive  and  accidental  colours  are,  therefore,  comple- 
ments of  each  other ;  and  hence  accidental  colours  have  been  called 
complementary  colours.  They  have  likewise  been  termed  harmonic, 
because  the  primitive  and  its  accidental  colour  harmonize  with  each 
other  in  painting.  It  has  been  supposed,  that  the  formation  of  these 
ocular  spectra  has  frequently  given  rise  to  a  belief  in  supernatural 
appearances, — the  retina,  in  certain  diseased  states  of  the  nervous  sys- 
tem, being  more  than  usually  disposed  to  retain  the  impressions,  so 
that  the  spectrum  remains  visible  for  a  long  time  after  the  cause  has 
been  removed.  Such  appears  to  be  the  view  of  Drs.  Ferriar,1  Hib- 
bert,2  and  Alderson,3 — the  chief  writers  in  modern  times,  on  appari- 
tions. This  subject  may  be  the  theme  of  future  discussion.  It  will  be 
sufficient,  at  present,  to  remark,  that  the  great  seat  and  origin  of 

1  An  Essay  towards  a  Theory  of  Apparitions,  Lond.,  1813. 

2  Sketches  of  the  Philosophy  of  Apparitions,  Edinb.,  1825. 

3  An  Essay  on  Apparitions,  &c.,  Lond.,  1823. 


262  SENSE  OF  SIGHT. 

spectral  illusions  is  the  brain,  and  that  the  retina  is  no  farther  con- 
cerned than  it  is  in  dreaming  or  in  the  hallucinations  of  insanity. 

The  retina  is  able  to  receive  visual  impressions  over  its  whole  sur- 
face, but  not  with  equal  distinctness  or  accuracy.  When  we  regard 
an  extensive  prospect,  that  part  of  it  alone  is  seen  sharply,  which  falls 
upon  the  central  part,  or  in  the  direction  of  the  axis  of  the  eye :  we 
always,  therefore,  in  our  examination  of  minute  objects,  endeavour  to 
cause  the  rays  from  them  to  impress  this  part  of  the  retina; — the  dis- 
tinctness of  the  impression  diminishing  directly  as  the  distance  from 
the  central  foramen  increases.  This  central  point,  called  the  point  of 
distinct  vision,  is  readily  discriminated  on  looking  at  a  printed  page. 
It  will  be  found,  that  although  the  whole  page  is  represented  on  the 
retina,  the  letter  to  which  the  axis  of  the  eye  is  directed  is  alone  sharply 
and  distinctly  seen ;  and,  accordingly,  the  axis  of  the  eye  is  directed  in 
succession  to  each  letter  as  we  read.  In  making  some  experiments  on 
indistinctness  of  vision  at  a  distance  from  the  axis  of  the  eye,  Sir  David 
Brewster1  observed  a  singular  peculiarity  of  oblique  vision,  namely, — 
that  when  we  shut  one  eye  and  direct  the  other  to  any  fixed  point, 
such  as  the  head  of  a  pin,  and  hence  see  all  other  objects  within 
the  sphere  of  vision  indistinctly,  if  one  of  these  objects  be  a  strip  of 
white  paper,  or  a  pin  lying  upon  a  green  cloth,  after  a  short  time,  the 
strip  of  paper  or  the  pin  will  altogether  disappear,  as  if  it  were  entirely 
removed,  the  impression  of  the  green  cloth  upon  the  surrounding  parts 
of  the  eye  extending  itself  over  the  part  of  the  retina,  which  the  image 
of  the  pin  occupied.  In  a  short  time,  the  vanished  image  will  re-ap- 
pear, and  again  vanish.  When  the  object  seen  obliquely  is  luminous, 
as  a  candle,  it  never  vanishes  entirely,  unless  its  light  is  much  weak- 
ened by  being  placed  at  a  great  distance;  but  it  swells  and  contracts, 
and  is  encircled  with  a  nebulous  halo, — the  luminous  impressions  ex- 
tending themselves  to  adjacent  parts  of  the  retina  not  directly  influ- 
enced by  the  light  itself. 

From  these,  and  other  experiments  of  a  similar  character,  Sir  David 
infers,  that  oblique  or  indirect  vision  is  inferior  to  direct  vision,  not 
only  in  distinctness,  but  from  its  inability  to  preserve  a  sustained  vision 
of  objects.  Yet  it  is  a  singular  fact,  that  indirect  has  a  superiority 
over  direct  vision  in  the  case  of  minute  objects,  such  as  small  stars, 
which  cannot,  indeed,  be  seen  by  the  latter.  A  mode  frequently 
adopted  by  astronomers  for  obtaining  a  view  of  a  star  of  the  last  degree 
of  faintness  is  to  direct  the  eye  to  another  part  of  the  field,  and  in  this 
way,  a  faint  star,  in  the  neighbourhood  of  a  large  one,  often  becomes 
'very  conspicuous,  so  as  to  bear  a  certain  illumination,  and  yet  it  en- 
tirely disappears,  as  if  suddenly  blotted  out,  when  the  eye  is  turned 
full  upon  it;  and,  in  this  way,  it  can  be  made  to  appear  and  disappear 
as  often  as  the  observer  pleases.  Sir  J.  F.  W.  Herschel,  and  Sir 
James  South,  who  describe  this  method  of  observation,  attempt  to 
account  for  the  phenomenon  by  supposing,  that  the  lateral  portions  of 
the  retina,  being  less  fatigued  by  strong  light,  and  less  exhausted  by 
perpetual  attention,  are  probably  more  sensible  to  faint  impressions 

1  Op.  citat,  p.  248. 


DISTINCT  VISION.  263 

than  the  central  ones;  and  the  suggestion  carries  with  it  an  air  of  veri- 
similitude. Sir  David  Brewster,  however, — from  the  result  developed 
by  his  experiments,  that,  "in  the  case  of  indirect  vision,  a  luminous 
object  does  not  vanish,  but  is  seen  indistinctly,  and  produces  an  en- 
larged image  on  the  retina,  besides  that  which  is  produced  by  the  defect 
of  convergency  in  the  pencils," — concludes  somewhat  mystically,  "that 
a  star,  seen  indirectly,  will  affect  a  large  portion  of  the  retina  from 
these  two  causes,  and,  losing  its  sharpness,  will  be  more  distinct."1 

In  order  that  the  image  of  any  object  may  impress  the  retina,  and 
be  perceived  by  the  mind,  it  must,  first  of  all,  occupy  a  space  on  the 
retina  sufficiently  large  for  its  various  parts  to  be  appreciated :  in  the 
next  place,  the  image  must  be  distinct  or  sharp, — in  other  words,  the 
luminous  rays  that  form  it  must  converge  accurately  to  a  focus  on  the 
retina :  and  lastly,  the  image  must  be  sufficiently  illuminated.  Each 
of  these  conditions  varies  with  the  size  of  the  body,  and  the  distance  at 
which  it  is  from  the  eye ;  and  there  are  cases,  where  they  are  all  want- 
ing, and  the  object  is  consequently  invisible.  An  object  may  be  so 
small,  that  the  eye  cannot  distinguish  it,  because  the  image,  formed  on 
the  retina,  is  too  minute.  To  remedy  this  inconvenience,  the  object 
must  be  brought  near  to  the  eye,  which  increases  the  divergence  of  the 
rays  and  the  size  of  the  image  ;  but  if  we  approach  it  too  close  to  the 
eye,  the  rays  are  not  all  brought  to  a  focus  on  the  retina,  and  the 
image  is  indistinct.  If,  therefore,  an  object  be  so  small,  that,  at  the 
visual  point,  to  be  presently  mentioned,  the  rays  proceeding  from  it 
do  not  form  an  image  of  sufficient  size  on  the  retina,  the  object  is 
not  seen.  To  obviate  this  imperfection  of  the  sense,  minute  bodies 
may  be  viewed  through  a  small  hole  in  a  piece  of  paper  or  card,  or 
with  the  instrument  called  a  microscope.  By  looking  through  the  small 
aperture  in  the  paper  or  card,  the  object  may  be  brought  much  nearer 
to  the  eye  ;  the  rays  of  greatest  divergence  are  prevented  by  the  small- 
ness  of  the  hole  from  impinging  upon  the  retina ;  and  the  rest  are 
converged  to  a  focus  upon  that  membrane,  so  that  a  sharp  and  distinct 
impression  is  received.  The  iris  is,  in  this  way,  useful  in  effecting  dis- 
tinct vision, — the  most  divergent  rays  being,  by  the  contraction  of  the 
pupil,  prevented  from  falling  upon  the  crystalline. 

Any  object  that  does  not  subtend  an  angle  of  the  sixtieth  of  a  degree 
is  invisible  ;  but  the  visual  power  differs  greatly  in  individuals.  Some 
eyes  are  much  more  capable  of  minute  inspection  than  others ;  and 
greater  facility  is  acquired  by  practice.  Professor  Ehrenberg,  how- 
ever, found,  that  in  regard  to  the  extreme  limits  of  vision,  there  is  little 
difference  among  persons  of  ordinarily  good  sight,  whatever  may  be  the 
focal  distance  of  their  eyes.  The  smallest  square  magnitude  usually 
visible  to  the  naked  eye,  either  of  white  particles  on  a  bLack  ground,  or 
of  black  upon  a  white  ground,  is  about  the  4  Jgth  of  an  inch  ;  but  parti- 
cles that  reflect  light  powerfully,  as  gold  dust,  may  be  discovered  with 
the  naked  eye  in  common  daylight,  when  not  exceeding  the  yVj^th  of 
an  inch  ;  and,  when  the  substance  viewed  is  in  lines  instead  of  particles, 
it  may  be  seen,  if  held  towards  the  light,  when  only  ^(jth  of  an  inch 
in  diameter. 

1  Op.  citat.,  p.  249. 


264  SENSE  OF  SIGHT. 

Again,  there  is  a  point  of  approximation  to  the  eye  beyond  which 
objects  cease  to  be  distinctly  seen,  in  consequence  of  the  rays  of  light 
striking  so  divergently  upon  the  eye,  that  the  focus  falls  behind  the 
retina.  This  point,  too,  varies  according  to  the  refractive  power  of 
the  eye  ;  and  is,  therefore,  different  in  different  individuals.  In  the 
myopic  or  short-sighted,  it  is  much  nearer  the  eye  than  common ;  in 
the  presbyopic  or  long-sighted,  more  distant.  The  iris  here,  again, 
plays  an  important  part,  by  its  action  in  shutting  off  the  most  diverging 
rays. 

There  is  also  a  limit  beyond  which  objects  are  no  longer  visible. 
This  is  owing  to  the  Light  from  them  becoming  absorbed  before  it  reaches 
the  retina,  or  so  feeble  as  not  to  make  the  necessary  impression.  The 
distance,  consequently,  at  which  an  object  may  be  seen,  will  depend 
upon  the  sensibility  of  the  retina,  and  partly  on  the  colour  of  the  ob- 
ject ;  a  light  colour  being  visible  to  a  greater  distance  than  a  darker. 
A  distant  object  may  also  be  imperceptible  owing  to  the  image,  traced 
on  the  retina,  being  too  minute  to  be  appreciated  ;  for  the  size  of  the 
image  diminishes  as  the  distance  of  the  object  increases.  The  range 
of  distinct  vision  varies,  likewise,  with  the  individual, — and  especially 
with  the  myopic  and  presbyopic ;  and  in  such  case  the  pupil  dilates  to 
admit  as  much  light  as  possible  into  the  interior  of  the  eye,  and  to  com- 
pensate in  some  measure  for  the  defect. 

Between  the  ranges  of  distant  and  near  vision,  a  thousand  different 
examples  occur.  In  all  cases,  however,  the  ocular  cone  must  be  brought 
to  a  focus  on  the  retina,  otherwise  there  cannot  be  perfect  vision.  It 
has  been  already  observed,  in  the  proem  on  light,  that  the  distance,  at 
which  the  ocular  cone  arrives  at  a  focus  behind  the  lens,  is  in  propor- 
tion to  the  length  of  the  objective  cone ;  or,  in  other  words,  that  the 
focus  of  a  lens  varies  with  the  distance  at  which  a  radiant  point  is 
situate  before  it :  where  the  point  is  near  the  lens  the  focus  will  be 
more  remote  behind  it ;  and  the  contrary.  If  this  occurs  in  the  human 
eye  it  must  necessarily  follow ; — either  that  it  is  not  necessary  for 
an  object  to  be  impressed  upon  the  retina ; — or  that  the  eye  is  capa- 
ble of  accommodating  itself  to  distances ; — or  if  it  does  not  occur,  it 
must  be  admitted,  that,  owing  to  the  particular  constitution  of  the  eye, 
the  impressions  are  so  made  on  the  retina  as  not  to  need  such  adapta- 
tion. The  whole  bent  of  the  foregoing  observations  on  vision  would 
preclude  the  admission  of  the  first  of  these  postulates.  The  second  has 
been  of  almost  universal  reception,  and  given  rise  to  many  ingenious 
speculations  ;  and  the  third  has  been  seriously  urged  of  late  years  only. 

It  would  occupy  too  much  space  to  dwell  at  length  upon  the  various 
ingenious  discussions,  and  the  many  interesting  and  curious  experiments, 
that  have  resulted  from  a  belief  in  the  power  possessed  by  the  eye  of 
accommodating  itself  to  distances.  It  is  a  subject,  however,  which 
occupies  so  large  a  field  in  the  history  of  physiological  opinions,  that 
it  cannot  be  passed  over.  The  chief  views,  that  have  been  entertained, 
are  : — First.  The  cornea  or  lens  must  recede  from,  or  approach  the 
retina,  according  to  the  focal  distance,  precisely  as  we  adapt  our  tele- 
scopes by  lengthening  or  shortening  the  tube.  Secondly.  If  we  suppose 
the  retina  to  be  stationary,  the  lens  must  experience  a  change  in  its 


ADAPTATION  OF  THE  EYE  TO  DISTANCES.  265 

refractive  powers,  by  an  alteration  of  its  shape  or  density  ;  or,  Thirdly. 
In  viewing  near  objects,  those  rays  only  must  be  admitted,  which  are 
nearest  the  axis  of  the  eye,  and  are  consequently  least  diverging. 

1.  The  hypothesis,  that  the  adjustment  of  the  eye  is  dependent  upon 
an  alteration  of  the  antero-posterior  diameter  of  the  organ,  or  on  the 
relative  position  of  the  humours  and  retina,  has  been  strongly  supported 
by  many  able  physiologists.  Blumenbach1  was  of  opinion,  and  his  views 
seem  to  have  been  embraced  by  Dr.  Hosack,2  that  the  four  straight 
muscles  of  the  eye,  by  compressing  the  eyeball,  cause  a  protrusion  of 
the  cornea,  and  thus  increase  the  length  of  the  axis.  Dr.  Monro  se- 
cundus3  believed,  that  the  iris,  recti  muscles,  the  two  oblique,  and  the 
orbicularis  palpebrarum  participate  in  the  accommodation;  and  Ham- 
berger,  Briggs,4  and  others,  that  the  oblique  muscles,  being  thrown  in 
opposite  directions  around  it,  may  have  the  effect  of  elongating  the 
axis  of  the  eye.  Kepler5  thought,  that  the  ciliary  processes  draw  the 
crystalline  forward,  and  increase  its  distance  from  the  retina.  Des 
Cartes6  imagined  the  same  contraction  and  elongation  to  be  effected  by 
muscularity  of  the  crystalline,  of  which  he  supposed  the  ciliary  pro- 
cesses to  be  the  tendons.  Porterfield,7  that  the  corpus  ciliare  is  con- 
tractile, and  capable  of  producing  the  same  effect.  Jacobson,8  that  the 
aqueous  humour,  by  entering  the  canal  of  Petit  through  the  apertures 
in  it,  distends  the  canal,  and  pushes  the  crystalline  forward.  Sir  Eve- 
rard  Home,9  that  the  muscular  fibres,  which  he  has  described  as  exist- 
ing between  the  ciliary  processes,  move  the  lens  nearer  to  the  retina, 
and  that  the  lens  is  brought  forward  by  other  means,  (which  he  leaves 
to  conjecture,)  when  the  distance  of  the  object  is  such  as  to  require  it. 
Dr.  Knox,10  that  the  annulus  albus,  or  the  part  which  unites  the  choroid 
and  sclerotic  coats,  is  muscular,  and  the  chief  agent  in  this  adjustment. 
Professor  Mile,11  of  Warsaw,  that  the  contraction  of  the  iris  changes 
the  curvature  of  the  cornea;  whilst  Sir  David  Brewster12  thinks  it 
"almost  certain,  that  the  lens  is  removed  from  the  retina  by  the  con- 
traction of  the  pupil." 

Without  examining  these  and  other  views  in  detail,  it  may  be  re- 
marked, that  the  nicest  and  most  ingenious  examination  by  the  late 
Dr.  Young13  could  not  detect  any  change  in  the  length  of  the  axis  of 
the  eyeball.  To  determine  this,  he  fixed  his  eye,  and  at  the  same  time 
forced  in  upon  the  ball  the  ring  of  a  key,  so  as  to  cause  a  very  accu- 
rately defined  phantom  within  the  field  of  perfect  vision;  then  looking 

1  Instit.  Physiolog.,  §  276,  or  Elliotson's  translation. 

2  Philosoph.  Transact,  for  1794,  p.  146. 

3  Three  Treatises  on  the  Brain,  the  Eye,  the  Ear,  p.  137,  Edinb.,  1797. 

4  Nova  Visionis  Theoria,  Lond.,  1685.  &  Haller,  Element.  Physiol.,  xvi.  4,  2. 

6  De  Homine,  p.  45,  Lugd.  Bat,  1664. 

7  A  Treatise  on  the  Eye,  the  Manner  and  Plienomena  of  Vision,  Edinb.,  1759. 

8  Magendie,  Precis,  &c.,  i.  78. 

9  Philosoph.  Transact,  for  1794,  1795,  1796,  and  1797;  and  Lectures  on  Comparative 
Anatomy,  iii.  213,  Lond.,  1823. 

10  Edinb.  Philos.  Transact.,  x.  56. 

»»  Magendie,  Journal  de  Physiologic,  vi.  166;  and  Elliotson's  Human  Physiology,  p.  571, 
Lond.,  1840. 

12  Edinburgh  Journal  of  Science,  i.  77;  and  Treatise  on  Optics,  op.  chat,  p.  253. 

13  Philos.  Transact,  for  1795. 


266  SENSE  OF  SIGHT. 

to  bodies  at  different  distances,  he  expected,  if  the  figure  of  the  eye 
were  modified,  that  the  spot,  caused  by  the  pressure,  would  be  altered 
in  shape  and  dimensions;  but  no  such  effect  occurred;  the  power  of 
accommodation  was  as  extensive  as  ever,  and  there  was  no  perceptible 
change  either  in  the  size  or  figure  of  the  oval  spot.  Again,  Sir  Everard 
Home  asserts,  that  all  the  ingenuity  of  the  distinguished  mechanician, 
Ramsden,  was  unable  to  decide,  whether,  in  the  adjustment  of  the  eye, 
there  be  any  alteration  produced  in  the  curvature  of  the  cornea.  These 
facts  would  alone  induce  a  doubt  of  the  existence  of  this  kind  of  adjust- 
ment, even  if  we  had  not  the  additional  evidence,  that  many  animals 
are  incapable  of  altering  the  shape  of  the  eyeball,  by  the  muscles  at 
least.  The  c%tacea,  the  ray  amongst  fishes,  and  the  lizard  amongst 
reptiles,  have  the  sclerotica  so  inflexible  as  to  render  any  variation  in  it 
impossible. 

With  regard  to  many  of  the  particular  views  that  have  been  men- 
tioned, they  are  mere  "cobwebs  of  the  brain,"  and  unworthy  of  serious 
argument.  In  the  action  of  the  orbicularis  palpebrarum,  as  suggested 
by  Dr.  Monro,  there  is,  however,  something  so  plausible,  that  many 
persons  have  been  misled  by  it.  He  made  a  set  of  experiments  to  show, 
that  this  muscle,  by  compressing  the  eyeball,  causes  the  cornea  to  pro- 
trude, and  thus  enables  the  eye  to  see  near  objects  more  distinctly. 
When  he  opened  his  eyelids  wide,  and  endeavoured  to  read  letters, 
which  were  so  near  the  eye  as  to  be  indistinct,  he  failed;  but  when  he 
kept  the  head  in  the  same  relation  to  the  book,  brought  the  edges  of 
the  eyelids  within  a  quarter  of  an  inch  of  each  other,  and  made  an  ex- 
ertion to  read,  he  found  he  could  see  the  letters  distinctly.  But  Sir 
Charles  Bell1  properly  remarks  on  this  experiment,  that  if  the  eyelids 
have  any  effect  upon  the  eyeball  by  their  approximation,  it  must  be  to 
flatten  the  cornea;  and  that  the  improvement  in  near  vision  produced 
by  such  approximation,  is  owing  to  the  most  divergent  rays  being  shut 
off, — as  in  the  experiment  of  the  pinhole  through  paper. 

2.  The  second  hypothesis,  which  attributes  the  adaptation  to  a  change 
of  figure  in  the  crystalline  itself,  has  been  embraced  by  all  who  regard 
that  body  to  be  muscular,  and  therefore  by  Leeuwenhoek,2  Des  Cartes,3 
and  Dr.  Young.4  These  muscular  fibres,  however,  could  never  be  ex- 
cited by  Dr.  Young  to  contraction  so  as  to  change  the  focal  power;  and 
their  very  existence  is  more  than  doubtful.  The  increasing  density  of 
the  lens  towards  its  centre  indicates  rather  a  cellular  structure,  the  cells 
being  filled  with  transparent  matter  of  various  degrees  of  concentration ; 
and  an  examination  into  its  intimate  physical  constitution  affords  no 
evidence  of  muscularity. 

Professor  Forbes,5  of  Edinburgh,  embraced  the  view,  that  the 
adaptation  is  owing  to  a  change  of  figure  in  the  crystalline ;  but  his 
explanation  of  its  mode  of  production  varies  from  that  given  by  pre- 

1  Anat.  and  Physiology,  Arner.  edit,  by  Dr.  Godman,  ii.  227,  New  York,  1827. 

2  Boerhaav.  Prselect.,  §  527,  torn.  iv.  p.  92;  and  Haller,  Element.  PhysioL  lib.  xvi.  sect.  2. 

3  Op.  cit.  4  Op.  citat. 

5  Proceedings  of  the  Royal  Society  of  Edinb.,  No.  25,  cited  in  the  Amer.  Journ.  of  the  Med. 
Sciences,  Oct.,  1845,  p.  504. 


ADAPTATION  OF  THE  EYE  TO  DISTANCES.  267 

ceding  writers.  The  lens,  he  says,  is  composed  of  coats  more  firm  and 
tenacious,  as  well  as  more  refractive  towards  the  centre,  and  less  so  at 
the  sides.  These  coats  are  also  nearly  spherical  in  the  centre,  forming 
a  nucleus  of  considerable  resistance.  Hence  he  supposes,  that  if  the 
lens  be  compressed  in  any  manner  by  a  uniform  hydrostatic  pressure, 
it  will  yield  more  readily  in  a  plane  at  right  angles  to  the  axis  of  vision ; 
and  the  lens  will  become  more  spheroidal,  and  consequently  more  re- 
fractive,— that  is,  adapted  for  the  vision  of  objects  at  small  distances. 
This  hydrostatic  pressure  is  believed  to  be  conveyed  from  the  humours 
of  the  eye,  between  which  the  lens  is  delicately  suspended,  and  to  ori- 
ginate in  the  action  of  the  muscles  that  move  the  eyeball  compressing 
simultaneously  the  tough  sclerotic  coat. 

It  is  somewhat  singular,  that  on  a  subject  where  so  many  opportuni- 
ties have  occurred  for  establishing  the  fact  definitively,  such  difference 
of  opinion  should  exist  regarding  the  question,  whether  an  eye  from 
which  the  crystalline  has  been  removed,  as  in  the  operation  for  cataract, 
be  capable  of  adjusting  itself  to  near  objects.  Haller1  and  Knox, 
amongst  others,  decide  the  question  affirmatively;  Porterfield,  Young, 
and  Travers,2  negatively.  M.  Magendie,  as  we  have  seen,  considers  the 
great  use  of  the  crystalline  to  be, — to  increase  the  brightness  and  sharp- 
ness of  the  image  by  diminishing  its  size.  Mr.  Travers  again,  regards 
the  adjustment  as  a  change  of  figure  in  the  lens;  not,  however,  from  a 
contractile  power  in  the  part  itself,  but  in  consequence  of  the  lamellae, 
of  which  it  is  composed,  sliding  over  each  other,  when  acted  upon  by 
external  pressure;  whilst  upon  the  removal  of  this  pressure,  its  elastic 
nature  restores  it  to  its  former  sphericity.  The  iris  is  conceived  to  be 
the  agent  in  this  process;  the  pupillary  part  of  the  organ  being,  in  the 
opinion  of  Mr.  Travers,  a  proper  sphincter  muscle,  which,  when  it  con- 
tracts and  relaxes,  tends,  by  the  intervention  of  the  ciliary  processes, 
to  effect  a  change  in  the  figure  of  the  lens,  which  produces  a  correspond- 
ing change  in  its  refractive  powers. 

3.  One  of  the  causes  to  which  the  faculty  of  seeing  at  different  dis- 
tances has  been  ascribed  is  the  contraction  and  dilatation  of  the  pupil. 
It  has  been  already  observed,  that  when  we  look  at  near  objects,  the 
pupil  contracts,  so  that  the 'most  divergent  rays  do  not  penetrate  the 
pupil;  and  vision  is  distinct.  Hence,  it  has  been  conceived  probable, 
by  De  La  Hire,3  Haller,4  and  others,  that  the  adjustment  of  the  eye  to 
various  distances  within  the  limits  of  distinct  vision  may  be  effected  by 
this  mechanism,  in  the  same  manner  as  it  regulates  the  quantity  of  light 
admitted  into  the  organ.  Certain  it  is,  that  if  we  look  at  a  row  of 
minute  objects,  extending  from  the  visual  point  outwards,  the  pupil  is 
seen  to  dilate  gradually  as  the  axis  of  the  eye  recedes  from  the  nearest 
object. 

An  experiment  made  by  the  author,  on  his  own  eye,5  when  a  student 
of  medicine,  has  been  quoted  by  Dr.  Fleming6  as  confirmatory  of  this 

1  Element.  Physiol.,  lib.  xvi.  sect.  4. 

*  A  Synopsis  of  the  Diseases  of  the  Eye,  Lond.,  1824. 

3  Memoir,  de  1'Acad.  des  Sciences  de  Paris,  torn.  ix.  p.  620. 

4  Element.  Physiol.,  torn.  v.  lib.  xvi.,  4. 

*  Annals  of  Philosophy,  x.  432.  6  Philosophy  of  Zoology,  i.  187,  Edinb.,  1822. 


268  SENSE  OF  SIGHT. 

view.  The  extract  of  belladonna  has  the  power,  when  applied  to  the 
eyelids,  of  dilating  the  pupil.  A  newly  prepared  article  was  thus  ap- 
plied, and  in  the  space  of  about  twenty  minutes  the  pupil  was  so  much 
dilated,  that  the  iris  was  almost  invisible.  From  the  time  that  preter- 
natural dilatation  occurred,  objects,  presented  to  this  eye  with  the  other 
closed,  were  seen  as  through  a  cloud.  The  focus  was  found  to  be  at 
twice  the  distance  of  that  of  the  sound  organ;  but,  in  proportion  as  the 
effects  of  the  belladonna  passed  off,  and  the  pupil  approached  its  natu- 
ral size,  vision  became  more  and  more  distinct,  and  the  focus  nearer  and 
nearer  the  natural.  In  the  open  air,  all  objects  except  those  near  were 
distinctly  seen;  but,  on  entering  a  room,  all  was  enveloped  in  mist. 

There  is,  indeed,  more  evidence  in  favour  of  the  utility  of  contraction 
and  dilatation  of  the  pupil  in  distinct  vision,  within  certain  limits  at 
least,  than  of  any  of  the  other  supposed  methods  of  adjustment;  and, 
accordingly,  the  majority  of  opticians  of  the  present  day  embrace  this 
view  of  the  subject;  but  without  being  able  to  explain  satisfactorily  the 
change  in  the  interior  of  the  eye  effected  by  its  movements.  "It  seems 
difficult,"  says  Sir  David  Brewster1 — one  of  the  latest  writers — "to 
avoid  the  conclusion,  that  the  power  of  adjustment  depends  on  the  me- 
chanism, which  contracts  and  dilates  the  pupil;  and  as  this  adjustment 
is  independent  of  the  variation  of  its  aperture,  it  must  be  effected  by 
the  parts  in  immediate  contact  with  the  base  of  the  iris.  By  consider- 
ing the  various  ways,  in  which  the  mechanism  at  the  base  of  the  iris 
may  produce  the  adjustment,  it  appears  to  be  almost  certain,  that  the 
lens  is  removed  from  the  retina  by  the  contraction  of  the  pupil."  The 
conclusion,  drawn  by  Sir  David,  does  not,  however,  impress  us  with  the 
same  degree  of  certainty. 

Muller2  thinks  it  most  probable,  that  the  faculty  of  the  eye,  which 
enables  it  to  adjust  itself  to  different  distances,  depends  on  an  organ, 
which  has  a  tendency  to  act  by  consent  with  the  iris,  but  yet  is  in  a  cer- 
tain degree  independent  of  it.  Reasoning  per  exclmionem,  he  thinks 
it  most  probable,  that  the  ciliary  body  has  this  motor  power,  and  this 
influence  on  the  position  of  the  lens;  but  admits,  that  we  have  no  posi- 
tive proof  of  its  possessing  contractility.  More  recently,  however, 
as  has  been  shown,3  the  existence  of  a  ciliary  muscle  has  been  de- 
monstrated, which,  by  its  contraction,  may  directly  or  indirectly  advance 
the  lens.  M.  Pouillet,  in  his  lectures  before  the  Faculte  des  Sciences 
of  Paris,4  explains  the  matter  with  no  little  confidence  by  the  double 
effect  of  the  crystalline  being  composed  of  different  layers,  and  the 
mobility  of  the  pupil ; — a  view,  which  had  been  previously  maintained 
in  its  essential  characters  by  Treviranus.5  As  these  layers  are  thinner 
towards  the  axis  of  the  crystalline  than  near  its  edges,  by  detaching 
them  successively  the  curvature  of  the  remainder  becomes  greater  and 
greater,  until  the  most  central  portion  has  the  shape  of  a  sphere. 
Hence,  such  an  apparatus  will  not  have  one  focus  only,  but  several, — 

1  Op.  citat,  p.  252.  a  Elements  of  Physiology,  by  Baly,  P.  v.  p.  1 150,  June,  1839. 

3  Baly  and  Kirkes,  Recent  Advances  in  the  Physiology  of  Motion,  the  Senses,  &c.,  p.  24, 
Lond.,  1848. 

4  Siemens  de  Physique  Experimental,  t.  iii.  p.  331,  Paris,  J832. 

5  Beitriige  zur  Anatora.  und  Physiol.  der  Sinnenwerkzeuge,  u.  s.  w.,  1828. 


ADAPTATION  OF  THE  EYE  TO  DISTANCES.  269 

as  many,  in  fact,  as  there  are  superposed  layers ; — the  foci  being  nearer 
and  nearer  as  we  approach  the  central  spherical  portion.  This  arrange- 
ment, he  says,  enables  us  to  see  at  all  distances,  inasmuch  as,  "having 
an  infinite  number  of  foci  at  our  disposal,  we  can  use  the  focus  that  suits 
the  object  we  are  desirous  of  viewing."  If,  for  example,  it  be  a  near 
object,  the  pupil  contracts,  so  as  to  allow  the  rays  to  fall  only  on  the 
central  parts;  if  more  distant,  the  pupil  is  dilated  to  permit  the  rays  to 
pass  through  a  part  that  has  a  more  distant  focus. 

It  is  obvious,  however,  that  in  such  a  case,  the  ordinary  inconve- 
nience of  the  aberration  of  sphericity  must  result;  for  when  the  pupil 
is  dilated,  the  rays  must  pass  through  the  more  marginal,  as  well  as 
the  central  part  of  the  lens.  M.  Pouillet  was  aware  of  this  difficulty, 
but  he  has  not  disposed  of  it  philosophically.  "It  may  be  said  that  in 
opening  the  pupil  widely,  the  light  is  not  precluded  from  passing  by 
the  centre,  and  that  a  kind  of  curtain  would  be  required  to  cover  the 
part  of  the  lens,  which  is  unemployed.  To  this  I  reply,  that  there  is 
no  necessity  to  prevent  the  rays  from  passing  by  the  axis  of  the  crys- 
talline ;  for  what  is  the  light,  which  passes  through  this  small  space, 
compared  with  that  which  passes  through  the  great  zone  of  the  crystal- 
line? It  may  be  looked  upon  as  null." 

It  must  be  admitted,  with  M.  Longet,1  that  if  the  fact  of  the  adapta- 
tion of  the  eye  to  vision  at  different  distances  be  received  as  incon- 
testable, the  mechanism  of  the  phenomenon  must  be  regarded  as  entirely 
unknown;  not  one  of  the  explanations  offered  being  able  to  carry 
conviction.  The  whole  affair  is,  indeed,  enveloped  in  perplexity,  and 
it  is  rendered  not  less  so  by  the  fact  mentioned  by  M.  Magendie,  that  if 
we  take  the  eye  of  an  albino  animal,  and  direct  it  towards  a  luminous 
object,  we  find  a  perfect  image  depicted  on  the  retina,  whatever  may 
be  the  distance  of  the  object; — the  image,  of  course,  being  smaller  and 
less  luminous  when  remote,  but  always  distinct.  Yet,  in  this  experi- 
ment, the  eye  being  dead,  there  can  be  neither  contraction  nor  dila- 
tation of  the  pupil.  This  result  has  induced  Magendie3 — and  not  too 
hastily,  we  think — to  draw  the  conclusion,  that  although  theory  may 
suggest,  that  there  ought  to  be  such  adaptation  as  has  been  presumed 
and  attempted  to  be  accounted  for,  observation  proves,  that  such  may 
not  be  the  case;  and,  consequently,  all  the  speculations  on  the  subject, 
however  ingenious  they  may  be,  must  fall  to  the  ground.  Dr.  Fletcher, 
too,  after  alluding  to  the  various  hypotheses  on  the  subject,  adds: — 
"It  appears  absurd  to  attempt  to  explain  a  fact  which  has  no  real 
existence,  since  it  has  never  been  proved  that  the  eyeball  has  any  ca- 
pability of  adapting  itself  to  different  distances,  or  that  any  such  adap- 
tation is  required."3  We  are,  indeed,  not  justified,  perhaps,  in  admit- 
ting more  than  a  slight  accommodation  from  the  contraction  of  the 
pupil  in  viewing  near  objects  effected  in  the  mode  already  explained. 
If  the  accommodation  existed  to  any  material  extent,  it  is  difficult  to 
understand,  why  minor  degrees  of  short  or  long-sightedness  should  not 

1  Traite  de  Physiologie,  ii.  70,  Paris,  1850. 

2  Precis  Elementaire,  i.  72. 

3  Rudiments  of  Physiology,  Part  iii.  p.  48,  Edinburgh,  1837. 


270  SENSE  OF  SIGHT. 

be  rectified.  Sir  Charles  Bell1  conceives,  "that  the  mechanism  of  the 
eye  has  not  so  great  a  power  of  adapting  the  eye  to  various  distances 
as  is  generally  imagined,  and  that  much  of  the  effect,  attributed  to 
mechanical  powers,  is  the  consequence  of  the  motion  of  the  pupil  and 
the  effect  of  light  and  of  attention.  An  object  looked  upon,  if  not 
attended  to,  conveys  no  sensation  to  the  mind.  If  one  eye  is  weaker 
than  the  other,  the  object  of  the  stronger  eye  alone  is  attended  to,  and 
the  other  is  entirely  neglected:  if  we  look  through  a  glass  with  one 
eye,  the  vision  with  the  other  is  not  attended  to."  "The  mind,"  he 
adds,  "not  the  eye,  harmonizes  with  the  state  of  sensation,  brightening 
the  objects  to  which  we  attend.  In  looking  on  a  picture  or  panorama, 
we  look  to  the  figures,  and  neglect  the  background;  or  we  look  to  the 
general  landscape,  and  do  not  perceive  the  near  objects.  It  cannot  be 
an  adaptation  of  the  eye,  but  an  accommodation,  and  association  of  the 
mind  with  the  state  of  the  impression." 

The  view,  which  we  have  expressed  upon  the  subject,  is  confirmed 
by  the  calculations  of  different  investigators.  From  the  refractive 
powers  of  the  different  media  of  the  eye  it-  was  calculated  by  Olbers, 
that  the  difference  between  the  focal  distances  of  the  images  of  an 
object  at  such  distance  that  the  rays  are  parallel,  and  of  one  at  the" 
distance  of  four  inches,  is  only  about  0.143  of  an  inch;  so  that  the 
change  in  the  distance  of  the  retina  from  the  lens  required  for  vision 
at  all  distances,  supposing  the  cornea  and  lens  to  maintain  the  same 
form,  would  not  be  more  than  about  a  line.  Again: — M.  de  Simonoff,2 
a  learned  Russian  astronomer,  asserts,  that  from  a  distance  of  four 
inches  to  infinity  the  changes  in  the  angle  of  refraction  are  so  small 
that  the  apices  of  luminous  cones,  in  a  properly  formed  eye,  must 
always  fall  within  the  substance  of  the  retina;  and  hence  no  variation 
in  the  shape  of  the  eye,  according  to  the  distance  of  the  object,  can  be 
necessary.  Such  facts  amply  justify  the  interrogatory  of  M.  Biot;3 — 
whether  the  aberration  of  the  focus  for  different  distances  may  not  be 
compensated  in  the  eye  by  the  intimate  composition  of  the  refractive 
bodies,  as  the  aberration  of  sphericity  probably  is?  Yet,  if  this  be  the 
case,  how  admirable  must  be  the  construction  of  such  an  instrument ! 
how  far  surpassing  any  effort  of  human  ingenuity !  an  instrument  capa- 
ble of  not  only  correcting  its  own  aberrations  of  sphericity,  and  refran- 
gibility,  but  of  seeing  at  all  distances.4 

It  has  been  before  observed,  that  the  visual  point  varies  in  different 
individuals.  As  an  average,  it  may  be  assumed  at  eight  inches  from 
the  eye.  There  are  many,  however,  who,  either  from  original  confor- 
mation of  the  organ,  or  from  the  progress  of  age,  wander  largely  from 
this  average;  the  two  extremes  constituting  myo-py  or  short-sightedness, 
and  presbyopy  or  long-sightedness. 

1  Anat.  and  Physiology,  edit,  cit.,  ii.  230. 

2  Magendie's  Journal  de  Physiologic,  torn.  iv.  and  Precis  de  Physiol.,  i.  73. 

3  Traite  de  Physiologic  Experimental,  Paris,  1816. 

4  Letters  of  Euler,  by  Sir    D.  Brewster,  Amer.  edit.,  i.  163,  New    York,  1833.     See,  on 
this  subject,  Volkmann,   Art.  Sehen,  in  Wagner's  Haridworterbuch  der  Physiologie,  14te 
Lieferurig,  s.  295,  Braunschweig,  1846;  and  Bily  and  Kirkes,  Recent  Advances  in  the  Phy- 
siology of  Motion,  the  Senses,  Generation  and  Development,  p.  20,  Lond.,  1848. 


MYOPIC  AND  PKESBYOPIC  EYE. 


271 


In  the  myopic  or  short-sighted  the  visual  point  is  so  close,  that  objects 
cannot  be  seen  unless  brought  near  the  eye.     This  defect  is  owing  to 
too  great  a  refractive  power   in   the 
transparent  parts  of  the  organ;  or  to  Fig.  1 19. 

too  great  a  depth  of  the  humours ;  or 
it  may  be  caused  by  unusual  convexity 
of  the  cornea  or  crystalline ;  or  from 
the  retina  being  too  distant  from  the 
latter.  From  any  one  or  more  of 
these  causes,  the  rays  of  light  pro- 
ceeding from  distant  objects,  are  Myopic  Vision, 
brought  to  a  focus  before  they  reach - 

the  retina,  and  the  objects  consequently  are  not  distinctly  visible. 
(Fig.  119.)  To  see  them  distinctly,  they  must  be  placed  close  to  the 
eye,  in  order  that  the  rays  may  fall  more  divergently;  and  the  focus 
be  thrown  farther  back  so  as  to  impinge  upon  the  retina.  The  defect 
may  be  palliated  by  the  use  of  concave  glasses,  which  render  the  rays, 
proceeding  from  the  object,  more  divergent.  It  is  by  no  means  unfre- 
quent  in  youth;  and  the  myope  has  been  consoled  with  the  common 
belief,  that,  in  the  progress  of  life,  and  in  the  alterations  which  take 
place  in  the  eye  from  age,  he  is  likely  to  see  well  without  spectacles, 
when  others  of  the  same  age  may  find  them  essential.  It  is  probable, 
however,  that  this  is,  in  many  cases  at  least,  a  vulgar  error;  as  we 
have  known  different  myopic  sexagenarians,  who  have  not  experienced 
the  slightest  improvement. 

The  presbyope,  presbytic,  or  long-sighted  labours  under  an  opposite 
defect.  The  visual  point  is  much  more  distant  than  the  average  ;  and 
he  is  unable  to  see  an  object  unless 

it  is  at  some  distance.     This  con-  Fig.  120. 

dition  is  owing  to  too  feeble  a  re- 
fractive power  in  the  transparent 
parts  of  the  eye;  to  insufficient 
depth  of  the  eyeball ;  to  too  close  an 
approximation  between  the  retina 
and  crystalline;  or  to  too  little  con- 
vexity of  the  cornea  or  crystalline ;  Presbyopic  Vision, 
so  that  the  rays  of  light  proceeding 

from  a  near  object  are  not  rendered  sufficiently  convergent  to  impinge 
upon  the  retina  ;  but  fall  behind  it.  This  defect,  which  is  experienced 
more  or  less  by  most  people  after  middle  age,  is  palliated  by  the  use  of 
convex  glasses,  which  render  the  rays  proceeding  from  an  object  more 
convergent,  and  enable  the  eye  to  refract  them  to  a  focus  farther  for- 
ward, or  on  the  retina. 

Although  the  presbyopic  eye  is  unusual  in  youth,  it  is  sometimes  met 
with.  A  young  friend,  at  ten  or  twelve  years  of  age,  was  compelled 
to  employ  spectacles  adapted  to  advanced  life ;  and  this  was  the  case 
with  several  of  the  members  of  a  family,  to  whom  the  arts  have  been 
largely  indebted  in  this  country.  One  of  them,  at  twenty,  was  com- 
pelled to  wear  spectacles  which  were  almost  microscopes. 

Both  the  myopic  and  the  presbyopic  conditions  exist  in  a  thousand 


272  SENSE  OP  SIGHT. 

degrees ;  and  hence  it  is  impossible  to  say,  a  priori,  what  is  the  precise 
lens,  that  will  suit  any  particular  individual.  This  must  be  decided 
by  trial.  The  opticians  have  their  spectacles  arbitrarily  numbered  to 
suit  different  periods  of  life;  but  each  person  should  select  for  himself 
such  as  will  enable  him  to  read  without  effort  at  the  usual  distance. 
A  degree  of  myopy  may  be  brought  on  by  long-protracted  attention 
to  minute  and  near  objects,  as  we  observe  occasionally  in  the  watch- 
maker and  engraver;  and,  again,  a  person  who  has  been  long  in  the 
habit  of  looking  out  for  distant  objects,  as  the  sailor,  or  the  watchman 
at  signal  stations,  is  rendered  less  fitted  for  minute  and  near  inspec- 
tion. During  the  domination  of  Napoleon,  when  the  conscript  laws 
were  so  oppressive,  the  young  men  frequently  induced  a  myopic  state, 
by  the  constant  use  of  glasses  of  considerable  concavity; — the  defect 
being  esteemed  a  sufficient  ground  of  exemption  from  military  service. 

Another  subject,  which  has  given  rise  to  much  disputation  and  ex- 
periment, is,  why,  as  we  have  two  eyes,  and  the  image  of  an  object  is 
impressed  upon  each  of  them,  we  do  not  see  such  object  double  ? 
Smith1  and  Buffon2  consider,  that  in  infancy  we  do  see  it  so;  and  that 
it  is  not  until  we  have  learned  by  experience, — by  the  sense  of  touch 
for  example, — that  one  object  only  exists,  that  we  acquire  the  power  of 
single  vision.  After  the  mind  has  thus  become  instructed  of  its  error, 
a  habit  of  rectification  is  attained,  until  it  is  ultimately  effected  uncon- 
sciously. The  objections  to  this  hypothesis  are  many  and  cogent. 
We  are  not  aware  of  any  instance  on  record,  jn  which  double  vision 
has  been  observed  in  those,  who,  having  laboured  under  cataract  from 
birth,  have  received  their  sight  by  an  operation;  and  we  are  obviously 
precluded  from  knowing  the  state  of  vision  in  the  infant,  although  the 
simultaneous  and  parallel  motions  of  the  eyes,  which  are  manifestly 
instinctive,  and  not  dependent  upon  habit,  would  induce  us  to  pre- 
sume, that  the  images  of  objects — as  soon  as  the  parts  have  attained 
the  necessary  degree  of  developement — are  made  to  fall  upon  corre- 
sponding points  of  the  retina.  It  may,  also,  be  remarked,  in  favour 
of  the  instinctive  nature  of  this  parallel  motion  of  the  eyes,  that  in  the 
blind, — although  we  may  find  much  irregularity  in  the  motions  of  the 
eyeball,  owing  to  no  necessity  existing  for  the  eyes  being  directed  to 
any  particular  point, — the  eyeballs  move  together,  unless  some  de- 
ranging influence  is  exerted.  The  truth  is,  as  we  have  already  ob- 
served, the  encephalon  is  compelled  to  receive  the  impression  as  it  is 
conveyed  to  it ;  and  even  in  cases,  in  which  we  are  aware  of  an  illu- 
sion, the  perception  of  the  illusion  still  exists  in  spite  of  all  experience. 
If  the  finger  be  pressed  on  one  side  of  the  eyeball,  an  object,  seen  in 
front,  will  appear  double,  and  the  perception  of  two  objects  will  be 
made  by  the  brain,  although  we  know  from  experience  that  one  only 
exists.  This  occurs  in  all  the  various  optical  illusions  to  be  presently 
mentioned. 

The  effect  of  intoxication  has  been  adduced  in  favour  of  this  hypo- 
thesis. It  is  said  that  in  these  cases  the  usual  train  of  mental  asso- 
ciation is  broken  in  upon,  and  hence  double  vision  results.  The  proper 

1  Optics,  Cambridge,  1738.  3  Memoir,  de  1'Academ.  des  Sciences,  1743. 


SINGLE  VISION.  273 

explanation,  however,  of  this  diplopia  of  the  drunkard  rests  upon  other 
grounds.  The  effects  of  inebriating  substances  on  the  brain  are  to 
interfere  with  all  its  functions;  and  most  sensibly,  with  the  voluntary 
motions,  which  become  irregularly  executed.  The  voluntary  muscles 
of  the  eye  partake  of  this  vacillation,  and  do  not  move  in  harmony, 
so  that  the  impressions  are  not  made  on  corresponding  points  of  the 
retina,  and  double  vision  necessarily  results. 

Another  hypothesis  has  been,  that  although  a  separate  impression 
is  made  upon  each  retina, — in  consequence  of  the  union  of  the  optic 
nerves,  the  impressions  are  amalgamated,  and  arrive  at  the  encephalon, 
so  as  to  cause  but  one  perception.  This  was  the  opinion  of  Briggs,1 
and  Ackermann;  and  at  one  time  it  was  generally  received.  Dr. 
Wollaston2  supposed  the  consentaneous  motion  of  the  eyes  to  be  con- 
nected with  the  partial  union  of  the  optic  nerves.  The  anatomical  and 
physiological  facts  relating  to  the  union  and  decussation  of  these  nerves 
have  already  engaged  us.  By  a  reference  to  that  subject  it  will  be 
found,  that  a  true  decussation  takes  place  between  them,  yet  that  each 
eye  probably  has  its  distinct  nerve  from  origin  to  termination;  and 
that  no  such  semi-decussation,  as  that  contended  for  by  Dr.  Wollaston, 
exists.  These  facts  are  unfavourable  to  the  hypothesis  of  amalgamation 
of  impressions:  besides,  if  we  press  slightly  on  the  eye,  we  have  a 
double  impression,  although  the  relation  of  the  optic  nerves  to  each 
other  is  the  same ;  and,  moreover,  the  same  explanation  ought  to  apply 
to  audition,  in  which  we  have  two  distinct  impressions,  but  only  a  single 
perception: — yet  no  one  conceives  that  the  auditory  nerves  decussate. 
The  fusion  of  the  two  images  into  one  seems  to  be  a  mental  operation. 

Another  opinion  has  been  maintained; — that  we  do  not  actually 
receive  the  perception  of  two  impressions  at  the  same  time;  and  that 
vision  consists  in  a  rapid  alternation  in  the  use  of  the  eyes,  according 
as  the  attention  is  directed  to  one  or  other  of  them  by  accidental  cir- 
cumstances. Such  was  the  opinion  of  M.  Dutours.3  A  modification 
of  this  view  was  entertained  by  M.  Le  Cat,4  who  asserts,  that,  although 
the  right  eye  is  not  always  the  most  powerful,  it  is  most  frequently 
employed;  and  Gall  denies,  that  we  use  both  eyes  at  the  same  time, 
except  in  the  passive  exercise  of  the  function.  In  active  vision,  he 
asserts,  we  always  employ  one  eye  only, — sometimes  one  and  sometimes 
the  other;  and  thus,  as  we  receive  but  one  impression,  we  necessarily 
see  but  one  object.  In  support  of  this  view,  he  remarks  that  in  many 
animals  the  eyes  are  situate  at  the  sides  of  the  head,  so  as  not  to  be 
capable  of  being  directed  together  to  the  same  object.  In  them,  con- 
sequently, one  eye  alone  can  be  used;  and  he  considers  this  a  presump- 
tion, that  such  is  the  case  in  man.  He  remarks  farther,  that  in  many 
cases  we  use  one  eye  by  preference,  in  order  that  we  may  see  better — 
as  in  shooting  or  in  taking  the  direction  of  objects  in  a  straight  line ; 
and  that  although,  in  other  cases,  both  eyes  may  be  open,  we  still 
use  but  one.  In  proof  of  this,  he  says,  if  we  place  a  small  object  be- 
tween the  eyes  and  a  lighted  body,  and  look  at  the  latter,  the  shade 
i 

1  Nova  Visionis  Theoria,  Lond.,  1685.  2  Philos.  Transact,  for  1824,  p.  222. 

3  Memoir,  presentees  a  1' Academic  cles  Sciences,  &c.,  t.  iii.  &  iv.  4  Op.  citat. 

VOL.  I. — 18 


274  SENSE  OF  SIGHT. 

does  not  fall  between  the  eyes,  on  the  root  of  the  nose,  as  it  ought  to 
do  if  the  body  were  looked  at  with  both  eyes ;  but  on  each  eye  alter- 
nately, according  as  the  one  or  the  other  is  directed  to  it;  and,  he 
adds,  if,  when  we  squint  voluntarily,  we  see  two  objects,  it  is  because 
one  eye  sees  passively,  whilst  the  other  is  in  activity.1 

Amongst  numerous  objections  to  this  view  of  the  subject,  a  few  may 
be  sufficient.  Every  one  must  have  observed  how  much  more  vividly 
an  object  is  seen  with  both  eyes  than  with  one  only.  The  difference 
according  to  Jurin2  is  a  constant  quantity;  and,  in  sound  eyes  of  the 
ordinary  degree  of  power,  amounts  to  one-thirteenth  of  the  whole  effect. 
But  we  have  experiment  to  show,  that  a  distinct  impression  is  made 
upon  each  eye.  If  a  solar  beam  be  admitted  into  a  dark  chamber,  and 
be  made  to  pass  through  two  glasses  of  tolerable  thickness,  but  of  dif- 
ferent colours,  placed  close  alongside  each  other,  provided  the  sight  be 
good  and  the  eyes  of  equal  power  the  light  perceived  will  not  be  of  the 
colour  of  either  of  the  glasses,  but  of  an  intermediate  shade;  and  if  this 
should  not  happen,  it  will  be  found,  that  the  eyes  are  of  unequal  power. 
When  such  is  the  case,  the  light  will  be  of  the  colour  of  the  glass  placed 
before  the  stronger  eye.  These  results  were  obtained  in  the  Cabinet 
de  Physique  of  the  Facult£  de  Medecine  of  Paris,  by  M.  Magendie,3  in 
the  presence  of  M.  Tillaye  the  younger. 

The  existence  of  this  double  impression  is  proved  in  another  way. 
If  we  place  any  tall,  slender  object  a  few  feet  before  us,  and  examine 
its  relative  situation  compared  with  a  spot  on  a  wall  in  the  distance, 
we  find,  that  if  the  spot  be  hidden  by  the  stick,  when  both  eyes  are 
open,  it  will  become  visible  to  each  eye,  when  used  singly;  and  be  seen 
on  the  side  of  the  stick  corresponding  to  the  eye  employed.  But  Pro- 
fessor Wheatstone4  has  instituted  experiments,  which  place  this  matter 
entirely  at  rest.  He  has  shown,  that  in  viewing  an  object  having 
length,  breadth,  and  thickness,  the  perspective  projections  upon  the 
two  retinae  differ  according  to  the  distance  at  which  the  object  is  placed 
before  the  eyes.  If  so  distant,  that  to  view  it  the  optic  axes  must  be 
parallel,  the  two  projections  are  precisely  similar;  but  if  so  near,  that 
to  view  it  the  optic  axes  must  converge,  a  different  perspective  pro- 
jection is  presented  to  each  eye,  and  these  perspectives  become  more 
dissimilar  as  the  convergence  of  the  optic  axes  becomes  greater.  Not- 
withstanding this  dissimilarity  between  the  two  pictures,  which  is  in 
some  cases  very  great,  the  object  is  still  seen  single,  although  not 
exactly  resembling  either  of  the  two  pictures  on  the  retinae. 

Having  thus  established,  that  the  mind  perceives  an  object  of  three 
dimensions  by  means  of  the  two  dissimilar  pictures  projected  by  it  on 
the  two  retinae,  Mr.  Wheatstone  inquired  what  would  be  the  visual 
effect  of  presenting  simultaneously  to  each  eye  instead  of  the  object 
itself  its  projection  on  a  plane  surface  as  it  appears  to  that  eye  ?  For 
this  purpose  he  imagined  an  instrument  which  he  calls  stereoscope.  It 

1  Adelon,  Physiologic,  2de  edit.,  i.  457,  Paris.  1829. 

2  Essay  appended  to  Smith's  Optics,  Cambridge,  1738;  and  Haller,  Element.  Physio!.,  lib. 
xvi.  4. 

3  Precis,  &c.,  i.  86.     Dutours,  in  Mem.  presentees  &  TAcadem.,  iii.  514,  &  iv.  499. 
*  Philosophical  Transactions,  P.  ii.,  Lond.,  1838. 


SINGLE  VISION. 


275 


consists  of  two  plane  mirrors,  with  their  backs  inclined  to  each  other  at 
an  angle  of  90°,  near  the  faces  of  which  two  monocular  pictures  are  so 
disposed,  that  their  reflected  images  are  seen  by  the  two  eyes,  each 
looking  into  one  of  the  mirrors  on  the  same  plane.  The  experiment 
may,  however,  be  made  sufficiently  well  by  the  subjoined  figures. 

Fig.  121. 


\ 


Binocular  Vision. — Professor  Wheatstone's  Experiment. 

Fix  the  right  eye  on  the  right-hand  figure,  and  the  left  eye  on  the 
left-hand  figure ;  hold  between  the  eyes,  in  front  of  the  nose,  the  board 
of  an  octavo  book.  The  two  figures  a  a  will  be  seen  to  approximate, 
and  to  run  into  one,  representing  the  skeleton  of  a  truncated  four-sided 
figure  in  bold  relief,  b; — a  fact,  which  shows,  that  the  visual  apprecia- 
tion of  solidity  or  projection  arises  from  the  combination  in  the  mind 
of  two  different  images.  These  could  not  exist  in  a  person  who  has 
never  had  more  than  one  eye ;  and  therefore  from  sight  alone  lie  could 
form  no  notion  of  solidity.  He  would  have  to  combine  with  sight  the 
evidence  afforded  by  touch. 

All  these  facts  demonstrate,  that  two  impressions  are  really  made  in 
all  cases, — one  on  each  eye ; — and  yet  the  brain  has  perception  of  but 


Fig.  122. 


Fig.  123. 


.binocular  Vision. 


one.  If  the  law  of  visible  direction,  which  Sir  David  Brewster  has 
pointed  out  (see  page  258),  be  adopted,  the  cause  of  single  vision  with 
two  eyes  must  be  admitted  as  a  necessary  consequence.  If  we  arc 


276 


SENSE  OF  SIGHT. 


Fig.  124. 


placed  at  one  end  of  a  room,  and  direct  the  axes  of  both  eyes  to  a  cir- 
cular aperture  in  a  window-shutter  at  the  other  end,  although  an  image 
of  this  aperture  may  be  formed  in  each  eye,  yet  because  the  lines  of 
visible  direction  from  similar  points  of  the  one  image  meet  the  lines 
of  visible  direction  from  similar  points  of  the  other,  each  pair  of 
similar  points  will  appear  as  one  point,  and  the  aperture  seen  by  one 
eye  will  exactly  coincide  with  the  aperture  seen  by  the  other.  But  if, 
when  an  object  is  seen  single  with  both  eyes,  we  press  one  eye  aside, 
the  image  formed  by  that  eye  will  separate  from  the  other  image,  and 
the  object  will  appear  double;  or,  if  the  axes  of  both  eyes  be  directed 
to  a  point  either  nearer  or  more  remote  than  the  aperture  in  the 
window-shutter,  then,  in  both  these  cases,  the  aperture  will  appear 
double,  because  the  similar  lines  of  visible  direction  no  longer  meet  at 
the  aperture.1  In  Fig.  122,  if  we  look  at  the  object  A,  the  more  dis- 
tant object,  B,  will  be  seen  double;  and  in  Fig.  123,  if  we  look  at  the 
object  B,  the  nearer  object  A  will  be  seen  double.  It  is  not  necessary, 

however,  that  the  axes  of  the  eyes  should 
be  directed  accurately  on  an  object,  in 
order  that  it  shall  be  seen  single  with  both 
eyes.  A  whole  range  of  objects  may  be 
seen  single  if  their  images  are  thrown  on 
corresponding  parts  of  the  retina  in  both 
eyes,  as  in  Fig.  124. 

After  all,  perhaps  the  true  condition  of 
single  vision  is,  that  the  two  images  of  an 
object  should  be  formed  on  portions  of  the 
two  retinae  that  are  accustomed  to  act  in 
concert.  In  cases  of  convergent  strabis- 
mus, the  patient  does  not  see  double;  but 
immediately  after  a  successful  operation, 
if  the  vision  of  the  two  eyes  be  good,  he 
does  so;  and  this  continues  until  the  parts  of  the  two  retinae  have 
become  habituated  to  act  in  concert. 

In  the  course  of  the  preceding  remarks,  it  was  stated,  that  the  eyes 
are  not  always  of  the  same  power.  The  difference  is  sometimes  sur- 
prising. M.  Adelon2  mentions  the  case  of  a  person,  one  of  whose  eyes 
required  a  convex  glass,  with  a  focus  of  five  inches;  the  other  a  concave 
glass,  with  a  focus  of  four  inches.  In  these  cases,  it  is  important  to 
use  one  unassisted  eye  only ;  as  confusion  must  necessarily  arise  from 
directing  both  to  an  object.  This  is  the  cause  why  we  close  one  eye 
in  looking  through  a  telescope.  The  instrument  has  the  effect  of  ren- 
dering the  focal  distance  of  the  two  eyes  unequal,  and  of  placing  them 
in  the  same  situation  as  if  they  were,  originally,  of  different  powers. 

From  what  has  been  said  it  will  be  understood,  that  if  from  any 
cause,  as  from  a  tumour  pressing  upon  one  eyeball,  from  morbid 
debility  of  the  muscles,  or  from  want  of  correspondence  in  the  sensi- 
bility of  the  two  retinae,  the  eyes  be  not  properly  directed  to  an  object, 

1  Optics,  p.  44,  in  Library  of  Useful  Knowledge,  Natural  Philosophy,  vol.  i.,  Lond.,  1829, 
and  Treatise  on  Optics,  edit.  cit. 
3  Physiologie,  edit,  cit.,  i.  459. 


Binocular  Vision. 


MULTIPLE  VISION  WITH  ONE  EYE.  277 

double  vision  will  be  the  consequence.  In  almost  all  cases,  however, 
of  distortion  of  the  eyeballs,  the  image  falls  upon  a  part  of  one  retina, 
which  is  more  sensible  than  the  portion  of  the  other  on  which  it  falls; 
the  consequence  will  be,  that  the  mind  will  acquire  the  habit  of  attend- 
ing to  the  impression  on  one  eye  only;  and  the  other  may  be  so  neg- 
lected, that  it  will  assume  a  position  to  interfere  as  little  as  possible 
with  the  vision  of  its  fellow: — so  that,  although  at  first,  in  squinting, 
there  may  be  a  double  impression,  vision  is  ultimately  single.  Buffon,1 
who  was  of  this  opinion,  affirms,  that  he  examined  the  eyes  of  many 
squinters,  and  found  that  they  were  of  unequal  power ;  the  weaker,  in 
all  cases,  having  turned  away  from  its  direction,  and  generally  towards 
the  nose,  in  order  that  fewer  rays  might  reach  it,  and  consequently 
vision  be  less  interfered  with.  Yet  it  is  always  found,  if  the  sound 
eye  be  closed,  that  the  other  resumes  its  proper  direction;  a  fact  which 
disproves  the  idea  of  De  La  Hire2  and  others  that  the  cause  of  strabis- 
mus or  squinting  is  a  difference  of  sensibility  in  the  corresponding 
points  of  the  retinae,  and  that  the  discordance  in  the  movements  of 
the  organs  occurs  in  order  that  the  images  may  still  fall  upon  points 
of  the  retinae  that  are  equally  sensible.  According  to  this  view,  both 
eyes  must  of  course  act. 

The  fact  of  the  diverted  eye  resuming  its  proper  direction  when  the 
sound  one  is  closed  is  of  practical  application.  Many  of  the  cases  of 
squinting  that  occur  in  infancy  have  been  caused  by  irregular  action 
in  the  muscles  of  the  eyeball ;  so  that  certain  of  them,  from  accident 
or  imitation,  having  been  used  more  frequently  than  others,  the  due 
equilibrium  has  not  been  maintained;  double  vision  has  resulted;  and 
the  affected  eye  has  gradually  attained  its  full  obliquity.  In  these 
cases,  we  can,  at  times,  remedy  the  defect,  by  placing  a  bright  or  con- 
spicuous object  in  such  a  position  as  to  exercise  the  enfeebled  muscles ; 
or,  we  can  compel  the  whole  labour  of  vision  to  be  effected  by  one  eye, 
and  that  the  affected  one,  which,  under  the  stimulus,  will  be  correctly 
executed,  and,  by  perseverance,  the  inequality  may  be  obviated. 
These,  indeed,  are  the  only  cases  in  which  we  can  expect  to  afford 
relief ;  for  if  the  defect  be  in  the  interior  of  the  eye,  in  a  radical  want 
of  correspondence  between  the  retinae,  or  in  inequality  of  the  foci,  it  is 
irremediable. 

It  would  appear,  then,  that  in  confirmed  squinting,  one  eye  is  mainly, 
if  not  solely  used,  and  vision  is  single, — and  that  the  inclination  of  one 
eye  inwards  may  be  so  great  as  to  deprive  it  of  function,  or  so  slight  as 
to  allow  the  organ  to  receive  rays  from  the  same  object  as  its  fellow, 
and  although  on  different  parts  of  the  retina,  yet  they  may  become  asso- 
ciated; but,  in  either  case,  it  would  seem,  that  they,  who  squint  habitu- 
ally, neglect  the  impressions  on  the  distorted  eye,  and  see  with  but  one. 

It  has  been  remarked,  that  the  eyeball  of  the  imperfect  eye  is  drawn 
towards  the  nose,  in  order  that  as  few  rays  as  possible  may  penetrate 
the  organ,  and  the  vision  of  the  sound  eye  be  less  liable  to  confusion. 
Sir  Everard  Home3  conceives,  that  it  takes  this  direction  in  consequence 

1  Mem.  de  1' Academic,  1743,  p.  231. 

*  Ibid.,  torn.  ix.  530;  Jurin,  in  Essay  appended  to  Smith's  Optics,  §§  178-194. 

3  Philos.  Transact.,  1797,  and  Lectures  on  Comparative  Anatomy,  iii.  238,  Lond.,  1823. 


278  SENSE  OF  SIGHT. 

of  the  adductor  muscle  being  stronger,  shorter,  and  its  course  more  in 
a  straight  line  than  that  of  any  of  the  other  muscles  ;  and  Sir  Charles 
Bell1  ingeniously  applies  his  classification  of  the  muscles  of  the  eye  to 
an  explanation  of  the  fact.  He  asserts,  that  the  recti  muscles  are  in 
activity  whilst  attention  is  paid  to  the  impression  on  the  retina, — but 
that,  when  the  attention  is  withdrawn,  the  recti  are  relieved,  and  the 
eyeball  is  given  up  to  the  influence  of  the  oblique  muscles,  whose  state 
of  equilibrium  exists  when  the  eyeball  is  turned,  and  the  pupil  pre- 
sented, upwards  and  inwards. 

Lastly,  in  persons  who  are  in  the  habit  of  making  repeated  celestial 
observations,  or  in  those  who  make  much  use  of  the  microscope,  the 
attention  is  so  entirely  directed  to  one  eye,  that  the  other  is  neglected, 
and,  in  time,  wanders  about,  so  as  to  produce  squinting  at  the  pleasure 
of  the  individual.  In  these  cases,  the  eyes  become  of  unequal  power  ; 
so  that  one  only  can  be  employed  where  distinct  vision  is  required. 

Thus  far  our  remarks  have  been  directed  to  double  vision,  where 
both  eyes  are  employed.  We  have  now  to  mention  a  singular  fact  con- 
nected with  double  and  multiple  vision  with  one  eye  only.  The  author 
has  distinct  double  vision  with  each  eye  ;  a  lighted  lamp,  for  example, 
presenting  to  one,  with  the  other  closed,  two  defined  images,  the 
one  in  advance  of  the  other.  If  a  hair,  a  needle,  or  any  small  object 
be  held  before  one  eye — the  other  being  closed — and  within  the  point 
of  distinct  vision,  so  that  the  bright  light  of  a  lamp  or  from  a  window 
shall  fall  upon  the  object  in  its  passage  to  the  eye,  or  be  reflected  from 
it — we  appear  to  see  not  one  object  but  many.  This  fact,  when  it  was 
first  observed  by  the  author,  appeared  to  him  to  have  escaped  the  ob- 
servation of  opticians  and  physiologists,  inasmuch  as  it  had  not  been 
noticed  in  any  of  the  works  recently  published  on  optics  or  physiology. 
On  reference,  however,  to  the  excellent  "  system,"  of  Smith,2  on  the  for- 
mer subject,  he  found  in  the  "Essay  upon  Distinct  and  Indistinct  Vision" 
by  Dr.  Jurin,  appended  to  it,  the  whole  phenomenon  explained,  and  elu- 
cidated at  considerable  length.  The  elaborate  character  of  the  expla- 
nation is  probably  the  cause,  why  the  fact  has  not  been  noticed  by  sub- 
sequent writers.  The  best  way  of  trying  the  experiment  is  that  sug- 
gested by  Dr.  Jurin.  Take  a  parallel  ruler,  and  opening  it  slightly, 
hold  it  directly  before  the  eye,  so  as  to  look  at  a  window  or  lamp  through 
the  aperture.  If  the  ruler  be  held  at  the  visual  point,  the  aperture  will 
appear  to  form  one  luminous  line ;  but  if  it  be  brought  nearer  to  the 
eye,  it  will  appear  double  ;  or  as  two  luminous  lines,  with  a  dark  line 
between  them  ;  and  according  as  the  aperture  is  varied — or  the  dis- 
tance from  the  eye — two,  three,  four,  five  or  more  luminous  and  dark 
parallel  lines  will  be  perceptible. 

At  first  sight,  it  might  seem,  that  this  phenomenon  should  be  referred 
to  the  diffraction  or  inflection,  which  light  experiences  in  passing  by  the 
edges  of  a  small  body, — as  the  hair  or  needle.  Newton  had  long  ago 
shown,  that,  when  a  beam  of  light  shines  upon  a  hair,  the  hair  will  cast 
several  distinct  shadows  upon  a  screen,  and,  of  course,  present  several 
images  to  the  eye.  Dr.  Bittenhouse3  explains,  on  the  same  principle,  a 

i  Anat.  and  Physiol.,  edit,  cit.,  ii.  235.  2  Optics,  edit.  cit. 

3  Amer.  Philos.  Transact.,  vol.  ii. 


MULTIPLE  VISION  WITH  ONE  EYE.  279 

curious  optical  appearance,  noticed  by  Mr.  Hopkinson,  in  which,  by  the 
inflection  of  light,  caused  by  the  threads  of  a  silk  handkerchief,  a  mul- 
tiple image  of  a  distant  lamp  was  presented.  The  objections,  however, 
to  the  explanation  by  inflection  are, — that  the  image  always  appears  sin- 
gle, if  the  object  be  not  within  the  distance  of  distinct  vision  ; — and 
that  the  same  multiple  image  is  presented,  when  the  object  is  seen  by 
reflection,  as  when  we  look  at  a  fine  line  drawn  upon  paper ;  or  at  a  fine 
needle  held  in  a  bright  light.  In  this  case,  a  considerable  number  of 
parallel  images  of  the  needle  may  be  seen,  all  equally  or  nearly  equally 
distinct ;  and  not  coloured. 

Dr.  Jurin  considers  the  phenomena  to  be  caused  by  fits  of  easy  re- 
fraction and  reflection  of  light.  Newton  demonstrated,  that  the  rays 
of  light  are  not,  in  all  parts  of  their  progress,  in  the  same  disposition 
to  be  transmitted  from  one  transparent  medium  into  another ;  and  that 
sometimes  a  ray,  which  is  transmitted  through  the  surface  of  the  second 
medium,  would  be  reflected  back  from  that  surface,  if  the  ray  had  a 
little  farther  to  go  before  it  impinged  upon  it.  This  change  of  dispo- 
sition in  the  rays, — to  be  either  transmitted  by  refraction,  or  to  be  re- 
flected by  the  surface  of  a  transparent  medium, — he  called  their  jits  of 
easy  refraction,  and  fits  of  easy  reflection;  and  he  showed,  that  these 
fits  succeed  each  other  alternately  at  very  small  intervals  in  the  pro- 
gress of  the  rays.  Newton  does  not  attempt  to  explain  the  origin  of 
these  fits,  or  the  cause  that  produces  them  ;  but  it  has  been  suggested, 
that  a  tolerable  idea  of  them  may  be  formed  by  supposing,  that  each 
particle  of  light,  after  its  emanation  from  a  body,  revolves  round  an 
axis  perpendicular  to  the  direction  of  its  motion,  and  presents  alter- 
nately to  the  line  of  its  motion  an  attractive  and  a  repulsive  pole,  in 
virtue  of  which  it  will  be  refracted,  if  the  attractive  pole  be  nearest  any 
refracting  surface  on  which  it  falls ;  and  reflected,  if  the  repulsive  pole 
be  nearest  the  surface. 

A  less  scientific  notion  of  the  hypothesis  has  been  suggested ;  by  sup- 
posing a  body  with  a  sharp  and  a  blunt  end  passing  through  space,  and 
successively  presenting  its  sharp  and  blunt  ends  to  the  line  of  its  mo- 
tion. When  the  sharp 

end  encounters  any  soft  Fis-  125- 

body  it  penetrates  it ; 
but  when  the  blunt  end 
encounters  the  same  body, 
it  is  reflected  or  driven 
back.  In  applying  this 
explanation  to  the  pheno- 
menon in  question,  Dr. 
Jurin  presumes,  that  the 
light,  in  passing  through 
the  humours  of  the  eye, 
experiences  these  fits  of 
easy  refraction  and  easy 

nj      .  m,  .         .,,    ,J  Multiple  Vision  with  One  Eye. 

reflection.      Inis  will  be 

elucidated  by  the  marginal  figure,  Fig.  125.      Suppose  a  number   of 

rays  of  light  to  proceed  from  the  point  A,  and  to  impinge,  with  dif- 


280 


SENSE  OF  SIGHT. 


ferent  degrees  of  obliquity,  on  the  denser  medium,  B  C  ;  all  the 
that  are  in  fits  of  easy  refraction  will  pass  through  the  medium  to 
the  point  D ;  whilst  those  that  are  in  fits  of  easy  reflection,  will  be 
thrown  back  into  the  medium  ABC;  so  that  we  may  presume,  that 
all  the  rays,  which  fall  upon  the  parts  of  the  medium  B  C,  correspond- 
ing to  the  bases  of  the  dark  cones,  will  be  reflected  back,  whilst  those 
that  correspond  to  the  bases  of  the  light  cones,  will  pass  to  a  focus  at 
D.  Now,  if  all  the  bundles  of  rays,  trans- 
mitted through  the  surface  B  C,  be  accurately 
collected  into  a  focus,  no  other  consequence 
will  arise  from  the  other  bundles  of  rays  hav- 
ing been  reflected  back,  than  that  the  focus  will 
be  less  luminous  than  it  would  have  been  had 
all  the  rays  been  transmitted  through  it.  This 
explains  why,  at  the  distance  of  distinct  vision, 
we  have  only  a  single  impression  made  on  the 
eye.  But  if  we  approach  the  object  A,  so  that 
the  focus  is  not  thrown, — say  upon  the  screen 
R  T,  which  may  be  presumed  to  represent  the 
retina  —  but  behind  it ;  the  dark  and  light 
spaces  will  be  represented  upon  the  screen, 
and,  of  course,  in  concentric  circles.  This  hap- 
pens to  the  eye,  when  the  hair  or  .needle  or 
other  object  is  brought  nearer  to  it  than  the 
visual  point.  We  can  thus  understand,  why 
concentric  circles,  of  the  nature  mentioned, 
should  be  formed  upon  the  retina ;  but  how  is 
it,  that  the  objects  seen  preserve  their  linear 
form  ?  Suppose  a  b,  Fig.  126,  to  be  a  luminous 
cone,  which  in  a  fit  of  easy  refraction  has  im- 
pinged upon  the  retina ;  and  A  B,  b  a,  the  concentric  circles,  corre- 
sponding to  the  rays  that  have  been  reflected.  It  is  obvious,  that  every 
point  of  the  object  will  be  the  centre  of  so  many  concentric  circles  on 
the  retina  ;  and  if  we  imagine  the  fits  of  easy  reflection  and  refraction 
to  be  the  same  around  those  points,  we  shall  have  the  dark  and  lucid 
lines  represented  by  the  tangents  to  these  circles  ;  and  hence  we  can 
comprehend  why,  instead  of  having  one  lucid  line  e  f,  we  have  three, 
separated  by  dark  lines  parallel  to  them ;  and  if  the  light  from  the 
luminous  point  be  strong  enough  to  form  more  lucid  rings  than  are  re- 
presented in  Fig.  126,  and  the  breadth  of  those  rings  be  not  too  minute 
to  be  perceived,  we  may  have  the  appearance  of  five,  seven,  or  more 
lucid  lines,  separated  by  parallel  dark  lines. 

The  undulatory  theory  of  light  offers  another  explanation  of  the 
phenomenon  of  fits.  The  waves  in  the  luminous  ether  along  a  ray  of 
light,  may  meet  the  surface  of  a  transparent  body  in  different  conditions 
of  condensation  or  rarefaction,  and  their  transmission  or  reflection  may 
be  determined  by  these  conditions. 

We  proceed  now  to  consider  the  advantages,  which  the  mind  derives 
from  the  possession  of  this  sense,  so  pre-eminently  entitled  to  the  epithet 


G       c  e  E 

Multiple  Vision  with  One  Eye 


INSENSIBILITY  OF  THE  EYE  TO  COLOURS.  281 

intellectual.  Its  immediate  function  is  to  give  us  the  sensation  of  light 
and  colour.  In  this  it  cannot  be  supplied  by  any  of  the  other  senses. 
The  action  is,  therefore,  the  result  of  organization ;  or  is  a  "  law  of 
the  constitution;"  requires  no  education;  but  is  exercised  as  soon  as 
the  organ  has  acquired  the  proper  developement.  Yet,  occasionally, 
we  meet  with  cases,  in  which  the  eye  appears  to  be  totally  insensible 
to  certain  colours,  although  capable  of  performing  the  most  delicate 
functions  of  vision.  Sir  David  Brewster1  has  collected  several  of  these 
cases  from  various  sources.  A  shoemaker  of  the  name  of  Harris,  at 
Allonby,  in  Cumberland,  could  only  distinguish  black  and  white;  and 
whilst  a  child,  could  not  discriminate  the  cherries  on  a  tree  from  the 
leaves,  except  by  their  shape  and  size.  Two  of  his  brothers  were  almost 
equally  defective.  One  of  them  constantly  mistook  orange  for  grass 
green,  and  light  green  for  yellow.  A  Mr.  Scott,  who  describes  his  own 
case,2  mistook  pink  for  pale  blue,  and  full  red  for  full  green.  His 
father,  his  maternal  uncle,  one  of  his  sisters,  and  her  two  sons,  had  the 
same  defect.  A  Mr.  R.  Tucker,  son  of  Dr.  Tucker,  of  Ashburton, 
mistakes  orange  for  green,  like  one  of  the  Harrises ;  and  cannot  dis- 
tinguish blue  from  pink,  but  almost  always  knows  yellow.  He  mistakes 
red  for  brown,  orange  for  green,  and  indigo  and  violet  for  purple.  A 
tailor  at  Plymouth,  whose  case  is  described  by  Mr.  Harvey,3  of  Ply- 
mouth, regarded  the  solar  spectrum  as  consisting  only  of  yellow  and 
light  blue;,  and  he  could  distinguish,  with  certainty,  only  yellow,  white 
and  gray.  He  regarded  indigo  and  Prussian  blue  as  black;  and  purple 
as  a  modification  of  blue.  G-reen  puzzled  him  exceedingly;  the  darker 
kinds  appearing  to  him  brown,  and  the  lighter  kinds  a  pale  orange. 
On  one  occasion,  he  repaired  an  article  of  dress  with  crimson  instead 
of  black  silk ;  and  on  another  occasion  patched  the  elbow  of  a  blue 
coat  with  a  piece  of  crimson  cloth.  A  still  more  striking  case  is  given 
by  Dr.  Nicholls4  of  a  person  in  the  British  navy,  who  purchased  a  blue 
uniform  coat  and  waistcoat,  with  red  breeches  to  match.  Sir  David 
Brewster  refers  to  a  case  that  fell  under  his  own  observation,  where 
the  gentleman  saw  only  the  yellow  and  blue  colours  of  the  spectrum. 
This  defect  was  experienced  by  Mr.  Dugald  Stewart,5  who  was  unable 
to  perceive  any  difference  between  the  colour  of  the  scarlet  fruit  of  the 
Siberian  crab  and  that  of  its  leaves.  Dr.  Dalton,6  the  chemist  and 
philosopher, — after  whom  the  defect  has  been  most  unjustifiably  termed 
daltonism, — could  not  distinguish  blue  from  pink  by  daylight ;  and  in 
the  solar  spectrum,  the  red  was  scarcely  visible ;  the  rest  of  it  appear- 
ing to  consist  of  two  colours,  yellow  and  blue.  Mr.  Troughton,  the 
optician,  was  fully  capable  of  appreciating  only  blue  and  yellow;  and 
when  he  named  colours,  the  terms  blue  and  yellow  corresponded  to  the 
more  or  less  refrangible  rays : — all  those  that  belong  to  the  former, 
exciting  the  sensation  of  blueness ;  and  those  that  belong  to  the  latter 
that  of  yellowness.  Dr.  Hays,7  who  has  collected  the  history  of  nume- 

1  Optics,  edit,  cit;  Letters  on  Natural  Magic;  and  art.  Optics,  in  Library  of  Useful  Know- 
ledge. 

2  Philos.  Trans,  for  1778.  3  Edinb.  Phil.  Transact.,  x.  253. 
4  Medico-Chirurgical  Trans.,  vii.  477,  ix.  359. 

6  Elements  of  the  Philosophy  of  the  Human  Mind,  ch.  iii. 

6  Manchester  Memoirs,  v.  28. 

7  Proceedings  of  the  American  Philosophical  Society  for  August  21,  1840. 


282  SENSE  OF  SIGHT. 


. 


rous  cases  of  achromatopsia, — as  this  defect  has  been  termed, — and 
has  added  the  history  of  one  which  fell  under  his  own  care,  was  led  to 
infer,  from  all  his  researches :  1,  that  entire  inability  of  distinguishing 
colours  may  co-exist  with  perfect  ability  to  perceive  the  forms  of  objects ; 
2,  that  the  defect  may  extend  to  all  but  one  colour,  and  in  such  case 
the  colour  recognised  is  always  yellow ;  and,  3,  that  the  defect  may 
extend  to  all  but  two  colours,  and  in  such  case  the  colours  recognised 
are  always  yellow  and  blue  ; — yet  that  this  is  not  the  fact  is  sufficiently 
shown  by  the  examples  already  given.  Dr.  Pliny  Earle1  has  referred 
to  a  number  of  cases,  which  came  within  his  knowledge,  and  most  of 
them  under  his  own  observation,  in  which  the  inability  would  seem  to 
have  been  hereditary.  Dr.  Earle's  maternal  grandfather  and  two  of 
his  brothers  were  characterized  by  it ;  and  among  the  descendants  of 
the  first  mentioned,  it  is  met  with  in  seventeen.  When  thus  entailed, 
it  would  appear  to  overleap,  at  times,  one  generation  or  more.  It  would 
appear,  too,  that  males  are  more  frequently  affected  than  females.  Dr. 
Earle  observed,  that  the  power  of  accurately  distinguishing  colours 
varies  at  different  times  in  the  same  person ;  and  that  it  is  not  unfre- 
quently  connected  with,  or  accompanied  by,  a  defect  in  the  power  of 
discriminating  musical  tones. 

The  opinions  of  philosophers  have  varied  regarding  the  cause  of 
this  singular  defect  in  eyes  otherwise  sound,  and  capable  of  performing 
every  other  function  of  vision  in  the  most  delicate  and  accurate  man- 
ner. By  some,  it  has  been  presumed  to  arise  from  a  deficiency  in  the 
visual  organ;  and  by  such  as  consider  the  ear  to  be  defective  in  func- 
tion in  those  that  are  incapable  of  appreciating  musical  tones,  this  de- 
ficiency in  the  eye  is  conceived  to  be  of  an  analogous  nature ;  and  the 
analogy  is  farther  exhibited  by  the  facts,  just  mentioned,  observed  by 
Dr.  Earle.  "  In  the  sense  of  vision,"  says  Dr.  Brown,2  "  there  is  a 
species  of  defect  very  analogous  to  the  want  of  musical  ear, — a  defect 
which  consists  in  the  difficulty,  or  rather  the  incapacity,  of  distinguish- 
ing some  colours  from  each  other — and  colours  which,  to  general 
observers,  seem  of  a  very  opposite  kind.  As  the  .want  of  musical  ear 
implies  no  general  defect  of  mere  quickness  of  hearing,  this  visual 
defect,  in  like  manner,  is  to  be  found  in  persons  who  are  yet  capable 
of  distinguishing,  with  perfect  accuracy,  the  form,  and  the  greater  or 
less  brilliancy  of  the  coloured  object ;  and  I  may  remark,  too,  in  con- 
firmation of  the  opinion,  that  the  want  of  musical  tone  depends  on 
causes  not  mental  but  organic,  that  in  this  analogous  case  some  at- 
tempts, not  absolutely  unsuccessful,  have  been  made  to  explain  the 
apparent  confusion  of  colours  by  certain  peculiarities  of  the  external 
organ  of  sight." 

Dr.  Dalton,  who  believed  the  affection  to  be  seated  in  the  physical 
part  of  the  organ,  has  endeavoured  to  explain  his  own  case,  by  sup- 
posing, that  the  vitreous  humour  is  blue,  and  therefore  absorbs  a  great 
portion  of  the  red  and  other  least  refrangible  rays ;  and  Sir  David 
Brewster,  in  the  "Library  of  Useful  Knowledge,"3  appears  to  think 

1  American  Journal  of  the  Medical  Sciences,  April,  1845,  p.  346. 

2  Lectures  on  the  Philosophy  of  the  Human  Mind,  vol.  i.,  Boston,  1826. 

3  Natural  Philosophy,  vol.  i.,  Optics,  p.  50,  Lond.,  1829. 


APPRECIATION  OF  DISTANCES.  283 

that  it  may  depend  upon  a  want  of  sensibility  in  the  retinae,  similar  to 
that  observed  in  the  ears  of  those  who  are  incapable  of  hearing  notes 
above  a  certain  pitch;  but  as  this  view  is  not  contained  in  his  more 
recent  "  Treatise  on  Optics,"  it  is  probably  no  longer  considered  by  him 
to  be  satisfactory. 

The  defect  in  question — dffficult  as  it  is  to  comprehend — has  always 
appeared  to  the  author  to  be  entirely  cerebral,  and  to  strikingly  re- 
semble, as  Dr.  Brown  has  suggested,  the  "  want  of  musical  ear."  As 
we  have  already  endeavoured  to  establish,  that  the  latter  is  dependent 
upon  a  defective  mental  appreciation,  the  parity  of  the  two  cases  will, 
of  course,  compel  us  to  refer  the  visual  defect,  or  the  want  of  the  "  fa- 
culty of  colouring,"  to  the  same  cause.  It  has  been  remarked,  that 
the  eye  in  these  cases  exercises  its  function  perfectly  as  regards 
the  form  and  position  of  objects,  and  the  degree  of  illumination  of 
their  different  portions.  The  only  defect  is  in  the  conception  of  colour. 
The  nerve  of  sight  is  probably  accurately  impressed,  and  the  deficiency 
is  in  the  part  of  the  brain  whither  the  impression  is  conveyed,  and 
where  perception  is  effected,  which  is  incapable  of  accurately  appreci- 
ating those  differences  between  rays,  on  which  their  colour  rests ;  and 
this  is  the  view  taken  of  it  by  one  of  the  most  eminent  philosophers 
of  the  present  day,  Sir  J.  F.  W.  Herschel.1 

The  mediate  or  auxiliary  functions  of  vision  are  numerous;  hence, 
the  elevated  rank  that  has  been  assigned  to  it.  By  it,  we  are 
capable  of  judging,  to  a  certain  extent,  of  the  direction,  position, 
magnitude,  distance,  surface,  and  motion  of  bodies.  Metaphysicians 
have  differed  greatly  in  their  views  on  this  subject ;  the  majority  be- 
lieving, that,  without  the  sense  of  touch,  the  eye  is  incapable  of  form- 
ing any  accurate  judgment  on  these  points;  others,  that  the  sense  of 
touch  is  no  farther  necessary  than  as  an  auxiliary;  and  that  a  correct 
appreciation  could  be  formed  by  sight  alone.  The  few  remarks  that 
may  be  necessary  on  this  subject  will  be  deferred  until  the  physical 
and  other  circumstances  which  enable  us  to  judge  of  distance,  &c.,  have 
been  canvassed. 

The  direction  or  position  of  objects  has  already  been  considered,  so 
far  as  regards  the  inverted  image  formed  by  them  on  the  retina.  The 
errors  that  arise  on  this  point  are  by  no  means  numerous,  and  seldom 
give  rise  to  much  inconvenience;  yet,  whenever  the  luminous  cone  meets 
with  reflection  or  refraction  before  reaching  the  eye,  the  retina  conveys 
erroneous  information  to  the  sensorium,  and  we  experience  an  optical 
illusion. 

To  ascertain  the  magnitude,  distance,  and  surface  of  bodies,  we  are 
obliged  to  take  into  consideration  several  circumstances  connected  with 
the  appearance  of  the  object, — such  as  its  apparent  size;  the  intensity 
of  light,  shade,  and  colour ;  the  convergence  of  the  axes  of  the  eyes ; 
the  size  or  position  of  intervening  objects,  &c.  Porterfield2  enumerates 
six  methods,  which  are  employed  in  appreciating  distance — 1.  The 

1  Encyclopaedia  Metropolitana,  art.  Light. 

3  A  Treatise  on  the  Eye,  ii.  409,  London,  1759. 


284 


SENSE  OF  SIGHT. 


apparent  magnitude  of  objects;  2.  The  vivacity  of  their  colours;  3. 
The  distinction  of  their  smaller  parts;  4.  The  necessary  conformation 
of  the  eyes  for  seeing  distinctly  at  different  distances;  5.  The  direction 
of  their  axes;  and  6.  The  interposition  of  objects.  Dr.  Brown1  re- 
duces them  to  three — 1.  The  difference  of  the  affections  of  the  optic 
nerve ;  2.  The  different  affections  of  the  muscles,  employed  in  varying 
the  refracting  power  of  each  eye,  according  to  the  distance  of  objects, 
and  in  producing  that  particular  inclination  of  the  axes  of  the  two  eyes 
which  directs  them  both  equally  on  a  particular  object;  and  3.  The 
previous  knowledge  of  the  distance  of  other  objects,  "  which  form,  with 
that  we  are  considering,  a  part  of  one  compound  perception."  Lastly, 
Dr.  Arnott2  enumerates  four  modes  by  which  this  is  effected — 1.  The 
space  and  place,  occupied  by  objects  in  the  field  of  view,  measured  by 
what  is  termed  the  visual  angle.  2.  The  intensity  of  light,  shade,  and 
colour.  3.  The  divergence  of  the  rays  of  light — and  4.  The  converg- 
ence of  the  axes  of  the  eyes.  This  enumeration  may  be  adopted  with 
some  slight  modifications.  The  circumstances,  in  our  opinion,  to  be 
considered,  are: — 

1.  The  visual  angle,  or  that  formed  by  two  lines,  which  shave  the 

extremities  of  an  object  and  cross  at 
F'is- 127.  the  centre  of  the  crystalline ;  so  that 

the  visual  angle,  subtended  by  the 
object,  as  A  B,  Fig.  127,  is  exactly 
equal  to  that  subtended  by  its  image 
a  b  on  the  retina.  It  is  obvious,  from 
this  figure,  that  if  all  objects  were 
equidistant  from  the  eye,  and  of  the 
same  magnitude,  they  would  subtend 

Visual  Angle.  the  same  angle;    and  if  not  of  the 

same  magnitude,  the  difference  would 

be  accurately  indicated  by  the  difference  of  the  visual  angles  subtended 
by  them.  The  two  arrows,  however,  which  are  of  different  sizes,  sub- 
tend the  same  visual  angle,  and  are  alike  represented  on  the  retina  by 
the  image  a  b.  It  is  clear,  then,  that  the  visual  angle  does  not  give 
us  a  correct  idea  of  the  relative  magnitudes  of  bodies,  unless  we  are 
acquainted  with  their  respective  distances  from  the  eye;  and,  con- 
versely, we  cannot  judge  accurately  of  their  distances,  without  being 
aware  of  their  magnitudes.  A  man  on  horseback,  when  near  us,  sub- 
tends a  certain  visual  angle;  but,  as  he  recedes  from  us,  the  angle  be- 
comes less  and  less;  yet  we  always  judge  accurately  of  his  size,  because 
aware  of  it  by  experience;  but  if  objects  are  at  a  great  distance,  so  as 
not  to  admit  of  their  being  compared  with  nearer,  by  simple  vision,  we 
are  in  a  constant  state  of  illusion, — irresistibly  believing,  that  they  are 
much  smaller  than  they  really  are.  This  is  the  case  with  the  heavenly 
bodies.  The  head  of  a  pin  held  close  to  the  eye  subtends  as  large  a 
visual  angle  as  the  planet  Jupiter,  which  is  one  thousand  two  hundred 
and  eighty-one  times  bigger  than  this  earth,  and  is  eighty-six  thousand 
miles  in  diameter.  In  like  manner,  a  five-cent  piece,  held  at  some 

1  Lectures  on  the  Philosophy  of  the  Human  Mind,  vol.  i.,  Boston,  1826. 
8  Elements  of  Physics,  new  Amer.  edit.,  p.  383,  Philad.,  1841. 


APPRECIATION  OF  DISTANCES. 


285 


distance  from  the  eye,  shuts  off  the  sun,  although  its  diameter  is  eight 
hundred  and  eighty-eight  thousand  miles.  The  sun  and  moon,  again, 
by  subtending  nearly  the  same  visual  angle,  appear  to  us  of  nearly  the 
same  size ;  and  the  illusion  persists  in  spite  of  our  being  aware  of  the 
mathematical  accuracy,  with  which  it  has  been  determined,  that  the 
former  is  ninety-six  millions  of  miles  from  us,  and  the  latter  only  two 
hundred  and  forty  thousand.  The  visual  angle,  again,  subtended  by 
an  object,  differs  greatly  according  to  the  position  of  the  object.  A 
sphere  has  the  same  appearance  or  bulk,  when  held  at  a  certain  dis- 
tance from  the  eye,  whatever  may  be  the  position  in  which  it  is  viewed ; 
and,  accordingly,  the  visual  angle,  subtended  by  it,  is  always  identical. 
Not  so,  however,  with  an  oval.  If  held,  so  that  the  rays  from  one  of 
its  ends  shall  impress  the  eye,  it  will  occasion  a  circular  image,  and 
subtend  a  much  smaller  angle  than  if  viewed  sideways,  when  the  image 
will  be  elliptical,  or  oval.  The  same  thing  must  occur  with  every 
object,  whose  longitudinal  and  transverse  diameters  differ.  It  is 
obvious,  that  if  any  such  object  be  held  in  a  sloping  position  towards 
the  eye,  it  will  appear  more  or  less  shortened;  in  the  same  manner  as 
the  slope  of  a  mountain  or  inclined  plane  would  appear  much  greater, 
if  placed  perpendicularly  before  the  eye.  This  appearance  is  what  is 
called  foreshortening  ;  and  it  may  be  elucidated  by  the  following  figure. 
Suppose  a  man  to  be  standing  on  a  level  plain,  with  his  eye  at  c  (Fig. 
128),  looking  down  on  the  plain.  The  portion  of  the  surface  a  d,  which 
is  next  to  him,  will  be  seen  without  any  foreshortening ;  but  if  we  sup- 
pose him  to  regard  succes- 
sively the  portions  df,fg, 
and  g  b  of  the  plain,  the 
angle,  subtended  by  each 
portion,  will  diminish;  so  that 
if  the  angle  a  c  d  be  45°,  d 
c/will  be  I8°,fcff  8°,  and 
so  on;  until,  at  length,  the 
obliquity  will  be  so  great, 
that  the  angle  becomes  inappreciable.  This  is  the  cause  why,  if 
we  look  obliquely  upon  a  long  avenue  of  trees,  we  are  unable  to 
see  the  intervals  between  the 
farthest  in  the  series ;  although 
that  between  the  nearest  to  us 
may  be  readily  distinguished. 
In  all  paintings,  of  animals 
especially,  the  principle  of  fore- 
shortening has  to  be  rigidly 
attended  to;  and  it  is  owing  to  a 
neglect  of  this  that  we  see  such 
numerous  distorted  representa- 
tions— of  the  human  figure 
especially.  It  has  been  already 
stated,  that  objects  appear 
smaller  according  to  their  dis- 
tance; hence,  the  houses  of  a  Perspective. 


Fig.  128. 


Foreshortening. 


Fig.  129. 


286  SENSE  OF  SIGHT. 

street,  or  the  trees  of  an  avenue,  that  are  nearest  to  us,  or  in  the  fore- 
ground, form  the  largest  images  on  the  retina,  and  there  is  a  gradual 
diminution,  so  that,  if  we  could  imagine  lines  to  be  drawn  along  the 
tops  and  bottoms  of  the  objects,  and  to  be  sufficiently  prolonged,  they 
would  appear  to  meet  in  a  point,  as  in  Fig.  129. 

The  art  which  traces  objects,  with  their  various  degrees  of  apparent 
diminution  on  account  of  distance,  and  of  foreshortening  on  account 
of  obliquity  of  position,  is  called  perspective. 

2.  The  intensity  of  light,  shade,  and  colour. — It  has  been  shown, 
that  the  intensity  of  light  diminishes  rapidly,  according  to  the  distance 
of  the  body  from  which  it  emanates;  so  that  it  is  only  one-fourth  as 
powerful  when  doubly  distant,  one-sixteenth  when  quadruply  distant, 
and  so  on.  This  fact  is  early  recognised ;  and  the  mind  avails  itself 
of  it  to  judge,  with  much  accuracy,  of  relative  distances.  It  is,  how- 
ever, a  pregnant  source  of  optical  illusions.  In  a  bright  sunshine, 
mountains  appear  much  nearer  to  us  than  when  seen  through  the  haze 
of  our  Indian  summer.1  In  a  row  of  lamps  along  a  street,  if  one  be 
more  luminous  than  the  rest,  it  seems  to  be  the  nearest ;  and,  in  the 
night,  we  incur  the  strangest  errors  in  judging  of  the  distance  of  a 
luminous  body.  The  sky  appears  nearer  to  the  earth  directly  above, 
than  it  does  towards  the  horizon ;  because  the  light  from  above  having 
to  pass  only  through  the  atmosphere  is  but  slightly  obstructed,  whilst 
a  portion  only  of  that,  which  has  to  pass  through  the  dense  hetero- 
geneous air,  near  the  surface  of  the  earth,  arrives  at  the  eye.  The 
upper  part  of  the  sky  being,  therefore,  more  luminous  seems  nearer ; 
and,  in  the  same  manner,  we  explain,  in  part,  why  the  sun  and  moon 
appear  larger  at  rising  and  setting. 

The  shade  of  bodies  keeps  pace  with  their  intensity  of  light ;  and 
accordingly,  the  shadows  of  objects  near  us,  are  strongly  defined ; — 
whilst  in  the  distance  they  become  confused,  and  the  light  altogether 
so  faint,  that  the  eye  at  last  sees  an  extent  of  distant  blue  mountain 
or  plain, — "appearing  bluish,"  says  Dr.  Arnott,2  "because  the  trans- 
parent air,  through  which  the  light  must  pass,  has  a  blue  tinge,  and 
because  the  quantity  of  light  arriving  through  the  great  extent  of  air 
is  insufficient  to  exhibit  the  detail."  "The  ridge  called  Blue  Mount- 
ains," he  adds,  "in  Australia,  and  another  of  the  same  name  in 
America,  and  many  others  elsewhere,  are  not  really  blue,  for  they 
possess  all  the  diversity  of  scenery,  which  the  finest  climates  can  give ; 
but  to  the  discoverer's  eye,  bent  on  them  from  a  distance,  they  all  at 
first  appeared  blue,  and  they  have  ever  since  retained  the  name."  As 
regards  the  Blue  Ridge  of  America,  Dr.  Arnott  labours  under  misap- 
prehension. Within  a  very  few  miles  from  the  whole  of  this  extensive 
chain,  as  well  as  from  a  distance,  the  blue  tinge  is  perceptible,  especially 

1  A  delightful  season,  in  the  southern  and  western  parts  of  North  America  more  espe- 
cially, generally  occurring  in  October  or  November;  and  having  nothing  similar  to  it.  so  far 
as  we  are  aware,  in  any  other  part  of  the  globe.  It  is  dependent  upon  some  meteorological 
condition  of  the  atmosphere,  and  occurs  only  when  the  wind  is  southerly,  or  from  the  warmer 
regions;  disappearing  immediately  as  soon  as  it  veers  to  the  north.  By  some,  this  pheno- 
menon has  been  supposed  to  be  caused  by  the  large  fires  in  the  western  prairies;  but  the 
warmth  that  attends  the  haze  cannot  be  explained  on  this  hypothesis,  independently  of  other 
sufficient  objections  to  it.  a  Op.  cit.,  p.  401. 


APPRECIATION  OF  DISTANCES.  287 

when  the  air  is  dense  and  clear,  soon  after  the  sun  has  descended  behind 
it ;  so  that  the  name  is  as  appropriate  in  the  vicinity  as  it  was  when 
"the  discoverer's  eye  was  bent  on  it  from  a  distance." 

It  is  obvious,  that  without  the  alternation  of  light  and  shade  we 
should  be  unable  to  judge,  by  the  eye,  of  the  shape  of  bodies, — to 
distinguish  a  flat  circle  from  a  globe ;  or  any  of  the  prominences  and 
depressions,  that  are  every  where  observable.  The  universe  would  seesi 
to  be  a  flat  surface,  the  outlines  of  which  would  not  even  be  perceptible ; 
and  the  only  means  of  discriminating  objects  would  be  by  their  differ- 
ence of  colour.  It  is  partly  by  attending  to  the  varying  intensity  of 
light  and  shade,  that  the  painter  succeeds  in  representing  the  near  as 
well  as  the  distant  objects  in  an  extensive  landscape :  those  in  the  fore- 
ground are  made  bold  and  distinct;  whilst  the  remote  prospect  is  made 
to  become  gradually  less  and  less  distinct,  until  it  fades  away  in  the 
distance.  This  part  of  his  art  is  called  aerial  perspective. 

3.  Convergence  of  the  axes. — When  an  object  is  situate  at  a  moderate 
distance  from  us,  we  so  direct  the  eyes,  that  if  the  axes  were  prolonged 
they  would  meet  at  it.     This  angle,  of  course,  varies  inversely  as  the 
distance;  so  that  if  the  axis  be  turned  to  a  nearer  object,  the  angle 
will  be  greater ;  if  to  one  more  distant,  less.     By  this  change  in  the 
direction  of  the  axes  the  mind  is  capable  of  judging,  to  a  certain  extent, 
of  near  distances.     A  definite  muscular  effort  is  required  for  each  par- 
ticular case;  and  the  difference  in  the  volition  necessary  to  effect  it 
enables  the  brain  to  discriminate,  precisely  in  the  same  manner  as  it 
judges  of  the  height  of  a  body,  by  the  muscular  action  required  to  carry 
the  axis  from  one  extremity  of  the  object  to  the  other.1     We  have  the 
most  satisfactory  evidence,  that  such  convergence  of  the  axes  is  indis- 
pensable for  judging  accurately  of  distance  in  near  vision.     If  we  fix 
a  ring  to  a  thread  suspended  from  a  beam,  or  attach  it  to  a  stand,  and 
endeavour,  with  one  eye  closed,  to  pass  a  hook,  fixed  to  the  extremity 
of  a  rod  four  or  five  feet  long,  into  the  ring,  we  shall  find  it  impracti- 
cable unless  by  accident  or  by  touching  the  ring  with  the  rod.     The 
hook  will  generally  be  passed  on  the  far  or  near  side  of  the  ring;  but 
if  we  use  both  eyes,  we  can  readily  succeed.     They,  however,  whose 
eyes  are  of  unequal  power,  cannot  succeed  with  both  eyes.     This  is 
shown  by  the  difficulty  experienced  by  those  who  have  lost  an  eye. 
M.  Magendie2  says  it  sometimes  takes  a  year,  before  they  can  form  an 
accurate  judgment  of  the  distance  of  objects  placed  near  the  eye.    The 
author  has  known  one  or  two  interesting  examples,  in  which  the  power 
was   never  regained;  notwithstanding   every  endeavour  to  train  the 
remaining  organ. 

It  need  scarcely  be  said,  that  the  convergence  of  the  axes  is  no  guide 
to  us  in  estimating  objects,  which  are  at  such  a  distance,  that  the  axes 
are  nearly  parallel, — as  the  sun  and  moon,  or  any  of  the  celestial  lumi- 
naries. 

4.  Interposition  of  known  objects. — Another  mode  of  estimating  the 
magnitude  or  distance  of  objects  is  by  a  previous  knowledge  of  the 
magnitude  or  distance  of  interposed  or  neighbouring  objects;  and  if  no 

1  Sir  C.  Bell,  in  Philos.  Transact,  for  1833.  5  Precis,  &c.,  i.  88. 


288  SENSE  OF  SIGHT. 

such  objects  intervene,  the  judgment  we  form  is  apt  to  be  inaccurate. 
This  is  the  reason  why  we  are  so  deceived  as  to  the  extent  of  an  un- 
varied plain  or  the  distance  at  which  a  ship  on  the  ocean  may  be  from 
us:  it  is  also  another  cause  why  the  sky  appears  to  us  to  be  nearer  at 
the  zenith  than  it  is  at  the  horizon.  The  artist  avails  himself  of  this 
means  of  judging  of  magnitude  in  his  representations  of  colossal  species 
of  the  animal  or  vegetable  kingdom,  or  of  the  works  of  human  labour 
and  ingenuity, — by  placing  a  well-known  object  alongside  of  them  as  a 
standard  of  comparison.  Thus,  the  representation  of  an  elephant  or  a 
giraffe  might  convey  but  imperfect  notions  of  its  size  to  the  mind,  with- 
out that  of  its  keeper  being  added  as  a  corrective. 

It  is  in  consequence  of  the  interposition  of  numerous  objects,  that  we 
are  able  to  judge  more  accurately  of  the  size  and  distance  of  those  that 
are  on  the  same  level  with  us,  than  when  they  are  either  much  above 
or  much  below  us.  The  size  and  distance  of  a  man  on  horseback  are 
easily  recognised  by  the  methods  already  mentioned,  when  he  is  riding 
before  us  on  a  dreary  plain;  the  man  and  horse  appearing  more  dimi- 
nutive, but,  being  seen  in  their  usual  position,  they  serve  as  mutual 
sources  of  comparison.  When,  however,  the  same  individual  is  viewed 
from  an  elevated  height,  his  apparent  magnitude,  like  that  of  the  objects 
around  him,  is  strikingly  less  than  the  reality.  Beautifully  and  accu- 
rately is  this  effect  depicted  by  the  great  dramatist : — 

"How  fearful 

And  dizzy  'tis  to  cast  one's  eyes  so  low ! 
The  crows  and  choughs,  that  wing  the  midway  air, 
Show  scarce  so  gross  as  beetles.     Half  way  down 
Hangs  one  that  gathers  samphire;  dreadful  trade  I 
Methinks  he  seems  no  bigger  than  his  head. 
The  fishermen  that  walk  upon  the  beach, 
Appear  like  mice ;  and  yon  tall  anchoring  bark, 
Diminish'd  to  her  cock;  her  cock  a  buoy 
Almost  too  small  for  sight."  KING  LEAR. 

The  apparent  diminution  in  the  size  of  objects  seen  from  a  height  is 
not  to  be  wholly  explained  by  the  foreshortening,  which  deprives  us  of 
our  usual  modes  of  judging.  It  is  partly  owing  to  the  absence  of  inter- 
vening bodies;  and  still  more  perhaps  to  our  not  being  accustomed  to 
view  objects  so  circumstanced.  Similar  remarks  apply  to  our  estimates 
of  the  size  and  distance  of  objects  placed  considerably  above  us.  A 
cross,  at  the  summit  of  a  lofty  steeple,  does  not  appear  more  than  one- 
fourth  of  its  real  size,  making  allowance  for  the  probable  distance ;  yet 
a  singular  anomaly  occurs  here: — the  steeple  itself  seems  taller  than 
it  really  is;  and  every  one  supposes  that  it  would  extend  much  farther 
along  the  ground,  if  prostrated,  than  it  would  in  reality.  The  truth, 
however,  is,  that  if  the  steeple  were  laid  along  the  ground,  unsurrounded 
by  objects  to  enable  us  to  form  an  accurate  judgment,  it  would  appear 
to  be  much  shorter  than  when  erect,  on  the  principles  of  foreshortening 
already  explained.  The  cause  of  this  small  apparent  magnitude  of  the 
cross  and  upper  part  of  the  steeple  is,  that  they  are  viewed  without  any 
surrounding  objects  to  compare  with  them:  they,  therefore,  seem  to  be 
smaller  than  they  are;  and,  seeming  smaller,  the  mind  irresistibly  refers 
them  to  a  greater  distance.  For  these  reasons,  then,  it  becomes  neces- 


APPRECIATION  OF  MOTION,  ETC.,  OF  BODIES.  289 

sary,  that  figures,  placed  on  lofty  columns,  should  be  of  colossal  mag- 
nitude. 

It  is  owing  partly  to  the  intervention  of  bodies,  that  the  sun  and 
moon  appear  to  us  of  greater  dimensions,  when  rising  or  setting,  although 
the  visual  angle,  subtended  by  them,  may  be  the  same.  "The  sun  and 
moon,"  says  Dr.  Arnott,1  "in  appearance  from  this  earth  are  nearly 
of  the  same  size,  viz. : — each  occupying  in  the  field  of  view  about  the 
half  of  a  degree,  or  as  much  as  is  occupied  by  a  circle  of  a  foot  in 
diameter,  when  held  one  hundred  and  twenty-five  feet  from  the  eye — 
which  circle,  therefore,  at  that  distance,  and  at  any  time,  would  just 
hide  either  of  them.  Now,  when  a  man  sees  the  rising  moon  apparently 
filling  up  the  end  of  a  street,  which  he  knows  to  be  one  hundred  feet 
wide,  he  very  naturally  believes,  that  the  moon  then  subtends  a  greater 
angle  than  usual,  until  the  reflection  occurs  to  him,  that  he  is  using,  as 
a  measure,  a  street  known,  indeed,  to  be  one  hundred  feet  wide,  but  of 
which  the  part  concerned,  owing  to  its  distance,  occupies  in  his  eye  a 
very  small  space.  The  width  of  the  street  near  him  may  occupy  sixty 
degrees  in  his  field  of  view,  and  he  might  see  from  between  the  houses 
many  broad  constellations  instead  of  the  moon  only ;  but  the  width  of 
the  street  afar  off  may  not  occupy,  in  the  same  field  of  view,  the  twen- 
tieth part  of  a  degree,  and  the  moon,  which  always  occupies  half  a 
degree,  will  there  appear  comparatively  large.  The  kind  of  illusion, 
now  spoken  of,  is  yet  more  remarkable,  when  the  moon  is  seen  rising 
near  still  larger  known  objects — for  instance,  beyond  a  town  or  a  hill 
which  then  appears  within  a  luminous  circle." 

Such  are  the  chief  methods  by  which  we  form  our  judgment  of  the 
distance  and  magnitude  of  bodies; — 1st,  by  the  visual  angle — 2dly,  by 
the  intensity  of  light,  shade,  and  colour — 3dly,  by  the  convergence  of 
the  axes  of  the  eyes — and  4thly,  by  the  interposition  of  known  objects. 

The  eye  also  enables  us  to  appreciate  the  motion  of  bodies.  This  it 
does  by  the  movement  of  their  images  upon  the  retina;  by  the  variation 
in  the  size  of  the  image ;  and  by  the  altered  direction  of  the  light  in 
reaching  the  eye.  If  a  body  be  projected  with  great  force  and  rapidity, 
we  are  incapable  of  perceiving  it; — as  in  the  case  of  a  shot  fired  from  a 
gun,  especially  when  near  us.  But  if  it  be  projected  from  a  distance, 
as  the  field  of  view  is  very  extensive,  it  is  more  easy  to  perceive  it. 
The  bombs,  sent  from  an  enemy's  encampment,  in  the  darkness  of  night, 
can  be  seen  far  in  the  air  for  some  time  before  they  fall;  and  afford 
objects  for  interesting  speculation  regarding  their  probable  destination. 

To  form  an  accurate  estimation  of  the  motion  of  a  body,  we  must  be 
ourselves  still.  When  sailing  on  a  river,  the  objects,  that  are  stationary 
on  the  banks,  appear  to  be  moving;  whilst  the  boat,  which  is  in  motion, 
seems  to  be  at  rest.  Bodies,  that  are  moving  in  a  straight  line  to  or 
from  us,  scarcely  appear  to  be  in  motion.  In  such  cases,  the  only  mode 
we  have  of  detecting  their  motion  is  by  the  gradual  increase  in  their 
size  and  illumination  when  they  approach  us;  and  the  converse,  when 
they  are  receding  from  us.  If  at  a  distance,  and  the  visual  angle  be- 
tween the  extreme  points  of  observation  be  very  small,  the  motion  of  an 

1  Op.  citat. 
VOL.  I. — 19 


290  SENSE  OF  SIGHT. 

object  will  likewise  appear  extremely  slow;  hence  the  difference  between 
a  carriage  dashing  past  us  in  the  street,  and  the  same  object  viewed 
from  a  lofty  column.  A  balloon  may  be  moving  along  at  the  rate  of 
nearly  one  hundred  miles  per  hour;  yet,  except  for  its  gradual  diminu- 
tion in  size  and  intensity  of  light,  it  may  appear  to  be  at  rest;  and, 
when  bodies  are  extremely  remote  from  us,  however  astonishing  may  be 
their  velocity,  it  can  scarcely  be  detected.  Thus,  the  moon  revolves 
round  the  earth  at  the  rate  of  between  thirty  and  forty  miles  a  minute — 
above  forty  times  swifter  than  the  fleetest  horse;  yet  her  motion,  during 
any  one  moment,  completely  escapes  detection ;  and  the  remark  applies 
still  more  forcibly  to  those  luminaries,  which  are  at  a  yet  greater  dis- 
tance from  the  earth.  These  are  cases  in  which  the  body  moves  with 
excessive  velocity,  yet  the  image  on  the  eye  is  almost  stationary;  but 
there  are  others  in  which  the  real  motion  is  extremely  slow  and  cannot 
be  at  all  observed;  as  that  of  the  hour-hand  of  a  clock  or  watch. 

It  will  be  obvious,  from  all  the  remarks  that  have  been  made  regard- 
ing the  information  derived  by  the  mind  from  the  sense  of  sight,  that 
a  strictly  intellectual  process  has  to  be  executed,  without  which  no  judg- 
ment can  be  formed;  and  that  nothing  can  be  more  erroneous  than  the 
notion,  at  one  time  prevalent,  that  the  method  by  which  we  judge  of 
distance,  figure,  &c.,  is  instinctive  or  dependent  upon  an  original  "law 
of  the  constitution,"  and  totally  independent  of  any  knowledge  gained 
through  the  medium  of  the  external  senses.  It  has  already  been  re- 
marked, that  metaphysicians  may  be  considered  as  divided  into  those, 
who  believe  that,  without  the  sense  of  touch,  the  eye  would  be  incapable 
of  forming  any  accurate  judgment  on  these  points ; — and  those  who 
think,  that  the  sense  of  touch  is  no  farther  necessary  than  as  an  aux- 
iliary, and  that  a  correct  appreciation  may  be  formed  by  sight  alone. 
Messrs.  Molyneux,1  Berkeley,2  Condillac,3  &c.,  support  the  former  view; 
MM.  Gall,4  Adelon,5  &c.,  the  latter. 

Of  the  precise  condition  of  the  visual  perception  during  early  infancy, 
we  are  of  course  entirely  ignorant.  So  far  as  our  own  recollections 
would  carry  us  back,  we  have  always  been  able  to  form  a  correct  judg- 
ment of  magnitude,  distance,  and  figure.  Observation,  however,  of  the 
habitudes  of  infants  would  seem  to  show,  that  their  appreciation  of  these 
points — especially  of  distance — is  singularly  unprecise;  but  whether  this 
be  owing  to  the  sense  not  yet  having  received  a  sufficient  degree  of  as- 
sistance from  touch,  or  from  want  of  the  necessary  development  in  the 
structure  or  functions  of  the  eyeball  or  its  accessory  parts,  we  are  pre- 
cluded from  judging.  The  only  succedaneum  is  the  information  to  be 
obtained  from  those  who  have  been  blind  from  birth,  and  have  been 
restored  to  sight  by  a  surgical  operation,  regarding  their  visual  sensa- 
tions. Although  in  the  numerous  operations  of  this  kind,  which  have 
been  performed,  it  might  seem,  that  cases  must  have  frequently  occurred 
for  examining  into  this  question,  such  is  not  the  fact;  and  metaphysi- 
cians and  physiologists  have  generally  founded  their  observations  on  the 

1  Locke's  Essay  on  the  Human  Understanding,  book  ii.  chap.  9. 

2  Essay  on  Vision,  2d  edit.,  Dublin,  1709.  3  Traite  des  Sensations,  Part  i. 
•»  Sur  les  Fonctions  du  Cerveau,  i.  80,  Paris,  1825. 

6  Physiologic  de  1'Homme,  edit,  cit.,  i.  466. 


ETC.  291 

well  known  case  described  by  Mr.  Cheselden.1  The  subject  of  this  was  a 
young  gentleman,  who  was  born  blind,  or  lost  his  sight  so  early,  that  he 
had  no  remembrance  of  ever  having  seen;  and  was  "couched," — so  says 
Cheselden, — "  between  thirteen  and  fourteen  years  of  age."  M.  Magen- 
die2  affirms,  that  there  is  every  reason  to  believe  that  the  operation  was 
not  for  cataract,  but  consisted  in  the  incision  of  the  pupillary  membrane. 
It  need  hardly  be  remarked,  that  Cheselden  must  be  the  best  possible 
authority  on  this  subject.  "When  he  first  saw,"  says  Cheselden,  ahe 
was  so  far  from  making  any  judgment  about  distances,  that  he  thought 
all  objects  whatever  touched  his  eyes  (as  he  expressed  it),  as  what  he 
felt  did  his  skin,  and  thought  no  objects  so  agreeable  as  those  which 
were  smooth  and  regular,  though  he  could  form  no  judgment  of  their 
shape,  or  guess  what  it  was  in  any  object  that  was  pleasing  to  him.  He 
knew  not  the  shape  of  any  thing,  nor  any  one  thing  from  another,  how- 
ever different  in  shape  or  magnitude;  but  upon  being  told  what  things 
were,  whose  form  he  before  knew  from  feeling,  he  would  carefully  ob- 
serve, that  he  might  know  them  again ;  but  having  too  many  objects  to 
learn  at  once,  he  forgot  many  of  them;  and  (as  he  said),  at  first  he 
learned  to  know,  and  again  forgot  a  thousand  things  in  a  day.  At  first 
he  could  bear  but  very  little  light,  and  the  things  he  saw  he  thought 
extremely  large ;  but,  upon  seeing  things  larger,  those  first  seen  he  con- 
ceived less,  never  being  able  to  imagine  any  lines  beyond  the  bounds  he 
saw:  the  room  he  was  in,  he  said,  he  knew  to  be  but  part  of  the  house, 
yet  he  could  not  conceive  that  the  whole  house  could  look  bigger." 

A  much  more  interesting  case,  in  many  respects,  than  this,  which 
has  always  appeared  to  us  too  poetical,  was  laid  before  the  Royal  So- 
ciety of  London,  in  1826,  by  Dr.  Wardrop.3  It  was  that  of  a  lady 
born  blind,  who  received  sight  at  the  age  of  forty-six,  by  the  formation 
of  an  artificial  pupil.  During  the  first  months  of  her  infancy,  this 
lady  was  observed  to  have  something  peculiar  in  the  appearance  of  her 
eyes;  and,  when  about  six  months  old,  a  Parisian  oculist  operated  on 
both  eyes,  with  the  effect  of  complete  destruction  of  the  one,  and  not 
the  slightest  improvement  of  the  other.  From  this  time,  she  continued 
totally  blind,  being  merely  able  to  distinguish  a  very  light  from  a  very 
dark  room,  but  without  the  power  of  perceiving  even  the  situation  of 
the  window  through  which  the  light  entered;  although  in  sunshine,  or 
bright  moonlight,  she  knew  its  direction :  she  was,  therefore,  in  greater 
darkness  than  the  boy  in  Cheselden's  case,  who  knew  black,  white,  and 
scarlet,  apart  from  each  other;  and,  when  in  a  good  light,  had  that 
degree  of  sight,  which  usually  exists  in  an  eye  affected  with  cataract; 
whilst  in  this  lady  the  pupil  was  completely  shut  up,  so  that  no  light 
could  reach  the  retina,  except  such  rays  as  could  pass  through  the  sub- 
stance of  the  iris.  After  a  third  operation  had  been  performed  for 
the  formation  of  an  artificial  pupil,  she  returned  from  Dr.  Wardrop's 
house  in  a  carriage,  with  her  eyes  covered  by  only  a  loose  piece  of 
silk.  The  first  thing  she  noticed  was  a  hackney-coach  passing  by, 
when  she  exclaimed,  "  What  is  that  large  thing  that  has  passed  by 

i  Philosophical  Transactions,  No.  402,  p.  477,  for  1728 ;  and  Anatomy  of  the  Human 
Body,  13th  edit.,  Lond.,  1792. 

*  Precis,  &c.,  i.  95.  a  Philosoph.  Transact.,  1826,  p.  529. 


292  SENSE  OF  SIGHT. 

us?"  In  the  course  of  the  evening  she  requested  her  brother  to  show 
her  his  watch,  when  she  looked  at  it  a  considerable  time,  holding  it 
close  to  her  eye.  "  She  was  asked  what  she  saw,  and  she  said  there  was 
a  dark  and  a  bright  side;  she  pointed  to  the  hour  of  twelve  and  smiled. 
Her  brother  asked  her  if  she  saw  anything  more;  she  replied  yes,  and 
pointed  to  the  hour  of  six,  and  to  the  hands  of  the  watch.  She  then 
looked  at  the  chain  and  seals,  and  observed  that  one  of  the  seals  was 
bright,  which  was  the  case,  being  a  solid  piece  of  rock  crystal."  On 
the  third  day,  she  observed  the  doors  on  the  opposite  side  of  the  street, 
and  asked  if  they  were  red.  They  were  of  an  oak  colour.  In  the 
evening  she  looked  at  her  brother's  face,  and  said  she  saw  his  nose  ; 
he  asked  her  to  touch  it,  which  she  did:  he  then  slipped  a  handker- 
chief over  his  face,  and  asked  her  to  look  again,  when  she  playfully 
pulled  it  off,  and  asked,  "  What  is  that?"  On  the  thirteenth  day,  she 
walked  out  with  her  brother  in  the  streets  of  London,  distinctly  dis- 
tinguishing the  street  from  the  foot  pavement,  and  stepping  from  one 
to  the  other,  like  a  person  accustomed  to  the  use  of  her  eyes. 
"Eighteen  days  after  the  last  operation,"  says  Dr.  Wardrop,  "I  at- 
tempted to  ascertain,  by  a  few  experiments,  her  precise  notions  of  the 
colour,  size,  and  forms,  positions,  motions,  and  distances  of  external 
objects.  As  she  could  only  see  with  one  eye,  nothing  could  be  ascer- 
tained respecting  the  question  of  double  vision.  She  evidently  saw 
the  difference  of  colours;  that  is,  she  received  and  was  sensible  of 
different  impressions  from  different  colours.  When  pieces  of  paper, 
one  and  a  half  inch  square,  differently  coloured,  were  presented  to 
her,  she  not  only  distinguished  them  at  once  from  one  another,  but 
gave  a  decided  preference  to  some  colours,  liking  yellow  most,  and  then 
pale  pink.  It  may  be  here  mentioned,  that,  when  desirous  of  examin- 
ing an  object,  she  had  considerable  difficulty  in  directing  her  eye  to 
it,  and  finding  out  its  position,  moving  her  hand  as  well  as  her  eye 
in  various  directions,  as  a  person,  when  blindfolded  or  in  the  dark, 
gropes  with  his  hand  for  what  he  wishes  to  touch.  She  also  distin- 
guished a  large  from  a  small  object,  when  they  were  both  held  up 
before  her  for  comparison.  She  said  she  saw  different  forms  in  va- 
rious objects,  which  were  shown  to  her.  On  asking  what  she  meant 
by  different  forms,  such  as  long,  round,  and  square,  and  desiring  her 
to  draw  with  her  finger  those  forms  on  her  other  hand,  and  then  pre- 
senting to  her  eye  the  respective  forms,  she  pointed  to  them  exactly; 
she  not  only  distinguished  small  from  large  objects,  but  knew  what 
was  meant  by  above  and  below;  to  prove  which,  a  figure  drawn  with 
ink  was  placed  before  her  eye,  having  one  end  broad  and  the  other  nar- 
row, and  she  saw  the  positions  as  they  really  were,  and  not  invert- 
ed [! !].  She  could  also  perceive  motions  ;  for  when  a  glass  of  water 
was  placed  on  the  table  before  her,  on  approaching  her  hand  near  it, 
it  was  moved  quickly  to  a  greater  distance,  upon  which  she  imme- 
diately said,  4  You  move  it;  you  take  it  away.'  She  seemed  to  have 
the  greatest  difficulty  in  finding  out  the  distance  of  any  object;  for, 
when  an  object  was  held  close  to  her  eye,  she  would  search  for  it  by 
stretching  her  hand  far  beyond  its  position,  while  on  other  occasions  she 
groped  close  to  her  own  face  for  a  thing  far  remote  from  her." 


ETC.  293 

The  particulars  of  this  case  have  been  given  at  some  length,  inas- 
much as  they  are  regarded  by  Dr.  Bostock1 — and  apparently  by  Dr. 
Wardrop  himself — as  strikingly  confirmatory  of  those  of  Cheselden, 
than  which  we  cannot  imagine  anything  more  dissimilar.  It  will 
have  been  noticed,  that,  from  the  very  first  after  the  reception  of 
sight,  she  formed  an  imperfect  judgment  of  objects,  and  even  of  dis- 
tances, although  she  was  devoid  of  the  elements  necessary  for  arriving 
at  an  accurate  estimate  of  the  latter, — the  sight  of  both  eyes.  This 
was,  doubtless,  the  chief  cause  of  that  groping  for  objects  described  by 
Dr.  Wardrop.  Of  forms,  too,  she  must  have  had  at  least  an  imperfect 
notion,  for  we  find,  that  on  the  thirteenth  day  after  the  operation,  she 
stepped  from  the  elevated  foot-pavement  to  the  street,  "  like  a  person 
accustomed  to  the  use  of  her  eyes." 

The  case  is,  we  think,  greatly  in  favour  of  the  view,  that  the  sight 
does  not  require  much  education  to  judge  with  tolerable  accuracy  of 
the  position,  magnitude,  distance,  surface,  and  motion  of  bodies;  and 
that,  by  a  combination  of  the  methods  already  pointed  out,  or  of  some 
of  them,  this  imperfect  knowledge  is  obtained  without  the  aid  of  any 
of  the  other  senses;  but  is  of  course  acquired  more  easily  and  accu- 
rately with  their  assistance,  especially  with  that  of  touch.  What  other 
than  visual  impressions  could  have  communicated  to  the  mind  of  Miss 
Biffin — whose  case  was  referred  to  under  another  head — the  accurate 
and  minute  information  she  possessed  regarding  the  bodies  surrounding 
her  at  all  distances?  Or  how  does  the  animal,  immediately  after  birth, 
acquire  its  knowledge  of  distance  ?  We  observe  the  young  of  certain 
animals,  immediately  after  they  are  extruded  from  the  uterus,  turn 
round  and  embrace  the  maternal  teat;  whilst  others,  as  the  partridge, 
follow  the  mother  in  a  short  time  after  they  have  burst  the  shell.  The 
experience  required  for  obtaining  an  imperfect  knowledge  of  distance, 
shape,  &c.,  must,  therefore,  be  trifling;  although  an  accurate  acquaint- 
ance may  demand  numerous  and  careful  comparisons.  This  first  degree 
of  knowledge  is  probably  obtained,  by  comparing  the  visual  angle  with 
the  intensity  of  light,  shade,  and  colour, — the  more  accurate  appre- 
ciation following  the  use  of  the  other  methods  already  described.  That 
the  convergence  of  the  axes  requires  education  is  demonstrated  by  the 
case  of  the  infant.  It  has  been  remarked,  that  the  eyeballs  harmonize 
instinctively  in  their  parallel  motions ;  but  the  convergence  requires  an 
effort  of  volition,  and  it  is  some  time  before  it  can  be  effected,  which  is 
probably  the  great  cause  of  the  mal-appreciation  of  near  distances,  that 
we  notice  in  the  infant;  whilst  it  seems  to  exhibit  its  capability  of 
judging  more  correctly  of  objects,  that  are  somewhat  more  remote; 
and  where  less  convergence,  and  consequently  less  muscular  effort,  is 
necessary. 

The  numerous  optical  illusions,  which  we  have  been  compelled  to 
describe  in  the  progress  of  the  preceding  remarks,  will  render  it  neces- 
sary to  refer  to  but  few  under  this  head.  It  has  already  been  said, 
that  we  lay  it  down  as  a  rule,  that  the  progress  of  light  to  the  eye  is 

1  Physiology,  3d  edit.,  p.  703,  Lond.,  1836.  See,  also,  the  case  of  a  gentleman  born  blind, 
and  successfully  operated  upon  in  the  eighteenth  year  of  his  age,  by  Dr.  J.  C.  Franz,  in 
Proceedings  of  the  Royal  Society,  1840-41,  No.  46. 


294 


SENSE  OF  SIGHT. 


always  in  a  straight  line  from  the  luminous  object;  and,  accordingly,  if 
the  course  of  the  rays  be  modified  before  they  reach  the  organ,  we  fall 
into  an  optical  illusion.  .Such  modifications  arise  either  from  the  re- 
flection or  refraction  of  the  rays  proceeding  from  the  object  that  causes 
the  sensation.  By  reflection  of  the  rays,  we  experience  the  illusion 
caused  by  mirrors.  A  ray  of  light,  K  C,  Fig.  77,  falling  upon  a  plane 
mirror,  I  J,  is  reflected  back  in  the  same  line ;  but,  as  we  have  seen,  the 
object  does  not  appear  to  be  at  K,  but  at  E.  Again,  a  ray  of  light, 
proceeding  obliquely  from  B,  and  impinging  on  a  plane  mirror  at  C,  is 
reflected  in  the  direction  of  C  A;  but  to  the  eye  at  A,  the  object  B 

appears  to  be  at  H,  in  the  prolon- 
Fis-  13°-  gation  of  the  ray  that  reaches  the 

eye. 

ci :"" If 


the 


be 


the 


Concave  Mirror. 


Fig.  131, 


mrror  e  concave, 
object  appears  magnified,  provided 
the  light  from  the  upper  part  of 
the  object,  as  A  B,  Fig.  130,  be 
reflected  to  an  eye  at  F,  and  that 
from  the  lower  part  of  the  object 
meet  the  other  at  this  point.  To 
an  eye  so  placed,  the  object  appears  magnified  and  seems  to  be  at  C 
D,  or  in  the  prolongation  of  the  rays  which  fall  upon  the  cornea.  If 
the  mirror  be  convex  (Fig.  131),  for  like  reasons,  the  cross  will  seem 
to  be  smaller. 

The  cornea  constitutes  a  mirror  of  this  class,  in  which  we  have  an 
accurate  miniature  representation  of  objects. 

Rays  that  are  refracted  in  passing  through 
different  media,  give  rise  to  visual  illusions. 
We  have  seen,  that  the  ray  from  an  object  at 
^^r      ,     F5  Fig.  77?  in  the  pool  of  water,  I  J,  does 
"""*\<C^  not  proceed  into  the  air  in  the  direction  of 

F  C  0,  but  in  that  of  the  line  F  C  A;  and  if 
we  suppose  the  eye  to  be  placed  at  A,  the 
object  will  not  be  seen  at  F,  but  will  appear 
to  be  at  /;  the  pool  will,  consequently,  appear 
shallower  than  it  really  is,  by  the  space  at 
which/  is  situate  above  the  bottom.  We  can  now  understand  why 
rivers  appear  less  deep  than  they  are,  when  viewed  obliquely;  and  why 
the  lower  end  of  a  pole,  immersed  in  water,  should,  when  seen  obliquely, 
appear  to  be  bent  towards  the  surface.  In  shooting  fish  in  the  water, 
or  in  attempting  to  harpoon  them,  this  source  of  error  has  to  be  cor- 
rected. Birds,  too,  that  live  upon  the  inhabitants  of  the  water,  have 
to  learn,  from  experience,  to  obviate  the  optical  illusion;  or  to  descend 
perpendicularly  upon  their  prey,  in  which  direction,  as  we  have  seen, 
no  refraction  takes  place.  Similar  remarks  apply  to  fish  that  leap  out 
of  the  streams  to  catch  objects  in  the  air.  The  Ohsetodon  rostratus, 
about  six  or  eight  inches  long,  frequents  the  sea-shores  in  the  East 
Indies:  when  it  observes  a  fly  sitting  on  the  plants  that  grow  in  shallow 
water  it  swims  to  the  distance  of  five  or  six  feet,  and  then,  with  sur- 
prising dexterity,  ejects  out  of  its  tubular  mouth  a  single  drop  of  water, 


Convex  Mirror. 


DURATION  OF  IMPRESSION  OF  LIGHT.  295 

which  never  fails  to  strike  the  fly  into  the  sea,  where  it  soon  becomes 
its  prey.1  Hommel — a  Dutch  governor — put  some  of  these  fish  into  a 
tub  of  water,  and  pinned  a  fly  on  a  stick  within  their  reach.  He  daily 
saw  the  fish  shoot  at  the  fly,  and  with  such  dexterity,  that  they  never 
failed  to  hit  the  mark.2  Pallas  describes  the  Sisena  jaculatrix  as 
securing  flies  by  a  similar  contrivance.3 

If  the  light,  before  reaching  the  eye,  passes  through  bodies  of  a  len- 
ticular shape,  it  undergoes  modifications,  which  have  given  occasion  to 
the  formation  of  useful  instruments  devised  for  modifying  the  sphere 
of  vision.  If  the  lens  be  double  convex,  the  body,  seem  through  it, 
appears  larger  than  it  is,  from  the  illusion,  so  often  referred  to,  that 
we  always  refer  the  object  in  the  direction  of  the  line  that  impinges 
upon  the  retina.  The  object,  consequently,  appears  to  be  greatly  aug- 
mented. (See  Fig.  83.)  For  the  same  reasons  an  object  seems  smaller 
to  the  eye  at  A,  Fig.  80,  when  viewed  through  a  double  concave  lens. 
Again,  if  the  light,  before  reaching  the  cornea,  be  made  to  pass  through 
a  diaphanous  body,  which  is  itself  coloured,  and  consequently  allows 
only  the  rays  of  its  own  colour  to  traverse  it,  the  object  is  not  seen  of 
its  proper  colour,  but  of  that  of  the  transparent  body. 

An  impression  of  light  continues  to  affect  the  retina  for  some  time 
after  the  impression  has  ceased,  certainly  for  the  sixth  part  of  a  second.4 
If,  therefore,  a  live  coal  be  whirled  round,  six  or  seven  times  in  a  second, 
it  will  seem  to  be  a  continuous  circle  of  fire.  It  is  owing  to  this  cir- 
cumstance, that  meteors  seem  to  form  a  line  of  light — as  in  the  case 
of  the  falling  star;  and  that  the  same  impression  is  conveyed  by  a  sky- 
rocket in  its  course  through  the  air.  We  have  an  elucidation  of  the 
same  fact  in  the  instrument  or  toy — called,  by  Dr.  Paris,  thaumatrope — 
which  consists  of  a  circle,  cut  out  of  a  card,  and  having  two  silken 
strings  attached  to  opposite  points  of  its  diameter :  by  twisting  these 
with  the  finger  and  thumb  the  card  may  be  twirled  round  with  consider- 
able velocity.  If  we  make  on  one  side  a  black  stripe  as  in  the  marginal 
figure  132,  and  on  the  other  side  one  at  right  angles  to  it,  Fig.  133,  and 
cause  the  card  to  revolve  rapidly,  we  shall  see  a  cross.  And  if  on  one  side 

Fig.  132.  Fig.  133. 


Thaumatrope. 


of  the  card  a  chariot  is  drawn  —  and  on  the  other  a  charioteer,  and  the  card 
be  twirled  round  six  or  seven  times  in  a  second,  the  charioteer  will  be 
seen  in  the  chariot,  —  the  duration  of  the  impressions  on  the  retina  being 

i  Fleming's  Philos.  of  Zoology,  i.  195.  2  Philos.  Trans.,  liv.  89. 

3  Philos.  Trans.,  Ivi.  186;  also,  Mr.  Sharon  Turner's  Sacred  History  of  the  World,  Amer. 
edit.,  i.  205,  New  York,  1832. 

4  D'Arcy,  Memoires  de  1'Academie  des  Sciences,  p.  439,  Paris,  1765;  and  Plateau,  Annales 
de  Chimie,  &c.,  vol.  Iviii.  p.  401. 


296  ADDITIONAL  SENSES. 

such  as  to  cause  the  figures,  drawn  on  both  sides  of  the  card,  to  be  seen 
at  nearly  the  same  time.  The  phantasmascope,  phenakistiscope  and 
anorthoscope,  act  upon  similar  principles.1 

It  is  by  accurate  attention  to  various  optical  illusions,  and  to  the 
laws  of  the  animal  economy  on  which  they  are  founded,  that  many  of 
them  can  be  produced  in  the  arts  at  pleasure.  Painting  is,  in  truth, 
little  more  than  depicting  on  canvass  the  various  optical  errors,  which 
we  are  habitually  incurring. 

To  conclude : — the  sense  of  sight  differs  materially  in  the  scale  of 
animals :  in  few  is  the  organization  more  perfect  or  the  function  better 
executed  than  in  man.  Situate  at  the  upper  and  anterior  part  of  the 
body,  the  organ  of  vision  is  capable  of  directing  its  regards  over  a  large 
extent  of  surface:  the  axes  of  the  two  organs  can  be  converged  upon 
objects  in  various  situations,  which  cannot  be  done  by  many  animals; 
and  they  are  very  movable  under  the  domination  of  a  muscular  appa- 
ratus of  admirable  arrangement.  Still,  the  eye  is  not  as  delicately 
organized  as  in  some  animals,  which  are  capable  of  seeing  objects  at  a 
distance  that  would  be  totally  beyond  the  reach  of  the  visual  powers  of 
man. 

Like  the-  other  senses,  sight  can  be  exerted  actively  and  passively ; 
hence  the  difference  between  simply  seeing,  and  looking.  In  the  latter, 
the  eye  is  directed  to  the  object  by  the  proper  muscles;  and  it  is  not 
improbable,  that  the  nerve  may  be  aroused  to  a  more  accurate  and  deli- 
cate reception  of  impressions,  as  we  have  reason  for  believing  is  the 
case  in  the  other  senses.  Like  them,  it  admits  of  great  improvement 
by  education.  The  painter,  and  the  worker  in  colours  are  capable  of 
nice  discrimination,  and  detect  ,the  minutest  shades  of  difference  with 
great  facility.  In  savage  life,  where  the  tracks  or  marks  through  the 
almost  interminable  forests,  or  over  the  pathless  wilds,  are  the  only 
guides,  the  greatest  acuteness  of  vision  is  necessary ;  and,  accordingly, 
we  find  the  North  American  Indian,  in  this  respect,  eminently  distin- 
guished. The  mariner,  too,  accustomed  to  look  out  for  land,  or  for  a 
hostile  sail,  detects  it  in  the  distant  horizon  long  before  it  can  be  per- 
ceived by  the  landsman,  and  appreciates  its  distance  and  course  with 
signal  accuracy, — education,  in  this  case,  not  only  communicating  to 
his  eye  facility  in  being  impressed,  but  improving  the  intellectual  pro- 
cess, by  which  the  estimation  of  distances  is  arrived  at. 

ADDITIONAL  SENSES. 

The  five  senses  constitute  so  many  special  nervous  systems,  each 
concerned  in  its  appropriate  function;  and,  although  conveying  ideas  of 
the  external  world  to  the  brain,  and  connected  with  that  organ,  they  are 
to  a  certain  extent  independent  of  it.  The  generality  of  physiologists 
admit  these  five  only;  but  some  have  suggested  others,  differing,  in 
general,  from  the  five,  in  having  no  orgJn  at  the  surface  of  the  body 
exclusively  concerned  in  the  function.  Buffon  regarded  as  a  sixth  sense 
the  intense  sensation  experienced  during  the  venereal  act;  but  this  can 

1  Muller,  Principles  of  Physics  and  Meteorology,  p.  310,  Philad.,  1848. 


ADDITIONAL  SENSES.  297 

only  be  esteemed  a  peculiar  variety  of  tact  in  the  mucous  membrane 
of  the  genital  organs, — differing  from  ordinary  tact  in  those  parts,  in 
requiring  in  both  sexes  a  special  condition  of  the  membrane;  and,  in  the 
male,  one  such,  that  the  sperm,  when  excreted,  shall  make  the  neces- 
sary impression  upon  it;  and,  consequently,  appertaining  to  both  the 
external  and  internal  sensations ; — the  state  of  the  membrane  being 
referable  to  the  latter,  and  the  effect  of  the  contact  of  the  sperm  to  the 
former.  Some  have  spoken  of  a  sense  of  heat  and  cold: — this  has  been 
referred  to  under  the  head  of  tact; — others  of  a  muscular  sense,  by 
which  we  acquire  a  knowledge  of  the  motions  that  muscular' contractions 
give  rise  to,  and  learn  to  apportion  the  effort  to  the  degree  of  effect  to 
be  produced.  Animal  magnetizers  have  suggested  a  sixth  sense,  to  which 
man  owes  the  capability  of  being  acted  upon  by  them:  but  this  is  suppo- 
sititious, and  the  facts  admit  of  a  more  ready  and  satisfactory  explana- 
tion. A  sense  of  hunger  has  been  described  as  situate  at  the  upper 
orifice  of  the  stomach : — a  sense  of  thirst  in  the  oesophagus,  and  a  pneu- 
matic sense  in  the  lungs ;  but  these  are  rather  internal  sensations. 

The  German  physiologists  have  suggested  another  sense,  which  they 
term  coenaesthesis,  Gemeingef  Uhl,  Gemeinsinn,  JKorpergefuhl, 
Lebenssinn,  Individualitatssinn,  and  Selbstgefiihl  ("common 
feeling,  common  sensation,  bodily  feeling,  feeling  of  life,  sense  of  life, 
sense  of  individuality,  and  self-feeling").  This  is  not  seated  in  any 
particular  part  of  the  body,  but  over  the  whole  system;  hence  termed 
"common."  It  is  indicated  by  the  lightness  and  buoyancy,  which  we 
occasionally  experience,  apparently  without  any  adequate  cause;  as  well 
as  by  a  sense  of  lassitude  and  fatigue  unconnected  with  muscular  action 
or  disease.  To  it,  likewise,  belong  the  involuntary  shuddering,  glow, 
and  chilliness,  experienced  under  like  circumstances.  It  is  manifestly 
one  of  the  numerous  internal  sensations,  felt  by  the  frame,  and  every 
portion  of  it,  according  as  they  are  in  a  perfect  state  of  health,  or 
labouring  under  irritation  or  oppression;  but  can  scarcely  be  regarded 
as  an  additional  or  sixth  sense.1 

It  has  been  supposed,  that  certain  animals  may  possess  other  senses 
than  the  five.  Of  this  we  can  have  no  positive  evidence.  We  are 
devoid  of  the  means  of  judging  of  their  sensations ;  and  if  we  meet 
with  an  additional  organ,  which  seems  adapted  for  such  a  purpose,  we 
have  nothing  but  conjecture  to  guide  us.  Under  the  sense  of  touch  it 
was  said,  that  the  bat  is  found  to  be  capable  of  avoiding  obstacles 
placed  in  its  way  intentionally,  when  the  eyes,  nostrils,  &c.,  have  been 
closed  up ;  and  that  it  readily  returns  to  the  holes  in  caverns  to  which 
it  is  habituated.  Spallanzani  supposed  that  this  was  owing  to  its  being 
possessed  of  a  sixth  sense.  We  have  seen,  that  the  circumstance  is 
explicable  by  unusual  delicacy  of  one  of  the  external  senses. 

Again ;  the  accuracy  with  which  migratory  animals  return  to  their 
accustomed  haunts,  has  given  rise  to  the  notion  of  a  sense  of  locality. 

Quadrupeds,  the  ape  not  excepted,  have  two  bones  in  the  face,  in 

1  Purkinje,  art.  Ccensesthesis,  in  Encycl.  Worterb.  der  Medicinisch.  Wissenschaft.  viii.  116, 
Berlin,  1832;  and  Miiller's  Elements  of  Physiology,  by  Baly,  P.  v.  p.  1087,  London,  1839. 
See,  also,  E.  H.  Weber,  art.  Tastsinn  und  das  Gemeingefuhl,  in  Wagner's  Handworterbuoh 
der  Physiologic,  22ste  Lieferung,  s.  562,  Braunschweig,  1849. 


298  ADDITIONAL  SENSES. 

addition  to  those  found  in  man.  These  contain  the  roots  of  the  dentes 
incisores,  when  such  are  present ;  but  they  also  exist  in  animals  that 
are  destitute  of  teeth.  They  are  termed  ossa  intermaxillaria,  ossa 
incisoria,  and  ossa  labialia;  and  are  situate,  as  their  names  import,  at 
the  anterior  part  of  the  jaw,  and  between  the  ossa  maxillaria  or  jaw 
bones.  Jacobson1  considers  them  to  be  an  organ  of  sense,  as  they 
communicate  with  the  exterior,  and  are  largely  supplied  with  vessels 
and  nerves.  Accordingly,  this  has  been  esteemed  a  sensitive  apparatus, 
connected  with  the  season  of  love  in  animals  ;  and,  by  other  naturalists, 
as  a  sense  intermediate  between  those  of  taste  and  smell,  and  intended 
to  guide  the  animal  in  the  proper  selection  of  food.  It  need  hardly 
be  said,  that  this  is  all  imaginary. 

M.  Adelon,2  it  was  remarked,  makes,  two  divisions  of  the  external 
sensations : — those  that  convey  information  to  the  mind ;  and  those 
that  do  not.  The  former  have  engaged  attention ;  the  latter  will  not 
occupy  us  long.  They  comprise  but  two — itching  and  tickling.  Both 
of  these  occur  in  the  skin  and  mucous  membranes,  and  near  the  com- 
munication of  the  latter  with  the  skin ;  or,  in  other  words,  near  the 
termination  of  tbe  outlets  which  they  line.  Itching,  however,  is  not 
always  an  external  sensation, — that  is,  not  always  caused  by  the  contact 
of  a  body  external  to  it.  It  frequently  arises  from  an  altered  condi- 
tion of  the  organic  actions  of  the  part  in  which  it  is  experienced,  as 
in  cutaneous  affections ;  in  itching  at  the  nose  produced  by  irritation 
in  the  intestinal  canal ;  itching  of  the  glans  penis  in  cases  of  calculi 
of  the  urinary  bladder,  &c. ;  but  commonly  the  sensation  is  caused  by 
an  extraneous  body,  and  we  are  irresistibly  led  to  scratch,  no  matter 
how  it  may  be  caused.  When  it  arises  extraneously,  it  can  generally 
be  readily  allayed ;  but,  when  dependent  upon  a  morbid  condition  of 
the  texture  of  the  part,  it  becomes  a  true  disease,  and  the  source  of 
much  suffering.  If  the  itching  be  accompanied  with  a  feeling  of  motion, 
or  of  purring  in  the  part,  it  is  called  tingling.  This  kind  of  purring 
often  occurs  without  itching. 

Tickling  or  titillation  is  always  caused  by  the  contact  of  some  ex- 
traneous substance ;  and  is  therefore  a  true  external  sensation.  Although 
occurring  in  the  skin,  and  in  the  commencement  or  termination  of  the 
mucous  membranes,  all  parts  are  not  equally  susceptible  of  it;  and 
some, — as  the  lining  membrane  of  the  genital  organs, — are  only,  or 
chiefly  so,  under  special  circumstances.  The  sides,  palms  of  the  hands, 
and  soles  of  the  feet,  are  the  most  sensitive  in  this  respect ;  not,  per- 
haps, because  the  nerves  are  more  numerous  in  those  parts,  but  because, 
owing  to  thinness  or  suppleness  of  skin,  or  to  other  inappreciable  cir- 
cumstances, they  are  more  susceptible  of  this  kind  of  excitation.  We 
find,  too,  that  individuals  differ  as  much  as  the  parts  of  the  body  do  in 
this  respect ; — some  being  not  ticklish,  or  incapable  of  being  thrown 
into  the  spasm,  which  the  act, — nay,  even  the  threatening  of  the  act, 
— produces  in  others.  Cases  are  on  record,  in  which  prolonged  titilla- 
tion has  caused  general  convulsions,  and  even  death.  Le  Cat3  terms 

1  Annales  clu  Musee,  xviii.  412. 

2  Physiologic  de  1'Homme,  2de  edit.,  i.  481,  Paris,  1829. 
»  Traite  des  Sens,  Paris,  1767. 


INTERNAL  SENSATIONS.  299 

it  an  hermaphroditic  sensation,  inasmuch  as,  whilst  it  excites  laughter, 
it  is  insupportable;  and,  consequently,  seems  to  be  intermediate  between 
pleasure  and  pain. 

c.  Internal  Sensations. 

The  external  sensations  make  us  acquainted  with  the  universe  sur- 
rounding us ;  and  convey  to  the  mind  a  knowledge  of  every  thing  that 
can  be,  in  any  manner,  inservient  to  our  necessities.  Such  necessities 
have,  however,  to  be  suggested  to  the  mind,  before  it  reacts  through 
the  aid  of  the  organs  of  prehension  or  otherwise  on  external  bodies, 
and  this  is  accomplished  by  the  internal  or  organic  sensations. 

Without  the  intervention  of  an  external  cause,  every  organ  of  the 
body  is  capable  of  transmitting  to  the  encephalon  a  number  of  different 
impressions,  many  of  which  impel  the  organs  to  acts  that  are  necessary 
not  only  for  the  preservation  of  the  individual  and  of  the  species,  but 
also  for  the  perfect  developement  of  the  faculties.  Such  are  the  sensa- 
tions of  hunger  and  thirst ;  the  impulse  that  leads  to  the  union  of  the 
sexes ;  and  the  feeling  we  have  of  the  necessity  for  intermission  in  the 
exercise  of  the  muscles,  and  the  intellect.  They  have  been  divided 
into  three  species  by  some  physiologists ; — the  first  arousing,  or  giving 
impulse  to,  the  action  of  organs,  and  warning  the  brain  of  the  different 
necessities  of  the  system.  They  have  been  called  wants  or  instinctive 
desires.1  Such  are  hunger,  thirst,  the  desire  to  evacuate  the  urine  and 
faeces;  that  of  respiration,  the  venereal  appetite  (le  genesique,  amour 
physique),  accouchement,  &c.  They  belong  to  those  that  arise,  when 
it  is  necessary  the  organs  should  act. — The  second  occur  during  the 
action  of  organs.  They  are  often  obscure,  but  sometimes  acute. 
Amongst  these  are  the  impressions  accompanying  the  different  excre- 
tions,— as  of  the  sperm,  urine,  &c.  (although,  as  we  have  seen,  these 
partly  belong  to  the  external  sensations);  the  impressions  that  warn 
us  of  our  partial  or  general  movements,  of  the  progress  of  digestion, 
and  of  intellectual  labours.  The  last  succeed  to  the  action  of  organs, 
especially  when  such  action  has  been  too  long  continued ;  hence  the 
inward  feeling  of  fatigue  after  too  long  exertion  of  the  functions  of 
the  senses,  of  the  intellectual  and  moral  faculties,  and  of  the  organs  of 
muscular  motion ;  the  necessity  of  repose  after  prolonged  muscular 
exertion ;  and  of  sleep,  to  recruit  the  nervous  system,  and  to  fit  it  for 
the  exertions  it  has  to  make  during  the  waking  condition. 

.The  mode  in  which  these  sensations  are  effected  is  analogous  to  that 
of  the  external  sensations.  There  is  an  impression  on  the  part  to 
which  the  sensation  is  referred;  an  action  of  perception  accomplished 
by  the  encephalon ;  and  one  of  transmission,  executed  by  a  nerve 
passing  between  the  two.  The  last  two  actions  are  probably  execute'd 
in  the  same  manner  as  in  the  external  sensations.  The  first,  or  the 
mode  in  which  the  impression  is  effected,  and  the  character  of  the  im- 
pression itself,  are  more  obscure.  In  the  external  sensations,  we  can 
refer  the  impression  to  a  known  irritant, — special  in  some  of  the  senses: 

1  Adelon,  art.  Besoins,  in  Diet,  de  Medecine,  i.  367,  Paris,  1821;  and  Physiologic  de 
1'Hornme,  i.  482. 


300  MORBID  SENSATIONS. 

— more  general  in  others.  We  know,  that  light  impresses  the  retina ; 
— aerial  undulations  the  acoustic  nerve,  &c. ;  but,  in  the  internal  sen- 
sations or  sentiments,  as  some  of  the  French  writers  term  them,  the 
source  of  the  irritation  is  in  some  modified  action  of  the  part  itself,  in 
the  very  tissue  of  the  organ,  and  hence  the  result  is  said  to  be  organic. 
In  the  internal  sensation  of  hunger,  for  example,  the  impression  is  en- 
gendered in  the  organ, — how,  we  know  not, — is  thence  conveyed  to 
the  brain,  and  the  sensation  is  not  effected  until  the  latter  has  acted. 
The  same  may  be  said  of  all  the  internal  sensations.  They  differ,  in 
other  respects,  also,  from  the  external.  Whilst  the  latter  may  be 
entirely  passive,  or  rendered  active  by  volition,  without  either  action 
being  the  cause  of  particular  pleasure  or  inconvenience,  the  former  are 
little  influenced  by  volition.  Constituting  the  wants — the  instinctive 
desires — which  impel  to  acts,  that  are  necessary  for  the  preservation 
and  full  developement  of  the  individual  and  of  the  species,  such  in- 
dependence is  of  course  essential.  On  many  of  them,  however,  habit 
or  accustomed  volition  has  a  certain  degree  of  influence;  and  they  can 
unquestionably  be  augmented  or  moderated  by  licentious  indulgence 
or  restraint.  The  influence  of  habit  is  exemplified  by  the  regularity 
with  which  the  appetite  returns  at  stated  intervals ;  and  by  the  differ- 
ence between  that  of  the  gourmand  and  of  the  temperate  individual. 
It  is  most  strikingly  evidenced,  however,  in  its  influence  over  the 
moral  wants ;  which  may  even  spring  up  from  social  indulgence,  and 
hence  are  not  instinctive  or  organic.  We  are  every  day  compelled 
to  witness  the  striking  difference  between  the  individual  who  practises 
restraint  upon  his  wants,  and  the  libertine,  who,  like  the  animals  sur- 
rounding him,  gives  unbridled  sway  to  his  natural  and  acquired  appe- 
tites. 

All  the  internal  sensations,  when  satisfied  or  responded  to  in  mode- 
ration, communicate  a  feeling  of  pleasure;  but  if  resisted,  pain  re- 
sults. If  hunger  be  prolonged,  there  is  a  general  feeling  of  uneasi- 
ness, which  rapidly  abates  after  food  is  received  into  the  stomach ;  but 
if  satiety  be  produced,  uneasiness  follows ;  and  this  applies  to  all  the 
appetites  or  wants.  The  special  internal  sensations  will  engage  us, 
when  the  functions  to  which  they  belong  fall  under  consideration. 
Like  the  external  sensations,  they  must,  of  course,  administer  to  the 
intellect,  to  an  extent  which  will  be  seen  hereafter.  Their  influence 
and  nature  were  entirely  neglected  until  of  comparatively  late  years, 
when  attention  was  directed  to  them  chiefly  through  the  labours  of 
MM.  Cabanis1  and  of  Destutt-Tracy  ;2  and  they  now  form  subjects  for 
interesting  speculation,  with  the  metaphysician  more  especially. 

The  morbid  sensations  belong  more  particularly  to  pathology ;  a 
brief  notice  of  them  will  consequently  be  all  that  is  necessary  here. 
They  are  comprised  under  the  term  pain.  In  its  enlarged  significa- 
tion, this  word,  as  is  well  known,  means  every  uneasy  or  disagreeable 
sensation  or  moral  affection; — thus  including  sadness,  anger,  terror, 
as  well  as  the  painful  impressions  felt  in  the  extremities  or  trunks  of 

1  Rapport  du  Physique  et  du  Morale  de  1'Homme,  torn,  ii.,  Paris,  1802. 
3  Siemens  d'Ideologie,  2de  edit.,  Paris,  1804. 


MENTAL  FACULTIES.  301 

the  nerves.  It  is  the  latter  only — or  physical  pain — that  concerns  us 
at  present.  Like  every  other  sensation,  although  it  may  be  referred 
exclusively  to  the  part  impressed,  pain  requires  the  intervention  of  the 
encephalon  ;  for  if  the  nerves,  proceeding  from  a  part  to  that  organ, 
be  cut,  tied,  compressed,  or  stupefied  by  narcotics ;  or  if  the  action  of 
the  brain  itself  be  blunted  from  any  cause,  as  by  the  use  of  opium, 
ether,  or  chloroform,  or  by  any  compression,  accidental  or  other,  the 
sensation  is  no  longer  experienced.  We  can  thus  understand  why  pain 
is  felt  less  during  sleep;  and  the  astonishing  cases  of  resistance  to  pain, 
witnessed  in  the  lunatic,  and  in  religious  or  other  enthusiasts  who  have 
been  subjected  to  bodily  torture.  An  opposite  condition  of  the  nerv- 
ous system  is  the  cause  of  the  great  sensibility  to  impressions  in  the 
nervous  and  hysterical. 

It  is  obvious,  that  pain  may  be  either  an  external  or  internal  sensa- 
tion, according  as  the  cause  of  irritation  is  extraneous,  or  seated  in 
the  tissue  of  organs  ;  and  that  it  must  vary  considerably,  both  as  re- 
gards the  precise  irritant,  and  the  part  affected  ;  hence  the  difference 
between  the  pain  caused  by  a  burn,  and  that  by  a  cutting  instrument; 
and  the  immense  variety  of  pains  to  which  the  human  frame  is  sub- 
ject, and  the  attentive  study  of  which  is  so  indispensable  to  the  patho- 
logist. 

So  much  for  the  sensations.  These,  we  have  seen,  are  innumerable, 
for  each  sense  is  capable  of  myriads  of  different  impressions.  We  now 
pass  to  the  consideration  of  those  functions  that  enable  man — although 
worse  provided  with  means  of  defence  and  offence  than  the  beasts  sur- 
rounding him,  and  possessing  no  covering  to  protect  him  from  the  sum- 
mer's heat  or  the  winter's  cold — to  provide  himself  means  of  defence  ; 
to  render  the  animals  around  him  subservient  to  his  use ;  to  cover  his 
nakedness,  and  protect  himself  against  atmospheric  changes  ;  to  devise 
mechanical  arts ;  to  fathom  the  laws,  that  govern  the  bodies  by  which 
he  is  surrounded,  and  to  establish  himself  undisputed  master  of  the 
earth. 

MENTAL  FACULTIES. 

The  external  senses  convey  to  the  brain  the  different  impressions 
made  upon  them  by  surrounding  bodies ;  but,  of  themselves,  they 
would  be  unable  to  instruct  the  mind  regarding  the  universe.  It  is 
necessary,  that  the  brain  should  act  before  any  perception  of  them  can 
exist.  The  mental  faculties,  in  other  words,  convert  the  impressions 
into  ideas.  The  internal  sensations,  on  the  other  hand,  consist,  as  we 
have  seen,  of  the  numerous  wants  and  appetites  necessary  for  the  pre- 
servation of  the  individual,  and  the  species.  In  addition  to  these,  man 
possesses  another  series  of  faculties,  which  influence  his  character  and 
disposition,  and  direct  his  social  existence :  these  are  the  affective  or 
emotive  faculties  or  faculties  of  the  heart.  The  study  of  these  different 
mental  and  moral  phenomena  constitutes  what  has  been  called  psycho- 
logy,— so  termed  from  an  idea,  that  they  are  exclusively  dependent 
upon  the  mind.  The  notion  was,  at  one  time,  universal,  and  hence  the 
appellation  metaphysician,  applied  to  such  as  were  considered  to  pro- 
ceed in  their  investigations  beyond  what  was  physical,  material,  or  cor- 
poreal. 


302  MENTAL  FACULTIES. 

There  is  no  subject,  which  has  given  occasion  to  so  much  excitement 
and  controversy,  as  that  of  the  connexion  of  the  mental  faculties  with 
the  encephalon.  "  It  has  unfortunately  happened,"  says  Dr.  Bostoek,1 
"  that  this  subject,  which  is  one  of  great  interest  and  curiosity,  has  sel- 
dom been  viewed  with  that  philosophical  spirit  which  should  always 
direct  our  investigations,  and  by  which  alone  we  can  expect  to  arrive 
at  truth.  It  is  admitted,  that  certain  errors  may  be  so  interwoven  with 
our  accustomed  associations,  on  topics  connected  with  morals  and  reli- 
gion, as  to  render  it  doubtful,  on  some  occasions,  how  far  we  ought  to 
attempt  their  removal ;  but  if  this  concession  be  made  on  the  one  hand, 
it  is  incumbent  upon  us,  on  the  other,  not  to  inflame  the  prejudices, 
which  may  exist  on  these  topics,  but  to  use  our  endeavours  to  correct 
all  undue  excitement,  and  thus  to  bring  the  mind  into  that  tranquil 
state,  which  may  enable  it  to  receive  truth  without  fear  of  injury."  In 
such  a  spirit  ought  every  discussion  on  the  subject  to  be  conducted  ;  and 
in  such  a  spirit  will  the  few  remarks  that  follow  be  offered. 

The  chief  opinions,  which  have  been  indulged  on  the  subject  are, — 
1st.  That  all  the  mental  phenomena  are  immaterial,  and  the  exclusive 
product  of  the  mind.  2dly.  That  the  sentient  principle  within  us  re- 
quires the  intervention  of  an  organ,  through  which  it  acts ;  in  other 
words,  that  mind  is  a  principle  superadded  to  organization ;  and  3dly. 
That  where  there  is  no  organization  there  is  no  perception  : — that  wher- 
ever an  organized  structure,  like  the  brain,  exists,  perception  exists  ; 
that  where  the  organization  is  imperfect,  perception  is .  imperfect ; 
where  the  organization  is  sound  and  vigorous,  perception  is  clear 
and  vigorous ;  where  it  is  impaired,  perception  is  impaired ;  and  that 
when  organization  ceases  perception  ceases  also.  This  last  view  is  ma- 
terialism. It  supposes,  that  a  certain  condition  of  matter  is  capable  of 
thinking,  reasoning,  and  understanding. 

The  doctrine, — that  our  intellectual  and  moral  acts  are  superadded 
to  organization,  and  that  there  is  an  organ  concerned  in  their  mani- 
festation, is  the  one  embraced  by  the  generality  of  physiologists,  and 
is  most  consistent  with  reason  and  analogy:  it  is  but  justice,  how- 
ever, to  admit,  that  the  views  of  those,  who  consider  that  a  certain 
organization  produces  thought,  are  not  deserving  of  the  anathemas 
that  have  been  directed  against  them  on  the  score  of  irreligion.  The 
charge  would  rather  apply  to  those  who  doubt  the  power  of  Omnipo- 
tence to  endow  matter  with  such  attributes.  Were  the  mental  and 
moral  phenomena  the  exclusive  products  of  the  immaterial  principle 
within  us,  they  would  hardly  form  subjects  for  physiological  inquiry. 
That  they  are  allied  to  organization  is  inferred  for  the  following  rea- 
sons. As  they  constitute  so  many  functions,  were  they  not  provided 
with  an  organ  or  organs,  they  would  form  so  many  exceptions ; — each 
of  the  sensations  requiring  an  organ  for  its  accomplishment.  Again, 
our  inward  feeling  induces  us  to  refer  them  to  a  particular  part  of  the 
frame :  whilst  thought  appears  to  be  effected  within  the  head,  the  chief 
expressions  of  the  passions  are  felt  in  the  region  of  the  heart  or  stomach. 
The  faculties,  moreover,  are  not  the  same  in  every  individual.  One 

1  Physiology,  3d  edit.,  p.  744,  Lond.,  1836. 


ORGAN  OF  THE  MENTAL  FACULTIES.  303 

man  is  a  poet ;  another  a  mathematician  ;  or  one  is  benevolent,  another 
cruel.  If  these  faculties  were  the  exclusive  product  of  the  mind,  and  of 
course  not  to  be  ascribed  to  diversity  of  organization,  we  should  have 
to  admit,  that  each  individual  has  a  different  immaterial  principle,  and 
of  course,  that  there  must  be  as  many  kinds  as  there  are  individuals. 
Lastly.  The  faculties  vary  in  the  same  individual  according  to  circum- 
stances. They  are  not  the  same  in  the  child  as  in  the  adult ;  in  the 
adult  as  in  one  advanced  in  life ;  in  health  as  in  disease  ;  in  waking  as 
in  sleep.  During  an  attack  of  fever  they  become  temporarily  deranged ; 
and  are  permanently  so  in  all  the  varieties  of  insanity.1  These  facts 
are  inexplicable  under  the  doctrine,  that  they  are  the  exclusive  product 
of  the  mind  or  immaterial  principle.  An  immaterial  or  spiritual  prin- 
ciple ought  to  be  immutable  ;  yet  we  should  have  to  suppose  it  capable 
of  alteration ;  of  growing  with  the  growth  of  the  body,  and  of  becom- 
ing old  with  it ;  of  being  awake  or  asleep ;  sound  or  diseased.  All 
these  modifications  must  be  caused  by  varying  organization — of  the 
brain  in  particular. 

We  may  conclude,  then,  that  the  intellectual  and  moral  faculties  are 
not  the  exclusive  product  of  the  mind;  that  they  require  the  interven- 
tion of  an  organ;  and,  that  this  organ  is  the  encephalon,  or  a  part  of  it 
— the  cerebrum  or  brain — is  announced  by  many  circumstances.  In 
the  first  place,  they  are  phenomena  of  sensibility,  and  hence  we  should 
be  disposed  to  refer  them  to  a  nervous  organ;  and,  being  the  most  ele- 
vated phenomena  of  the  kind,  to  the  highest  of  the  nervous  organs.  In 
the  second  place,  inward  feeling  impels  us  to  refer  them  thither.  We 
not  only  feel  the  process  there,  during  meditation ;  but  the  sense  of 
fatigue,  which  succeeds  to  hard  study,  is  felt  there  likewise.  The  brain, 
again,  must  be  in  a  state  of  integrity,  otherwise  the  faculties  are  de- 
ranged; or,  for  the  time,  abolished.  In  fever,  it  becomes  affected  directly 
or  indirectly,  and  the  consequence  is,  perversion  of  the  intellect,  in  the 
form  of  delirium.  If  the  organ  be  more  permanently  disordered,  as 
by  the  pressure  of  an  exostosis  or  tumour,  or  by  some  alteration  in  its 
structure  or  functions — less  appreciable  in  its  nature — insanity,  in  some 
form,  may  be  the  result. 

In  serious  accidents  to  the  encephalon,  we  observe  the  importance 
of  the  cerebrum  to  the  proper  exercise  of  the  mental  faculties  clearly 
evinced.  A  man  falls  from  a  height,  and  fractures  his  skull.  The 
consequence  is,  depression  of  a  portion  of  bone,  which  exerts  a  degree 
of  compression  upon  the  brain;  or  extravasation  of  blood  from  some  of 
the  encephalic  vessels  attended  with  simitar  results.  From  the  moment 
of  the  infliction  of  the  injury,  the  whole  of  the  mental  and  moral  mani- 
festations are  suspended,  and  do  not  return  until  the  compressing  cause 
is  removed  by  the  operation  of  the  trephine.  M.  Richerand  cites  the  case 
of  a  female,  who  had  a  portion  of  the  brain  accidentally  exposed,  and 
in  whom  it  was  found,  that  pressing  on  the  brain  completely  suspended 
consciousness,  which  was  not  restored  until  the  pressure  was  removed. 
A  similar  case  occurred  to  Professor  Wistar;  and  another  is  related  by 

1  Adelon,  art.  Encephale,  Diet,  de  Medecine,  vol.  vii. ;  and  Physiologie  de  1'Homme,  torn.  i. 
edit.  cit. 


304  MENTAL  FACULTIES. 

M.  Lepelletier.1  A  patient  of  a  M.  Pierquien  had  an  extensive  caries 
of  the  os  frontis,  with  perforation  of  the  bone,  which  exposed  the  brain 
covered  by  its  membranes.  When  she  slept  soundly,  the  organ  sank 
down;  when  she  dreamed,  or  spoke  with  feeling,  turgescence  and 
marked  oscillations  were  perceptible ;  when  the  brain  was  pressed  upon, 
she  stopped  in  the  middle  of  a  sentence  or  a  word,  and  when  the  pres- 
sure was  removed,  she  resumed  the  conversation,  without  any  recollec- 
tion of  the  experiment  to  which  she  had  been  subjected.  An  important 
difference  in  the  effect  is,  however,  noticed  in  such  cases  according  to 
the  suddenness  or  tardiness  with  which  the  pressure  is  made.  Whilst 
a  sudden  compression  suspends  the  intellectual  and  moral  manifesta- 
tions for  a  time;  slow  pressure,  produced  by  the  gradual  formation  of 
a  tumour,  may  exist  without  exhibiting,  in  any  manner,  the  evidences 
of  its  presence.  Accordingly,  the  anatomist  is  at  times  surprised  to 
discover  such  morbid  formations  in  the  brains  of  persons  who  have  never 
laboured  under  any  mental  aberration. 

A  negative  argument  in  favour  of  this  function  of  the  brain  has  been 
deduced  from  the  fact,  that  disease  of  other  portions  of  the  body,  even 
of  the  principal  organs,  may  exist  and  pass  on  to  a  fatal  termination, 
leaving  those  faculties  almost  unimpaired.  Such  is  proverbially  the 
case  with  phthisis  pulmonalis;  the  subject  of  which  may  be  flattering 
himself  with  hopes  never  to  be  realized,  and  devising  schemes  of  future 
aggrandizement  and  pleasure  until  within  a  few  hours  of  his  dissolution. 

The  intellectual  faculties  differ  in  each  individual,  and  vary  mate- 
rially with  the  sex.  The  brain  is,  in  all  these  cases,  equally  different. 
Much  may  depend  upon  education;  but  it  may,  we  think,  be  laid  down 
as  an  incontrovertible  position,  that  there  is  an  original  difference  in 
the  cerebral  organization  of  the  man  of  genius  and  of  him  who  is  less 
gifted;  and  that,  as  a  general  rule,  in  the  former  the  brain  is  much 
more  developed  than  in  the  latter.  Whilst  the  brain  of  the  man  of 
intellect  may  measure  from  nineteen  to  twenty-two  inches  in  circum- 
ference, that  of  the  idiot  frequently  does  not  exceed  thirteen,  or  is  not 
greater  than  in  the  child  one  year  old.  It  was  an  ancient  observation, 
that  a  large  development  of  the  anterior  and  superior  parts  of  the 
head  is  a  characteristic  of  genius;  and,  accordingly,  we  find,  that  all 
the  statues  of  the  sages  and  heroes  of  antiquity  are  represented  with 
high  and  prominent  foreheads.  In  the  older  poets,  we  meet  with  many 
evidences,  that  the  height  of  the  forehead  was  regarded  as  an  index  of 
the  intellectual  or  moral  character  of  the  individual.  Thus  Shakspeare: 


"We  shall  lose  our  time, 
And  all  be  turn'd  to  barnacles,  or  to  apes, 
With  foreheads  villanous  low." 

CALIBAN,  in  "  TEMPEST." — Act  iv. 


And  again : — 


"Ay,  but  her  forehead's  low,  and  mine's  as  high." 

JULIA,  in  the  "  Two  GENTLEMEN  OF  VERONA." — Act  iv. 

The  relation  between  the  size  of  the  head  and  the  mental  manifesta- 
tions has,  indeed,  interwoven  itself  into  our  ordinary  modes  of  speech. 

1  Physiologic  Medicale,  &c.,  iii.  242,  Paris,  1832. 


THE  BRAIN  THE  ORGAN  OF  THE  MENTAL  FACULTIES.  305 

"Let  it  not  be  believed,"  says  a  distinguished  writer,1  "an  affair  of 
accident,  that  a  head"  of  considerable  dimensions  is  found,  from  time  to 
time,  to  coincide  with  a  distinguished  genius.  Although  the  amour 
propre  may  object,  the  law  is  general.  I  have  neither  met  in  antiquity, 
nor  in  modern  times  a  man  of  vast  genius,  whose  head  ought  not  to  be 
ranged  in  the  latter  class,  which  I  have  just  established,  especially  if 
attention  be  paid  to  the  great  developement  of  the  forehead.  Look  at 
the  busts  and  engravings  of  Homer,  Socrates,  Plato,  Demosthenes, 
Pliny,  Bacon,  Sully,  Galileo,  Montaigne,  Corneille,  Racine,  Bossuet, 
Newton,  Leibnitz,  Locke,  Pascal,  Boerhaave,  Haller,  Montesquieu, 
Voltaire,  J.  J.  Rousseau,  Franklin,  Diderot,  Stoll,  Kant,  Schiller,  &c." 
Yet  we  are  not  always  accurate  in  estimating  the  size  of  the  brain 
from  the  developement  of  the  head.  Dr.  Sewall2  has  clearly  shown, 
that  skulls  of  the  same  dimensions,  as  measured  by  the  craniometer, 
differ  largely  as  to  the  quantity  of  cerebral  substance,  which  they  are 
capable  of  containing.  With  the  assistance  of  Dr.  Thomas  P.  Jones,  of 
Washington,  and  of  Professor  Ruggles,  of  the  Columbian  College,  he 
instituted  various  experiments.  In  the  first  series,  he  ascertained  the 
volume  of  each  skull,  brain  included  :  in  the  second  series,  the  volume 
of  the  brain  alone  or  the  capacity  of  the  cerebral  cavity  ;  and  in  order 
to  render  the  difference  in  capacity  more  obvious,  the  volume  of  each 
skull,  brain  included,  was  reduced  to  the  dimensions  of  70  fluidounces. 
The  results  of  the  experiments  on  five  skulls,  delineated  in  the  plates 
of  Dr.  Sewall's  work,  were  as  follows  : — 


Volume  of  Skull,  Brain  included.                  Volume  of  Brain. 

Plate  II. 

70  oz.   - 

56-22  oz. 

III.      - 

do. 

51-72 

IV. 

do.       - 

46-21 

V.      - 

do. 

34-79 

VII. 

do.       - 

25-33 

In  two  of  these  skulls,  consequently,  of  the  same  external  dimen- 
sions, there  was  a  difference  in  the  volume  of  brain  of  31-89  oz.  Dr. 
Sewall  infers  from  his  observations,  that  no  phrenologist,  however  ex- 
perienced, can,  by  any  inspection  of  the  living  head,  ascertain  whether 
a  person  has  a  skull  of  one  inch  or  one-eighth  of  an  inch  in  thickness ; 
or  whether  he  has  56-22  ounces  of  brain,  or  only  25-33  ounces. 

To  the  view,  that  the  mental  capacity  is  in  a  ratio  with  the  size  of  the 
brain  there  must  be  numerous  exceptions  ;  for,  independently  of  bulk, 
there  may  obviously  be  an  organization  productive  of  results,  in  which 
the  largely  developed  organ  may  be  greatly  deficient.  Size  is  only  one 
of  the  elements  of  activity  of  an  organ.  "  Whilst  there  is  an  evident 
connexion,"  says  a  recent  writer,3  "between  a  large  quantity  of  cere- 
bral matter,  and  a  highly  developed  intellect,  the  quality  of  the  mind 
and  that  of  the  brain-substance  may  also  be  supposed  to  have  a  close 
relation  to  each  other.  In  great  power  of  action  a  large  muscle  is 
needed,  but  for  vigorous  and  well-adjusted  muscular  movement  a  cer- 

1  Gall,  Sur  les  Fonctions  du  Cerveau,  ii.  342,  Paris,  1825. 

a  An  Examination  of  Phrenology,  in  Two  Lectures,  2d  edit.,  p.  66,  Boston,  1839. 

3  Todd  and  Bowman,  The  Physiological  Anatomy  and  Physiology  of  Man,  p.  262,  Lond.,  1845. 

VOL.  i.— 20 


306  MENTAL  FACULTIES. 

tain  quality  of  fibre  is  also  necessary  to  give  full  scope  to  the  nervous 
power.  It  is  impossible  toi determine  what  the  peculiarity  in  quality  is, 
but  some  idea  of  the  great  influence  which  it  may  possess  in  the  exer- 
cise of  the  two  great  vital  forces,  the  muscular  and  nervous,  may  be 
gained  from  comparing  the  energy  and  action  of  a  well-bred  horse,  with 
one  of  those,  which,  in  the  language  of  the  turf,  shows  little  or  no 
breeding.  The  actual  amount  of  muscular  or  nervous  fibre  may  be  the 
same  in  both,  or  it  may  be  less  in  the  horse  of  good  breeding  than  in 
the  other,  yet  the  former  does  his  work  and  endures  fatigue  better." 

The  difference  between  the  moral  of  the  male  and  the  female  is  sig- 
nal ;  and  there  is  no  less  in  the  shape  of  the  encephalon  in  the  two  sexes. 
Observation,  not  only  by  anatomists  but  by  sculptors  and  painters, 
shows,  that  the  superior  and  anterior  parts  of  the  brain  are  less  deve- 
loped in  the  female,  whose  forehead  is,  therefore,  as  a  general  rule, 
smaller ;  whilst  the  posterior  are  larger.  In  the  system  of  Gall,  the 
anterior  and  superior  parts  are  considered  to  be  connected  with  the  intel- 
lectual manifestations,  which  are  more  active  in  man  ;  whilst  the  poste- 
rior are  concerned  in  the  softer  feelings,  which  predominate  in  the  cha- 
racter of  the  female.  The  mental  and  moral  faculties  vary  also,  in  the 
same  individual,  according  to  age,  health,  and  disease  ;  and  in  the 
waking  and  sleeping  state.  In  all  these  conditions,  we  have  reason  to 
believe  the  state  of  the  encephalon  is  as  various.  The  anatomist  notices 
a  manifest  difference  between  its  organization  in  the  infant  and  in  the 
adult  or  aged.  Like  the  other  organs  of  the  body,  it  is  gradually  de- 
veloped until  the  middle  period  of  life  ;  after  which  it  decays  with  the 
rest  of  the  frame.  Our  acquaintance  with  the  minute  organization  of 
the  body  does  not  enable  us  to  say  on  what  changes  these  differences 
are  dependent.  We  see  them  only  in  their  results.  By  the  minutest 
examination  of  the  special  nerves  of  sense  we  are  incapable  of  saying, 
why  one  should  appreciate  the  contact  of  sapid  bodies,  another  that  of 
light,  &c.  During  sleep,  again,  in  which  the  functions  of  the  brain  are 
more  or  less  suspended,  the  condition  of  the  organ  is  modified  ;  and 
mania  or  delirium  probably  never  occurs  without  the  physical  condition 
of  the  brain  having  undergone  some  change,  directly  or  indirectly.  It 
is  true,  that,  on  careful  examination  of  the  brains  of  the  insane,  it  has 
often  happened,  that  no  morbid  appearance  has  presented  itself;  but 
the  same  thing  has  been  observed  on  inspecting  those  who  have  died  of 
apoplexy  or  paralysis,  in  which  not  a  doubt  is  entertained  that  the  cause 
is  seated  in  the  encephalon,  and  that  it  consists  in  a  physical  alteration 
of  its  tissue.  These  are  a  few  of  the  cases  which  make  us  sensible  of 
the  limited  nature  of  our  powers  of  observation.  They  by  no  means 
encourage,  in  the  most  sceptical,  the  belief,  that  the  tissue  of  the  organ 
is  not  implicated.  The  investigations  of  the  morbid  anatomist,  conse- 
quently, afford  us  few  data  on  which  to  form  our  opinions  on  this  sub- 
ject. 

The  effect  of  intoxicating  substances  is  mainly  exerted  on  the  brain. 
When  taken  in  moderation,  all  the  faculties  are  excited  ;  but  if  pushed 
too  far,  the  intellectual  and  moral  manifestations  become  perverted. 
This  can  only  be  through  their  action  on  the  cerebral  organ.  We 
can  thus  understand,  how  regimen  may  cause  important  modifications 


THE  BKAIN  THE  ORGAN  OF  THE  MENTAL  FACULTIES.      SOT 

in  the  brain.  Climate  has  probably  a  similar  influence ;  hence,  the  dif- 
ference between  the  characters  of  different  nations  and  races.  The  skull 
of  the  Mongol  is  different  from  that  of  the  Kelto-Goth  or  of  the  Ethio- 
pian ;  and  the  brain,  as  well  as  its  functions,  exhibits  equal  diversity. 

Again,  it  has  been  argued,  that  the  facts  noticed  in  the  animal  king- 
dom are  in  favour  of  the  brain  being  the  organ  concerned  in  the  men- 
tal manifestations  ;  that,  if  each  animal  species  has  its  own  psychology, 
in  each  the  encephalon  has  a  special  organization ;  and  that  in  those 
which  exhibit  superior  powers,  the  brain  is  found  large,  and  more  com- 
plicated. To  a  great  extent  this  is  true.  Nothing,  indeed,  seems  more 
erroneous  than  the  notion,  that  even  sensibility  to  pain  is  equal  in 
every  variety  of  the  animal  creation.  As  we  descend  in  the  scale,  the 
nervous  system  is  found  becoming  less  and  less  complicated ;  until 
ultimately  it  assumes  the  simplest  original  character,  which  has  laid 
the  foundation  for  one  of  the  divisions  of  Sir  Charles  Bell's  system ; 
and  although  it  is  impossible  to  change  places  with  the  animal,  we  have 
the  strongest  reasons  for  believing,  that  the  sensibility  diminishes  as  we 
descend ;  and  that  the  feeling,  expressed  by  the  poet,  that  the  beetle, 
which  we  tread  upon — 

"  In  corporal  sufferance  finds  a  pang  as  great 
As  when  a  giant  dies" — 

however  humane  it  may  be,  is  physiologically  untrue.  The  phenomena 
in  favour  of  this  view  that  present  themselves  to  the  naturalist  are 
numerous  and  interesting  ;  and  afforji  signal  evidence  of  creative  wis- 
dom in  endowing  the  frames  of  those  beings  of  the  animal  kingdom, 
that  are  most  exposed  to  injury  and  torture,  with  a  less  sensible  organi- 
zation. The  frog  continues  sitting,  apparently  unconcerned,  for  hours 
after  it  has  been  eviscerated ;  the  tortoise  walks  about  after  having  lost 
its  head ;  and  the  divisions  of  the  polypus,  made  by  the  knife,  form  so 
many  distinct  animals.  Redi  removed  the  whole  of  the  brain  of  a 
common  land  tortoise :  the  eyes  closed  to  open  no  more ;  but  the  ani- 
mal walked  as  before, — groping,  as  it  were,  its  way  for  want  of  vision. 
It  lived  nearly  six  months.  All  have  noticed  the  independence  of  the 
parts  of  a  wasp,  after  the  head  has  been  severed  from  the  body.  It 
will  try  to  bite,  and,  for  a  considerable  time,  the  abdomen  will  attempt 
to  sting.  An  illustrative  instance  of  the  kind  occurred  to  Dr.  Harlan.1 
He  cut  off  the  head  of  a  rattlesnake ;  and,  grasping  the  part  of  the 
neck  attached  to  the  head  with  his  finger  and  thumb,  the  head  twisted 
itself  violently,  endeavouring  to  strike  him  with  its  fangs.  A  live 
rabbit  was  presented  to  the  head,  which  immediately  plunged  its  fangs 
deep  into  the  animal ;  and  when  the  tail  of  the  snake  was  laid  hold  of, 
the  headless  neck  was  bent  quickly  round  as  if  to  strike  the  experi- 
menter. The  experiments  of  Dr.  Le  Conte,2  of  Savannah,  Georgia, 
and  of  Dr.  Bennet  Dowler,3  of  New  Orleans,  on  the  Alligator — croco- 
dilus  lucius — exhibit  like  results,  and  would  lead  to  the  inference,  that 
in  that  animal,  phenomena  essentially  resembling  those  which  in  the 

i  Medical  and  Physical  Researches,  p.  503,  Philad.,  1835. 
a  New  York  Journal  of  Medicine,  Nov.  1845,  p.  335. 
3  Contributions  to  Physiology,  New  Orleans,  1849. 


308  MENTAL  FACULTIES. 

upper  classes  of  animals  are  referable  to  the  encephalon,  may  be  more 
diffused  in  their  origin.  In  one  experiment  by  the  latter  gentleman, 
and  Dr.  Young,  aided  by  Mr.  Barbot,  the  head  of  the  animal,  for  more 
than  an  hour  after  decollation,  exhibited  that  it  possessed  sensation, 
perception,  vision,  passion,  and  voluntary  motion.  "  It  saw  its  ene- 
mies; opened  its  mouth  to  bite  at  the  proper  time;  and  nictated  when 
a  foreign  body  approached  the  eye;"  and  for  three  or  four  hours  the 
headless  trunk,  during  extensive  mutilations  by  two  operators,  "  mani- 
fested, in  a  still  higher  degree,  sensation,  intelligence,  definite,  well- 
directed  muscular  actions.  There  was,  as  usual,  a  complete  loss  of 
progressive  or  forward  motion.  The  test  used  to  elicit  sensation  and 
voluntary  movements  were  pinching,  puncturing  and  burning.  Its  sen- 
sibility and  motions  appeared  to  be  nearly  as  acute,  quick  and  varied 
as  in  the  unmutilated  animal.  The  direction  of  the  limbs  was  not  such 
as  could  be  deemed  habitual,  as  in  walking  and  swimming.  Some  of 
these  motions  are  of  difficult  execution  in  the  entire  animal  from  its 
anatomical  conformation,  such  as  reaching  up  between  the  shoulders  or 
hips  to  remove  an  irritant." 

In  another  experiment  performed  in  the  presence  of  Drs.  Cartwright, 
Smith,  Nutt,  Powell,  Hire,  Mr.  Barbot,  and  Professor  Forshey — in  which 
decollation  was  practised  with  a  dull  hatchet,  and,  in  consequence,  the 
hemorrhage  was  not  great,  although  considerable — Dr.  Dowler  carried 
the  handle  of  a  knife  towards  the  eye,  to  ascertain  whether  it  would 
wink;  "  whereupon  the  ferocious,  separated  head"  sprang  up  from  the 
table  with  great  force  at  him,  passing  very  near  his  breast,  which  re- 
ceived several  drops  of  blood ;  and  then  alighted  upon  the  floor  from 
six  to  eight  feet  distant  from  its  original  position.  It  missed  him  be- 
cause he  was  standing  at  the  side,  and  not  in  front  of  the  head.  uFor 
about  two  hours," — says  Dr.  Dowler — "  the  headless  trunk  exhibited 
such  phenomena  as  are  usually  attributed  to  the  brain, — namely,  sen- 
sation, volition,  and  intelligential  motion,  as  tested  by  the  application  of 
bits  of  ignited  paper,  wounds,  and  the  like,  whereupon  the  usual  indi- 
cants of  pain  were  elicited  with  great  promptness  and  precision :  it 
trembled,  receded,  rolled  over,  curved,  placed  its  limbs  accurately  to 
the  exact  spot,  and  removed  the  offending  cause.  In  certain  places, 
this  was  exceedingly  difficult,  as  on  the  spine  between  or  near  the 
shoulders  or  hips.  It  always  used  the  limb  the  best  adapted  for  the 
purpose.  If  the  fire  was  too  remote,  as  when  applied  to  the  tail,  the 
whole  body  was  thrown  into  the  most  favourable  position  for  the  pur- 
pose of  reaching  and  removing  the  same.  If  the  fire  was  placed  on 
the  table,  in  a  position  to  annoy,  yet  without  touching,  the  animal,  as 
if  endowed  with  sight,  reached,  and  always  accurately,  to  the  exact  spot, 
and  either  extinguished  the  fire,  or  removed  it.  As  upon  former  occa- 
sions, if  the  animal  found  that  the  fire  was  continued  at  the  same  spot, 
and  that  it  could  not  remove  it,  which  was  sometimes  the  case,  owing 
to  continuous  or  repeated  applications,  and  carefully  manoeuvring,  it 
curved  the  body, — scratched  Violently,  manoeuvred  skilfully,  and  then, 
as  a  last  resort,  rolled  quite  over,  laterally,  always  from,  never  towards 
the  fire  and  operator." 

Still,  the  position,  that  in  man  and  the  upper  classes  of  animals, 


ENCEPHALIC  SEAT  OF  THE  PASSIONS.  309 

the  brain  is  the  organ  through  which  the  mind  acts  in  the  production 
of  the  different  mental  and  moral  manifestations,  can  scarcely  be 
contested.1  Yet,  amongst  those  who  admit  the  accuracy  of  this  conclu- 
sion, a  difference  of  sentiment  exists, — some  conceiving  that  other 
organs  participate  in  the  function.  To  each  of  the  known  tempera- 
ments as  many  intellectual  and  moral  dispositions  have  been  ascribed. 
It  has  been  affirmed,  that  if  the  brain  be  manifestly  the  organ  of  intel- 
lect the  passions  must  be  referred  to  the  organs  of  internal  or  organic 
life;  whilst  others  have  regarded  the  brain  as  a  great  central  apparatus 
for  the  reception  and  elaboration  of  the  different  impressions  made  upon 
the  external  senses; — thus  conceiving  the  latter  to  be  direct  agents  in 
the  execution  of  the  function,  as  well  as  the  brain. 

The  influence  of  the  temperaments  upon  the  mental  and  bodily  pow- 
ers is  much  less  invoked  at  the  present  day  than  it  was  of  old.  The 
ancients  esteemed  organized  bodies  to  be  an  assemblage  of  elements, 
endowed  with  different  qualities,  but  associated  and  combined  so  as  to 
moderate  and  temper  each  other.  Modern  physiologists  mean  by  tem- 
perament, the  reaction  of  the  different  organs  of  the  body  upon  each 
other  consistently  with  health;  so  that  if  one  set  or  apparatus  of  organs 
predominates,  the  effect  of  such  predominance  may,  it  is  conceived,  be 
exerted  on  the  whole  economy.  In  the  description  of  the  tempera- 
ments in  different  authors  we  find  a  particular  character  of  intellectual 
and  moral  faculties  assigned  to  each.  The  man  of  sanguine  tempera- 
ment is  described  as  of  ready  conception,  retentive  memory,  and  lively 
imagination;  inclined  to  pleasure,  and  generally  of  a  good  disposition; 
but  inconstant  and  restless.  He  of  the  bilious,  on  the  other  hand,  is 
said  to  be  hasty,  violent,  ambitious,  and  self-willed  ;  whilst  the  lym- 
phatic  temperament  bestows  feeble  passions;  cold  imagination;  tend- 
ency to  idleness ;  and  the  melancholic  disposes  to  dulness  of  concep- 
tion, and  to  sadness  and  moroseness  of  disposition.  M.  Gall2  has 
animadverted  on  this  assignment  of  any  intellectual  or  moral  faculty 
to  temperament.  If  we  look  abroad,  he  affirms,  we  find  the  excep- 
tions more  numerous  than  the  rule  itself;  so  numerous,  indeed,  as  to 
preclude  us  from  establishing  any  law7  on  the  subject.  Moreover,  the 
idiot,  who  possesses  a  temperament  like  other  persons,  has  no  intel- 
lectual faculties.  The  temperament,  doubtless,  influences  the  brain 
within  certain  limits,  as  it  does  other  functions :  this,  he  suggests,  it 
probably  does  by  impressing  them  with  a  character  of  energy  or  of 
languor,  but  without,  in  any  respect,  regulating  the  intellectual  sphere 
of  the  individual. 

Bichat,3  again,  maintained,  that  whilst  the  encephalon  is  evidently 
the  seat  of  the  intellectual  functions,  the  organic  nervous  system,  and, 
consequently,  the  different  organs  of  nutrition,  which  are  supplied  by 
it,  are  the  seat  of  emotions  or  passions.  That  distinguished  physiolo- 
gist, than  whom,  as  M.  Corvisart  wrote  to  the  First  Consul,  on  an- 
nouncing his  death,  "  personne  en  si  peu  de  temps  n'a  fait  tant  de 

1  Gall,  Sur  les  Fonctions  du  Cerveau,  ii.  69,  Paris,  1825  ;  Adelon,  art.  Encephale,  Diet,  de 
Medec.,  vii.  517 ;  and  Physiologic  de  1'Homme,  ed.  cit.,  i.  496. 

2  Op.  citat.,  ii.  140.  3  Sur  la  Vie  et  la  Mort,  Part  i.,  Paris,  1806. 


310  MENTAL  FACULTIES. 

choses  et  aussi  bien,"1  rests  his  views  upon  the  following  considerations : 
— 1st.  That  while  inward  feeling  induces  us  to  refer  intellectual  acts 
to  the  brain,  the  passions  are  referred  to  the  viscera  of  the  thorax  or 
abdomen.  2dly.  That  the  effects  of  intellectual  labour  are  referred  to 
the  encephalon,  as  indicated  by  redness  and  heat  of  face,  and  beating 
of  the  temporal  arteries  in  violent  mental  contentions,  &c. :  whilst  the 
passions  affect  the  organic  functions,  the  heart  is  oppressed,  and  its 
pulsations  are  retarded  or  suspended;  the  respiration  becomes  hurried 
and  interrupted ;  the  digestion  impeded  or  deranged,  &c. ;  and  3dly. 
That  whilst  our  gestures  and  language  refer  intellect  to  the  encepha- 
lon, they  refer  emotions  to  the  nutritive  organs.  If  we  wish  to  express 
any  action  of  the  mind,  or  are  desirous  of  recalling  something  that 
has  escaped  the  memory,  the  hand  is  carried  to  the  head ;  and  we  are 
in  the  habit  of  designating  a  strong  or  weak  intellect  as  a  "  strong  or 
weak  head;"  or  we  say,  that  the  possessor  has  "much  or  little  brain.". 
On  the  other  hand,  if  desirous  of  depicting  the  passions,  the  hand  is 
carried  to  the  region  of  the  stomach  or  heart;  and  the  possessor  of 
benevolent  or  uncharitable  sentiments  is  said  to  have  a  good  or  a  bad 
heart.  Bichat  properly  adds,  that  this  idea  is  not  novel,  inasmuch  as 
the  ancients  conceived  the  seat  of  the  passions  to  be  in  the  epigastric 
centre ; — that  is,  in  the  nervous  plexuses  situate  in  that  region.  He 
remarks  that  amidst  the  varieties  presented  by  the  passions,  according 
to  age,  sex,  temperament,  idiosyncrasy,  regimen,  climate,  and  disease, 
there  is  always  a  ratio  between  them  and  the  degree  of  predominance 
of  the  different  nutritive  apparatuses;  and  he  concludes  with  a  de- 
duction, which  ought  not  to  have  been  hazarded  without  full  reflection, 
— that  as  the  functions  of  the  nutritive  organs,  in  which  he  ranges  the 
passions,  are  involuntary,  and  consequently  uninfluenced  by  education, 
education  can  have  no  influence  over  the  passions,  and  the  disposition 
is  consequently  incapable  of  modification. 

The  answer  of  MM.  Gall2  and  Adelon3  to  the  views  of  Bichat  appears 
to  us  to  be  irrefragable.  How  can  we  conceive,  that  viscera,  whose 
functions  are  known,  and  which  differ  so  much  from  each  other,  are 
agents  of  moral  acts?  The  passions  aresensorial  phenomena,  and  like 
all  phenomena  of  the  kind,  must  be  presumed  to  be  seated  in  essentially 
nervous  organs.  Again ; — when  an  injury  befalls  t^e  brain,  and  the 
intellectual  faculties  are  perverted  or  suspended  by  it,  the  same  thing 
happens  to  the  affective  faculties;  and  if  the  viscera  fulfil  the  high  office 
assigned  to  them,  why  are  not  the  passions  manifested  from  early  in- 
fancy, a  period  when  the  viscera  are  in  existence  and  active?  The 
argument  of  Bichat — that  the  phenomena  which  attend  and  follow  the 
passions,  are  referable  to  the  nutritive  organs — is  not  absolute.  The 
functions  of  animal  life  are  frequently  disturbed  by  the  passions,  as 
well  as  those  of  organic  life.  It  is  not  uncommon  for  them  to  induce 
convulsions,  mania,  epilepsy,  and  other  affections  of  the  encephalon. 
The  effect  here,  as  M.  Adelon  remarks,  is  mistaken  for  the  cause.  The 

»  Eloge  de  Xavier  Bichat,  pl^^quel,  p.  58,  Paris,  1823. 
8  Op.  citat.,  i.  94. 

8  Art.  Enc^ph.  (Physiol.)  in  Diet,  de  Med.,  vii.  521,  and  Physiologic  de  1'Homme,  edit, 
cit.,  i'.  510. 


SOURCES  OF  THE  INTELLECTUAL  SPHERE.  311 

heart  certainly  beats  more  forcibly  in  anger,  but  the  legs  fail  us  in  fear ; 
and  if  we  refer  anger  to  the  heart,  we  must,  by  parity  of  reasoning, 
refer  fear  to  the  legs.  By  reasoning  of  this  kind,  the  passions  might 
be  referred  to  the  whole  system,  as  there  is  no  part  which  does  not  suffer 
more  or  less  during  their  violence.  The  error  arises  from  our  being 
impressed  with  the  most  prominent  effect  of  the  passion — the  feeling 
accompanying  it — and  this  is  the  cause  of  the  gesture  and  the  descriptive 
language,  to  which  Bichat  has  given  unnecessary  weight  in  his  argu- 
ment. If,  then,  the  views  of  Bichat,  regarding  the  seat  of  the  passions, 
(be  unfounded,  the  mischievous  doctrine  deduced  from  them — that  they 
are  irresistible,  and  cannot  be  modified  by  education — falls  to  the  ground. 
His  notion  was,  that  the  nutritive  organs  are  the  source  of  irritative 
irradiations,  which  compel  the  brain  to  form  the  determinations  that 
constitute  the  passion,  and  to  command  the  movements  by  which  it  is 
appeased  or  satisfied.  A  similar  view  is  embraced  by  M.  Broussais,1 
who,  however,  conceives,  that  the  passions  can  be  fomented  and  increased 
by  attention,  until  they  become  predominant.  Daily  experience,  indeed, 
exhibits  the  powerful  effect  produced  on  the  passions  by  well-directed 
moral  restraint.  How  many  gratifying  instances  have  we  of  persons, 
whose  habitual  indulgence  of  the  lowest  passions  and  propensities  had 
rendered  them  outcasts  from  society,  having  become  restored  to  their 
proper  place  by  exerting  due  control  over  their  vicious  inclinations  and 
habits!  We  can  not  only  curb  the  expression  of  the  passions,  as  we 
are  constantly  compelled  to  do,  in  social  intercourse ;  but  even  modify 
the  internal  susceptibility  by  well-directed  habits  of  repression. 

Lastly.  Many  physiologists  have  considered  the  brain  as  a  great 
nervous  centre  for  the  reception  and  elaboration  of  different  impressions 
conveyed  thither  by  the  external  senses;  and  absolutely  requiring  such 
impressions  for  the  mental  manifestations.  They  consequently  rank, 
amongst  the  conditions  necessary  for  such  manifestations,  not  only  the 
brain  which  elaborates  them,  but  the  parts  that  convey  to  it  the  impres- 
sions or  materials  on  which  it  has  to  act;  and  conceive,  that  a  necessary 
connexion  exists  between  these  two  orders  of  parts.  The  supporters  of 
these  opinions  ascribe  the  differences  observed  in  the  intellectual  and 
moral  faculties  of  different  persons  as  much  to  diversity  in  the  number 
and  character  of,  the  impressions,  as  to  differences  in  the  encephalon 
itself.  They  do  not  all,  however,  agree  as  to  the  source  of  the  impres- 
sions, which  they  conceive  to  be  the  raw  material  for  the  intellectual  and 
moral  acts.  M.  Condillac2and  his  school  admit  only  one  kind; — those 
proceeding  from  the  external  senses,  which  they  term  external  impres- 
sions. M.  Cabanis,3  in  addition  to  these,  admits  others  proceeding  from 
every  organ  in  the  body,  which  he  terms  internal  impressions. 

The  school  of  Condillac  set  out  with  the  maxim  ascribed  to  Aristotle, 
''nihil  est  in  intelleetu  quod  non  prius  fuerit  in  sensu;"  and  they  adopt, 
as  an  elucidation  of  their  doctrine,  the  ingenious  idea  of  Condillac — of 
a  statue,  devoid  of  all  sensation,  which  is  made  to  receive  each  of  the 

1  Examen  des  Doctrines  Medicales,  ii.  388,  and  Physiology  applied  to  Pathology,  Drs.  Bell 
and  La  Roche's  translation,  p.  136,  Philadelphia,  1832. 

2  Traite  des  Sensations,  i.  119. 

3  Rapport  du  Physique  et  du  Moral  de  I'Homme,  4eme  edit.,  par  G.  Pariset,  Paris,  1824. 


312  MENTAL  FACULTIES. 

five  senses  in  succession;  and  which,  he  attempts  to  show,  from  the 
impressions  received,  may  be  able  to  develope  gradually  the  different 
intellectual  and  moral  faculties.  All  these,  he  affirms,  are  derived  from 
impressions  made  on  the  external  senses ;  and  he  considers  the  whole  of 
human  consciousness  to  be  sensation  variously  transformed. 

The  views  of  M.  Condillac  have  been  largely  embraced,  with  more 
or  less  modification;  and,  at  the  present  day,  many  metaphysicians 
believe,  that  impressions  on  the  senses  are  the  necessary  and  exclusive 
materials  for  all  intellectual  acts.  His  case  of  the  statue  seems,  how- 
ever, to  be  by  no  means  conclusive.  It  must,  of  course,  be  possessed 
of  a  centre  for  the  reception  of  impressions  made  upon  different  senses, 
otherwise  no  perception  could  occur;  and  if  we  can  suppose  it  possible 
for  such  a  monstrous  formation  as  a  being  totally  devoid  of  external 
senses  to  exist;  such  a  being  must  not  only  be  defective  in  the  nerves 
which,  in  the  perfect  animal,  are  destined  to  convey  impressions  to  the 
brain,  but  probably  in  the  cerebral  or  percipient  part  likewise.  From 
defective  cerebral  conformation,  therefore,  the  different  mental  phe- 
nomena might  not  be  elicited.1  If,  however,  we  admit  in  such  a  case  the 
possibility  of  the  cerebral  structure, — particularly  of  those  portions  that 
are  especially  concerned  in  the  function  of  thought, — being  properly 
organized,  it  appears  to  us,  that  certain  mental  or  moral  manifestations 
ought  to  exist.  Of  course,  all  knowledge  of  the  universe  would  be  pre- 
cluded, because  deprived  of  the  instruments  for  obtaining  such  know- 
ledge; but  the  brain  would  act  as  regarded  the  internal  sensations.  In 
order  that  such  a  being  may  live,  he  must  be  supplied  with  the  neces- 
sary nourishment;  possess  all  those  internal  sensations  or  wants  that 
are  inseparably  allied  to  organization ;  and  must,  consequently,  feel 
the  desires  of  hunger  and  thirst;  but  we  have  seen,  that  these  sensa- 
tions require  the  intervention  of  the  brain  as  much  as  the  external 
sensations.  Supposing  him,  again,  to  survive  the  period  of  puberty,  he 
must  experience  the  instinctive  changes,  which  occur  at  this  period,  and 
which  must  furnish  impressions  to  the  encephalon.  In  this  assumed 
case,  then,  a  certain  degree  of  mental  action  might  exist;  and,  under 
the  supposition  of  a  properly  organized  brain,  ideas — limited,  it  is  true, 
in  consequence  of  the  privation  of  the  ordinary  inlets  of  knowledge — 
might  be  formed;  and  memory,  imagination,  and  judgment  be  com- 
patible within  certain  limits. 

The  objections  to  the  view,  that  the  intellectual  and^  moral  sphere  of 
man  and  animals  is  proportionate  to  the  number  and  perfection  of  the 
external  senses  are  overwhelming.  Animals  have  the  same  number  of 
senses  as  man,  and,  frequently,  have  them  more  perfect ;  yet  in  none 
is  the  mental  sphere  co-extensive.  The  idiot  has  the  external  senses 
as  delicate  as  the  man  of  genius,  and  often  much  more  so;  many  of 
those  of  the  greatest  talents  having  the  senses  extremely  obtuse.  It 
has  been  already  remarked,  that  the  superiority  of  the  human  intellect 
has  been  referred  entirely  to  the  sense  of  touch,  and  to  the  happy 
organization  of  the  human  hand;  but  the  case  of  Miss  Biffin,  and  others, 
and  that  of  the  young  artist  cited  by  M.  Magendie,2  negative  this  pre- 

1  Adelon,  op.  citat.,  i.  519.  a  See  page  140'of  this  volume. 


MENTAL  SPHERE  OP  THE  DEAF,  DUMB,  AND  BLIND.  313 

sumption.  The  senses  are  important  secondary  instruments, — indis- 
pensable for  accomplishing  certain  manifestations  of  the  mind,  but,  in 
no  way,  determining  its  power. 

The  example  of  the  deaf  and  dumb  is  illustrative  of  this  matter.1  If 
a  child  be  born  deaf,  he  is  necessarily  dumb ;  inasmuch  as  he  is  unable 
to  hear  those  sounds  which,  by  their  combination,  constitute  language; 
and  cannot  therefore  imitate  them; — a  connexion  between  the  functions 
of  hearing  and  speech,  which  was  not  well  known  to  the  ancients.  For 
a  length  of  time,  these  objects  of  compassionate  interest  were  esteemed 
to  be  beyond  the  powers  of  any  kind  of  intellectual  culture,  and  were 
permitted  to  remain  in  a  state  of  the  most  profound  ignorance.  The 
ingenuity  of  the  scientific  philanthropist  has,  however,  devised  modes 
of  instruction,  by  which  their  mental  power  has  been  exhibited  in  the 
most  gratifying  manner,  and  in  a  way  to  prove,  that  the  sense  of  hear- 
ing is  not  indispensable  for  mental  development;  but  that  its  place  may 
be  supplied,  to  a  great  extent,  by  the  proper  exercise  of  others.  The 
deaf  and  dumb,  deprived  of  the  advantages  of  spoken  language,  are 
compelled  to  have  recourse  to  the  only  kind  available  to  them, — that 
addressed  to  the  eye.  In  this  typical  way,  by  a  well-devised  system  of 
instruction  they  can  be  taught  to  preserve  their  ideas,  and  to  multiply 
them,  like  the  perfectly  formed,  by  the  spoken  and  written  language, — 
without  one  or  the  other  of  which  the  human  mind  would  have  remained 
in  perpetual  infancy.  Thus,  the  deaf  and  dumb  have  not  only  like 
ideas ;  but  the  same  words  to  convey  them  to  others. 

Yet  the  deaf  and  dumb  are  not  so  much  the  objects  of  our  commise- 
ration as  they  who  have  been  -  deprived,  from  birth  or  from  early  in- 
fancy, of  both  sight  and  hearing,  and  have  thus  been  devoid  of  two  of 
the  most  important  inlets  for  the  entrance  of  impressions  from  the  sur- 
rounding world.  In  such  case,  it  is  obvious,  they  are  shut  out  from  all 
instruction,  except  what  can  be  afforded  by  the  senses  of  touch,  smell, 
and  taste;  yet  even  here  we  have  the  strongest  evidence  of  independent 
intellect.  One  of  the  most  striking  cases  of  the  kind  is  that  of  the 
Scotch  boy  Mitchell,  the  object  of  much  interest  to  Spurzheim  and  to 
Dugald  Stewart,2  both  of  whom  have  described  his  case  in  their 
writings.  It  is  matter  of  uncertainty,  whether  either  his  deafness  or 
blindness  was  total.  The  evidences  of  the  sensation  of  hearing  were, 
in  a  high  degree,  vague  and  unsatisfactory;  but  he  gave  more  con- 
vincing proofs  of  the  possession  of  partial  vision.  He  could,  for  exam- 
ple, distinguish  day  from  night;  and,  when  quite  young,  amused  himself 
by  looking  at  the  sun  through  crevices  in  the  door,  and  by  kindling  a 
fire.  At  the  age  of  twelve,  the  tympanum  of  each  ear  was  perforated ; 
but  without  any  advantage.  In  his  fourteenth  year,  the  operation  for 
cataract  was  performed  on  the  right  eye,  after  which  he  recognized 
more  readily  the  presence  of  external  objects;  but  never  made  use  of 
sight  to  become  acquainted  with  the  qualities  of  bodies.  Before  and 
after  this  period,  red,  white,  and  yellow  particularly  attracted  his  at- 

1  Gall,  op.  cit.,  i.  119. 

1  Elements  of  the  Philosophy  of  the  Human  Mind,  &c. ;  Transactions  of  the  Royal  Society 
of  Edinburgh,  vol.  vii.;  and  Dr.  Gordon,  ibid!,  vol.  vi.;  also,  History  of  James  Mitchell,  a  boy 
born  blind  and  deaf,  by  James  Wardrop,  London,  1813. 


314  MENTAL  FACULTIES. 

tention.  The  senses,  by  which  he  judged  of  external  bodies,  were  those 
of  touch  and  smell.  His  desire  to  become  acquainted  with  objects  was 
great.  He  examined  every  thing  he  met  with,  and  each  action  indi- 
cated reflection.  In  his  infancy,  he  smelt  at  every  one  who  approached 
him ;  and  their  odour  determined  his  affection  or  aversion.  He  always 
recognized  his  own  clothes  by  their  smell;  and  refused  to  wear  those 
which  he  found  to  belong  to  others.  Bodily  exercises,  such  as  rolling 
down  a  small  hill,  turning  topsy-turvy,  floating  wood  or  other  objects 
on  the  river  that  passed  his  father's  house;  gathering  round,  smooth 
stones,  laying  them  in  a  circle,  and  placing  himself  in  the  middle,  or 
building  houses  with  pieces  of  turf,  &c.,  were  a  source  of  amusement  to 
him.  After  the  operation  on  his  right  eye,  he  could. better  distinguish 
objects.  His  countenance  was  very  expressive;  and  his  natural  lan- 
guage not  that  of  an  idiot,  but  of  an  intelligent  being.  When  hungry, 
he  carried  his  hand  to  his  mouth,  and  pointed  to  the  cupboard  where 
the  provisions  were  kept;  and,  when  he  wished  to  lie  down,  reclined  his 
head  on  one  side  upon  his  hand,  as  if  he  wished  to  lay  it  upon  the  pil- 
low. He  easily  recollected  the  signification  of  signs  that  had  been 
taught  him ;  all  of  which  were  of  course  of  the  tactile  kind.  To  make 
him  comprehend  the  number  of  days  before  an  event  would  happen, 
they  bent  his  head  as  a  sign  that  he  would  have  to  go  to  bed  so  many 
times.  Satisfaction  was  expressed  by  patting,  him  on  the  shoulder  or 
arm;  and  discontent  by  a  sharp  blow.  He  was  sensible  of  the  caresses 
of  his  parents ;  and  susceptible  of  different  emotions — hatred,  passion, 
malice,  and  the  kindlier  feelings.  He  was  fond  of  dress,  and  had  great 
fears  of  death,  of  the  nature  of  which  he  had  manifestly  correct  notions. 
Mitchell's  case  has  been  pregnant  with  interest  to  the  metaphysician ; 
but  it  is  not  so  elucidative  as  it  would  have  been  had  the  privation  of 
the  senses  in  question  been  total. 

There  is,  or  was,  in  the  American  Asylum  at  Hartford  in  Connecti- 
cut, a  being  not  less  deserving  of  attention  than  Mitchell.1  Her 
name  is  Julia  Brace.  She  is  the  daughter  of  John  and  Rachel  Brace, 
natives  of  Hartford,  and  was  born  in  that  town  in  June,  1807 ;  so  that 
she  is  now  (1850)  forty- three  years  old.  At  four  years  of  age  she  was 
seized  with  typhus  fever ;  was  taken  sick  on  the  evening  of  Monday, 
November  29,  1811;  and, 'on  the  Saturday  morning  following,  became 
both  blind  and  deaf.  Prior  to  her  illness,  she  had  not  only  learned  to 
speak,  but  to  repeat  her  letters,  and  to  spell  words  of  two  or  three 
syllables ;  and,  for  some  time  after  the  loss  of  her  sight  and  hearing, 
she  was  fond  of  taking  a  book,  and  spelling  words  and  the  names  of 
her  acquaintances.  She  retained  her  speech  pretty  well  for  about  a 
year ;  but  gradually  lost  it,  and  appears  to  be  now  condemned  to  per- 
petual silence.  For  three  years  she  could  still  utter  a  few  words,  one 
of  the  last  of  which  was  "mother."  At  first  she  was  unconscious  of 
her  misfortune,  appearing  to  think,  that  a  long  night  had  come  upon 
the  world;  and  often  said,  "It  will  never  be  day."  She  would  call 
upon  the  family  to  "  light  the  lamp,"  and  was  impatient  at  their  seeming 

1  Twenty -first  Report  of  the  Directors  of  the  American  Asylum  at  Hartford,  for  the  Edu- 
cation and  Instruction  of  the  Deaf  and  Dumb,  p.  15,  Hartford,  1837,  et  seq. 


CASE  OF  JULIA  BRACE.  315 

neglect,  in  not  even  answering  her.  At  length,  in  passing  a  window, 
she  felt  the  sun  shining  warmly  upon  her  hand ;  and  pointed  with  de- 
light to  indicate  that  she  recognized  this.  From  the  January  after  her 
illness,  until  the  following  August,  she  would  sleep  during  the  day,  and 
be  awake  through  the  night ;  and  it  was  not  until  autumn,  by  taking 
great  pains  to  keep  her  awake  during  the  day,  that  she  was  set  right. 
At  present,  she  is  as  regular  in  this  respect  as  other  persons.  From 
the  period  of  her  recovery,  she  seemed  to  perceive  the  return  of  Sab- 
bath ;  and,  on  Sunday  morning,  would  get  her  own  clean  clothes,  and 
those  of  the  other  children.  If  her  mother  was  reading,  she  would 
find  a  book,  and  endeavour  to  do  so  likewise.  The  intervention  of  a 
day  of  fasting  or  thanksgiving  confused  her  reckoning  ;  and  some  time 
elapsed  before  she  got  right.  During  the  first  winter  after  her  recovery, 
she  was  irritable  almost  to  madness ;  would  exhibit  the  most  violent 
passion,  and  use  the  most  profane  language.  The  next  summer  she 
became  calmer ;  and  her  mother  could  govern  her,  to  some  extent,  by 
shaking  her,  in  sign  of  disapprobation ;  and  stroking  or  patting  her 
head,  when  she  conducted  herself  well.  She  is  now  habitually  mild, 
obedient  and  affectionate.  During  the  first  summer  after  her  illness, 
she  was  very  unwilling  to  wear  clothes,  and  would  pull  them  off  vio- 
lently. At  length,  her  mother  took  one  of  her  frocks  and  tried  it  on 
her  sister,  with  a  view  of  altering  it  for  her.  Julia  had  ever  been 
remarked  for  her  sense  of  justice  in  regard  to  property.  This  seemed 
to  be  awakened ;  and  she  took  the  frock  and  put  it  on  herself.  After 
this  she  was  willing  to  wear  clothes,  and  even  cried  for  new  ones.  She 
has  ever  since  been  fond  of  dress.  At  nine  years  of  age  she  was  taught 
to  sew;  and,  since  that  time,  has  learned  to  knit.  She  has  been  a 
resident  for  several  years  in  the  American  Asylum  at  Hartford ;  where 
she  is  supported  in  part,  by  the  voluntary  contributions  of  visitors,  and, 
in  part,  by  her  own  labours  in  sewing  and  knitting.  A  language  of 
palpable  signs  was  early  established  as  a  means  of  communication  with 
her  friends ;  and  this  has  been  so  improved  as  to  be  sufficient  for  all 
necessary  purposes.  Her  countenance,  as  she  sits  at  work,  is  said  to 
exhibit  the  strongest  evidence  of  an  active  mind,  and  a  feeling  heart : 
"thoughts  and  feelings,"  says  a  writer  who  describes  her  case,  "seem 
to  flit  across  it  like  the  clouds  in  a  summer  sky:  a  shade  of  pensiveness 
will  be  followed  by  a  cloud  of  anxiety  or  gloom ;  a  peaceful  look  will 
perhaps  succeed ;  and,  not  unfrequently,  a  smile  lights  up  her  counte- 
nance, which  seems  to  make  one  forget  her  misfortunes.  But  no  one 
has  yet  penetrated  the  darkness  of  her  prison  house,  or  been  able  to 
find  an  avenue  for  intellectual  or  moral  light.  Her  mind  seems,  thus 
far,  inaccessible  to  all  but  her  Maker." 

A  still  more  interesting  example  is  cited  by  Dr.  Abercrombie1  from 
the  Medical  Journals  of  the  time.  A  gentleman  in  France  lost  every 
sense  except  feeling  on  one  side  of  his  face ;  yet  his  family  acquired  a 
method  of  holding  communication  with  him,  by  tracing  characters  upon 
the  part  which  retained  its  sensation.  These  cases  are  not,  perhaps, 
so  unfrequent  as  has  been  supposed.  Dr.  Howe,  the  superintendent  of 

.<! 

1  Inquiries  concerning  the  Intellectual  Powers,  &c.,  Amer.  edit.,  p.  56,  New  York,  1832. 


316  MENTAL  FACULTIES. 

the  Perkins  Institution  and  Massachusetts  Asylum  for  the  Blind,  stated, 
some  years  ago,  that  four  cases  in  New  England,  besides  that  of  Julia 
Brace,  had  come  within  his  own  observation.  One  of  these  had  been 
in  1841  upwards  of  three  years  under  his  care ;  and  the  results  of  his 
diligence  and  judgment  in  this  instance  have  furnished  more  gratifying 
results  to  .the  psychologist  and  philanthropist  than  any,  perhaps,  on 
record. 

Laura  Bridgman,  the  subject  of  the  case,  was  born  in  December,  1829. 
At  two  years  of  age,  her  eyes  and  ears  inflamed,  suppurated,  and  their 
contents  were  discharged.  At  the  expiration  of  two  more  years  of  suf- 
fering, it  was  discovered,  that  her  sense  of  smell  was  almost  wholly 
destroyed;  and,  consequently,  that  her  taste  was  much  blunted.  She 
had,  therefore,  but  one  sense  remaining,  that  of  touch,  by  which  she 
could  become  acquainted  with  the  external  world.  Whilst  at  home, 
before  her  reception  into  the  Asylum,  she  would  explore  the  house ; 
become  familiar  with  the  form,  density,  weight,  and  temperature  of 
every  article  she  could  lay  her  hands  upon;  followed  her  mother;  felt 
her  hands  and  arms,  and  endeavoured  'to  repeat  every  thing  herself. 
She  even  learned  to  sew  a  little,  and  to  knit.  She  exhibited  warm 
affection  towards  the  members  of  her  family;  but  the  means  of  com- 
municating with  her  were  limited.  When  it  was  desired  that  she  should 
go  to  a  place,  she  was  pushed;  or  that  she  should  approach,  she  was 
drawn  towards  the  person.  Gently  patting  on  the  head  signified  appro- 
bation; on  the  back,  disapprobation.  She  had  made,  however,  a  natural 
language  of  her  own;  and  had  a  sign  to  express  her  idea  of  each  member 
of  the  family, — such  as  drawing  her  finger  down  each  side  of  her  face, 
to  allude  to  the  whiskers  of  one;  twirling  her  hand  and  arm  around,  in 
imitation  of  the  spinning-wheel,  for  another,  &c. 

In  October,  1837,  she  was  received  into  the  Institution  for  the  Blind, 
in  Boston.  The  first  experiments  made  with  her  consisted  in  taking 
articles  in  common  use;  such  as  knives,  forks,  spoons,  keys,  &c.,  and 
pasting  labels  upon  them  with  their  names  printed  in  raised  letters. 
These  she  felt  very  carefully;  and  speedily  found,  that  the  crooked  lines 
spoon  differed  as  much  from  the  crooked  lines  key,  as  the  spoon  dif- 
fered from  the  key  in  form.  Small  detached  labels,  with  the  same  words 
printed  upon  them,  were  then  put  into  her  hands,  and  she  soon  observed, 
that  they  were  similar  to  the  ones  pasted  on  the  articles.  She  showed 
her  perception  of  this  similarity  by  laying  the  label  key  upon  the  key, 
and  the  label  spoon  upon  the  spoon.  In  this  manner  she  proceeded 
to  acquire  a  knowledge  of  language;  used  the  manual  alphabet  of  the 
deaf  mutes  with  great  facility  and  rapidity,  and  increased  her  vocabu- 
lary so  as  to  comprehend  the  names  of  all  common  objects.  She  could 
soon  count  to  high  numbers;  and  add  and  substract  small  ones.  But 
the  most  gratifying  acquirement  which  she  made,  and  the  one  which 
gave  her  the  most  delight,  was  the  power  of  writing  a  legible  hand,  and 
expressing  her  thoughts  upon  paper.  She  writes  with  a  pencil  in  a 
grooved  line,  and  makes  her  letters  clear  and  distinct.  The  author  has 
a  favourable  specimen  now  before  him,  in  a  recent  well  conceived,  and 
well  expressed,  letter  to  a  friend.  She  is  expert  with  her  needle; 
knits  easily,  and  can  make  twine  bags  and  various  fancy  articles  very 


CASE  OF  LAURA  BRIDGMAN.        .  317 

prettily;  is  docile;  has  a  quick  sense  of  propriety;  dresses  herself  with 
great  neatness,  and  is  always  correct  in  her  deportment.  No  definite 
course  of  instruction  could  be  marked  out ;  for  her  inquisitiveness  was 
so  great,  that  she  was  very  much  disconcerted  if  any  question,  which 
occurred  to  her,  was  deferred  until  the  lesson  was  over.  It  was  deemed 
best  to  gratify  her,  if  her  inquiry  had  any  bearing  on  the  lesson ;  and 
often  she  led  her  teacher  far  away  from  the  objects  with  which  he  com- 
menced. With  regard  to  the  sense  of  touch  it  is  very  acute,  even  for 
a  blind  person.  It  is  shown  remarkably  in  the  readiness  with  which 
she  distinguishes  persons.  There  were,  a  few  years  ago,  forty  inmates 
in  the  female  wing,  with  all  of  whom  she  was  acquainted.  Whenever 
she  is  walking  through  the  passage-way,  she  perceives  by  the  jar  of  the 
floor,  or  the  agitation  of  the  air,  that  some  one  is  near  her,  and  it  is 
exceedingly  difficult  to  pass  her  without  being  recognized.  Her  arms 
are  stretched  out,  and  the  instant  she  grasps  a  hand,  a  sleeve,  or  even 
part  of  the  dress,  she  knows  the  person,  and  lets  him  pass  on  with  some 
sign  of  recognition. 

The  details  concerning  this  interesting  being,  and  her  gradual  pro- 
gress in  moral  and  intellectual  culture,  can  be  learned  from  the  annual 
reports  of  the  Institution,  which  Dr.  Howe  so  ably  superintends.1 

How  strongly  do  these  cases  demonstrate  the  independence  of  the 
organ  of  intellect ;  requiring,  indeed,  the  external  senses  for  its  perfect 
developement,  but  still  capable  of  manifesting  itself  without  the  presence 
of  many,  and  probably  of  any,  of  them;  and  how  inaptly,  although 
humanely,  does  the  law  regard  such  beings!  "A  person,"  says  Black- 
stone,2  "born  deaf,  dumb,  and  blind,  is  looked  upon  by  the  law  as  in 
the  same  state  with  an  idiot,  he  being  supposed  incapable  of  any  under- 
standing, as  wanting  all  those  senses  which  furnish  the  human  mind 
with  ideas."  But  if  he  grow  deaf,  dumb,  and  blind,  not  being  born  so, 
he  is  deemed  non  compos  mentis,  and  the  same  rules  apply  to  him  as  to 
other  persons  supposed  to  be  lunatics.  With  regard  to  the  deaf  and 
dumb,  they  are  properly  held  to  be  competent  as  witnesses,  provided 
they  evince  sufficient  understanding,  and  to  be  liable  to  punishment  for 
a  breach  of  the  criminal  laws. 

M.  Cabanis3  embraces  the  views  of  Condillac  regarding  the  external 
senses ;  but  thinks,  that  impressions  from  these  are  insufficient  to  con- 
stitute the  materiel  of  the  mental  and  moral  manifestations.  In  con- 
firmation of  this  opinion,  he  observes,  that  the  young  infant,  and  animals 
at  the  very  moment  of  birth,  frequently  afford  evidences  of  complicated 
acts  originating  in  the  nervous  centres;  and  yet  the  external  senses 
can  have  been  but  little  impressed.  How  can  we,  he  asks,  refer  to  the 
operation  of  the  external  senses  the  motions  of  the  foetus  in  utero, 
which  are  perceptible  to  the  mother,  for  the  latter  half  of  utero-gesta- 
tion;  or  the  act  of  sucking  executed  from  the  first  day  of  existence? 
Can  we  refer  to  this  cause  the  fact  of  the  chick,  as  soon  as  it  is  hatched, 
pecking  the  gr^in  that  has  to  nourish  it  ?  or  the  one,  so  frequently 

1  Annual  Reports  of  the  Trustees  of  the  Perkins  Institution  and  Massachusetts  Asylum 
for  the  Blind  to  the  .Corporation,  for  the  years  1837,  et  seq. 

2  Commentaries  on  the  Laws  of  England,  i.  304. 

3  Rapport  du  Physique  et  du  Moral,  edit.  cit. 


318  MENTAL  FACULTIES. 

quoted  from  Galen,  of  the  young  kid,  scarcely  extruded  from  the  ma- 
ternal womb,  and  yet  able  to  select  a  branch  of  the  cytisus  from  other 
vegetables  presented  to  it?  Man  and  animals,  continues  M.  Cabanis, 
during  the  course  of  their  existence,  experience  mental  changes  as 
remarkable  as  they  are  frequent;  yet  nothing  in  the  condition  of  the 
senses  can  account  for  such  difference.  For  example,  at  the  period  of 
puberty,  a  new  appetite  is  added ;  and  this,  even,  when  the  being  is  kept 
in  a  complete  state  of  isolation.  This,  he  argues,  it  is  impossible  to 
refer  to  any  change  in  the  external  senses ;  which,  if  they  furnished  the 
materials  at  all,  must  have  been  doing  so  from  early  infancy ;  and  he 
concludes,  that  the  difference  observable  in  the  mental  manifestations, 
according  to  sex,  temperament,  climate,  state  of  health  or  disease,  re- 
gimen, &c.,  cannot  be  referable  to  the  senses,  as  they  remain  the  same; 
and,  consequently,  we  must  look  elsewhere  for  the  causes  of  such  differ- 
ence. These  M.  Cabanis  conceives  to  be  the  movements  by  which  the 
organs  of  internal  life  execute  their  functions.  Such  movements,  he 
says,  although  deep-seated  and  imperceptible,  are  transmitted  to  the 
brain,  and  furnish  that  organ  with  a  fresh  set  of  materials.  At  puberty, 
when  the  testicles  become  developed,  and  their  function  is  established 
by  the  secretion  of  sperm,  the  organic  movements  during  the  secretion 
are  the  materials  of  the  new  desires,  which  appear  at  that  age.  These 
impressions  he  calls  internal,  in  contradistinction  to  the  external,  or 
those  furnished  by  the  five  senses ;  and  he  considers,  that  whilst  the 
external  senses  serve  as  the  basis  for  all  that  we  include  under  the  term 
intellect,  the  internal  impressions  are  the  materials  of  what  are  called 
instincts;  and,  as  the  organs  of  internal  life,  whence  the  internal  im- 
pressions proceed,  vary  more  than  the  senses,  according  to  age,  sex, 
temperament,  climate,  regimen,  &c.,  it  is  more  easy  to  find  in  them 
organic  modifications,  which  coincide  with  those  exhibited  by  the  mind 
under  those  various  circumstances. 

In  proof  of  these  opinions,  he  adduces,  besides  others,  the  following 
specious  affirmations.  First.  As  the  venereal  appetite  appears  in  man 
and  animals  synchronously  with  the  developement  of  the  testicles,  and 
is  never  exhibited  when  they  are  removed  in  infancy,  we  have  reason 
to  believe,  that  the  impressions,  which  constitute  the  materials  for  this 
new  catenation  of  ideas,  must  proceed  from  the  testicles.  Secondly. 
Numerous  facts  demonstrate,  that  the  condition  of  the  uterus  has  much 
influence  on  the  mental  and  moral  manifestations  of  the  female.  The 
period  of  the  developement  of  that  organ,  for  example,  is  the  one  at 
which  new  feelings  arise,  and  all  those  manifestations  'assume  more 
activity;  and  there  is  generally  a  ratio  between  their  activity  and  that 
of  the  uterus.  If  the  state  of  the  uterus  be  modified,  as  it  is  at  the 
menstrual  period,  or  during  pregnancy,  or  after  delivery,  the  mind  is  so 
likewise.  All  these  facts  ought  to  induce  a  belief,  he  thinks,  that  im- 
pressions are  continually  emanating  from  that  organ,  which,  by  their 
variety,  occasion  the  diversity  in  the  state  of  mental  and  moral  facul- 
ties observed  in  those  different  cases.  Thirdly.  It  is  impossible  in  the 
hypochondriac  and  melancholic  constitutions,  to  mistake  the  influence 
exerted  upon  the  mind  by  the  abdominal  organs.  According  as  they 
execute  their  functions  more  or  less  perfectly,  the  thinking  faculty  is 


VIEWS  OF  CABANIS,  GALL,  ETC.  319 

more  or  less  languid  or  brilliant;  and  the  affections  more  or  less  vivid 
and  benevolent,  or  the  contrary;  hence  the  expressions  melancholy1  and 
hypochondriasis?  assigned  to  the  states  of  mind  characterizing  those 
constitutions,  which  denote  that  the  cause  must  be  referred  to  the 
abdominal  organs.  The  origin  of  the  alternations  of  inactivity  and 
energy  in  the  intellect,  of  benevolent  and  irascible  fits  of  humour,  as 
well  as  of  insanity,  is  also  referable,  he  says,  to  the  abdominal  viscera. 
Hence — M.  Cabanis  concludes — it  is  evident,  that  the  abdominal  organs 
are  the  source  of  fortuitous  and  abnormous  impressions  which  excite 
the  brain  to  irregular  acts ; — and  is  it  not,  he  asks,  probable,  that 
what  takes  place  in  excess,  in  these  morbid  movements,  may  happen  to 
a  less  and  more  appropriate  extent  in  health ;  and  that  thus  impressions 
may  emanate  in  a  continuous  manner  from  every  organ  of  the  body, 
which  may  be  indispensable  to  the  production  of  the  mental  and  moral 
acts?  M.  Cabanis,  therefore,  considers  that  the  axiom  of  Aristotle 
should  be  extended;  and  that  the  statue  of  Condillac  is  incomplete,  in 
not  having  internal  organs  for  the  emanation  of  internal  impressions, 
which  are  the  materials  of  the  instincts.  In  this  way  he  accounts  for 
the  instincts,  which,  by  some  metaphysicians,  have  been  looked  upon  as 
judgments,  executed  in  the  ordinary  manner,  but  so  rapidly,  that  the 
process  has  ceased  from  habit  to  be  perceptible.  Finally,  he  remarks, 
there  is  a  ratio  between  the  duration  and  intensity  of  the  intellectual 
results  and  the  kind  of  impressions,  which  have  constituted  their  mate- 
rials. All  the  mental  and  moral  acts,  for  instance,  that  are  derived  from 
impressions  engendered  in  the  very  centre  of  the  nervous  system  or  in  the 
brain, — such  as  those  of  the  maniac, — are  the  strongest  and  most  dur- 
able. After  these  come  the  instincts,  of  which  the  internal  impressions 
are  the  materials:  they  are  powerful  and  constant; — and  lastly,  the 
intellectual  acts,  which  are  more  transient,  because  they  emanate  from 
external  impressions,  themselves  fickle,  and  somewhat  superficial. 

According  to  the  views,  then,  of  M.  Cabanis  and  his  followers, 
amongst  the  organic  conditions  of  the  mental  and  moral  manifestations 
must  be  placed,  not  only  those  of  the  encephalon  and  external  senses, 
but  of  the  different  organs  of  the  body,  which  furnish  the  various  internal 
impressions.  The  influence  of  the  external  senses  on  the  intellectual 
and  moral  developement  has  already  been  canvassed :  we  have  seen, 
that  they  are  only  secondary  instruments  for  making  us  acquainted  with 
external  bodies,  and  that  they  in  nowise  regulate  the  intellectual  and 
moral  sphere.  The  notion  of  internal  impressions  is  ingenious,  and  has 
led  to  important  improvements  in  the  mode  of  investigating  the  different 
mental  and  moral  phenomena.  It  was  suggested,  as  has  been  shown, 
by  M.  Cabanis,  in  consequence  of  the  external  senses  appearing  to  him 
insufficient  to  explain  all  the  phenomena.  By  MM.  Gall,  Adelon,3  and 
others,  however,  all  these  cases  are  considered  explicable  by  the  vary- 
ing condition  of  the  brain  itself.  In  the  foetus  in  utero ;  in  the  new- 
born animal,  there  are  already  parts  of  the  brain,  they  say,  sufficiently 
developed ;  and,  accordingly,  we  witness  the  actions  to  which  reference 

1  From  ^ue\af,  "  black,"  and  ^ox»j,  "  bile."  a  Disease  of  the  hypochondres. 

3  Physiologic  de  1'Homme,  2de  i&dit.,  i.  251. 


320  MENTAL  FACULTIES. 

has  been  made  by  M.  Cabanis ;  and  if  the  intellectual  and  moral  manifes- 
tations vary  according  to  sex,  temperament,  climate,  regimen,  state  of 
health,  &c.,  it  is  because  the  encephalon  is,  under  these  circumstances, 
in  different  conditions.  The  chief  facts,  on  which  M.  Cabanis  rests  his 
doctrine,  are, — the  coincidence  between  the  developement  of  the  testi- 
cles arid  the  appearance  of  the  venereal  appetite;  and  the  suppression 
of  this  appetite  after  castration.  It  must  be  recollected,  however,  that 
these  are  not  the  only  changes,  that  happen  simultaneously  at  puberty. 
The  voice  assumes  a  very  different  character ;  but  the  change  in  the 
voice  is  not  a  cerebral  phenomenon.  It  is  dependent  upon  the  deve- 
lopement of  its  organ,  the  larynx.  Yet  castration,  prior  to  puberty, 
has  a  decided  effect  upon  it ;  preventing  it  from  becoming  raucous  and 
unmelodious.  All  these  developements  are  synchronous ;  but  not  di- 
rectly consequent  upon  each  other.  The  generative  function  has  two 
organs, — one  central,  the  other  external;  and  it  is  not  surprising,  that 
both  should  undergo  their  developement  at  the  same  period. 

On  the  whole,  we  are  perhaps  justified  in  concluding,  that  the  brain 
alone  is  the  organ  of  the  intellectual  and  moral  faculties.  Yet,  as 
before  remarked,  there  is  great  force  in  the  facts  and  arguments  brought 
forward  by  Dr.  Carpenter  in  favour  of  the  emotional  acts  being  seated 
in  what,  he  terms,  the  sensorial  ganglia :  and  that  as  we  descend  in  the 
animal  scale,  the  cerebrum  or  organ  of  the  mental  manifestations  be- 
comes less  and  less  developed,  until  we  ultimately  find  an  encephalic 
organization  in  which  a  common  sensorium  for  the  reception  of  sensation 
and  the  origination  of  motion  may  alone  exist ;  without  any  organ  for 
the  recording  of  impressions  like  the  cerebrum  in  more  highly  endowed 
organisms.  In  such  case,  the  motions  may  be  mere  responses  to  sen- 
sations experienced,  without  the  presence  of  the  slightest  consciousness 
on  the  part  of  the  being,  or  knowledge  of  the  adaptation  of  means  to 
ends.  Still,  it  may  be  a  question  whether  such  sensations  and  responsive 
motions  are  not  possessed  by  animals  devoid  of  anything  resembling  the 
encephalic  sensory  ganglia  of  higher  organisms,  and  which  are  wholly 
supplied  with  nerves  of  the  excito-motory  class — as  the  stomato-gastric. 
The  interesting  topic  of  the  various  instinctive  operations  of  the  frame 
will  be  considered  in  another  part  of  this  work.  We  shall  there  find, 
that  instinct  cannot  in  all  cases  be  defined,  in  the  language  of  M. 
Broussais,1  to  consist  in  sensations  originating  in  the  internal  and  ex- 
ternal sensitive  surfaces,  which  solicit  the  cerebral  centre  to  acts  neces- 
sary for  the  exercise  of  the  functions, — such  acts  being  frequently 
executed  without  the  participation  of  mind,  and  even  in  its  absence, — 
inasmuch  as  it  is  not  confined  to  beings  possessed  of  brain,  but  exists 
also  in  the  vegetable. 

Having  now  decided  upon  the  organ  of  the  mental  and  moral  facul- 
ties, it  would  be  necessary,  according  to  the  system  adopted  in  this  work, 
to  describe  its  anatomy;  but  this  has  been  done  elsewhere. 

1  Physiol.  appliquee  a  la  Pathologie,  ch.  vii. ;  or  Drs.  Bell  and  La  Roche's  translation, 
PhilacL  1832. 


INTELLECTUAL  AND  MORAL  FACULTIES.  321 

PHYSIOLOGY  OF  THE  INTELLECTUAL  AND  MORAL  FACULTIES. 

When  the  organ  of  the  intellect  is  exposed  by  accident,  and  we  regard 
it  during  the  reception  of  a  sensation,  the  exercise  of  volition,  or  during 
any  intellectual  or  moral  operation,  the  action  is  found  to  be  too  mole- 
cular to  admit  of  detection.  At  times,  during  violent  mental  conten- 
tion, a  redness  of  the  surface  of  the  brain  has  been  apparent,  as  if  the 
blood  had  been  forced  more  violently  into  the  vessels;  but  no  light  has 
been  thrown  by  such  examination  on  the  wonderful  actions  that  consti- 
tute thought.  We  ought  not,  however,  to  be  surprised  at  this,  when 
we  reflect,  that  the  most  careful  examination  of  a  nerve  does  not  convey 
to  us  the  slightest  notion  how  an  impression  is  received  by  it  from  an 
external  body;  and  how  such  impression  is  conveyed  to  the  brain.  All 
that  we  witness  in  these  cases  is  the  result;  and  we  are,  therefore,  com- 
pelled to  study  the  intellectual  and  moral  acts  by  themselves,  without 
considering  the  cerebral  movements  concerned  in  their  production. 
Such  study  is  the  basis  of  a  particular  science — metaphysics,  ideology, 
or  philosophy.  Apart  from  organization,  this  subject  'does  not  belong 
to  physiology;  but  as  some  of  the  points  of  classification,  &c.,  are  con- 
cerned in  questions  that  will  properly  fall  under  consideration,  it  may 
be  well  to  give  a  short  sketch  of  the  chief  objects  of  metaphysical 
inquiry;  which  are,  indeed,  intimately  connected  in  many  of  their  bear- 
ings,— as  commonly  treated  by  the  metaphysician, — with  physiology. 
M.  Broussais  has  considered,  that  metaphysics  and  physiology  should 
be  kept  distinct;  and  that  all  the  investigations  of  the  metaphysician 
should  be  confined  to  the  ideal.  "  I  wish  metaphysicians,  since  they  so 
style  themselves,"  he  remarks,  somewhat  splenetically,  "would  never 
treat  of  physiology ;  that  they  would  only  occupy  themselves  with  ideas 
as  ideas,  and  not  as  modifications  of  our  organs;  that  they  would  never 
speak  either  of  the  brain,  the  nerves,  the  temperaments,  or  of  the  influ- 
ence of  climates,  of  localities,  or  of  regimen;  that  they  would  never 
inquire  whether  there  are  innate  ideas,  or  whether  they  come  through 
the  medium  of  the  senses;  that  they  would  not  undertake  to  follow  their 
developements  according  to  age  or  state  of  health ;  for  I  am  convinced 
that  they  cannot  reason  justly  on  these  points.  Such  questions  belong 
to  physiologists,  who  can  unite  a  knowledge  of  the  moral  nature  with 
that  of  the  structure  of  the  human  body."  "It  is  possible,"  he  adds, 
"that  particular  ci«*umstances  may  oblige  them  to  introduce  physiolo- 
gical considerations  into  their  calculations;  as  when  it  is  necessary  to 
estimate  the  influence  of  certain  laws  or  customs  in  relation  to  temper- 
ature, to  the  nature  of  the  soil,  the  prevailing  diseases,  &c.,  but  then, 
they  should  avail  themselves  of  the  experience  of  physiologists  and 
physicians."1  A  more  appropriate  recommendation  would  be  that  the 
metaphysician  should  make  a  point  of  becoming  acquainted  with  physio- 
logical facts  and  reasoning;  and,  conversely,  that  metaphysics  should 
form  a  part  of  the  study  of  every  physiologist. 

The  cerebral  manifestations  comprise  two  very  different  kinds  of 
acts; — the  intellectual  and  the  moral;  the  former  being  the  source  of 

1  De  1'Irritation  et  de  la  Folie,  Paris,  1828:  or  Dr.  Cooper's  translation,  Columbia,  S.  C., 
1831. 

VOL.  I.— 21 


322  MENTAL  FACULTIES. 

all  the  knowledge  we  possess  regarding  ourselves  and  the  bodies  sur- 
rounding us;  the  latter  comprising  our  internal  feelings,  appetites, 
desires,  and  affections,  by  which  we  are  incited  to  establish  a  relation 
with  the  beings  around  us: — the  two  sets  of  acts  respectively  embracing 
the  qualities  of  the  mind,  and  those  of  the  heart.1 

If  we  attend  to  the  different  modes  in  which  the  intellectual  mani- 
festations are  evinced  in  our  own  persons,  we  find,  that  there  are  several 
acts  which  are  by  no  means  identical.  We  are  conscious  of  the  differ- 
ence between  appreciating  an  impression  made  upon  one  of  the  external 
senses,  which  constitutes  perception,  and  the  recalling  of  such  impres- 
sion to  the  mind,  which  is  the  act  of  memory;  as  well  as  the  distinction 
between  feeling  the  relations,  that  connect  one  thing  with  another,  con- 
stituting judgment;  and  the  tendency  to  act  in  any  direction,  which 
we  call  will.  The  consciousness  of  these  various  mental  processes  has 
induced  philosophers  to  admit  the  plurality  of  the  intellectual  acts,  and 
to  endeavour  to  reduce  them  all  to  certain  primary  faculties;  in  other 
words,  to  faculties  which  are  fundamental  or  elementary,  and  by  their 
combination  give  rise  to  other  and  more  complex  manifestations.  To 
this  analytical  method  they  have  been  led  by  the  fact,  that  the  different 
acts,  which  they  esteem  elementary,  exhibit  great  variety  in  their  degrees 
of  activity:  one,  for  example,  maybe  impressed  with  a  character  of  en- 
ergy— as  the  memory; — whilst  another,  as  the  judgment,  may  be  sin- 
gularly feeble; — and  conversely.  M.  Broussais  conceives,  that  without 
the  memory  we  cannot  exercise  a  single  act  of  judgment;  as  it  is  always 
necessary,  in  order  to  judge,  that  we  should  experience  two  successive 
perceptions;  which  we  could  not  do,  unless  possessed  of  the  faculty  of 
renewing  that  which  we  had  felt  before ;  in  other  words,  unless  we  pos- 
sessed memory.  Hence  the  loss  of  this  faculty,  he  says,  necessarily 
occasions  that  of  judgment,  and  reduces  man  to  a  state  of  imbecility. 
To  a  certain  extent  this  is  true.  Total  privation  of  memory  must  be 
attended  with  the  results  described.  If  an  individual  retains  no  con- 
sciousness of  that  which  impressed  him  previously,  there  can  obviously 
be  no  comparison.  A  man  may,  however,  have  an  unusual  memory  for 
certain  things  and  not  for  others ;  he  may  astonish  us  by  the  extreme 
accuracy  of  his  recollection  of  numbers,  places,  or  persons;  and  yet  he 
may  be  singularly  deficient  in  judging  of  other  matters; — his  memory 
suggesting  only  one  train  of  objects  for  comparison. 

In  enumerating  the  faculties,  which,  by  their  union,  constitute  the 
intellect,  we  observe  great  discrepancy  amongst  metaphysicians.  Some 
admit  will,  imagination,  understanding,  and  sensibility  ;  others,  sensi- 
bility, imagination,  memory,  and  reason;  others  will,  intelligence,  and 
memory ;  and  others,  again,  imagination,  reflection,  and  memory.  The 
views  of  M.  Condillac2  on  this  subject  have  perhaps  excited  more  atten- 
tion than  those  of  ai^y  other  individual.  Professing,  as  we  have  seen, 
that  all  our  ideas  are  derived  from  successive  operations  of  the  senses 
and  the  mind,  he  admits  the  following  constituent  faculties  of  the  in- 
tellect : — sensation,  attention,  comparison,  judgment,  reflection,  imagin- 

1  Adelon,  Facultes  de  1'Esprit  et  de  1'Atne,  in  Diet,  de  Med.,  via.  469,  Paris,  1823;  and 
Physiologic  de  1'Homme,  edit,  cit.,  i.  527. 
3  Op.  citat. 


FACULTIES  THAT  CONSTITUTE  THE  INTELLECT.         323 

ation,  and  reason.  Sensation  he  defines  to  be — the  faculty  of  the  mind, 
which  affords  the  perception  of  any  sensitive  impression.  Attention, 
the  faculty  of  sensation,  applied  exclusively  to  a  determinate  object; 
being,  as  the  word  imports,  the  tension  of  the  mind  upon  a  particular 
object.  Comparison,  the  faculty  of  sensation,  applied  to  two  objects  at 
once.  Judgment,  the  faculty  by  which  the  mind  perceives  the  con- 
nexions, that  exist  between  the  objects  compared.  Reason,  the  faculty 
of  running  through  a  succession  of  judgments,  which  are  connected 
with,  and  deduced  from,  each  other.  Reflection,  as  the  word  indicates, 
the  faculty  by  which  the  mind  returns  upon  itself,  upon  its  own  products, 
to  prove  their  correctness,  and  to  subject  them  again  to  its  power;  and 
imagination,  to  which  Condillac  attaches  memory, — the  faculty  pos- 
sessed by  the  mind  of  reproducing  at  will  the  different  impressions,  and 
all  the  products  of  its  own  operations.  With  regard  to  the  order  of 
catenation  of  these  different  faculties,  he  considers  sensation  to  be  first 
put  in  play;  and  if,  amongst  the  perceptions,  there  is  one,  of  which  we 
have  a  more  lively  consciousness,  and  which  attracts  the  mind  to  it 
alone,  it  is  the  product  of  attention :  then  comes  comparison,  which  is 
nothing  more  than  double  attention :  comparison  is  irresistibly  succeeded 
by  judgment:  if,  from  one  judgment,  we  pass  to  another  deduced  from 
it,  we  reason;  if  the  mind  turns  back  on  its  own  production,  we  reflect: 
and  lastly,  if  the  mind  spontaneously  awakens  its  different  perceptions 
imagination  is  in  action.  All  these  faculties  are  thus  made  to  be  de- 
duced from  each  other;  to  originate  in  the  first  or  sensation;  and  all 
are  sensation  successively  transformed. 

The  doctrine  of  M.  Condillac,  abstractly  considered,  has  already 
engaged  attention.  The  division  of  the  faculties,  which  he  conceives, 
by  their  aggregation,  to  form  the  intellect,  is  simple  and  ingenious,  and 
appears  to  be  more  easily  referable  to  physiological  principles  than  that 
of  other  metaphysicians ;  accordingly,  it  has  been  embraced,  with  more 
or  less  modification,  by  certain  physiological  writers. 

The  power  of  reflection,  according  to  M.  Broussais,  is  the  character- 
istic of  the  human  intellect ;  and  to  reflect  is  to  feel.  Man  not  only 
feels  the  stimulation  produced  by  external  agents,  and  by  the  move- 
ments of  his  own  organs,  which  constitutes  sensation  or  perception,  but 
he  is  conscious  that  he  has  felt  these  stimulations:  in  other  words,  he 
feels  that  he  has  felt;  he  has,  consequently,  a  perception  of  his  actual 
perception,  which,  M.  Broussais  says,  constitutes  mental  reflection.  This 
process  he  can  repeat  as  often  as  he  thinks  fit,  and  can  observe  all  his 
sensations,  and  the  different  modes  in  which  he  felt,  whilst  occupied  with 
his  feelings.  From  this  study  he  derives  an  idea  of  his  own  existence. 
"He  distinguishes  himself,"  to  quote  the  dry  description  of  M.  Broussais, 
"in  the  midst  of  creation,  and  paying  regard  only  to  his  own  exist- 
ence, compared  with  all  that  is  not  himself,  he  pronounces  the  word 
I,  (moi,)  and  says,  I  am;  and  viewing  himself  in  action,  says,  I  act, 
I  do,  &c.  Perception  of  himself  and  of  other  bodies  procures  him  what 
are  denominated  ideas.  This  is,  therefore,  another  result  of  reflection; 
in  other  words,  of  the  faculty  he  possesses  of  feeling  himself  feel.  But 
man  feels,  besides,  that  he  has  already  felt:  this  constitutes  memory. 
In  comparing  two  perceptions  with  each  other,  which  are  felt  in  sue- 


324  MENTAL  FACULTIES. 

cession,  a  third  perception  results,  which  is  judgment.  Consequently, 
to  judge  is  only  to  feel."  "  Hence,"  he  concludes,  "sensation,  reflection, 
and  judgment  are  absolutely  synonymous,  and  present  to  the  physiolo- 
gist nothing  more  than  the  same  phenomenon.  The  will,  or  the  faculty 
by  virtue  of  which  man  manifests  his  liberty  by  choosing,  among  dif- 
ferent perceptions,  the  one  he  must  obey ; — the  faculty,  which  gives  him 
the  power  of  resisting,  to  a  certain  extent,  the  suggestions  of  instinct — 
is  founded  on  reflection.  Consequently,  when  we  consider  it  in  a 
physiological  point  of  view,  we  can  only  discover  in  it  the  faculty  of 
feeling  ourselves,  and  of  perceiving  that  we  feel  ourselves." 

Some  of  the  later  French  metaphysicians  have  proposed  certain 
modifications  of  the  system  of  Condillac.  M.  De  La  Romiguiere,1  for 
instance,  denies  that  sensation  is  the  original  faculty,  and  derives  all 
from  attention.  The  mind,  he  remarks,  is  passive  during  the  reception 
of  sensation,  and  does  not  commence  action  until  directed  to  some  ob- 
ject, or  until  it  attends.  According  to  him,  the  intellect  consists  of 
three  faculties — attention;  comparison  or  double  attention  ;  and  reason 
or  double  comparison.  Judgment,  imagination,  and  memory  are  not 
primary  faculties  :  judgment  is  the  irresistible  product  of  comparison ; 
memory  is  but  the  trace,  which  every  perception  necessarily  leaves 
behind  it ;  and  imagination  is  but  a  dependence  on  reason.  M.  Des- 
tutt-Tracy,2  again,  reduces  the  number  of  primary  faculties  to  four — 
perception,  memory,  judgment,  and  will  or  desire.  According  to  him, 
attention  is  not  an  elementary  faculty.  It  is  but  the  active  exercise  of 
the  intellectual  faculties.  The  same  applies  to  reflection  and  reason, 
which  are  only  a  judiciously  combined  employment  of  those  faculties; 
and  to  comparison  and  imagination,  both  of  which  enter  into  the  judg- 
ment. This  division  is  embraced  by  M.  Magendie.3  Mr.  Dugald 
Stewart's4  classification  is  into,  1,  Intellectual  powers,  and,  2,  Active 
and  moral  powers;  including,  in  the  former,  perception,  attention,  con- 
ception, abstraction,  the  associating  principle,  memory,  imagination, 
and  reason.  Dr.  Brown5  reduces  all  the  intellectual  states  to  simple 
suggestion  and  relative  suggestion, — comprising  in  the  former,  concep- 
tion, memory,  and  imagination, — in  the  latter,  judgment,  reason,  ab- 
straction, and  taste.  Dr.  Abercrombie6  considers  the  mental  operations 
to  be  chiefly  referable  to  four  heads, — memory,  abstraction,  imagina- 
tion, and  reason  or  judgment;  whilst  Kant  has  twenty-five  primary 
faculties  or  forms ;  pure  conceptions  or  ideas  a  priori. 

These  are  a  few  only  of  the  discrepant  divisions  of  psychologists. 
The  list  might  have  been  extended  by  the  classifications  of  Aristotle, 
Bacon,  Hobbes,  Locke,  Bonnet,  Hume,  Vauvenargues,  Diderot,  Reid, 
and  others.  Perhaps  the  most  prevalent  opinion  at  present  is,  that  the 
original  faculties  are — perception,  memory,  judgment,  and  imagination. 
It  is  impossible,  were  it  even  our  province,  to  reconcile  these  discre- 

1  Lemons  de  Philosophie,  torn.  i.  4eme  lecon. 

2  Elemens  d'ldeologie,  2de  edit.,  Paris,  1804.  3  Precis  Elementaire,  i.  196. 

*  Elements  of  the  Philosophy  of  the  Human  Mind,  3d  edit.,  Lond.,  1808;  and  Amer. 
edit.,  Brattleborough,  Vt.,  IS  13. 

5  Lectures  on  the  Philosophy  of  the  Human  Mind,  Amer.  edit.,  Boston,  1826. 

6  Inquiries  concerning  the  Intellectual  Powers,  Amer.  edit.,  p.  91,  New  York,  1832. 


AFFECTIVE  FACULTIES.  325 

pancies.  They  are  too  considerable  to  hope,  that  this  will  ever  be 
effected  by  metaphysical  inquiry.  We  must,  therefore,  look  to  physio- 
logical investigation,  if  no't  with  well-founded — with  the  only — hopes, 
we  can  entertain,  for  the  elucidation  of  the  subject ;  and  we  shall  find 
presently,  that  the  minds  of  metaphysical  physiologists  have  been  turned 
in  this  direction,  and  that  many  interesting  facts  and  speculations  have 
been  the  result. 

A  second  topic  of  metaphysical  inquiry  regards  the  formation  of 
the  intellectual  notions.  On  this,  there  have  been  two  principal  opin- 
ions; some,  as  Plato,  Des  Cartes,  the  Kantists,  Kanto-Platonists,  &c., 
believing  in  the  existence  of  innate  ideas; — others,  as  Bacon,  Locke, 
and  Condillac,  denying  the  existence  of  such  innate  ideas,  and  assert- 
ing that  the  human  intellect,  at  birth,  is  a  tabula  rasa;  and  that  the 
mind  has  to  acquire  and  form  all  the  ideas  it  possesses  from  impres- 
sions made  on  the  senses.  The  truth  includes  probably  both  these  pro- 
positions,— the  action  of  the  senses  and  intellectual  faculties  being 
alike  necessary ; — the  former  receiving  the  external  and  internal  irq- 
pressions,  and  transmitting  them  to  the  mind,  which,  through  the 
cerebral  organ,  produces  the  latter. 

Under  the  terms  affective  faculties,  affections,  and  passions,  are 
comprehended  all  those  active  and  moral  powers,  which  connect  us  with 
the  beings  that  surround  us,  and  are  the  incentives  to  our  social  and 
moral  conduct.  To  this  class  belong, — the  feeling,  which  attaches  the 
parent  to  the  child  ;  that  which  attracts  the  sexes ;  and  compassion, 
by  which  we  are  led  to  assist  a  suffering  fellow-creature.  They  are,  in 
truth,  internal  sensations,  but  of  a  higher  cast  than  those  of  hunger 
and  thirst ; — the  latter  being  purely  physical,  and  announcing  physical 
necessities;  the  former  suggesting  social  and  moral  relations.  Such 
affective  faculties  are  the  foundation  of  what  are  called  moral  wants ; 
and,  like  the  internal  sensations  in  general,  are  the  source  of  pleasure, 
when  satisfied, — of  pain,  when  resisted  ;  and  it  is  only  when  they  are 
extreme  and  opposed,  that  they  acquire  the  name  of  passions.1  The 
analysis  of  these  is  attended  with  the  same  difficulties  as  that  of  the 
intellectual  faculties.  Their  plurality  is  universally  admitted,  but  still 
greater  discrepancy  exists  as  to  their  precise  number  and  connexion.2 
Many  moralists  have  united  the  moral  faculties  under  the  head  of  will 
or  desires.  Condillac3  is  one  of  those.  Every  sensation,  he  observes, 
has  the  character  of  pleasure  or  pain,  none  being  indifferent ;  as  soon, 
therefore,  as  a  sensation  is  experienced,  the  mind  is  excited  to  act. 
This  tendency  is  at  first  but  slightly  marked,  and  is  only  an  uneasiness 
(malaise);  but  it  soon  increases  and  becomes  restlessness  or  inquietude; — 
in  other  words,  a  difficulty  experienced  by  the  mind  of  remaining  in 
the  same  situation.  This  gradually  becomes  desire,  torment,  passion, 
and  finally  will  excited  totthe  execution  of  some  act.  Some  have  en- 
deavoured, by  ultimate  analysis,  to  derive  all  the  affective  faculties 
from  one  principal  faculty — that  of  self-love, — the  inward  feeling, 
which  induces  all  to  attend  to  themselves,  their  own  preservation,  and 

1  From  patior,  I  suffer. 

2  Adelon,   art.   Affection,    Dictionnaire  de   Medecine,   lere   edit.;    and   Physiologie   de 
1'Homme,  edit,  cit.,  i.  537.  3  Qp.  citat. 


326  MENTAL  FACULTIES. 

welfare.  All  the  faculties,  they  assert,  are  returns  of  this  self-love 
upon  itself;  and,  as  in  the  case  of  the  intellectual  faculties,  attempts 
have  been  made  to  classify  them  ;  but  scarcely  two  metaphysicians 
agree.  ^  Some  have  divided  them  into  the  agreeable  and  distressing; 
others  into  those  of  love  and  hatred;  many — regarding  their  effects 
upon  society — into  the  virtuous,  vicious,  and  mixed ; — the  first  com- 
prising those  that  are  useful  to  society, — as  filial,  parental,  and  con- 
jugal love,  which  form  the  foundation  of  families ;  goodness,  pity,  and 
generosity,  which,  by  inducing  men  to  assist  each  other,  facilitate  the 
social  condition;  and  the  love  of  labour,  honour,  and  justice,  which 
have  the  same  result,  by  constituting  so  many  social  guarantees.  The 
vicious  passions,  on  the  contrary,  are  such  as  injure  man  individually, 
and  society  in  general,  as  pride,  anger,  hatred,  and  malice.  Lastly, 
the  mixed  passions  are  such  as  are  useful  or  injurious,  according  to 
their  use  or  abuse ;  as  ambition,  which  may  be  a  laudable  emulation, 
or  an  insatiable  passion,  according  to  its  extent  and  direction. 

Again,  the  passions  have  been  divided  into  the  animal  or  such  as 
belong  to  physical  man,  and  the  social  or  such  as  appertain  to  man  in 
society.  The  first  are  guides  for  his  preservation  as  well  as  for  that  of 
the  species.  To  them  belong  fear,  anger,  sadness,  hatred,  excessive 
hunger,  the  venereal  desires  when  vehement,  jealousy,  &c.  In  the 
second  are  included  all  the  social  wants  when  inordinately  experienced. 
These  vary  according  to  the  state  of  civilization  of  the  individual  and 
the  community.  Ambition,  for  instance,  it  is  said,  may  be  regarded, 
when  inordinate,  as  excessive  love  of  power: — avarice,  as  an  exaggera- 
tion of  the  desire  for  fortune: — hatred,  and  vengeance,  as  the  natural 
and  impetuous  desire  of  injuring  those  that  injure  us,  &c.  Mr.  Dugald 
Stewart's1  division  of  the  active  and  moral  powers  embraces,  1.  Instinct- 
ive principles,  and  2.  Rational  principles, — the  former  including  appe- 
tites, desires,  and  affections  ;  the  latter  self-love  and  the  moral  faculty  ; 
all  of  which  Dr.  Brown2  comprises  under  emotions,  immediate,  retrospect- 
ive, or  prospective ; — and  lastly,  Dr.  Abercrombie3  refers  all  the  prin- 
ciples, which  constitute  the  moral  feelings,  to  the  following  heads : 
1.  The  desires,  the  affections,  and  self-love;  2.  The  will;  3.  The 
moral  principle,  and  4.  The  moral  relation  of  man  towards  the  Deity. 

It  is  obvious,  that  the  analysis  of  the  moral  faculties  has  been  still 
less  satisfactorily  executed  than  that  of  the  intellectual ;  and  that  little 
or  no  attempt  has  been  made  to  distinguish  those  that  are  primary  or 
fundamental,  from  those  that  are  more  complex;  consequently,  the 
remarks  which  were  made  regarding  the  only  quarter  we  have  to  look 
to,  for  any  improvement  in  our  knowledge  of  the  intellectual  acts,  apply 
d  fortiori  to  the  moral ;  although  it  must  be  admitted,  that  the  difficul- 
ties attendant  upon  the  investigation  of  the  latter  are  so  great  as  to 
appear  to  be  almost  insuperable. 

As  the  brain,  then,  is  admitted  to  be  the  organ  of  the  intellectual 
and  moral  faculties,  it  is  fair  to  presume  that  its  structure  may  be 

i  Op.  citat.  2  Op.  citat. 

3  Philosophy  of  the  Moral  Feelings,  Amer.  edit.,  p.  35,  New  York,  1833. 


SIZE  OF  THE  BRAIN.  327 

found  to  vary  according  to  the  number  and  character  of  those  •  and  if 
there  be  primary  or  fundamental  faculties,  each  may  be  conceived  to 
have  a  special  organ  concerned  in  its  production,  as  each  of  the  exter- 
nal senses  has  its  organ.  According  to  this  view,  the  cerebral  organi- 
zation of  animals  ought  to  differ  according  to  their  psychology :  where 
one  is  simple,  the  other  should  be  so  likewise.  This  seems,  so  far  as 
we  can  observe,  to  be  essentially  the  fact.  "  In  the  series  of  animals," 
says  M.  Adelon,1  "we  observe  the  brain  more  complicated  as  the  men- 
tal sphere  is  more  extensive ;  and  in  this  double  respect  a  scale  of  gra- 
dation may  be  formed  from  the  lowest  animals  to  man.  If  he  has 
the  most  extensive  moral  sphere,  if  he  alone  has  elevated  notions  of 
religion  and  morality,  he  also  has  the  largest  brain,  and  one  composed 
of  more  parts ;  so  that  if  the  physiology  of  the  brain  were  more  ad- 
vanced, we  might  be  able,  by  comparing  the  brains  of  animals  with  his, 
to  detect  the  material  condition,  which  constitutes  humanity.  If  the 
brain  were  not  constructed  a  priori  for  a  certain  psychology,  as  the 
digestive  apparatus  is  for  a  certain  alimentation  ;  and  if  the  mental  and 
moral  faculties  were  not  as  much  innate  as  the  other  faculties,  there 
would  be  nothing  absolute  in  legislation  or  morals.  The  brain  and  its 
faculties  are,  however,  in  each  animal  species,  in  a  ratio  with  the  role, 
which  such  species  is  called  upon  to  play  in  the  universe.  If  man  is, 
in  this  respect,  in  the  first  rank  ;  if  he  converts  into  the  delicate  affec- 
tions of  father,  son,  husband,  and  country,  those  brute  instincts  by 
which  the  animal  is  attached  to  its  young,  its  female,  or  kennel ;  if, 
in  short,  he  possesses  faculties  which  animals  do  not, — religious  and 
moral  feelings,  with  all  those  that  constitute  humanity, — it  is  owing  to 
his  having  a  more  elevated  vocation  ;  to  his  being  not  only  king  of  the 
universe,  but  destined  for  a  future  existence,  and  specially  intended  to 
live  in  society.  Hence  it  was  necessary,  that  he  should  not  only  have 
an  intellect  sufficiently  extensive  to  make  all  nature  more  or  less  sub- 
ject to  him,  but  also  a  psychology  such,  that  he  might  establish  social 
relations  with  his  fellows.  It  was  necessary,  that  he  should  have 
notions  of  the  just  and  the  unjust,  and  be  able  to  elevate  himself  to  the 
knowledge  of  God ; — to  those  sublime  feelings,  which  cause  him  so  to 
regulate  his  conduct  as  to  maintain  with  facility  his  mortal  connexions, 
and  deserve  the  future  life  to  which  he  is  called." 

But  if  the  intellectual  sphere  be  regulated  by  the  cerebral  develope- 
ment,  can  we  not,  it  has  been  asked,  estimate  the  connexion  between 
them  ?  And  if  there  be  different  primary  cerebral  faculties,  each  of 
which  must  have  an  organ  concerned  in  its  production,  can  we  not 
point  out  such  organ  in  the  brain  ?  Several  investigations  of  this  cha- 
racter have  been  attempted,  with  more  or  less  success:  generally, 
however,  they  have  added  but  little  to  our  positive  knowledge,  and  this, 
principally,  from  the  intricacy  of  the  subject.  Until  of  late  years, 
attention  was  chiefly  paid  to  the  mass  and  size  of  the  encephalon;  and 
it  was,  at  one  time,  asserted  that  the  larger  it  is,  in  any  species  or  in- 
dividual, the  greater  the  intellect.  Man,  however,  has  not  absolutely 
the  largest  encephalon,  although  he  is  unquestionably  the  most  intelli- 
gent of  beings.  The  weight  of  the  encephalon  of  a  child  six  years  of 

1  Art.  Encephale,  in  Diet,  de  Med.,  vii.  526  ;  and  Physiologie  de  THomme,  edit,  cit.,  i.  524. 


328  MENTAL  FACULTIES. 

age  is  given  by  Haller  at  two  pounds  three  ounces  and  a  half ;  whilst 
that  of  the  adult  is  estimated  by  Sommering  at  from  two  pounds  three 
ounces,  to  three  pounds  three  ounces  and  three-quarters  j1  by  Tiede- 
mann2  at  from  three  pounds  three  ounces,  to  four  pounds  eleven 
ounces  troy, — the  brain  of  the  female  weighing,  on  an  average,  from 
four  to  eight  ounces  less  than  that  of  the  male.  The  average  weight, 
after  the  meninges  have  been  stripped  off,  is,  in  the  healthy  adult  male, 
according  to  M.  Lelut,3  about  1346  grammes,  or  three  pounds  and  a  half 
avoirdupois ;  of  which  the  cerebrum  weighs  1170,  the  cerebellum  176 
grammes.  In  the  female,  the  weight  of  the  encephalon  was  about  Jgth 
less.  From  the  tables  of  weights  of  the  brain  given  by  Dr.  Sims, 
Clendinning,4  Tiedemann,  and  Dr.  John  Reid,5  it  was  found  that  in  a 
series  of  278  cases  the  maximum  weight  of  the  adult  male  brain  was  65 
ounces:  the  minimum  weight  34  oz.  In  a  series  of  191  cases,  the  maxi- 
mum weight  of  the  brain  of  the  adult  female  was  56  oz. : — the  minimum 
weight  31  oz.  By  taking  the  mean  of  all  the  cases,  an  average  weight 
was  deduced  of  49 J  oz.  for  the  male;  and  of  44  oz.  for  the  female  brain]; 
and  although  many  female  brains  exceed  in  weight  particular  male 
brains,  it  is  found  that  the  adult  male  encephalon  is  heavier  than  that 
of  the  female,  by  from  five  to  six  ounces  on  an  average.6  The  encephalon 
of  the  elephant,  according  to  Haller,  weighs  from  seven  to  ten  pounds. 
The  brain  of  an  African  elephant,  seventeen  years  old,  was  found  by 
Perrault  to  weigh  nine  pounds;  that  of  an  Asiatic  elephant,  weighed 
by  A.«  Moulins,  was  ten  pounds.  Sir  Astley  Cooper  dissected  one  that 
weighed  eight  pounds  one  ounce  and  two  grains,  avoirdupois.7  These 
facts,  consequently,  overthrow  the  proposition;  and,  moreover,  in  certain 
insects,  the  bee  and  the  ant,  we  meet  with  evidences  of  singular  intel- 
ligence. The  proposition  was  therefore  modified,  and  it  was  laid  down, 
that  the  larger  the  encephalon,  compared  with  the  rest  of  the  body,  the 
greater  the  mental  sphere.  When  the  subject  was  first  investigated  in 
this  way,  the  result,  in  the  case  of  the  more  common  and  domestic 
animals,  was  considered  so  satisfactory,  that  without  farther  compari- 
son, the  proposition  was  considered  established.  More  modern  re- 
searches have  shown,  that  it  admits  of  numerous  exceptions;  and  that 
several  of  the  mammalia,  and  many  diminutive  and  insignificant  ani- 
mals have  the  advantage  over  man  in  this  respect.  It  has,  indeed, 
been  properly  observed  by  Mr.  Lawrence,8  that  it  cannot  be  a  very 
satisfactory  mode  of  proceeding,  to  compare  the  body,  of  which  the 
weight  varies  so  considerably,  according  to  illness,  emaciation,  or  em- 
bonpoint, with  the  brain,  which  is  affected  by  none  of  those  circum- 

1  Weber's  Hildebrandt's  Handbuch  der  Anatomic,  Band  iii.  423;  Rudolphi,  Grundriss,  u. 
s.  w.  ii.  11,  Berlin,  1823. 

3  Proceedings  of  the  Royal  Society  for  1836;  also  Das  Him  des  Negers  mit  des  Eu- 
ropiiers  und  Orang-outangs  vergleichen,  Heidelb.,  1837,  cited  in  Brit,  and  For.  Med.  Rev., 
for  Oct.  1839,  p.  374. 

3  Gazette  Medicale;  and  Medico-Chirurgical  Review  for  Oct.,  1837,  p.  507. 

4  Medico-Chirurgical  Transactions,  xix.  353. 

6  Lond.  and  Edinb.  Monthly  Journal  of  Medical  Science,  April,  1843,  p.  298. 

6  Quain's  Human  Anatomy,  by  Quain  and  Sharpey,  Amer.  edit,  by  Leidy,  ii.  185,  Philad., 
1849. 

7  Dr.  Todd,  art.  Nervous  Centres,  in  Cyclop,  of  Anat.  and  Physiol.  Pt.  xxv.  p.  664, 
Lond.,  1844. 

8  Lectures  on  Physiology,  Zoology,  &c.,  p.  191,  Lond.,  1819. 


SIZE  OF  THE  BRAIN. 


329 


stances,  and  appears  to  remain  constantly  the  same.  This  is  the 
cause,  why,  in  the  cat,  the  weight  of  the  encephalon  compared  with 
that  of  the  body  has  been  stated  as  1  to  156  by  one  comparative  ana- 
tomist ;  and  as  1  to  82  by  another  ;  that  of  the  dog  as  1  to  305  by  one, 
and  as  1  to  47  by  another,  &c. 

The  following  table,  taken  chiefly  from  Haller1  and  Cuvier,2  exhibits 
the  proportion  borne  by  the  encephalon  to  the  rest  of  the  body,  in  man 
and  certain  animals. 


Child,  6  years  old 

Adult 

Gibbon 

Sapajous,  from 

Apes 

Baboons 

Lemurs 

Bat  (vespertilio) 

Mole 

Bear 

Hedgehog    . 

Fox 

Wolf 

Beaver 

Hare 

Rabbit 

Rat 

Mouse 

Wild  Boar  . 

Domestic  do. 


•  2*2 


4V 
T*I 


S'B 
5-r 


A 


225 


T 


to 


•    A 

•     5^2 


5T2 


Elephant    . 

Stag 

Roebuck  (young) 

Sheep 

Ox 

Calf 

Horse 

Ass 

Dolphin 

Eagle 

Goose 

Cock 

Canary  Bird 

Humming  Bird3 

Turtle 

Tortoise     . 

Frog 

Shark 

Pike 

Carp 


sii  to  TJ2 
7iu  to  sJs 

-     2!? 

?J(J  tO   4 Jc> 
35>   5()?  TTJ2 


224<J 

rh 

24^5 
T3\>5 


In  9  males,  between  27  and  50  years  of  age,  who  died  immediately, 
or  within  a  few  hours,  after  accidents,  and  other  external  causes  of 
death,  and  who  had  been  previously  in  good  health,  Dr.  John  Reid4 
obtained  the  following  results; — the  weight  used  being  avoirdupois: — 

Average  weight  of  body  (9  weighed)  .  .  . 
Average  of  encephalon  (6  weighed)  .  .  . 
Average  of  cerebellum  (4  weighed)  .  .  . 
Average  of  cerebellum  with  pons  and  medulla 

(5  weighed) 

Or,  taking  the  average  of  the  four  cases  only 

in  which  the  cerebellum  was  taken  .  . 
Average  of  heart  (9  weighed) 

Relative  weight  of  body  to  encephalon  (6  weighed) 
Relative  weight  of  body  to  heart  (9  weighed)  .  . 
Relative  weight  'of  encephalon  to  cerebellum  (4 

weighed) as  1 

Relative  weight   of  encephalon   to   cerebellum,  with 

pons  and  medulla  (5  weighed) as  1  to 


134 
3 

» 

led) 

Ibs.  31 
Ibs.  4 

5 

6 

6 
12 

.  as 
.  as 

oz. 
oz. 
oz. 

oz. 

oz. 
oz. 

1  to 
1  to 

4|  dr. 
7*  dr. 

6  dr. 

7|  dr. 
6  dr. 

40J 
173i 

to 


9| 


2  Le§ons  d'Anat.  Comp.,  ix.  art.  5. 


i  Element.  Physiol.,  x.  sect.  1. 

3  On  the  authority  of  ex-President  Madison. 

4  Lond.  and  Edinb.  Monthly  Journal  of  Med.  Science,  April,  1843,  p.  322. 


330  MENTAL  FACULTIES. 

M.  Bourgery1  found,  that  the  mean  weight  of  the  encephalon  being 
20393-5  grains  troy,  the  cerebral  hemispheres  weigh  16940-46  grains; 
the  cerebellum,  2176*7  grains ;  the  cephalic  prolongation  of  the  cere- 
bro-spinal  axis,  1312-2  grains  ;  of  which  the  optic  thalami  and  corpora 
striata  make  879-9  grains  ;  the  medulla  oblongata  with  the  pons  Varolii 
432-2  grains  ;  and  the  spinal  cord  710-1  grains.  Hence,  in  man,  the 
cerebral  hemispheres  include  a  nervous  mass,  which  is  four  times  greater 
than  the  rest  of  the  cerebro-spinal  mass ;  nine  times  greater  than  the 
cerebellum ;  thirteen  times  greater  than  the  cephalic  stem  of  the  spinal 
cord ;  and  twenty-four  times  greater  than  the  spinal  cord  itself. 

It  has  been  the  general  belief,  that  the  brain  of  the  negro  is  inferior 
to  that  of  the  white  variety  of  the  species ;  but  certain  observations  of 
M.  Tiedemann  led  him  to  the  belief,  that  there  is  no  perceptible  differ- 
ence either  in  its  average  weight  or  average  size  in  the  two  varieties, 
and  that  the  nerves  compared  with  the  size  of  the  brain  are  not  larger 
in  the  former  than  in  the  latter.  In  the  external  form  of  the  brain  of 
the  negro  a  very  slight  difference  only  could  be  traced ;  and  he  affirmed 
further,  that  there  is  absolutely  no  difference  in  its  external  structure, 
nor  does  the  negro  brain  exhibit  any  greater  resemblance  to  that  of  the 
ourang  outang  than  the  brain  of  the  European,  excepting,  perhaps,  in 
the  more  symmetrical  disposition  of  its  convolutions.  Tiedemann's 
observations  were  made,  however,  upon  few  subjects  ;  and  his  own  facts 
do  not  bear  out  all  his  deductions.  He  admits,  that  the  anterior  part 
of  the  hemispheres  was  something  narrower  than  is  usually  the  case  in 
Europeans,  "  which," — says  Dr.  Combe,2 — "as  the  anterior  portion  is 
the  seat  of  intellect,  is  really  equivalent  to  conceding  that  the  negro  is 
naturally  inferior  in  intellectual  capacity  to  the  European  !"  M.  Tiede- 
mann established  that  the  average  capacity  of  the  Ethiopian  skull  is 
somewhat  less  than  that  of  the  European,  and  that  a  large  sized  skull  is 
considerably  less  frequent  among  them  than  among  any  other  races  of 
mankind.3 

The  following  table,  drawn  up  by  Dr.  Morton,4  exhibits  the  absolute 
capacity  of  the  cranium  or  bulk  of  the  brain  in  cubic  inches,  obtained 
by  filling  the  cavity  of  the  crania  with  leaden  shot,  one-eighth  of  an 
inch  in  diameter,  in  different  races  and  families  of  man.5  It  sufficiently 
exhibits  how  little  can  be  judged,  in  this  manner,  of  their  relative  intel- 
lectual aptitudes. 

1  Lond.  Med.  Gaz.,  Jan.,  1845,  p.  462. 

2  Phrenological  Journal.  No.  liv.,Dec.,  1837. 

3  Brit,  and  For.  Med.  Rev.,'for  Oct.,  1839,  p.  379. 

4  Catalogue  of  Skulls  of  Man  and  the  Inferior  Animals  in  the  collection  of  Samuel  George 
Morton,  M.D.,  &c.,  3d  edit.,  p.  viii.,  Philad.,  1849. 

6  For  the  ingenious  process  invented  by  Mr.  J.  S.  Phillips,  of  Philadelphia,  by  which  these1 
measurements  were  taken,  see  Dr.  Morton's  Crania  Americana,  p/203,  Philad.  and  Lond., 
1839. 


SIZE  OF  THE  BRAIN. 


331 


TABLE, 

Showing  the  Size  of  the  Brain  in  cubic  inches,  as  obtained  from  the  measurements 
of  623  Crania  of  various  Races  and  Families  of  Man. 

(N.  B.— I.  C.  means  Internal  Capacity.) 


RACES  AND  FAMILIES. 

No.  of 
Skulls. 

Larger 

Smallest. 

i.e. 

Mean. 

Mean. 

MODERN  CAUCASIAN  GROUP. 

TEUTONIC  FAMILY. 

Germans, 

18 

114 

70 

90 

) 

English, 

5 

105 

91 

96 

[  92 

Anglo-Americans, 

7 

97 

82 

90 

j 

PELASGIC  FAMILY. 

1 

Persians, 

Armenians, 

10 

94 

75 

84 

Circassians, 

J 

CELTIC  FAMILY. 
Native  Irish, 

I       6 

97 

78 

87 

INDOSTANIC  FAMILY. 
Bengalees,  &c., 

-     32 

91 

67 

80 

SEMITIC  FAMILY. 
Arabs, 

-       3 

98 

84 

89 

NILOTIC  FAMILY. 
Fellahs, 

}  * 

96 

66 

80 

ANCIENT  CAUCASIAN  GROUP. 

0  oo  f  PELASGIC  FAMILY. 
rS'g             Grceco-Egyptians, 

1  - 

97 

74 

88 

s  §1 

2  3      NILOTIC  FAMILY. 
^0  I          Egyptians, 

I     55 

96 

68 

80 

MONGOLIAN  GROUP. 

CHINESE  FAMILY, 

6 

91 

70 

82 

MALAY  GROUP. 

MALAYAN  FAMILY, 

20 

97 

68 

86 

1  85 

POLYNESIAN  FAMILY, 

3 

84 

82 

83 

r  QO 

AMERICAN  GROUP. 

TOLTECAN  FAMILY. 

•> 

Peruvians, 

155 

101 

58 

75 

Mexicans, 

22 

92 

67 

79 

BARBAROUS  TRIBES. 

L  7Q 

Iroquois, 

C  ' 

Lenape", 

-  161 

104 

70 

84 

Cherokee, 

Shoshone",  &c., 

• 

NEGRO  GROUP. 

NATIVE  AFRICAN  FAMILY, 
AMERICAN-BORN  NEGROES, 

62 
12 

99 
89 

65 
73 

83 
82 

j  83 

HOTTENTOT  FAMILY, 

3 

83 

68 

75 

ALFORIAN  FAMILY. 
Australians, 

}       * 

83 

63 

75 

332 


MENTAL  FACULTIES. 


From  this  table  it  appears,  that  the  smallest  mean  cranial  capacity 
is  found  in  the  Hottentots  and  Australians,  which  is  75  cubic  inches; 
whilst  that  of  the  Teutonic  races  is  92  cubic  inches.  It  may  be  inte- 
resting to  add,  that  from  the  examination  of  four  skulls  of  the  Enge-ena, 
a  quadrumanous  animal — Troglodytes  gorilla  of  Savage — from  Gaboon 
in  Africa,  Dr.  Jeffries  Wyman1  found  the  mean  capacity,  measured 
according  to  the  method  employed  by  Dr.  Morton,  to  be  28*9J  cubic 
inches,  or  considerably  less  than  one-half  the  mean  of  the  Hottentots 
and  Australians,  who  afford  the  minimum  average  for  the  human  family. 
The  mean  cranial  capacity  of  three  adult  Chimpanzees  was  even  less,  or 
24  cubic  inches. 

Wrisberg  and  Sommering2  proposed  another  point  of  comparison — 
the  ratio  of  the  mass  of  the  encephalon  to  that  of  the  rest  of  the 
nervous  system;  and  they  asserted,  that  in  proportion  as  any  animal 
possesses  a  larger  share  of  the  former;  or,  in  other  words,  in  proportion 
as  the  percipient  and  intellectual  organ  exceeds  the  other  or  the  organ 
of  the  external  senses — the  mental  sphere  may  be  expected  to  be  more 
diversified  and  developed.  But  although  man  is,  in  general,  pre-eminent 
in  this  respect,  he  is  not  absolutely  so.  It  would  be  still  more  important 

to  know  the  ratio,  which  the  cere- 
brum or  brain  proper  bears  to 
the  cerebellum  and  medulla  ob- 
longata.  The  first  is  essentially 
the  organ  of  intellect;  and  the 
most  striking  character  of  the 
human  brain  is  the  large  deve- 
lopement  of  the  cerebral  hemi- 
spheres, of  which  we  have  no 
parallel  in  the  animal  kingdom. 
The  last  is  the  encephalic  part  in 
which  the  nerves  of  sense  arise 
or  terminate. 

The  assertion,  that  man  has 
the  largest  cerebrum  in  propor- 
tion to  the  cerebellum,  is  not  ac- 
curate. The  Wenzels3  found  the 
ratio,  in  him,  to  be  as  G/^g  or 
8T452T  to  1;  in  the  horse,  4J  to  1; 
in  the  cow,  5  Jff  to  1 ;  in  the  dog, 
624s  to  1;  in  the  cat,  4T4g  to  1; 
in  the  mole,  3|  to  1 ;  and  in  the 
mouse,  6-f  to  1.  Nor  is  it  true 
that  man  has  the  largest  cere- 
Facial  Line  and  Angle  of  Man.  brum  in  proportion  to  the  medulla 

1  A  description  of  two  additional  Crania  of  the  Enge-ena,  &c.,  read  before  the  Boston 
Society  of  Natural  History,  Oct.  3,  1849;  and  published  in  the  American  Journal  of  Science 
and  Arts,  second  series,  vol.  ix. 

2  Corpor.  Human.  Fabric,  iv.  §  92 ;  and  Blumenbach's  Comp.  Anat.  by  Lawrence,  p.  292, 
Lond.,  1807. 

3  De  Penitiori  Structur.  Cerebr.  Hominis  et  Brutorum,  tab.  iv. 


CAMPER'S  FACIAL  LINE  AND  ANGLE.  333 

oblongata  and  medulla  spinalis;  although  to  this  position  there  are 
perhaps  fewer  objections  than  to  the  others.  None  of  them,  it  is  ob- 
vious, are  distinctive  between  man  and  animals,  or  assist  us  in  solving 
the  great  problem  of  the  source  and  seat  of  the  numerous  psychological 
differences  we  observe. 

Various  plans  have  been  devised  for  appreciating  the  comparative 
size  of  the  cranium, — which  is  generally  in  a  ratio  with  that  of  the  brain, 
— and  of  the  bones  of  the  face.  As  the  former  contains  the  organ  of 
the  intellect,  and  the  latter  those  of  the  external  senses  and  of  mastica- 
tion, it  has  been  presumed,  that  the  excess  of  the  former  would  indicate 
the  predominance  of  thought  over  sense;  and,  conversely,  that  the 
greater  developement  of  the  face  would  place  the  animal  lower  in  the 
scale. 

One  of  these  methods,  first  proposed  by  Camper,1  is  by  taking  the 
course  of  the  facial  line,  and  the  amount  of  the  facial  angle.  The 
facial  line  is  a  line  drawn  from  the  projecting  part  of  the  forehead  to 
the  alveoli  of  the  incisor  teeth  of  the  upper  jaw;  the  facial  angle  is 
that  formed  between  this  line  and  another  drawn  horizontally  backwards 
from  the  upper  jaw.  The  course  of  the  horizontal  line  and  its  point  of 
union  with  the  facial  line  are  not  uniform  in  all  the  figures  given  by 
Camper :  sometimes,  it  is  made  to  pass  through  the  meatus  auditorius 
externus;  but  it  often  falls  far  below  it;  yet  Dr.  Bostock  thinks2  "we 
cannot  hesitate  to  admit  the  correctness  of  Camper's  observations,  and 
we  can  scarcely  refuse  our  assent  to  the  conclusion  that  he  deduces  from 
them."  In  man,  whose  face  is' situate  perpendicularly  under  the  cra- 
nium,, the  facial  angle  is  very  large.  In  animals,  the  face  is  placed  in 
front  of  the  cranium ;  and  as  we  descend  from  man  the  angle  becomes 
less  and  less,  until  it  is  finally  lost ;  the  cranium  and  face  bejng  in  most 
reptiles  and  fish  on  a  level.  The  marginal 
figure  (Fig.  134)  exhibits  the  difference  be-  Fig.  135. 

tween  the  facial  angle  of  those  of  European 
descent,  and  that  of  the  negro.  By  covering 
with  the  finger  the  parts  below  the  nose  al- 
ternately, we  have  the  countenance  of  the 
white,  and  negro,  in  which  the  facial  angle 
differs  as  much  as  10°,  or  15°.  Fig.  135 
exhibits  the  facial  line  and  angle  of  the 
ourang-outang.  Animals  that  have  the 
snout  long,  and  the  facial  angle  consequently 
small,  have  been  proverbially  esteemed  fool- 
ish,3— such  are  the  snipe,  stork,  crane,  &c.  r 
whilst  superior  intelligence  has  been  ascribed 
to  those  in  which  the  angle  is  more  largely 
developed, — as  the  elephant  and  the  owl; 
although  in  them,  the  large  facial  angle  is  _ 
caused  by  the  size  of  the  frontal  sinusts,  or  *  —1L-e  and  Angle  oft 

1  Dissertation  Physique  de  M.  Camper,  sur  les  Differences  Reelles  que  presentent  les 
Traits  du  Visage,  &c.,  traduit  du  Hollandois,  par  D.  B.  Q.  Disjonval,  Autrecht,  1791. 

2  Physiology,  3d  edit.,  p.  804,  Lond.,  1836. 
8  Lawrence,  op.  citat.,  p.  168. 


334 


MENTAL  FACULTIES. 


by  the  wide  separation  between  the  two  tables  of  the  skull,  and  is 
necessarily  no  index  of  the  size  of  the  brain.  Yet,  from  this  cause, 
perhaps,  the  owl  was  chosen  as  an  emblem  of  the  goddess  of  wisdom ; 
and  the  elephant  has  received  a  name  in  the  Malay  language,  indicating 
an  opinion,  that  he  is  possessed  of  reason.  The  following  .table  exhibits 
the  facial  angle  in  man  and  certain  animals,  taken  by  a  line  drawn 
parallel  to  the  floor  of  the  nostrils,  and  meeting  another,  drawn  from 
the  greatest  prominence  of  the  alveoli  of  the  upper  jaw  to  the  promi- 
nence of  the  forehead: — 


Man  . 
Sapajou  . 
Ourang-outang 
Guenon  . 
Mandril . 
Coati 


68°  to  88°  or  more 
65° 

56°  or  58° 
57° 

30°  to  42° 
28° 


Polecat 
Pug  dog 
Mastiff 
Hare 
Ram 
Horse     , 


31° 
35° 
41° 
30° 
30° 
23° 


The  facial  angle  may,  then,  exhibit  the  difference  between  man  and 
animals;  and,  to  a  certain  extent,  between  the  species  or  individuals 
of  the  latter;  but,  farther,  it  is  of  little  or  no  use.1  In  man,  it  may  be 
considered  to  vary  from  70°  to  85°  in  the  adult;  but  in  children  it 
reaches  as  high  as  90°  and  upwards;  a  sufficient  proof,  that  it  cannot 
be  regarded  as  a  measure  of  the  intellect.  In  the  European,  it  has 
been  estimated,  on  the  average,  at  perhaps,  80°,  in  the  Mongol,  75°, 
and  in  the  negro,  70°,  not  many  degrees  above  the  Sapajou.2 

The  following  table,  drawn  up  from  the  average  of  actual  measure- 
ments of  the  skulls  of  different  races  and  families  of  man,  in  the  col- 
lection of  Dr.  Morton,3  will  afford  more  precise  information  on  this 
matter. 


Arab  (2  cases) 

European  and  Anglo-American 
Egyptian        .... 
Bengalee        .... 
Circassian      .... 
Sandwich  Islander  (one  case) 
Chinese  (one  case) 
Guanche  (one  case) 
Negro  .... 

Indian  .... 

Hottentot  (one  case) 
Peruvian        .... 
Malay  .... 


FACIAL  ANGLE. 

Average.    Highest.    Lowest. 


82 

80 

79-3 

79-3 

78-5 

78 

78 

77 

76-8 

76-1 

75 

74-9 

74-6 


38 
85 
86 
83 
81 


83 


SI 

82 


76 

77 
73 
76 
75 


69 

70 

68 
69 


It  is  found,  that  the  skulls  of  different  nations,  and  of  individuals  of 
the  same  nation,  may  agree  in  the  facial  angle,  whilst  there  may  be 
striking  distinctions  in  the  shape  of  the  cranium  and  face,  in  the  air 
and  character  of  the  whole  head ;  as  well  as  in  the  particular  features, — 
the  inclination  of  the  facial  line  being  more  dependent  on  the  promi- 
nence of  the  upper  jaw  and  frontal  sinuses  than  on  the  general  form  of 

1  Dr.  Morton,  in  his  splendid  work,  Crania  Americana,  Philad.,  1839,  describes  a  "Facial 
Goniometer,"  originally  suggested  by  Dr.  Turnpenny,  of  Philadelphia,  which  is  admirably 
adapted  for  measuring  the  facial  angle. 

2  Prichard's  Physical  History  of  Mankind,  i.  288,  3d  edit.,  Lond.,  1836. 

3  Catalogue  of  Skulls  of  Man,  &c.,  3d  edit.,  Philad.,  1849. 


CAMPER'S  FACIAL  LINE  AND  ANGLE.  335 

the  head.  The  ancients  were  impressed  with  the  intellectual  air  exhi- 
bited by  the  open  facial  angle;  for  we  find  in  all  their  statues  of  legis- 
lators, sages,  and  poets,  an  angle  of  at  least  90°,  and  in  those  of  heroes 
and  superhuman  natures  it  is  as  high  as  100°.  This  angle,  according 
to  Camper,  never  existed  in  nature;  and  yet  he  conceives  it  to  be  the 
beau  ideal  of  the  human  countenance,  and  to  have  been  the  ancient 
model  of  beauty.  It  was,  more  probably,  the  model  of  superior  intel- 
lectual endowment,  although  ideas  of  beauty  might  have  been  connected 
with  it.  Every  nation  forms  its  notions  of  beauty,  derived  from  this 
source,  chiefly  from  the  facial  angle  to  which  it  is  accustomed.  With 
the  Greeks  it  was  large,  and  therefore  the  vertical  facial  line  was  highly 
estimated.  For  the  same  reason,  it  is  pleasing  to  us;  but  such  would 
not  be  the  universal  impression.  Savage  tribes  on  our  own  continent, 
have  preferred  the  pyramidal  shape  of  the  head,  and  made  use  of  every 
endeavour,  by  unnatural  compression  in  early  infancy,  to  produce  it; 
whilst  others,  not  satisfied  with  the  natural  shape  of  the  frontal  bone, 
have  forced  back  the  forehead,  either  by  applying  a  flat  piece  of  board 
to  it,  like  the  Indians  of  our  own  continent,  or  by  iron  plates,  like  the 
inhabitants  of  Arracan.  By  this  practice  the  Caraibs  are  said  to  be 
able  to  see  over  their  heads. 

M.  Daubenton,1  again,  endeavoured,  by  taking  the  occipital  line  and 
angle,  to  measure  the  differences  between  the  skulls  of  man  and  ani- 
mals. A  line  is  drawn  from  the  posterior  margin  of  the  foramen 
magnum  of  the  occipital  bone  to  the  inferior  margin  of  the  orbit,  and 
another  from  the  top  of  the  head  to  the  space  between  the  occipital 
condyles.  In  man,  these  condyles,  as  well  as  the  foramen  magnum, 
are  so  situate,  that  a  line  drawn  perpendicular  to  them  will  be  a  con- 
tinuation of  the  vertebral  column;  but  in  animals  they  are  placed  more 
or  less  obliquely;  the  perpendicular  will,  therefore,  necessarily  be  thrown 
farther  forward,  and  the  angle  be  rendered  more  acute.2  Blumenbach 
says,  that  Daubenton's  method  maybe  adapted  to  measure  the  degrees 
of  comparison  betwixt  man  and  brutes,  but  not  varieties  of  national 
character;  for  he  found  it  even  different  in  the  skulls  of  two  Turks, 
and  three  Ethiopians.  The  methods  of  Camper  and  Daubenton  com- 
bined, were,  also,  insufficient  to  indicate  the  varieties  in  national  and 
individual  character.  He  accordingly  describes  a  new  method, — which 
he  calls  norma  verticalis.3  It  consists  in  selecting  two  bones ;  the  frontal 
from  those  of  the  cranium,  and  the  superior  maxillary  from  those  of 
the  face;  comparing  these  with  each  other,  by  regarding  them  verti- 
cally, placing  the  great  convexity  of  the  cranium  directly  before  him, 
and  marking  the  relative  projections  of  the  maxillary  bone  beyond  the 
arch  of  the  forehead.  The  Asiatic  Georgian  is  found  to  be.  character- 
ized by  the  great  expanse  of  the  upper  and  outer  part  of  the  cranium, 

1  Memoires  de  1'Academie  des  Sciences  de  Paris,  p.  568,  Paris,  1764. 

3  By  some  writers,  Daubenton's  method  is  said  to  consist  of  "  a  line  drawn  from  the  pos- 
terior margin  of  the  occipital  foramen  to  the  inferior  margin  of  the  orbit;  and  another  drawn 
horizontally  through  the  condyles  of  the  occipital  bone."  It  is  obvious,  that  little  or  no  com- 
parative judgment  of  the  cranium  and  face  could  be  formed  from  this. 

3  Decad.  Collections  suae  Craniorum  diversarum  Gentium ;  and  De  Gener.  Human.  Var. 
Nativ.,  edit.  3a,  Getting.,  1795. 


y 
336  MENTAL  FACULTIES. 

which  hides  the  face.  In  the  Ethiopian,  the  narrow,  slanting,  forehead 
permits  the  face  to  appear,  whilst  the  cheeks  and  jaws  are  compressed 
laterally  and  elongated  in  front ;  and  in  the  Tungoose,  the  maxillary, 
malar,  and  nasal  bones  are  widely  expanded  on  each  side ;  and  the  two 
last  rise  to  the  same  horizontal  level  with  the  space  between  the  frontal 
sinuses — the  glabella.  Blumenbach's  method,  however,  only  affords  us 
the  comparative  dimensions  of  the  two  bones  in  one  direction.  It  does 
not  indicate  the  depth  of  either,  or  their  comparative  areas.  The  view 
thus  obtained  is,  therefore,  partial. 

Finding  the  inapplicability  of  other  methods  to  the  greater  part  of 
the  animal  creation — to  birds,  reptiles,  and  fishes,  for  example — M.  Cu- 
vier1  suggested  a  comparison  between  the  areas  of  the  face  and  cranium 
under  the  vertical  section  of  the  head.  The  result  of  his  observations 
is — that,  in  the  European,  the  area  of  the  cranium  is  four  times  that 
of  the  face,  excluding  the  lower  jaw.  In  the  Calmuck,  the  area  of 
the  face  is  one-tenth  greater  than  in  the  European;  in  the  negro,  one- 
fifth,  and  in  the  sapajou,  one-half.  In  the  mandril,  the  two  areas  are 
equal;  and,  in  proportion  as  we  descend  in  the  scale  of  animals,  the 
area  of  the  face  gains  over  that  of  the  cranium;  in  the  hare,  it  is  one- 
third  greater;  in  the  ruminant  animals  double;  in  the  horse,  quad- 
ruple, &c. ;  so  that  the  intelligence  of  the  animal  appeared  to  be 
greater  or  less  as  the  preponderance  of  the  area  of  the  face  over  that 
of  the  skull  diminished  or  increased. 

The  truth,  according  to  Sir  Charles  Bell,2  is,  that  the  great  differ- 
ence between  the  bones  of  the  cranium  and  face  in  the  European  and 
negro  is  in  the  size  of  the  jaw-bones.  In  the  negro,  these  bear  a  much 
greater  proportion  to  the  head  and  to  the  other  bones  of  the  face  than 
in  the  European;  and  the  apparent  size  of  the  bones  of  the  negro 
face  was  discovered  to  proceed  solely  from  the  size  and  shape  of  the 
jaw-bones;  whilst  the  upper  bones  of  the  face,  and,  indeed,  all  that 
had  no  relation  to  the  teeth  and  to  mastication,  were  less  than  those  of 
the  European  skull. 

Other  methods,  of  a  similar  kind,  have  been  proposed  by  natu- 
ralists, as  Spigel,3  Herder,4  Mulder,5  Walther,6  Doornik,7  Spix,8  and 
Oken,  but  they  are  all  insufficient  to  enable  us  to  arrive  at  a  satis- 
factory comparison.9  Blumenbach  asserts,  that  he  found  the  facial 
and  occipital  angles  nearly  alike  in  three-fourths  of  known  animals. 

1  Le£ons  d'Anatomie  Compar.,  No.  viii.  art.  i.  tom^ii.  p.  1. 

2  Anatomy  of  Expression,  3d  edit.,  Lond.,  1844. 

s  Linese  Cephalometricae  Spigelii,  in  Spigel,  De  Human.  Corpor.  Fabric.,  i.  8. 

4  Nackenlinien  (Linese  nuchales  Herderi),  in  Herder's  Ideen  zur  Philosophic  der  Geschichte 
der  Menschheit,  Th.  iii.  s.  186,  Tubing.,  1806. 

6  Vorderhauptwinkel  (Angulus  sincipitalis  Mulderi),  in  art.  Kopflinien,  in  Pierer's  Anat. 
Physiol.  Real  Worterb.,  iv.  524,  Leipz.,  1821. 

6  Schitdelwinkel  (Angulus  Cranioscopicus  Waltheri),  in  Walther,  Kritische  Darstellung 
der   Gallschen  Anat.  Physiol.  Untersuch.  des   Gehirn   und   Schildeibaues,  s.  108,  Zurich, 
1802. 

7  Wijsgeerig   Natuurkundig  Onderzoek   aangande    den  Oorsprongliken   Mensch  en  de 
Oorspronglike  Stammen  van  deszelfs  Geslacht,  Amsterd.,  1808. 

8  Cephalogenesis,  Monach.,  1815. 

9  Oken,  Lehrbuch  der  Zoologie,  Abth.  ii.  s.  660.     A  description  of  all  these  methods  is 
given  by  Choulant,  in  Pierer,  loc.  cit. 


, 
VIEWS  OF  PHRENOLOGISTS.  337 

Moreover,  it  by  no  means  follows,  that,  in  the  same  species,  there 
should  be  a  correspondence  between  the  size  of  the  cranium  and  face. 
In  the  European,  the  face  may  be  unusually  large ;  and  yet  the  mental 
endowments  may  be  brilliant.  Leo  X.,  Montaigne,  Leibnitz,  Racine, 
Haller,  Mirabeau,  and  Franklin,  had  all  large  features.1 

All  these  methods,  again,  are  confined  to  the  estimation  of  the  size 
of  the  whole  encephalon;  whereas  the  brain,  we  have  seen,  is  alone 
concerned  in  the  intellectual  and  moral  manifestations;  although  Gall 
includes  the  cerebellum.  It  has  already  been  remarked,  that  no  ani- 
mal equals  man  in  the  developement  of  the  cerebral  hemispheres.  In 
the  ape  they  are  less  prominent ;  and  below  it  in  the  scale  of  creation, 
they  become  less  and  less;  the  middle  lobes  are  less  arched  down- 
wards; and  the  posterior  lobes  are  ultimately  wanting,  leaving  the 
cerebellum  uncovered;  the  convolutions  are  less  and  less  numerous 
and  deep,  and  the  brain  at  length  is  found  entirely  smooth.  The  ex- 
periments of  Rolando  of  Turin,  and  Flourens2  of  Paris,  are  likewise 
confirmatory  of  this  function  of  the  brain  proper.  These  gentlemen 
experimented  upon  different  portions  of  the  encephalon,  with  the  view 
of  detecting  their  functions ; — endeavouring,  as  much  as  possible,  not  to 
implicate  any  part  except  the  one  which  was  the  subject  of  investiga- 
tion ;  and  they  found,  that  if  the  cerebral  hemispheres  were  alone 
removed,  the  animal  was  thrown  into  a  state  of  stupor  or  lethargy; 
was  insensible  to  all  impressions;  to  every  appearance  asleep,  and 
evidently  devoid  'of  all  intellectual  and  affective  faculties.  On  the 
other  hand,  when  other  parts  of  the  encephalon  were  mutilated — the 
cerebellum,  for  example — leaving  the  cerebral  hemispheres  uninjured, 
the  animal  was  deprived  of  certain  other  faculties — that  of  moving,  for 
instance — but  retained  its  consciousness,  and  the  exercise  of  all  its 
senses. 

M.  Desmoulins,3  in  his  observations  on  the  nervous  system  of  verte- 
brated  animals,  is  in  favour  of  a  view,  embraced  by  M.  Magendie,4 
that  the  intellectual  sphere  of  man  and  animals  depends  exclusively 
on  the  cerebral  convolutions ;  and  that  an  examination  of  the  convolu- 
tions will  exhibit  the  intellectual  differences,  not  only  between  different 
species,  but  between  individuals  of  the  same  species.  According  to 
him,  the  cerebral  convolutions  are  numerous  in  animals  in  proportion 
to  their  intelligence;  and,  in  animals  of  similar  habitudes,  have  a 
similar  arrangement.  In  the  same  species,  they  differ  sensibly,  ac- 
cording to  the  degree  in  which  the  individuals  possess  the  qualities  of 
their  nature: — for  example,  they  vary  in  the  fetus  and  adult;  are  mani- 
festly less  numerous  and  smaller  in  the  idiot ;  and  become  effaced  in 
protracted  cases  of  insanity.  He  farther  remarks,  that  the  morbid 
conditions  of  the  encephalon,  which  occasion  mental  aberration,  are 
especially  such  as  act  upon  the  convolutions;  and  that  whilst  apo- 
plectic extravasation  into  the  centre  of  the  organ  induces  paralysis  of 

1  Gall,  Sur  les  Fonctions  du  Cerveau,  ii.  296. 

2  Recherches  Experimentales  sur  le  Systeme  Nerveux,  2de  edit,  Paris,  1842. 

3  Anatomie  des  Systernes  Nerveux  des  Animaux  a  Vertebres,  Paris,  1825. 

4  Precis  Elementaire,  edit,  cit.,  i.  185. 

VOL.  i.— 22 


338  MENTAL  FACULTIES. 

sensation  and  motion,  the  slightest  inflammation  of  the  arachnoid 
membrane  causes  delirium.  Hence,  he  deduces  the  general  principle, 
that  the  number  and  perfection  of  the  intellectual  faculties  are  in  a 
ratio  with  the  extent  of  the  cerebral  surfaces.  It  would  seem,  however, 
from  some  experiments  by  M.  Baillarger,1  that  the  amount  of  intel- 
lectual developement  in  man,  and  in  the  various  classes  of  animals,  is 
far  from  being  proportionate  to  the  extent  of  surface  presented  by  the 
brain  of  each.  That  of  man,  for  instance,  has,  in  proportion  to  its 
volume,  a  much  less  extent  of  surface  than  the  brains  of  the  lower 
mammalia;  and  the  brain  of  the  rabbit  has,  in  proportion  to  its  volume, 
an  extent  of  surface  two  and  a  half  times  greater  than  that  presented 
by  the  brain  of  man. 

The  view  of  M.  Desmoulins,  so  far  as  regards  the  sea.t  of  the  intel- 
lectual and  moral  faculties,  accords  with  one  to  which  attention  must 
now  be  directed ;  and  which  has  given  rise  to  more  philosophical  in- 
quiry, laborious  investigation,  and,  it  must  be  admitted,  to  more  idle 
enthusiasm  and  intolerant  opposition,  than  any  of  the  psychological 
doctrines  advanced  in  modern  times :  we  allude  to  the  views  of  M. 
Gall.2  These  are,  1st,  That  the  intellectual  and  moral  faculties  are 
innate.  2dly,  That  their  exercise  or  manifestation  is  dependent  upon 
organization.  3dly,  That  the  encephalon  is  the  organ  of  all  the  appe- 
tites, feelings,  and  faculties ;  and,  4thly,  That  the  encephalon  is  com- 
posed of  as  many  particular  organs  as  there  are  appetites,  feelings, 
and  faculties,  differing  essentially  from  each  other. 

The  importance  of  Gall's  propositions;  the  strictly  physiological 
direction  they  have  taken — the  only  one,  as  we  have  said,  which  ap- 
pears likely  to  aid  us  in  our  farther  acquaintance  with  the  psychology 
of  man — require  that  the  physiological  student  should  have  them 
placed  before  him  as  they  emanated  from  the  author.  The  work  of 
Gall  on  the  functions  of  the  encephalon  comprises,  however,  six 
octavo  volumes,  not  distinguished  for  unusual  method  or  clearness  of 
exposition.  Fortunately,  the  distinguished  biologist,  M.  Adelon,  to 
whom  we  have  so  frequently  referred,  has  spared  us  the  necessity  of  a 
tedious  and  difficult  analysis,  by  the  excellent  and  impartial  view  he 
has  given  in  the  Dictionnaire  de  Medecine*  which  has  since  been  trans- 
ferred to  his  Physiologic  de  VHomme;  both  being  abridgments  of  the 
Analyse  d'un  Qours  du  Dr.  Gall,  published  by  him  in  1808. 

The  foundation  of  this  doctrine  is,  that  the  encephalon  is  not  a 
single  organ,  but  is  composed  of  as  many  nervous  systems  as  there  are 
primary  and  original  faculties  of  the  mind.  In  the  view  of  Gall,  it  is 
a  group  of  several  organs,  each  of  which  is  concerned  in  the  produc- 
tion of  a  special  moral  act;  and,  according  as  the  encephalon  of  an 
animal  contains  a  greater  or  less  number  of  organs,  and  of  a  greater 
or  less  degree  of  developement,  the  animal  has,  in  its  moral  sphere,  a 
greater  or  less  number  of,  or  more  or  less  active,  faculties.  In  like 

1  Revue  Medicale,  Mai,  1845. 
a  Sur  les  Fonctions  du  Cerveau,  Paris,  1825. 

3  Art.  Encephale  (Physiologie),  Paris,  1823,  and  art.  Facultes  de  1'Esprit  et  de  1'Ame, 
&c.,  in  Diet,  de  Medecine,  viii.  469,  Paris,  1823. 


VIEWS  OF  PHRENOLOGISTS.  339 

manner,  as  there  are  as  many  sensorial  nervous  systems  and  organs  of 
sense  as  there  are  external  senses,  so  there  are,  it  is  maintained,  as 
many  encephalic  nervous  systems  as  there  are  special  moral  faculties 
or  internal  senses.  Each  moral  faculty  has,  in  the  encephalon,  a 
nervous  part  concerned  in  its  production;  as  each  sense  has  its  special 
nervous  system ;  the  sole  difference  being,  that  the  nervous  systems  of 
the  senses  are  separate  and  distinct,  whilst  those  of  the  encephalon  are 
crowded  together  in  the  small  cavity  of  the  cranium,  and  appear  to 
form  but  one  mass. 

The  proofs,  adduced  by  Gall1  in  favour  of  his  proposition,  are  the 
following : — 1st.  It  has  been  established  as  a  principle,  that  differences 
in  the  psychology  of  man  and  animals  correspond  to  varieties  in  the 
structure  of  the  encephalon,  and  that  the  latter  are  dependent  on  the 
former.  Now,  differences  of  the  encephalon  consist  less  in  changes  of 
the  general  form  of  the  organ,  than  in  parts,  which  are  present  in  some 
and  not  in  others ;  and  if  the  presence  or  absence  of  such  parts  is  the 
cause  why  certain  animals  have  a  greater  or  less  number  of  faculties 
than  others,  they  ought  certainly  to  be  esteemed  special  organs  of  such 
faculties.  2dly.  The  intellectual  and  moral  faculties  are  multiple. 
This  every  one  admits.  Each,  consequently,  ought  to  have  its  special 
organ ;  and  the  admission  of  a  plurality  of  intellectual  moral  faculties 
must  induce  that  of  a  plurality  of  encephalic  organs,  in  the  same  man- 
ner as  each  external  sense  has  its  proper  nervous  system.  3dly.  In 
different  individuals  of  the  same  species, — in  different  men, — much 
psychological  variety  is  observable.  The  cause  of  this  is  doubtless  in 
the  encephalon ;  but  we  can  hardly  ascribe  it  to  a  difference  in  the 
general  shape  of  the  organ,  which  is  sensibly  the  same.  It  is  owing 
rather  to  differences  in  its  separate  parts.  Are  not  such  parts,  there- 
fore, he  asks,  distinct  nervous  systems  ?  4thly.  In  the  same  individual — 
in  the  same  man — the  intellectual  and  affective  faculties  have  never  the 
same  degree  of  activity:  whilst  one  predominates,  another  may  be 
feeble.  Now,  this  fact,  which  is  inexplicable  under  the  hypothesis, 
that  the  encephalon  is  a  single  organ,  is  readily  intelligible  under  the 
theory  of  the  plurality  of  organs.  Whilst  the  encephalic  part,  which 
is  the  agent  of  the  one  faculty,  is  proportionably  more  voluminous  or 
more  active,  that  which  presides  over  the  other  is  less  so.  Why,  he 
asks,  may  not  this  happen  with  the  encephalic  organs,  as  with  the 
other  organs  of  the  body,— the  senses,  for  example  ?  Cannot  one  of 
these  be  feeble,  and  the  other  energetic?  5thly.  In  the  same  indi- 
vidual, all  the  faculties  do  not  appear,  nor  are  they  all  lost  at  the  same 
period.  Each  age  has  its  own  psychology.  How  can  we  explain  these 
intellectual  and  moral  varieties  according  to  age,  under  the  hypothesis 
that  the  encephalon  is  a  single  organ  ?  Under  the  doctrine  of  the 
plurality  of  encephalic  organs,  the  explanation  is  simple.  Each  ence- 
phalic system  has  its  special  period  of  developement  and  decay.  6thly. 
It  is  a  common  observation,  that  when  we  are  fatigued  by  one  kind  of 
mental  occupation,  we  have  recourse  to  another;  yet  it  often  happens, 
that  the  new  labour,  instead  of  adding  to  the  fatigue  experienced  by 

1  Op.  cit.,  ii.  394. 


340  MENTAL  FACULTIES. 

the  former,  is  a  relaxation.  This,  Gall  remarks,  would  not  be  the 
ease  if  the  encephalon  were  a  single  organ,  and  acted  as  such;  but  it 
is  readily  explicable  under  the  doctrine  of  plurality  of  organs.  It  is 
owing  to  a  fresh-  encephalic  organ  having  been  put  in  action.  Tthly. 
Insanity  is  frequently  confined  to  one  single  train  of  ideas,  as  in  the 
variety  called  monomania,  which  is  often  caused  by  the  constancy  and 
tenacity  of  an  original  exclusive  idea.  This  is  frequently  removed  by 
exciting  another  idea  opposed  to  the  first,  which  distracts  attention 
from  it.  Is  it  possible,  Gall  asks,  to  comprehend  these  facts  under  the 
hypothesis  of  unity  of  the  encephalon  ?  Sthly.  Idiocy  and  dementia 
are  often  only  partial,  and  it  is  not  easy  to  conceive,  under  the  idea 
of  the  unity  of  the  encephalon,  how  one  faculty  remains  amidst  the 
abolition  of  all  the  others.  9thly.  A  wound  or  a  physical  injury  of 
the  encephalon  frequently  modifies  but  one  faculty,  paralyzing,  or  aug- 
menting it,  and  leaving  every  other  uninjured.  lOthly,  and  lastly. 
Gall  invokes  the  analogy  of  other  nervous  parts;  and,  as  the  great 
sympathetic,  medulla  oblongata,  and  medulla  spinalis  are — in  his  view 
at  least — groups  of  special  nervous  systems,  it  is  probably,  he  says, 
the  same  with  the  encephalon. 

Such  are  the  main  arguments  employed  by  Gall  for  proving,  that 
the  encephalon  consists  of  a  plurality  of  organs,  each  of  which  is  con- 
cerned in  the  production  of  a  special  intellectual  or  moral  faculty ;  and 
should  they  not  carry  conviction,  it  must  be  admitted  that  many  of 
them  are  ingenious  and  forcible,  and  all  merit  attention. 

It  is  a  prevalent  idea,  that  this  notion  of  a  plurality  of  organs  is  a 
fantasy,  which  originated  with  Gall.  Nothing  is  more  erroneous :  he 
has  adduced  the  opinions  of  numerous  writers  who  preceded  him,  some 
of  whom  have  given  figures  of  the  cranium,  with  the  seats  of  the  dif- 
ferent organs  and  faculties  marked  upon  it.  To  this  list  might  be 
added  numerous  others.  Aristotle,  in  whose  works  are  found  the  germs 
of  many  discoveries  and  speculations,  thought  that  the  first  or  anterior 
ventricle  of  the  brain,  was  the  ventricle  of  common  sense;  because, 
from  it,  according  to  him,  the  nerves  of  the  five  senses  branched  off. 
The  second  ventricle,  connected  by  a  minute  opening  with  the  first, 
he  designated  as  the  seat  of  imagination,  judgment,  and  reflection; 
and  the  third,  as  a  storehouse  into  which  the  conceptions  of  the  mind, 
digested  in  the  second  ventricle,  were  transmitted  for  retention  and 
accumulation:  he  regarded  it  as  the  seat  of  memory.  Bernard  Gor- 
don, in  a  work  written  in  1296,  gives  nearly  the  same  account  of  the 
brain.  It  contains,  he  says,  three  cells  or  ventricles.  In  the  anterior 
part  of  the  first  lies  common  sense;  the  function  of  which  is  to  take 
cognizance  of  the  various  forms  and  images  received  by  the  several 
senses.  In  the  posterior  part  of  the  first  ventricle  he  places  phantasia; 
and  in  the  anterior  part  of  the  second,  imaginativa  ;  in  the  posterior 
part  of  the  middle  lies  estimativa.  It  would  be  a  waste  of  time  and 
space,  to  adduce  the  absurd  notions  entertained  by  Gordon  on  this 
subject.  He  thinks  there  are  three  faculties  or  virtues — imaginatio, 
cogitatio,  and  memoria — each  of  which  has  a  special  organ  engaged  in 
its  production. 


VIEWS  OF  PHRENOLOGISTS. 


341 


Fig.  136. 


For  many  centuries  it  was  believed,  that  the  cerebrum  was  the  organ 
of  perception,  and  the  cerebellum  that 
of  memory.  Albert  the  Great,  in  the 
thirteenth  century,  sketched  a  head  on 
which  he  represented  the  seat  of  the 
different  intellectual  faculties.  In  the 
forehead  and  first  ventricle  he  placed 
common  sense  and  imagination  ;  in  the 
second  intelligence  and  judgment;  and 
in  the  third,  memory  and  the  motive 
force.  The  head  in  the  margin  (Fig. 
136),  is  from  an  old  sketch  contained  in 
the  Book  Rarities  of  the  University  of 
Cambridge.  Servetus  conceived,  that 
the  two  anterior  cerebral  cavities  are 
for  the  reception  of  the  images  of  ex- 
ternal objects;  the  third  is  the  seat  of 
thought;  the  aqueduct  of  Sylvius, 'the 
seat  of  the  soul ;  and  the  fourth  ventri- 
cle that  of  memory.  .  In  1491,  Peter 
Montagnana  published  an  engraving, 
in  which  were  represented  the  seat  of 
the  sensus  communis,  a  cellula  imagina- 
tiva,  cellula  estimativa  seu  cogitativa,  a 
cellula  memorativa,  and  a  cellula  ra- 
tionalis.  A  head  by  Ludovico  Dolci 
exhibits  a  similar  arrangement.  (Fig. 
137.)' 

The  celebrated  Dr.  Thomas  Willis,  in 
1681,  asserted,  that  the  corpora  striata 
are  the  seat  of  perception;  the  medul- 
lary part  of  the  brain  that  of  memory 
and  imagination;  the  corpus  callosum 
that  of  reflection ;  and  the  cerebellum 
furnished  the  vital  spirits  necessary  for 
the  involuntary  motions.2  It  would  ap- 
pear, too,  that  Swedenborg,  half  a  cen- 
tury before  the  promulgation  of  Gall's 
theory,  maintained  the  doctrine,  that 
every  man  is  born  with  a  disposition  to 
all  sorts  of  evil,  which  must  be  checked 
by  education,  and,  as  far  as  possible,  rooted  out;  and  that  the  degree 
of  success  or  failure  in  this  respect  would  be  indicated  by  the  shape  of 
the  skull.  "The  peculiar  distinctions  of  man,  will  and  the  understand- 
ing," he  argued,  "have  their  seats  in  the  brain,  which  is  excited  by 
the  fleeting  desires  of  the  will,  and  the  ideas  of  the  intellect.  Near 

1  See  Burton's  Anatomy  of  Melancholy,  llth  edit.,  i.  32,  Lond.,  1813;  and  Margarita 
Philosophica,  lib.  ix.  cap.  40,  Basil.,  1508,  cited  by  Dr.  John  Redman  Coxe,  in  Dunglison's 
American  Medical  Intelligencer,  i.  58,  Philad.,  1838. 

8  Gall,  Sur  les  Fonctions  du  Cerveau,  ii.  350,  Paris,  1835. 


Old  Phrenological  Head. 


Fig.  137. 


Olfactus 


Gustus 


Phrenological  Head  by  Dolci,  A.  D.  1562. 


342  MENTAL  FACULTIES. 

the  various  spots  where  these  irritations  produce  their  effects,  this  or 
that  part  of  the  brain  is  called  into  a  greater  or  less  degree  of  activity, 
and  forms  along  with  itself  corresponding  parts  of  the  skull."1  This 
view,  that  exercise  of  the  encephalic  organs  occasions  their  develope- 
ment  in  bulk,  and  want  of  due  exercise  their  decrease,  is  now  main- 
tained by  many  phrenologists;  but  denied  by  others. 

The  above  examples  are  sufficient  to  show,  that  the  attempt  to  assign 
faculties  to  different  parts  of  the  brain;  and,  consequently,  the  belief, 
that  the  brain  consists  of  a  plurality  of  organs,  had  been  long  indulged 
by  anatomists  and  philosophers.  The  views  of  Gall  are  resuscitations 
of  the  old;  but  resembling  them  little  more  than  in  idea.  Those  of 
the  older  philosophers  were  the  merest  fantasies,  unsupported  by  ob- 
servation: the  speculations  of  the  modern  physiologist  have  certainly 
been  the  result  of  long  and  careful  investigation,  and  deep  meditation. 
Whilst,  therefore,  we  may  justly  discard  the  former,  the  latter  are 
worthy  of  careful  and  unprejudiced  examination. 

Admitting,  with  M.  Gall,  the  idea  of  the  plurality  of  organs  in  the 
encephalon,  the  inquiry  would  next  be, — how  many  special  nervous 
systems  are  there  in  that  of  man,  and  what  are  the  primary  intellectual 
and  moral  faculties  over  which  they  preside?  This  Gall  has  attempted. 
To  attain  this  double  object,  he  had  two  courses  to  adopt; — either, 
first  to  indicate  anatomically  the  nervous  systems  that  constitute  the 
encephalon;  and  then  to  trace  the  faculties  of  which  they  are  the 
organs ;  or,  contrariwise,  to  point  out  first  the  primary  faculties,  and 
afterwards  to  assign  to  each  an  organ  or  particular  seat.  The  first 
course  was  impracticable.  The  encephalic  organs  are  not  distinct, 
isolated :  and  if  they  were,  simple  inspection  could  not  indicate  the 
faculty  over  which  they  preside,  any  more  than  the  appearance  of  a 
nerve  of  sense  could  indicate  the  kind  of  sensation  for  which  it  is  des- 
tined. It  was,  only,  therefore,  by  observing  the  faculties,  that  he  could 
arrive  at  a  specification  of  the  primary  encephalic  organs.  But  here, 
again,  a  source  of  difficulty  arose.  How  many  primary  intellectual  and 
moral  faculties  are  there  in  man?  and  what  are  they?  The  classifi- 
cations of  the  mental  philosophers, — differing,  as  we  have  seen  they 
do,  so  intrinsically  and  essentially  from  each  other, — could  lead  him  to 
no  conclusion.  He  first,  however,  followed  the  views  on  which  they 
appeared  to  be  in  accordance;  and  endeavoured  to  find  particular 
organs  for  the  faculties  of  memory,  judgment,  imagination,  &c.  But 
his  researches  in  this  direction  were  fruitless.  He,  therefore,  took  for 
his  guidance  the  common  notions  of  mankind ;  and  having  regard  to 
the  favourite  occupations,  and  different  vocations  of  individuals,  to 
those  marked  dispositions,  which  give  occasion  to  the  idea,  that  a 
man  is  born  a  poet,  musician,  or  mathematician,  he  carefully  examined 
the  heads  of  such  as  presented  these  predominant  qualities,  and  endea- 
voured to  discover  in  them  such  parts  of  the  encephalon  as  were  more 
prominent  than  usual,  and  might  be  considered  as  special  nervous 
systems, — organs  of  those  faculties.  After  multitudinous  empirical 
researches  on  living  individuals,  on  collections  of  crania,  and  casts 

1  Dr.  Sewall,  Examination  of  Phrenology,  2d  edit.,  p.  14,  Boston,  1839. 


VIEWS  OF  PHRENOLOGISTS.  343 

made  for  the  purpose;  attending  particularly  to  the  heads  of  such  as 
had  one  of  their  faculties  predominant,  and  who  were,  as  he  remarks, 
geniuses  on  one  point, — to  the  maniac,  and  the  monomaniac ; — after  a 
sedulous  study,  likewise,  of  the  heads  of  animals,  comparing  especially 
those  that  have  a  particular  faculty  with  such  as  have  it  not,  in  order 
to  see  if  there  did  not  exist  in  the  encephalon  of  the  former  some  part 
which  was  wanting  in  that  of  the  latter ;  hy  this  entirely  experimental 
method,  he  ventured  to  specify,  in  the  encephalon  of  animals  and  man, 
a  certain  number  of  organs ;  and,  in  their  psychology,  as  many  facul- 
ties, truly  primary  in  their  character. 

But,  in  order  that  such  a  mode  of  investigation  be  applicable  it  must 
be  admitted,  1st.  That  one  of  the  elements  of  the  activity  of  a  function 
is  the  developement  of  its  organ.  2dly.  That  the  encephalic  organs 
end,  and  are  distinct,  at  the  surface  of  the  encephalon.  3dly.  That 
the  cranium  is  moulded  to  the  encephalon,  and  is  a  faithful  index  of  its 
shape;  for  it  is,  of  course,  through  the  skull  and  the  integuments 
covering  it,  that  Gall  attempts,  in  the  living  subject,  to  appreciate  the 
state  of  the  encephalon. 

Within  certain  limits,  these  positions  are  true.  In  the  first  place, 
we  judge  of  the  activity  of  a  function,  by  the  size  of  the  organ  that 
executes  it :  the  greater  the  optic  nerve,  the  more  acute  we  expect  to 
find  the  sense  of  sight.  In  the  second  place,  according  to  the  anato- 
mical theory  of  Gall,  the  encephalic  convolutions  are  the  final  expansions 
of  the  encephalon:  if  we  trace  back  the  original  fasciculi,  which,  by 
their  terminations,  form  the  hemispheres  of  the  brain,  they  are  observed 
to  increase  gradually  in  size  in  their  progress  towards  the  circumference 
of  the  organ,  and  to  end  in  the  convolutions.  Lastly,  to  a  certain 
extent  the  cranium  is  moulded  to  the  encephalon;  and  participates  -in 
all  the  changes  which  the  latter  undergoes  at  different  periods  of  life 
and  in  disease.  For  example,  during  the  first  days  after  the  formation 
of  the  encephalon  of  the  foetus,  the  cranium  is  membraneous,  and  has 
exactly  the  shape  of  that  viscus.  On  this  membrane,  ossific  points  are 
deposited,  so  that,  when  the  membrane  has  become  bone,  the  cranium 
has  still  the  shape  'of  the  encephalon.  In  short,  nature  having  made 
the  skull  to  contain  the  encephalon  has  fitted  the  one  to  the  other, 
and  this  so  accurately,  that  its  internal  surface  exhibits  sinuosities 
corresponding  to  the  vessels  that  creep  on  the  surface;  and  digitations 
corresponding  to  the  encephalic  convolutions.  The  encephalon,  in  fact, 
rigidly  regulates  the  ossification  of  the  cranium ;  and  when,  in  the  pro- 
gress of  life,  it  augments,  the  capacity  of  the  cranium  is  augmented 
likewise;  not  by  the  effect  of  mechanical  pressure,  but  owing  to  the  two 
parts  being  catenated  in  their  increase  and  nutrition.  This  remark 
applies  not  only  to  the  skull  and  encephalon,  regarded  as  a  whole, 
but  to  their  separate  parts.  Certain  portions  of  the  encephalon  are  not 
developed  simultaneously  with  the  rest  of  the  organ ;  and  the  same 
thing  happens  to  the  portions  of  the  skull  that  invest  them.  The  fore- 
head, for  example,  begins  to  be  developed  after  the  age  of  four  months; 
but  the  inferior  occipital  fossae  do  not  increase  in  proportion  until  the 
period  of  puberty.  Again;  when  the  encephalon  fades  and  wastes  in 
advanced  life,  the  cavity  of  the  cranium  contracts,  and  its  ossification 


344  MENTAL  FACULTIES. 

takes  place  on  a  less  and  less  outline.  In  advanced  life,  however, 
according  to  Gall,  the  correspondence  between  the  encephalon  and  the 
inner  table  of  the  skull  is  alone  maintained  ;  the  table  appearing  to  be 
a  stranger  to  all  nutritive  movement,  and  preserving  its  dimensions. 
Lastly,  the  cranium  partakes  of  all  the  variations  experienced  by  the 
encephalon  in  disease.  If  the  latter  be  wanting,  as  in  the  acephalous 
monster,  the  cranium  is  wanting  also.  If  a  portion  of  the  encephalon 
exists,  the  corresponding  portion  of  the  cranium  exists.  If  the  ence- 
phalon is  smaller  than  natural,  as  in  the  idiot,  the  cranium  is  also. 
If,  on  the  contrary,  it  is  distended  by  hydrocephalus,  the  cranium  has 
a  considerable  capacity :  and  this,  not  owing  to  a  separation,  at  the 
sutures,  of  the  bones  composing  it,  but  to  ossification  taking  place  on 
a  larger  outline.  If  the  encephalon  be  much  developed  in  any  one 
part,  and  not  in  another,  the  cranium  is  protuberant  in  the  former; 
restricted  in  the  latter ;  and  lastly,  in  cases  of  mania,  the  cranium  is 
often  affected,  being,  for  example,  unusually  thick,  dense,  and  heavy. 

These  reasons,  adduced  by  €rall,  may  justify  the  admission,  that, 
within  certain  limits,  the  skull  is  moulded  to  the  encephalon ;  and,  if 
this  be  conceded,  the  method  followed  by  him  of  specifying  the  organs 
of  the  mental  faculties  may  be  conceived  practicable. 

Such  is  the  basis  of  the  system  of  craniology  proposed  by  Gall.  It 
has  also  been  called  cranology,  org analogy,  phrenology,  and  cranioscopy: 
although,  strictly  speaking,  it  is  by  cranioscopy  that  we  acquire  a  know- 
ledge of  craniology, — the  art  of  prejudging  the  intellectual  and  moral 
aptitudes  of  man  and  animals,  from  an  examination  of  the  cranium.  It 
is,  of  course,  limited  in  its  application.  Gall  admits,  that  it  is  not 
available  in  old  age,  owing  to  the  physiological  fact  before  stated, — 
that  the  external  table  of  the  skull  is  no  longer  modified  by  the  changes, 
that  happen  to  the  encephalon ;  and  he  acknowledges,  that  its  employ- 
ment is  always  difficult,  and  liable  to  errors.  We  cannot,  for  example, 
touch  the  crajiium  directly;  for  it  is  covered  by  hair  and  integument. 
The  skull  is  made  rough,  in  parts,  by  muscular  impressions;  and  these 
roughnesses  must  not  be  confounded  with  what  are  termed  "protu- 
berances"— prominences,  formed  by  a  corresponding  developement  of 
the  encephalon.  In  this  respect,  craniology  presents  more  difficulties 
in  animals,  owing  to  their  heads  being  more  covered  with  muscles,  and 
from  the  inner  table  of  the  skull  being,  alone,  in  contact  with  the 
encephalon  beneath.  Other  errors  may  be  incurred  from  the  frontal 
and  superior  longitudinal  sinuses  ;  and  from  the  possible  separation  of 
the  hemispheres  at  the  median  line.  The  difficulty  is,  of  course, 
extremely  great  in  appreciating  the  parts  of  the  encephalon,  that  are 
situate  behind  the  eyes ;  and  craniology  must  be  entirely  inapplicable 
to  those  encephalic  organs  that  terminate  at  its  base. 

Gall  has  taken  especial  pains  to  remark,  that  by  craniology  we  can 
only  prejudge  the  dispositions  of  men,  not  their  actions;  and  can 
appreciate  but  one  of  the  elements  of  the  activity  of  organs — their 
size? — not  what  belongs  to  their  intrinsic  activity,  and  to  the  impulse  or 
spring  they  may  receive  from  the  temperament  or  general  formation. 
Setting  out,  however,  with  the  principle,  that  the  predominance  of  a 
faculty  is  in  a  great  measure  dependent  on  the  developement  of  the 


VIEWS  OF  PHRENOLOGISTS. 


345 


portion  of  the  encephalon  which  is  its  organ,  he  goes  so  far  as  to  par- 
ticularize, in  this  developement,  what  is  owing  to  the  length  of  the 
encephalic  fibres,  and  what  to  their  breadth;  referring  the  activity  of 


Fig.  138. 


139. 


Fig.  140. 


Phrenological  Organs  according  to  Gall. 

the  faculty  to  the  former,  and  its  intensity  to  the  latter.  In  applying 
cranioscopy  to  animals,  he  observes,  that  the  same  encephalic  organ 
frequently  occupies  parts  of  the  head,  that  seem  to  be  very  different, 
on  account  of  the  difference  between  station  in  animals  and  man,  and 
of  the  greater  or  less  number  of  systems,  that  compose  their  encephalon. 
The  following  are  the  encephalic  organs  enumerated  by  Gall,  with 
the  corresponding  faculties: — the  numbers  corresponding  with  those  of 
the  above  illustrations. 


] .  Instinct  of  generation,  of  reproduction  •  ^ 
amativeness.  Instinct  of  propagation;  I 
venereal  instinct. 

(German.)   Zeugungstrieb, 
.     Fo  r  tp  flan  z  u  n  gs  t  r  i  e  b, 
Geschlechtstrieb. 


Seated  in  the  cerebellum.  It  is  manifested 
at  the  surface  of  the  cranium  by  two  round 
protuberances,  one  on  each  side  of  the  nape 
of  the  neck. 


346 


MENTAL  FACULTIES. 


Indicated   at   the    external   occipital   protube- 


2.  Love  of  progeny  •  phikprogenitiveness. 
(G.)    Jungenliebe,    Kinder 

liebe.  )       rance- 

3.  Attachment,  friendship.  )  About  the  middle  of  the  posterior  margin  of 
(G.)  Freundschaftsinn.                    $       the  parietal  bone ;  anterior  to  the  last. 

4.  Instinct  of  defending  self  and  property  •  ^ 

love  of  strife  and  combat;  combative  ness  ;       Seated  a  little  above  the  ears;   in  front  of  the 
courage.  |»      last,  and  towards  the  mastoid  angle  of  the 

(G.)   Muth,  Raufsinn,  parietal  bone. 

Zanksinn.  J 

f  Greatly  developed  in  all  the  carnivorous  ani- 

5.  Carnivorous  instinct ;  inclination  to  mur-   |        mals  ;  forms  a  prominence  at  the  posterior 
der ;  destructiveness ;  cruelty.  ^        and  superior  part  of  the  squamous  surface 

(G.)  Wurgsinri,  Mordsinn.  of  the   temporal    bone,  above   the   mastoid 

process. 
secretive-  ~\ 

Above  the  meatus   auditorius  externus,  upon 
the  sphenoidal  angle  of  the  parietal  bones. 


6.  Gunning;  finesse;    address, 
ness. 

(G.)List,  Schlauheit,  Klug- 
h  e  i  t . 

7.  Desire  of  property ;  provident   instinct; 
cupidity ;  inclination  to  robbery ;    acqui- 
sitiveness. 

(G.)  Eigenthumssinn,  Hang  zu 
steh  leri,  Einsammlungssinn, 
D  i  e  b  s  i  n  n . 

8.  Pride ;   haughtiness;    love  of  authority  ; 
elevation. 

(G.)  Stolz,  Hochmuth,  Hohen- 
sinn,  Herrschsucht. 

9.  Vanity  ;  ambition ;  love  of  glory. 

(G)  Eitelkeit,  Ruhmsucht, 
E  h  r  g  e  i  t  z . 

10.  Circumspection  ;  foresight. 

(G.)  B  e  h  u  t  sa  m  k  e  it,  Vorsicht, 
Vor  sic  ht  ig  k  e  i  t. 

1 1 .  Memory  of  things  ;    memory  of  facts  ; 
sense   of  things  ;   educabilily ;  perfectibi- 
lity;  docility. 

( G.)  Sachgedachtniss,  E  r  - 
ziehungsfahigkeit,  S  a  c  h  - 
s  i  n  n. 

12.  Sense  of  locality ;  sense  of  the  relation 
of  space ;  memory  of  places. 

(G.)  Ortsinn,  Raumsinn. 

13.  Memory  of  persons  ;  sense  of  persons. 
(G.)   Personensinn. 

14.  Sense  of  words  ;  sense  of  names  ;  verbal 
memory. 

(G.)  Wortg.edachtniss,  Na- 
me n  s  i  n  n  . 

15.  Sense  of  spoken  language  ;  talent  of  phi- 
lology ;  study  of  languages. 

(G.)  IS  p  rachforschungssinn, 
Wortsinn,  Sprachsinn. 

16.  Sense  of  the  relations  of  colour ;  talent 
of  painting. 

(G.)  Farbensinn. 

17.  Sense  of  the  relations  of  tones;  musical 
talent. 

(G.)  Tons  inn. 

18.  Sense  of  the  relations  of  numbers;  ma- 
thematics. 

(G.)  Zah  lensinn. 


Anterior  to  that  of  cunning,  of  which  it  seems 
to  be  a  prolongation,  and  above  that  of  me- 
chanics, with  which  it  contributes  to  widen 
the  cranium,  by  the  projection  which  they 
form  at  the  side  of  the  frontal  bone. 

Behind  the  top  of  the  head,  at  the  extremity 
of  the  sagittal  suture,  and  on  the  parietal 
bones. 

Situate  at  the  side  of  the  last,  neau  the  poste- 
rior internal  angle  of  the  parietal  bones. 

Corresponds  to  the  parietal  protuberances. 


Situate  at  the  root  of  the  nose,  between  the  two 
eyebrows,  and  a  little  above  them. 


Answers  to  the  frontal  sinuses,  and  is  indicated 
externally  by  two  prominences  at  the  inner 
edge  of  the  eyebrows,  near  the  root  of  the 
nose,  and  outside  the  organ  of  memory  of 
things. 

At  the  inner  angle  of  the  orbit. 

Situate  at  the  posterior  part  of  the  base  of  the 
two  anterior  lobes  of  the  brain,  on  the  fron- 
tal part  of  the  bottom  of  the  orbit,  so  as  to 
make  the  eye  prominent. 

Also  at  the  top  of  the  orbit,  between  the  pre- 
ceding and  that  of  the  knowledge  of  colour. 

The  middle  part  of  the  eyebrows ;  encroach- 
ing a  little  on  the  forehead. 

A  little  above  and  to  one  side  of  the  last; 
above  the  outer  third  of  the  orbitar  arch. 

On  the  outside  of  the  organ  of  the  sense  of 
the  relations  of  colour,  and  below  the  last. 


VIEWS  OF  PHKENOLOGISTS.  347 

19.  Sense  of  mechanics  •  sense  of  construe-  }  A  round  protuberance  at  the  lateral  base  of  the 

tion ;  talent  of  architecture  ;  industry.        >  frontal  bone,  towards  the    temple,  and  be- 

(G.)  Kunstsinn,Bausinn.               )  hind  the  organs  of  music  and  numbers. 

2a  Comparative  sagacity                                 )  At  |he  midd]e  and  anterior           of  the  frontal 

(G.)     Vergleichender     Scharf-  V  bone  above  that  of  the  memory  of  things. 

sinn.  ) 

21.     Metaphysical  penetration ;     depth    of  "]  In  part,  confounded  with  the  preceding.     Indi- 

mind.                                                               I  cated,  at  the  outer  side  of  this  last,  by  two 

(G.)    Metaphysischer     Tief-   [  protuberances,  which  give  to  the  forehead  a 

s  i  ri  n .  peculiar  hemispherical  shape. 

^  At  the  lateral  and  outer  part  of  the  last;   and 

(  giving  greater   width  to  the  frontal  promi- 

$  nences. 

23.  Poetical  talent.                                            >  On  tne  outer  si(^e  OI"  tne  lastl  divided  into  two 
(G.)  Dichtergeist.                                  >  halves  by  the  coronal  suture. 

24.  Goodness  ;  benevolence ;  mildness  ;  com-  ^ 

passion;    sensibility;   moral   sense;    con-   \  Indicated  by  an  oblong  prominence  above  the 

science;  bonhommie.                                       [  organ  of  comparative  sagacity ;  almost  at  the 

(  G.)     G  u  t  m  u  t  h  i  g  k  e  i  t ,    M  i  1 1  e  i  -  f  frontal  suture, 
den,     moralischer      Sinn,   j 
Gewissen.                                           J 

25.  Irritation ;  mimicry.                                    >  id      f  ^    } 
(G.)  Nachahmungssinn.                   > 

26.  God  and  religion  ;  theosophy.                     )  At  the^top  of  the  frontal  bone  and  at  the  supe- 
( G.)  Theosophisches    Sinn.           5  rior  angles  of  the  parietal  bones. 

constancy;    perseverance;  )  The  top  Qf  tfae  he&d  .  at  the  anterior  and  most 

festerSinn           S  elevated  part  of  the  parietal  bones. 


The  first  nineteen  of  those,  according  to  Gall,  are  common  to  man 
and  animals:  the  remaining  eight,  man  possesses  exclusively.  They 
are,  consequently,  the  attributes  of  humanity. 

Dr.  Spurzheim,1  a  fellow-labourer  with  Gall,  who  accompanied  him 
in  his  travels,  and  was  associated  with  him  in  many  of  his  publications, 
added  other  faculties,  so  as  to  make  the  whole  number  thirty-five;  but 
they  were  not  embraced  by  Gall;  indeed,  several  of  the  positions  of 
Spurzheim  are  repudiated  by  Gall's  followers.2  The  organs  admitted 
by  Spurzheim  are  given  on  the  next  page:  the  numbers  correspond 
with  those  of  the  illustrations. 

On  the  situation  of  the  different  encephalic  organs,  Gall  remarks, — 
1st.  That  thos.e  which  are  common  to  man  and  animals  are  seated  in 
parts  of  the  encephalon  common  to  both : — at  the  posterior,  inferior, 
and  anterior  inferior,  portions.  On  the  contrary,  those,  that  are  exclu- 
sive to  man,  are  situate  in  parts  of  the  encephalon  that  exist  only  in  him; 
— in  the  anterior  superior  parts,  which  form  the  forehead.  2dly.  The 
more  indispensable  a  faculty,  and  the  more  important  to  the  animal 
economy,  the  nearer  is  its  organ  to  the  median  line,  and  to  the  base  of 
the  encephalon.  3dly,  and  lastly.  The  organs  of  the  faculties,  that  aid, 
or  are  similar  to  each  other,  are  generally  situate  in  proximity. 

In  his  exposition  of  each  of  these  organs,  and  of  the  reasons  that 
induce  him  to  assign  it  as  the  seat  of  a  special  faculty,  he  sets  out  by 
demonstrating  the  necessity  of  the  faculty,  which  he  regards  as  funda- 
mental and  primary,  and  to  which  he  assigns  a  special  nervous  system 
or  organ  in  the  encephalon.  2dly.  He  endeavours  to  show,  that  this 

1  Phrenology,  Amer.  edit.,  Boston,  1833. 

3  Elliotson,  Human  Physiology,  p.  384,  and  1147,  London,  1840. 


348 


MENTAL  FACULTIES. 


faculty  is  really  primary.     He  considers  it  to  be  such,  whenever  psychi- 
cal facts  show,  that  it  has  its  exclusive  source  in  organization;  for 


Fig.  141. 


Fig.  14-2. 


Fig.  143. 


Phrenological  Organs  according  to  Spurzheim. 

1.  Amativeness.  2.  Philoprogenitiveness.  3.  Inhabitiveness.  4.  Adhesiveness  or  Attachment. 
5.  Combativeness.  6.  Destructiveness.  7.  Construetiveness.  8.  Acquisitiveness.  9.  Secretiveness. 
10.  Self-esteem.  11.  Love  of  Approbation.  12.  Cautiousness.  13.  Benevolence.  14.  Veneration. 
15.  Firmness.  16.  Conscientiousness  or  Justice.  17.  Hope.  18.  Marvellousness.  19.  Wit.  20.  Ide- 
ality. 21.  Imitation.  '2-2.  Individuality.  23.  Form.  24.  Size.  25.  Weight  and  Resistance.  2t».  Co- 
lour. 27.  Locality.  28.  Numeration.  '29.  Order.  30.  Eventuality.  31.  Time.  32.  Melody  or  Tune. 
33.  Language.  34.  Comparison.  35.  Causality. 

example,  when  it  is  not  common  to  all  animals  and  sexes;  when,  in  the 
one  possessing  it,  it  does  not  exhibit  itself  in  a  ratio  with  the  other 
faculties ;  has  its  distinct  periods  of  developement  and  decrease ;  and 
does  not,  in  this  respect,  coincide  with  the  other  faculties ;  when  it  can 


VIEWS  OF  PHRENOLOGISTS.  349 

be  exerted,  be  diseased,  and  continue  sound  alone,  or  be  transmitted 
alone  from  parent  to  child,  &c.  Lastly,  he  points  out  the  part  of  the 
encephalon,  which  he  considers  to  be  its  organ,  founding  his  decision 
on  numerous  empirical  observations  of  the  encephalon  of  men  and  ani- 
mals, that  have  possessed,  or  been  devoid  of,  the  faculty  and  organ  in 
question  ;  or  have  had  them  in  unequal  degrees  of  developement. 

It  is  impossible,  in  a  work  of  this  kind,  to  exhibit  all  the  views  of 
Gall,  and  the  arguments  he  has  adduced  in  favour  of  the  existence  of 
his  twenty-seven  faculties.  The  selection  of  one — the  instinct  of  gene- 
ration— will  be  sufficient  to  show  how  he  treats  of  the  whole.  Gall's 
instinct  of  generation  is  that,  which,  in  each  animal  species,  attracts  the 
individuals  of  different  sexes  towards  each  other  for  the  purpose  of  effect- 
ing the  work  of  reproduction.  The  necessity  for  such  an  impulse  for  the 
general  preservation  of  animals  is  manifest.  It  is  to  the  continuance 
of  the  species  what  the  sensation  of  hunger  is  to  that  of  the  individual. 
Again:  it  is  certainly  primary  and  fundamental,  for  it  is  independent 
of  all  external  influence.  It  does  not  make  its  appearance  until  puberty, 
and  disappears  long  before  other  faculties.  In  many  animals  it  returns 
periodically.  In  each  animal  species,  and  in  each  individual,  it  has  a 
special  and  different  degree  of  energy  ;  although  external  circumstances 
may  be  much  the  same  in  all,  or  at  least  may  not  present  differences 
in  any  manner  proportionate  to  those  of  the  instinct.  It  may  be  either 
alone  active,  amidst  the  languor  of  other  faculties ;  or  may  be  alone 
languishing.  Lastly,  it  cannot  be  referred  to  the  genital  organs,  for  it 
has  been  observed  in  children,  whose  organs  have  not  been  developed : 
it  has  frequently  continued  to  be  felt  in  eunuchs ;  and  has  been  expe- 
rienced by  females  who,  owing  to  original  monstrosity,  have  had  neither 
ovary  [?]  nor  uterus.  The  part  of  the  encephalon  which  is  the  organ 
of  the  instinct,  is,  according  to  Gall,  the  cerebellum.  His  reasons  for 
this  belief  are  the  following.  1st.  In  the  series  of  animals,  a  cerebel- 
lum exists  only  in  those  which  are  reproduced  by  copulation,  and  which, 
consequently,  must  have  the  instinct  in  question.  2dly.  There  is  a  per- 
fect coincidence  between  the  periods  at  which  the  cerebellum  becomes 
developed,  and  the  appetite  appears.  In  infancy,  it  does  not  exist ; 
and  the  organ  is  therefore  small.  3dly.  In  every  species  of  animal 
and  in  every  individual,  there  is  a  ratio  between  the  size  of  the  cere- 
bellum and  the  energy  of  the  inclination.  In  males,  in  whom  it  is 
generally  more  imperious,  the  cerebellum  is  larger.  4thly.  A  ratio 
exists  between  the  structure  of  the  cerebellum  and  the  kind  of  genera- 
tion. In  oviparous  animals,  for  instance,  the  cerebellum  is  smaller  at 
its  median  part ;  and  it  is  only  in  the "  viviparous,  that  hemispheres 
exist.  5thly.  A  similar  ratio  obtains  between  the  cerebellum  and  exter- 
nal genital  organs.  If  the  latter  are  extirpated  at  an  early  age,  the  de- 
velopement of  the  cerebellum  is  arrested,  and  it  continues  small  for  the 
remainder  of  life.  Neighbouring  parts,  which  are  attributes  of  the 
male  sex,  as  the  horns  of  the  stag,  and  the  crest  of  the  cock,  are  often 
similarly  stunted.  On  the  other  hand,  the  cerebellum,  in  its  turn, 
exerts  an  intimate  influence  on  the  venereal  appetite  ;  and  modifies  the 
external  genital  organs.  Injuries  of  the  cerebellum  either  render  the  per- 
son impotent,  or  excite  erotic  mania.  In  nymphomania,  the  patient  often 


350  MENTAL  FACULTIES. 

complains  of  acute  pain  in  the  nape  of  the  neck ;  and  this  part  is  more 
tumid  and  hot  in  animals  at  the  rutting  season.  Gall  asserts,  that  he 
had  noticed  in  birds,  that  the  cerebellum  is  not  the  same  in  size  and  ex- 
citement during  the  season  of  love  as  at  other  times  ;  and  he  affirms, 
that  if  erection  be  observed  in  those  who  are  hanged,  or  in  consequence 
of  the  application  of  a  blister  or  a  seton  to  the  nape  of  the  neck,  or  of 
the  use  of  opium,  or  in  such  as  are  threatened  with  apoplexy,  especially 
when  the  apoplexy  is  cerebellous,1  or  during  sleep,  the  effect  is,  in  all 
these  cases,  owing  to  congestion  of  blood  in  the  brain  in  general,  and  in 
the  cerebellum  in  particular.  From  these  data,  Gall  concludes,  that  the 
cerebellum  is  the  organ  of  the  instinct  of  reproduction  ;  and  he  remarks, 
that  as  this  organ  presides  over  one  of  the  most  important  faculties,  it 
is  situate  on  the  median  line ;  and  at  the  base  of  the  skull.  In  this 
manner,  he  proceeds,  with  more  or  less  success,  in  his  investigation  of 
the  other  cerebral  organs  and  faculties. 

But  Gall  does  not  restrict  himself  to  the  physiological  applications 
of  his  system.  He  endeavours  to  explain  the  differences  that  exist 
between  him  and  other  philosophers.  He  rejects  the  primary  faculties 
of  instinct,  intelligence,  will,  liberty,  reason,  perception,  memory,  judg- 
ment, &c.,  of  the  metaphysician,  as  mere  generalizations  of  the  mind, 
or  common  attributes  of  the  true  primary  faculties.  Whilst,  in  the 
study  of  physics,  the  general  and  special  qualities  of  matter  have  been 
carefully  distinguished,  and  the  latter  have  been  regarded  as  alone 
deciding  the  particular  nature  of  bodies,  the  metaphysician,  says  Gall, 
has  restricted  himself  to  general  qualities.  For  example,  it  is  asserted, 
that  "to  think  is  to  feel."  Thought  is,  doubtless,  a  phenomenon  of 
sensibility;  but  it  is  a  sensitive  act  of  a  certain  kind.  To  adhere 
rigidly  to  this  expression,  says  Gall,  is  but  to  express  a  generality, 
which  leaves  us  in  as  much  ignorance  as  to  what  thought  is,  as  we 
should  be  of  a  quadruped  or  bird,  by  saying  that  it  is  an  animal ;  and 
as,  to  become  acquainted  with  such  animals,  their  qualities  must  be 
specified,  so  to  understand  thought,  the  kind  of  sensation  that  consti- 
tutes it  must  be  specified.  Instinct,  according  to  him,  is  a  general 
expression,  denoting  every  kind  of  internal  impulse ;  and,  consequently, 
there  must  be  as  many  instincts  as  there  are  fundamental  faculties. 
Intelligence  is  likewise  a  general  expression,  designating  the  faculty  of 
knowledge ;  and  as  there  are  many  instincts,  so  there  are  many  kinds 
of  intelligence.  Philosophers,  he  thinks,  have  erroneously  ascribed 
instinct  to  animals,  and  intelligence  to  man.  All  animals  have,  to  a 
certain  extent,  intelligence ;  and  in  man  many  faculties  are  instincts. 
Neither  is  the  will  a  fundamental  faculty.  It  is  only  a  judgment 
formed  amongst  several  motives,  and  the  result  of  the  concourse  of 
actions  of  several  faculties.  There  are  as  many  desires  as  faculties ; 
but  there  is  only  one  will,  which  is  the  product  of  the  simultaneous 
action  of  the  intellectual  forces.  So  that  the  will  is  frequently  in  op- 

1  A  case  of  Arachnitis  Cerebelli — in  which  there  was  genital  excitement — is  reported  by 
the  author,  in  Lond.  Med.  Rep.  for  Oct.,  1822.  For  cases  of  cerebellous  disease,  without 
genital  excitement,  see  Duplay,  in  Archives  Generales  de  Medecine,  Nov.,  1836;  Miiller's 
Elements  of  Physiology,  by  Baly,  1st  edit.  p.  833,  Lond.,  1838  ;  and  Longet,  Anat.  et  Physiol. 
du  Systeme  Nerveux,  torn.  i.  Paris,  1842;  and  Traite  de  Physiologic,  ii.  267,  Paris,  1850. 


VIEWS  OF  PHRENOLOGISTS.  351 

position  to  the  desires.  The  same  may  be  said  of  liberty  and  reason  ; 
to  the  former  applies  what  has  been  remarked  of  the  will,  and  the  latter 
is  only  the  judgment  formed  by  the  superior  intellectual  faculties.  In 
this  respect,  however,  he  remarks,  it  must  not  be  confounded  with  in- 
telligence :  many  animals  are  intelligent,  but  man  alone  is  rational. 

On  the  other  hand,  what  are  termed,  in  the  intellect,  perception, 
memory,  judgment,  imagination,  &c.,  are  attributes  common  to  all  the 
intellectual  faculties ;  and  cannot,  consequently,  be  considered  primary 
faculties.  Each  faculty  has  its  perception,  memory,  judgment,  and 
imagination;  and,  therefore,  there  are  as  many  kinds  of  perception, 
memory,  judgment,  and  imagination,  as  there  are  primary  intellectual 
faculties.  This  is  so  true,  says  Gall,  that  we  may  have  the  memory 
and  the  judgment  perfect  upon  one  point,  and  totally  defective  upon 
another.  The  memory  of  musical  tones,  for  instance,  is  not  the  same 
as  that  of  language ;  and  he  who  possesses  the  one  may  not  have  the 
other.  The  imaginations,  again,  of  the  poet,  musician,  and  philoso- 
pher, differ  essentially  from  each  other.  These  faculties  are,  therefore, 
according  to  him,  nothing  more  than  different  modes  of  the  activity  of 
all  the  faculties.  Each  faculty  perceives  the  notion  to  which  it  has 
been  attracted,  or  has  perception ;  each  preserves  and  renews  the  re- 
collection of  this  notion,  or  has  memory.  All  are  disposed  to  act 
without  being  excited  to  action  from  without,  when  the  organs  are 
largely  developed,  or  have  considerable  intrinsic  activity:  this  gives 
rise  to  imagination;  and,  lastly,  every  faculty  exerts  its  function  with 
more  or  less  perfection,  whence  results  judgment.  Attention,  in  his 
view,  is  only  the  active  mode  of  exercise  of  the  fundamental  faculties 
of  the  intellect;  and  being  an  attribute  of  all,  it  cannot  be  called  a 
primary  faculty. 

As  regards  the  affective  faculties,  or  wrhat  have  been  called  the 
passions  and  affections.  Gall,  in  the  first  place,  asserts,  that  the  term 
passion  is  faulty  when  used  to  indicate  a  primary  faculty.  It  ought 
only  to  designate  the  highest  degree  of  activity  of  any  faculty.  Every 
faculty  requires  to  be  put  into  action,  and  according  to  the  degree  of 
activity  which  it  possesses,  it  is  a  desire,  a  taste,  an  inclination,  a  want, 
or  a  passion.  If  it  be  only  of  the  medium  energy,  it  is  a  taste  :  if  ex- 
tremely active,  a  passion.  There  may,  consequently,  be  as  many 
passions  as  there  are  faculties.  We  speak  of  a  passion  for  study,  or 
a  passion  for  music,  as  we  do  of  the  passion  of  love,  or  of  ambition. 
Gall  objects,  also,  to  the  word  affection,  which,  according  to  him, 
expresses  only  the  modifications  presented  by  the  primary  faculties, 
according  to  the  mode  in  which  external  and  internal  influences  affect 
them.  Some  of  these  are  common  to  all  the  faculties,  as  those  of 
pleasure  and  pain.  Every  faculty  may  be  the  occasion  of  one  or  the 
other.  Other  affections  are  special  to  certain  faculties;  as  pretension, 
which,  he  says,  is  an  affection  of  pride,  and  repentance  an  affection  of 
the  moral  sense.  Finally,  affections  are  simple  or  compound:  simple 
when  they  only  bear  upon  one  faculty,  as  anger,  which  is  a  simple 
affection  of  the  faculty  of  self-defence; — compound,  when  several 
faculties  are  concerned  at  the  same  time,  as  shame,  which  ^is  an  affec- 
tion of  the  primary  faculties  of  the  moral  sense  and  vanity'. 


852  MENTAL  FACULTIES. 

Gall  reproaches  the  moralists  with  having  multiplied  too  much  the 
number  of  primary  affective  faculties: — in  his  view,  the  modifications  of 
a  single  faculty,  and  the  combination  of  several,  give  rise  to  many 
sentiments,  that  are  apparently  different.  For  instance,  the  primary 
faculty  of  vanity  begets  coquetry,  emulation,  and  love  of  glory.  That 
of  self-defence  gives  rise  to  temerity,  courage,  a  quarreling  spirit,  and 
fear.  Contempt  is  the  product  of  a  combination  of  the  faculties  of 
pride  and  the  moral  sense,  &c. 

Lastly ;  as  regards  their  psychical  differences,  Gall  divides  all 
men  into  five  classes.  First.  Those  in  whom  all  the  faculties  of 
humanity  predominate;  and  in  whom,  consequently,  organization  ren- 
ders the  developement  of  the  mind  and  the  practice  of  virtue  easy. 
Secondly.  Those  in  whom  the  organs  of  the  animal  faculties  predomi- 
nate; and  who,  being  less  disposed  to  goodness,  need  the  aid  of  educa- 
tion and  legislation.  Thirdly.  Those  in  whom  all  the  faculties  are 
equally  energetic,  and  who  may  be  either  worthy,  or  great  criminals, 
according  to  the  direction  they  take.  Fourthly.  Those  who,  with  the 
rest  of  the  faculties  nearly  equal,  and  mediocre,  may  have  one  pre- 
dominant. Fifthly,  and  lastly.  Those  who  have  the  faculties  alike 
mediocre: — which  is  the  most  numerous  class.  It  is  rare,  however,  he 
remarks,  that  the  characters  and  actions  of  men  proceed  from  a  single 
faculty.  Most  commonly,  they  are  dependent  upon  the  combination  of 
several;  and,  as  the  possible  combinations  of  so  many  faculties  are 
almost  innumerable,  the  psychical  varieties  of  mankind  must  be  ex- 
tremely various.  Again,  as  each  of  the  many  organs  of  the  brain  may 
have,  in  different  men,  a  particular  degree  of  developement  and  activity, 
seeing  that  each  of  the  faculties,  which  are  their  products,  has  most 
commonly  a  particular  shade  in  every  individual;  as  these  organs  can 
establish  between  each  other  a  great  number  of  combinations;  and  as 
men,  independently  of  the  differences  in  their  cerebral  organization, 
which  give  rise  to  their  dispositions,  never  cultivate  and  exert  their 
faculties  in  an  equal  and  similar  manner,  it  may  be  conceived,  that 
nothing  ought  to  be  more  variable  than  the  intellectual  and  moral  cha- 
racters of  men;  and  we  may  thus  explain,  why  there  are  no  two  men 
alike  in  this  respect. 

Such  is  a  general  sketch  of  the  physiological  doctrine  of  Gall, 
which  we  may  sum  up  in  the  language  of  the  author,  in  his  Revue 
Sommaire,  appended  to  his  great  work.  "I  have  established,  by  a 
considerable  number  of  proofs,  as  well  negative  as  positive,  and  by  the 
refutation  of  the  most  important  objections,  that  the  encephalon  alone 
has  the  immense  advantages  of  being  the  organ  of  the  mind.  Farther 
researches  on  the  measure  of  the  degree  of  intelligence  of  man  and 
animals  have  shown,  that  the  encephala  are  more  simple  or  more 
complex,  as  their  instincts,  desires,  and  faculties  are  more  simple  or 
more  compound;  that  the  different  regions  of  the  encephalon  are  con- 
cerned in  different  categories  of  function;  and,  finally,  that  the  ence- 
phalon of  every  species  of  animal,  and,  consequently,  that  of  man, 
constitutes  an  aggregation  of  as  many  special  organs,  as  there  are  essen- 
tially different  moral  qualities  and  intellectual  faculties  in  the  man  or 


VIEWS  OF  PHRENOLOGISTS.  353 

animal.  The  moral  and  intellectual  dispositions  are  innate.  Their 
manifestation  is  dependent  upon  organization.  The  encephalon  is  the 
exclusive  organ  of  the  mind.  Such  are  four  incontestable  principles, 
forming  the  whole  physiology  of  the  encephalon;" — and  he  adds; — 
"  the  detailed  developement  of  the  physiology  of  the  encephalon  has 
unveiled  the  deficiencies  of  the  hypotheses  of  philosophers  regarding 
the  moral  and  intellectual  powers  of  man ;  and  has  been  the  means  of 
bringing  to  light  a  philosophy  of  man,  founded  on  his  organization,  and, 
consequently,  the  only  one  in  harmony  with  nature.''1 

It  is  impossible  to  enter,  at  length,  into  the  various  facts  and  hypo- 
theses developed  in  the  preceding  exposition.  The  great  points  of 
doctrine  in  the  system  of  Gall,  are  : — First.  That  the  encephalon 
consists  of  a  plurality  of  organs,  each  engaged  in  a  separate,  distinct 
office, — the  production  of  a  special  intellectual  or  moral  faculty. 
Secondly.  That  each  of  these  organs  ends  at  the  periphery  of  the  ence- 
phalon; and  is  indicated  by  more  or  less  developement  of  the  part;  and 
Thirdly.  That,  by  observation  of  the  skull,  we  may  be  enabled  to  de- 
tect the  protuberance,  produced  by  such  encephalic  developement;  and 
thus  indicate  the  seat  of  the  encephalic  organs  of  the  different  faculties. 
It  has  been  shown,  in  the  preceding  history,  that  the  notion  of  the 
plurality  of  organs  has  prevailed  extensively  in  all  ages ;  and  what- 
ever may  be  the  merit  of  the  arguments  adduced  by  Gall  on  this  sub- 
ject, it  is  difficult  not  to  conceive,  that  different  primary  faculties  may 
have  their  corresponding  organs.  Simple  inspection  of  the  encepha- 
lon indicates  that  it  consists  of  numerous  parts,  differing  essentially  in 
structure  and  appearance  from  each  other ;  and  it  is  but  philosophical  to 
presume,  that  these  are  adapted  to  equally  different  functions,  although 
our  acquaintance  with  the  physiology  of  the  organs  may  not  be  suffi- 
ciently extensive  to  enable  us  to  designate  them.  Of  the  innate  cha- 
racter of  several  of  the  faculties  described  by  Gall,  it  is  scarcely  possible 
for  us  to  admit  a  doubt.  Take,  for  instance,  the  instincts  of  generation 
and  of  love  of  progeny.  Without  the  existence  of  these,  every  animal 
species  would  soon  be  extinct.  It  seems  fair,  then,  to  presume,  that 
these  instincts  or  innate  faculties  may  have  encephalic  organs  specially 
concerned  in  their  manifestation.  Gall  places  them  in  the  posterior 
part  of  the  head, — the  instinct  of  generation  in  the  cerebellum;  and 
his  causes  for  so  doing  have  been  cited;  yet,  striking  as  his  statement 
in  regard  to  the  encephalic  seat  of  the  instinct  of  generation  seems  to 
be,  it  has  been  contested  by  many  physiologists, — by  MM.  Broussais, 
Foville,  and  Pinel-Grandchamp,  Rolando,  Flourens,  Desmoulins,  Cal- 
meil,  and  others;  and,  not  only  by  argument,  but  by  that  which  must 
be  the  test  of  the  validity  of  the  doctrines  of  the  phrenologists — direct 
experiment.  It  has  been  shown,  indeed,  that  the  genital  excitement 
which  is  supposed  by  the  followers  of  Gall  to  be  seated  in  the  cerebellum, 
can  be  equally  produced  by  irritating  the  posterior  column  of  the  spinal 
marrow;  and  it  would  seem,  that  coincidence  of  disease  of  the  spinal 
cord  with  affection  of  the  genital  organs  is  much  more  frequent.2  Ac- 

1  Sur  les  Fonctions  du  Cerveau,  vi.  500,  Paris,  1825. 

3  Muller's  Elements  of  Physiology,  by  Baly,  p.  833,  Lond.,  1838. 

VOL.  i.— 23 


354  MENTAL  FACULTIES. 

cording  to  Burdach,  the  proportion  of  cases  of  disease  of  the  cerebellum, 
in  which  there  is  any  manifest  affection  of  the  sexual  organs,  is  really 
very  small, — not  above  one  in  seventeen.  The  results,  too,  of  unpre- 
judiced observation,  as  to  the  comparative  size  of  the  cerebellum  in 
different  animals,  are  by  no  means  favourable  to  the  phrenological  doc- 
trine. There  are  many  highly  salacious  animals — as  the  kangaroo,  and 
the  monkey — which  are  not  distinguished  for  unusual  size  of  cerebellum. 
A  strong  argument,  as  before  observed,  in  favour  of  this  function  of 
the  cerebellum,  is  founded  on  the  assertion,  over  and  over  again  re- 
peated, that  in  animals  that  have  been  castrated  young,  it  is  much 
smaller  than  in  the  entire  male ;  but  the  results  of  the  experiments  of 
M.  Lassaigne,  suggested  by  M.  Leuret,1  are  directly  opposed  to  this. 
These  were  made  on  ten  stallions,  of  the  ages  of  from  nine  to  seventeen 
years;  on  twelve  mares,  aged  from  seven  to  sixteen  years;  and  on 
twenty-one  geldings,  aged  from  seven  to  seventeen  years.  The  weight 
of  the  cerebrum,  estimating  the  cerebellum  as  1,  was  thus  expressed. 

Average.  Highest.  Lowest. 

Stallions 7-07  7-46             6-25 

Mares             6-59  7-00             5'09 

Geldings         .         .         .         .         .         .         .         5-97  7-44             5-16 

The  average  proportional  size  of  the  cerebellum  in  geldings  was  there- 
fore positively  greater  than  in  entire  horses  and  mares.  It  was  also 
found  to  be  absolutely  heavier  in  the  following  proportions. 

Average.  Highest.  Lowest. 

Stallions          ..!....           61  65 .               56 

Mares             61  66                 58 

Geldings 70  76                64 

It  would  seem,  that  the  dimensions  of  the  cerebrum  are  usually  re- 
duced by  castration ;  as  in  the  following  table. 

Average.  Greatest.  Least. 

Stallions 433  485  350 

Mares             402  432  336 

Geldings 419  566  346 

These  observations  are  certainly  entirely  opposed  to  the  statements 
of  the  phrenologists ;  and  are  more  favourable  to  the  idea  of  the  cere- 
bellum being  connected  with  muscular  power.  Geldings,  as  is  well 
known,  are  employed  in  active  labour;  whilst  stallions  are  rarely  called 
upon  to  exert  much  effort,  being  kept  especially  to  propagate  their  kind. 
The  views,  however,  regarding  the  influence  of  the  cerebellum,  some 
of  which  have  an  essential  bearing  on  this  question,  will  be  given  under 
the  head  of  MUSCULAR  MOTION.  It  will  be  obvious,  moreover,  that  if 
a  single  case  of  absence  of  the  cerebellum  should  be  observed  in  which 
erotic  desires  exist;  it  would  be  fatal  to  the  views  of  the  phrenologist. 
Such  cases  are  rare,  but  one  has  been  witnessed  and  recorded  by  M. 
Combette,2  and  no  doubt  can  exist  as  to  its  authenticity.  On  examin- 
ing the  encephalon  of  a  young  girl,  who  had  been  addicted  to  mastur- 
bation, a  gelatiniform  membrane  of  a  semicircular  shape,  united  to  the 

*  Anat.  Com  par.  du  Systeme  Nerveux,  torn.  i.  p.  427. 

2  Revue  Medicale,  ii.  57,  Paris,  1831 ;  Cruveilhier,  Anat.  Pathol,  livr.  xv.  pi.  v. ;  and  Longet 
Anat.  et  Physiol.  du  Systeme  Nerveux,i.  755,  Paris,  1842 ;  and  Traite  de  Physiologic,  ii.  270, 
Paris,  1850. 


VIEWS  OF  PHRENOLOGISTS.  355 

medulla  oblongata  by  two  membranous  and  gelatinous  peduncles,  was 
observed  in  place  of  the  cerebellum.  The  one  on  the  right  side  had 
been  torn.  Near  these  peduncles,  M.  Combette  found  two  small  masses 
of  white  substance,  isolated  and  detached,  as  it  were,  of  the  size  of  a  pea. 
It  is  not,  therefore,  a  matter  of  astonishment,  that  from  an  examina- 
tion of  all  the  evidence  adduced  on  this  matter,  M.  Longet1  should  have 
concluded,  that  neither  pathology,  morbid  anatomy,  comparative  ana- 
tomy nor  experimental  physiology  leads  to  the  admission  of  the  views 
of  the  phrenologist  in  regard  to  the  functions  of  the  cerebellum. 

In  regard,  too,  to  the  cerebral  seat  of  the  love  of  progeny — philo- 
progenitiveness,  as  it  is  termed — it  is  a  fatal  objection,  that,  although 
the  instinct  is  strongly  developed  in  the  lower  animals,  the  posterior 
lobes  recede  as  we  descend  in  the  scale  from  man,  and  ultimately  leave 
the  cerebellum  uncovered. 

One  of  the  greatest  objections  brought  against  the  system  of  Gall  is 
the  independence  of  the  different  faculties  of  each  other.  Each  is  made 
to  form  a  separate  and  independent  state,  with  no  federative  jurisdiction 
to  produce  harmony  in  their  actions,  or  to  regulate  the  numerous  inde- 
pendent movements  and  complicated  associations,  which  must  inevitably 
occur  in  the  various  intellectual  and  moral  operations.  Gall  appears 
indeed  to  have  lost  sight  of  the  important  doctrine  of  association,  which 
applies  not  only  to  the  ideas,  but  to  every  function  of  the  frame;  and 
with  which  it  is  so  important  for  the  pathologist  particularly  to  be 
acquainted. 

The  second  point  of  doctrine, — that  each  of  the  cerebral  organs  ends 
at  the  periphery  of  the  encephalon,  and  is  indicated  by  more  or  less 
developement  of  the  part, — is  attended  with  equal  difficulties.  It  is 
admitted,  as  we  have  seen,  by  the  most  eminent  physiologists,  that 
the  exterior  of  the  brain  is  probably  chiefly  concerned  in  the  mental 
and  moral  manifestations.  Almost  all  believe,  that  this  function  is 
restricted  to  the  brain  proper.  Gall  and  his  followers  include  the  cere- 
bellum. Yet  we  meet  with  cases,  which  appear  to  militate  strongly 
against  this  notion.  Hernia  of  the  brain  is  one:  in  this  affection,  owing 
to  a  wound  of  the  cranium  and  dura  mater,  a  portion  of  the  cerebral 
substance  may  protrude  and  be  removed;  yet  the  individual  may,  to  all 
appearance,  retain  his  faculties  unimpaired.  This  is  explained  by  the 
craniologist,  by  presuming,  that  as  the  fibres  of  the  brain  are  vertical, 
their  extremities  alone  have  been  removed,  a  sufficient  amount  of  fibres 
remaining  for  the  execution  of  the  function;  and  he  farther  entrenches 
himself  in  the  difficulty  of  observing  accurately,  whether  the  faculties 
be  really  in  their  pristine  integrity.  He  asserts,  that  it  is  frequently 
difficult  to  prove  the  existence  of  mental  aberration;  that  the  precise 
line  of  demarcation  between  reason  and  unsoundness  of  mind  is  not 
easily  fixed;  and  that  commonly,  in  these  cases,  attention  is  paid  only 
to  the  most  general  qualities;  and  if  the  patient  be  seen  to  take  food 
and  medicine  when  offered,  to  reply  to  questions  put  to  him,  and  to  have 
consciousness,  the  moral  sense  is  esteemed  to  be  free,  and  in  a  state  of 

1  Op.  cit.,  p.  272. 


356  MENTAL  FACULTIES. 

integrity.  It  must,  however,  be  admitted,  that  the  explanation  of  the 
craniologist  on  these  topics  is  feeble  and  unsatisfactory.  It  is  gratui- 
tously assuming,  that  observation  in  such  cases  has  been  insufficient ; 
and  if  he  finds,  that  the  fact  in  question  militates  against  the  faith  he 
has  embraced,  he  is  too  apt  to  deny  its  authenticity  altogether.  With 
all  the  candour  which  Gall  possessed,  this  failing  is  too  perceptible  in 
his  writings. 

In  many  of  the  cases  of  severe  injury  of  the  brain  on  record,  but  one 
hemisphere  was  implicated ;  and,  accordingly,  the  impunity  of  the 
intellectual  and  moral  manifestations  has  been  ascribed  to  the  cerebrum 
being  a  double  organ  ;  so  that,  although  one  hemisphere  may  have  been 
injured, — the  other,  containing  similar  organs,  may  be  capable  of  car- 
rying on  the  function ;  as  one  eye  can  still  execute  vision,  when  the 
other  is  diseased  or  lost.  Cases,  however,  have  occurred  in  which  the 
faculty  was  lost,  when  only  one  hemisphere  was  implicated.  One  in- 
teresting example,  the  author  heard  Mr.  Combe  relate.  A  gentleman 
suddenly  forgot  all  words  but  yes  and  no;  and  after  death  a  lesion  was 
found  in  the  left  hemisphere  of  the  brain,  involving  the  phrenological 
organ  of  language.  The  explanation  by  Mr.  Combe  of  this  phenome- 
non is  plausible,  but  not  probable.  It  appears  to  me,  he  observed, 
"  that  the  lesion's  being  on  one  side  only  accounts  for  his  power  of 
understanding  words,  while  he  had  not  the  power  of  employing  them."1 
Many  cases,  again,  are  recorded,  in  which  injury  was  sustained  by  both 
hemispheres,  and  in  corresponding  parts,  yet  the  faculties  persisted  ;2 
whence  Muller  has  concluded,  that  the  histories  of  injuries  of  the 
head  are  directly  opposed  to  the  existence  of  special  regions  of  the 
brain,  destined  for  special  mental  faculties.  An  interesting  case  of 
this  nature  was  reported  to  the  Royal  Academy  of  Sciences  of  Paris, 
by  M.  Blaquiere  of  Mexico.3  A  child,  playing  with  a  loaded  pistol, 
discharged  it  accidentally.  The  ball  struck  his  younger  brother,  four 
years  and  a  half  old ;  entered  at  one  temporal  region,  and  came  out  at 
the  other.  For  twenty-six  days  after  the  accident,  the  child  apparently 
possessed  all  its  intellectual  faculties.  Memory  and  judgment  did  not 
seem  to  be  in  the  slightest  degree  impaired:  the  boy  was  as  gay  as  usual ; 
had  appetite,  and  slept  pretty  well.  The  wounds  were  both  situate  about 
an  inch  and  a  half  below  the  external  commissures  of  the  eyes.  On 
the  26th  day,  symptoms  of  cerebral  inflammation  supervened,  and  the 

1  Combe's  Lectures,  by  Boardman,  p.  261,  New  York. 

2  For  many  such  cases,  see  Longet,  Anatomie  et  Physio logie  du  Systeme  Nerveux,  i.  670, 
Paris,  1 842  ;  and  a  remarkable  one  by  Mr  Ford,  and  another  by  Dr.  Cowan,  copied  into  the 
Amer.  Journ.  of  the  Med.  Sciences,  Jan.,  1846.    See,  also,  a  fatal  case  of  disorganization  of  the 
brain,  without  corresponding  derangement  of  the  intellectual  and  moral  acts,  by  Dr.  G.  W. 
Boerstler,  of  Lancaster,  Ohio,  in  Dunglison's  American  Medical  Intelligencer,  No.  1,  for  April 
1,  1837.     Mr.  Combe,  in   his  work, — "  Notes  on  the  United  States  of  North  America,  during  a 
phrenological  visit  in  1838-39-40  ;"  Phila.,  184] — refers  to  a  case  of  injury  of  both  hemispheres, 
which,  he  thinks,  from  examining  the  case,  was  confined  almost  entirely  to  the  organs  of 
Eventuality.     The  man  recovered,  and  was  exhibited  to  Mr.  Cornbe  with  a  history  of  his 
case  by  Drs.  Knight  and  Hooker,  of  New  Haven.     In  the  opinion  of  the  latter,  the  intellec- 
tual faculties  were  not  impaired. — Vol.  ii.  p.  276.    See,  also,  connected  with  this  subject,  Dr. 
A.  L.  Wigan,  The  Duality  of  the  Mind  proved  by  the  Structure,  Functions,  and  Diseases  of 
the  Brain,  &c..  Lond.,  1 844. 

3  Comptes  Rendus,  23d  Sept.,  1844. 


VIEWS  OF  PHRENOLOGISTS.  357 

boy  died  on  the  29th.  On  examination  after  death,  the  anterior  and 
superior  regions  of  both  hemispheres  were  found  to  have  been  traversed 
by  the  ball.  The  ventricles  were  untouched.  Throughout  the  whole 
track  of  the  ball  suppuration  existed.  The  meninges  were  inflamed. 
M.  Blaquiere  considers  the  case  to  be  fatal  to  phrenological  doctrines, 
as  the  seats  of  several  important  phrenological  faculties  were  destroyed, 
and  yet  no  functional  affection  of  the  brain  was  discovered.  Cases  of 
hydrocephalic  patients  are  likewise  cited,  who  have  preserved  their 
faculties  entire.  These  Gall1  explains,  by  affirming,  that  the  brain  is 
not  dissolved  in  the  fluid  of  the  dropsy ;  that  it  is  only  deployed,  and 
distended  by  the  presence  of  the  fluid ;  and  as  the  distension  takes 
place  slowly,  and  the  pressure  is  moderate,  the  organ  may  be  so  habitu- 
ated to  it  as  to  be  able  to  continue  its  functions.  Lastly,  some  expe- 
riments of  Duverney2  have  been  adduced  as  objections  to  the  view  of 
Gall.  These  consisted  in  removing  the  whole  of  the  brains  of  pigeons ; 
yet  no  change  seemed  to  be  produced  in  their  faculties;  but,  in  reply 
to  this,  it  is  asserted,  that  Duverney  could  only  have  removed  some  of 
the  superficial  parts  of  the  organ  ;  for,  whenever  the  experiment  has 
been  repeated  so  as  to  implicate  the  deeper-seated  portions,  opposite 
results  have  been  obtained. 

The  truth  is,  that  under  any  view  of  the  subject  these  facts  are  equally 
mysterious.  We  cannot  understand  why,  in  particular  cases,  such 
serious  effects  should  result  from  severe  injury  of  the  encephalon ; 
and,  in  others,  the  comparative  immunity  attendant  upon  injury  to  all 
appearance  equally  grave.  Pressure,  of  whatever  nature,  seems  to  be 
more  detrimental  than  any  other  variety  of  mechanical  mischief ;  and 
it  is  not  uncommon  for  us  to  observe  a  total  privation  of  all  mental  and 
moral  acts,  by  the  sudden  effusion  of  blood,  of  no  greater  magnitude 
than  that  of  a  pea,  into  the  substance  of  the  brain ;  whilst  a  gun-shot 
wound,  that  may  occasion  the  loss  of  several  tea-spoonfuls  of  brain,  or 
a  puncture  of  the  organ  by  a  pointed  instrument,  may  be  entirely  con- 
sistent with  the  presence  of  perfect  consciousness. 

The  doctrine,  that  by  observation  of  the  skull  we  may  be  able  to 
detect  the  protuberances  produced  by  the  encephalic  organs  of  the  dif- 
ferent faculties,  has,  as  we  have  seen,  laid  the  foundation  for  the  whole 
system  of  craniology,  with  all  the  extensions  given  to  it  by  absurdity 
and  vain  enthusiasm.  It  has  been  before  remarked,  that  the  size  of  an 
organ  is  but  one  of  the  elements  of  its  activity;  that  by  cranioscopy 
we  can  of  course  judge  of  this  element  only ;  and  it  need  scarcely  be 
said,  that  myriads  of  observations  would  be  necessary  before  we  could 
arrive  at  any  accurate  specification  of  the  seats  of  the  encephalic  facul- 
ties, even  were  we  to  grant,  that  separate  organs  can  be  detected  by  the 
mode  of  examination  proposed  by  the  cranioscopists.  Gall  asserts,  that 
the  whole  "physiology  of  the  encephalon  is  founded  on  observations, 
experiments,  and  researches  a  thousand  and  a  thousand  times  repeated 
on  man  and  animals;"  yet  the  topographical  division  of  the  skull  pro- 
posed by  him  can  hardly  be  regarded  otherwise  than  premature,  to 

1  Op.  citat.,  ii.  263. 

*  Adelon,  Physiologie  de  I'Homme,  2de  6dit.,  i.  502,  Paris,  1829. 


358  MENTAL  FACULTIES. 

* 

say  the  least  of  it;1  and  the  remark  applies  a  fortiori  to  that  of  Spurz- 
heim. 

It  is,  indeed,  difficult  to  grant,  that  the  same  convolutions  can  be  the 
encephalic  organs  of  distinct  faculties;  and  if  the  views  now  adopted 
by  many  of  the  phrenologists,  be  admitted,  that  the  number  and  size 
of  the  convolutions  and  the  depth  of  the  anfractuosities  be  any  index 
of  the  developement  of  an  organ;  it  is  obviously  impossible  by  an  ex- 
amination of  the  skull  to  form  the  slightest  judgment  on  these  points. 
Messrs.  Leuret  and  Carpenter2  are  of  opinion,  that  comparative  anatomy 
and  psychology — which  have  been  so  much  invoked — when  their  evi- 
dence is  fairly  weighed,  are  very  far  from  supporting  the  system.  M. 
Flourens3  and  Retzius4  have  opposed  it  on  anatomical,  physiological, 
and  psychological  grounds ;  and  Muller5  thinks  Magendie  right  in 
placing  cranioscopy  in  the  same  category  with  astrology  and  alchemy. 
The  author  would  not  go  so  far ;  but  he  must  candidly  admit,  that  year 
after  year's  observation  and  reflection  render  him  less  and  less  disposed 
to  consider,  that  even  the  fundamental  points  of  the  doctrine  are  found- 
ed on  a  just  appreciation  of  the  encephalic  functions. 

It  is  the  mapping  of  the  skull,  accompanied  by  the  self-conceit  and 
quackery  of  many  of  the  soi-disant  phrenologists  or  craniologists,  that 
has  excited  the  ridicule  of  those  who  are  opposed  to  the  doctrine  of 
innate  faculties,  and  to  the  investigation  of  points  connected  with  the 
philosophy  of  the  human  mind  in  any  other  mode  than  that  to  which 
they  have  been  accustomed.  Were  we,  indeed,  to  concede,  that  the 
fundamental  principles  of  craniology  are  accurate,  we  might  hesitate 
in  adopting  the  details ;  and  still  more  in  giving  any  weight  to  it  as  a 
practical  science.  Gall  and  Spurzheim  would  rarely  venture  to  pro- 
nounce on  the  psychical  aptitudes  of  individuals  from  an  examination  of 
their  skulls ;  and  when  they  did,  they  frequently  failed.  "  When  Gall," 
says  Dr.  Burrows,6  "  was  in  England,  he  went  in  company  with  Dr.  H. 
to  visit  the  studio  of  the  eminent  sculptor,  Chantry.  Mr.  C.  being  at 
the  moment  engaged,  they  amused  themselves  in  viewing  the  various 
efforts  of  his  skill.  Dr.  Gall  was  requested  to  say,  from  the  organs 
exhibited  in  a  certain  bust,  what  was  the  predominant  propensity  or 
faculty  of  the  individual.  He  pronounced  the  original  must  be  a  great 
poet.  His  attention  was  directed  to  a  second  bust.  He  declared  the 
latter  to  be  that  of  a  great  mathematician :  the  first  was  the  bust  of 
Troughton,  and  the  second  that  of  Sir  Walter  Scott!" 

This  kind  of  hasty  judgment  from  manifestly  inadequate  data  is  the 
every-day  practice  of  the  itinerant  phrenologist,  whose  oracular  dicta 
too  often  draw  ridicule  not  only  on  the  empiric  himself,  but  on  a  sys- 
tem which  is  worthy  of  a  better  fate.  Ridicule  is  the  harmless  but 

1  Miiller's  Elements  of  Physiology  by  Baly,  p.  837,  Lond.,  1838. 

2  Human  Physiology,  p.  226,  Lond.,  1842. 

3  Journal  des  Savans,  Nov.,   1841,  &  Fevr.  &  Avril,  1842;  and  Phrenology  Examined, 
translated  from  the  second  edition  of  1845,  by  Professor  Meigs,  Phi  lad.,  1846. 

4  Beurtheilung  der  Phrenologie  vom  Standpunkte  der  Anatomic  aus.,  Miiller's  Archiv., 
Heft  3,  s.  233,  Berlin,  1848. 

s  Op.  citat.,  p.  837. 

6  Commentaries  on  the  Causes,  Forms,  Symptoms,  and  Treatment  of  Insanity,  Lond., 
1828. 


VIEWS  OF  PHEENOLOGISTS.  359 

attractive  weapon,  which  has  usually  been  wielded  against  it;  and  too 
often  by  those  who  have  been  ignorant  both  of  its  principles  and 
details.  It  is  not  above  twenty  years  since  one  of  the  most  illustrious 
poets  of  Great  Britain  included  in  his  satire  the  stability  of  the  cow-pox, 
galvanism,  and  gas,  along  with  that  of  the  metallic  tractors  of  Perkins  — 

"The  cow-pox,  tractors,  galvanism,  and  gas, 

In  turns  appear  to  make  the  vulgar  stare 
v        Till  the  swoll'n  bubble  bursts,  and  all  is  air." 

English  Bards  and  Scotch  Reviewers" 


Yet,  how  secure  in  its  operation,  how  unrivalled  in  its  results,  has  vac- 
cination every  where  exhibited  itself  ! 

Indiscriminate  divination  from  measurement  of  heads  has  been  a  sad 
detriment  to  phrenology  as  a  branch  of  physiological  science  ;  and  has 
been  grievously  deplored  by  enlightened  phrenologists.  "  Highly  as 
we  estimate  the  discovery  of  Gall,"  —  says  one  of  the  ablest  of  these1  — 
"  immense  as  we  regard  the  advantages  which  may  be  ultimately  de- 
rived from  phrenology,  we  confess  that  we  wish  to  see  it  less  regarded, 
studied,  and  pursued  as  a  separate  science,  and  more  as  a  branch  of 
general  physiology;"  and  he  adds:  "  In  reviewing  the  circumstances 
which  have  tended  to  lower  phrenology  in  the  estimation  of  scientific 
men,  and,  consequently,  to  retard  both  its  progress  as  a  science,  and 
the  general  recognition  of  its  leading  truths,  we  should  but  very  im- 
perfectly perform  our  task,  if  we  did  not  refer,  in  the  strongest  possible 
terms  of  reproof  and  condemnation,  to  the  too  prevalent  proceeding  of 
examining  living  heads  in  minute  detail  and  indiscriminately,  and  sup- 
plying the  owners  with  an  account  of  the  'developement,'  often  on  the 
receipt  of  a  fee,  varying  in  amount,  as  there  is  furnished  or  omitted  a 
general  deduction  as  to  the  character  and  probable  conduct  of  the  indi- 
vidual, with  or  without  the  'philosophy,'  according  to  the  phraseology 
of  practitioners  of  this  art.  We  unhesitatingly  maintain,  that  the 
science  is  not  sufficiently  advanced  to  supply  evidence  of  its  truth  from 
every  head,  or  from  any  one  head,  and  consequently,  that  such  practice, 
as  a  general  one,  is  so  much  pure  charlatanism.  Where  any  strongly 
marked  peculiarity  of  individual  character  exists,  its  outward  sign,  in 
appropriate  subjects,  will  certainly  be  detected  ;  but,  from  the  very 
nature  of  the  thing,  these  cases  must  constitute  not  the  rule,  but  the 
exception.  The  practice  we  condemn,  however,  makes  no  distinction 
of  instances.  Injudicious  zeal,  the  common  ally  of  ignorance,  a  wish 
for  effect,  not  unfrequently  more  sordid  motives,  stimulate  the  self-styled 
phrenologist  in  this  empirical  career  ;  and,  as  a  matter  of  course,  the 
errors  and  mistakes  perpetually  made  are  constantly  appealed  to  as 
indicative  of  the  sandy  foundations  of  the  entire  phrenological  edifice. 
We  write  advisedly  in  this  our  unqualified  reprobation  of  the  popular 
custom  of  i  taking  developements.'  We  believe  it  to  be  an  extension 
of  the  practical  application  of  phrenology  much  beyond  its  legitimate 
bounds  ;  and  we  appeal  to  any  one  having  acquaintance  with  its  results, 
whether  any  thing  like  uniformity  —  the  true  test  of  accuracy  —  is  ob- 
tained in  the  majority  of  cases,  even  when  the  most  experienced  and 

1  British  and  Foreign  Medical  Review,  July,  1842. 


360  MENTAL  FACULTIES. 

dexterous  pronounce  their  judgment,  if  their  explorations  be  conducted 
separately.  We  ourselves  have  even  witnessed  the  greatest  possible 
discrepancies.  Nay,  we  have  seen  the  same  phrenologists  furnish  one 
character  from  the  head,  and  a  totally  different  one  from  the  cast,  whilst 
in  ignorance  of  the  original  of  this  latter.  This  we  have  known  to 
happen,  not  merely  in  the  practice  of  one  of  your  shilling-a-head  itine- 
rants, but  in  that  of  one  not  unknown  to  fame  in  the  annals  of  the 
science."  Such  are  the  views  of  one,  who,  unlike  the  author,  expects 
much  from  phrenology ;  and  has  done  much  to  give  it  countenance. 
Yet  men  will  still  form  their  judgments  in  this  manner;  and  a  solitary 
coincidence,  as  in  all  analogous  cases,  will  outweigh  a  dozen  failures.1 

The  doctrine  of  Gall  requires  repeated  unbiassed  and  careful  experi- 
ments, which  it  is  not  easy  for  every  one  to  institute;  and  this  is  one 
of  the  causes  why  the  minds  of  individuals  must  long  remain  in  doubt 
regarding  the  merits  or  demerits  of  the  system.  From  mere  metaphy- 
sicians, who  have  not  attended  to  the  organization  and  functions  of 
the  frame,  especially  of  its  encephalic  portion,  it  has  ever  experienced 
the  greatest  hostility;  although  their  conflicting  views  regarding  the 
intellectual  and  moral  faculties  was  one  of  the  grounds  for  the  divi- 
sion of  the  phrenologist.  It  is  now,  however,  we  believe,  generally 
admitted  by  the  liberal  and  scientific,  that  if  we  are  to  obtain  a  far- 
ther knowledge  of  the  mental  condition  of  man,  it  must  be  by  a  com- 
bination of  sound  psychological  and  physiological  observation  and 
deduction.  It  is  time,  indeed,  that  such  a  union  should  be  effected, 
and  that  the  undisguised  and  inveterate  hostility,  which  exists  between 
certain  of  the  professors  of  these  interesting  departments  of  anthro- 
pology, should  be  abolished.  "  To  fulfil,  definitely,  the  object  we  had 
proposed  to  ourselves,"  says  M.  Broussais,2  "we  must  infer  from  all  the 
facts  and  reasoning  comprised  in  this  work, — 1st.  That  the  explana- 
tions of  psychologists  are  romances,  which  teach  us  nothing  new.  2dly. 
That  they  have  no  means. of  affording  the  explanations  they  promise. 
3dly.  That  they  are  the  dupes  of  the  words  they  employ  in  disserting 
on  incomprehensible  things.  4thly.  That  the  physiologist  alone  can 
speak  authoritatively  on  the  origin  of  our  ideas  and  knowledge ;  and 
5thly.  That  men,  who  are  strangers  to  the  science  of  animal  organi- 
zation, should  confine  themselves  to  the  study  of  the  instinctive  and 
intellectual  phenomena  in  their  relations  with  the  different  social  states 
of  existence." 

This  is  neither  the  language  nor  the  spirit  that  ought  to  prevail 
among  the  promoters  of  knowledge. 

Lastly. — Physiologists  have  inquired,  whether  there  may  not  be 
some  particular  portion  of  the  brain,  which  holds  the  rest  in  subservi- 
ence; some  part  in  which  the  mind  exclusively  resides; — for  such  was 
probably  the  meaning  of  the  researches  of  the  older  physiologists 
into  the  seat  of  the  soul.  It  is  certain,  that  it  is  in  the  encephalon, 
but  not  in  the  whole  of  it ;  for  the  organ  may  be  sliced  away,  to  a 

1  See,  on  these  subjects,  the  author's  Medical  Student,  second  edit.,  p.  256,  Philadelphia, 
1844. 

2  De  I'lrritation  et  de  la  Folie,  Paris.  1828 ;  or  Amer.  edit,  by  Dr.  T.  Cooper,  Columbia, 
S.  C.,  1831. 


VIEWS  OF  PHRENOLOGISTS.  361 

certain  extent,  with  impunity.  Gall,  we  have  seen,  does  not  admit 
any  central  part,  which  holds  the  others  in  subordination.  He  thinks, 
that  each  encephalic  organ,  in  turn,  directs  the  action  of  the  others, 
according  as  it  is,  at  the  time,  in  a  state  of  greater  excitation.  On 
the  other  hand,  different  physiologists  admit  of  a  central  cerebral 
part,  which  they  assert  to  be  the  seat  of  the  4w»  moi  or  mind.  They 
differ,  however,  regarding  the  precise  situation  of  its  domicile.  At  one 
time,  the  strange  notion  prevailed,  that  the  seat  of  perception  is  not 
in  the  brain,  but  in  its  investing  membranes.  Des  Cartes,1  again,  em- 
braced the  singular  hypothesis,  that  the  pineal  gland  is  entitled  to  this 
pre-eminence.  This  gland  is  a  small  projection,  seen  in  Fig.  9  (page 
80),  at  the  posterior  part  of  the  third  ventricle ;  and,  consequently,  at 
the  base  of  the  brain.  Being  securely  lodged,  it  was  conjectured  by 
that  philosopher,  that  it  must  be  inservient  to  some  important  purpose; 
and,  upon  little  better  grounds,  he  supposed,  that  the  soul  is  resident 
there.  The  conjecture  was  considered  to  be  confirmed  by  the  cir- 
cumstance, that,  on  examining  the  encephala  of  certain  idiots,  the 
gland  was  found  to  contain  a  quantity  of  sabulous  matter.  This  was 
supposed  to  be  an  extraneous  substance,  which,  owing  to  accident  or 
disease,  had  lodged  in  the  gland  and  impeded  its  functions ;  and  the 
inference  was  drawn,  that  the  part,  in  which  such  functions  were  im- 
peded, was  the  seat  of  the  soul.  Nothing,  however,  is  now  better  esta- 
blished than  that  the  pineal  gland  of  the  adult  always  contains  earthy 
matter.2  Others,  again,  as  Bontekoe,3  La  Peyronie,4  and  Louis,  placed 
the  mind  in  the  corpus  callosum ;  Yieussens  in  the  centrum  ovale  ; 
Digby5  in  the  septum  lucidum ;  Drelincourt6  in  the  cerebellum ;  Ack- 
ermann  in  the  Sinneshiigel7  (prominence  or  tubercle  of  the 
senses) ;  Sommering8  in  the  fluid  of  the  ventricles ;  and  the  greater 
part  of  physiologists  in  the  point  where  the  sensations  are  received  and 
volition  sets  out, — the  two  functions,  which,  together,  form  the  sen- 
serial  power  of  Dr.  Wilson  Philip.9  Dr.  Darwin10  had  previously  em- 
ployed this  term  in  a  more  extended  sense,  as  including  the  power  of 
muscular  contraction;  but  in  Dr.  Philip's  acceptation,  it  is  restricted 
to  those  physiological  changes  in  which  the  mind  is  immediately  con- 
cerned.11 

The  discrepancy  among  physiologists  sufficiently  demonstrates,  that 
we  have  no  positive  knowledge  on  the  subject. 

1  De  Passion.  Anira.,  Amst.,  1664,  and  De  Hoxriine,  p.  78,  Lugd.  Bat.,  1664. 
1  Somrnering,  De  Lapillis  vel  prope  vel  intra  Glandulam  Pinealem  sitis,  Mognnt,  1785. 
3  Haller.  Bibl.  Anat.,  i.  673.  *  Mem.  de  1'Academ.  des  Sciences,  Paris,  1741. 

5  Of  the  Nature  of  Bodies  and  the  Nature  of  Man's  Soul,  London,  1658. 

6  Opera.  Anat.,  Lugd.  Bat.,  1684. 

'  This  term  he  applies  to  the  optic  thalamiand  corpora  striata  ;  because,  according  to  the 
then  received  opinion,  the  optic  nerves  originate  in  the  optic  thalami;  and  the  olfactory 
nerves  from  the  corpora  striata. — Gall,  Sur  ies  Fonctions  du  Cerveau,  ii.  57,  Paris,  1825. 

8  De  Corp.  Human.  Fabric.,  iv.  §  98. 

9  An  Experimental  Inquiry  into  the  Laws  of  the  Vital  Functions,  p.  186,  London,  1817. 

10  Zoonomia,  3d  edit.,  ii.  103,  Lond.,  1801. 

»i  Dr.  W.  Philip,  ibid.;  and  especially  his  paper  on  the  Powers  of  Life,  in  the  Lond.  Mod. 
Gazette  for  March  18  and  25,  1837;  also,  his  Treatise  on  Protracted  Indigestion,  &c.,  Amer, 
edit.,  Philad.,  1843. 


362  MUSCULAR  MOTION. 


CHAPTER  II. 

MUSCULAR   MOTION,  ESPECIALLY  LOCOMOTILITY  OR  VOLUNTARY  MOTION. 

THE  functions  hitherto  considered  are  preliminary  to  those  that  have 
now  to  attract  attention.  The  former  instruct  us  regarding  the  bodies 
that  surround  us;  the  latter  enable  us  to  act  upon  them;  to  execute 
all  the  partial  movements,  that  are  necessary  for  nutrition  and  repro- 
duction; and  to  move  about  from  place  to  place.  All  these  last  acts 
are  of  the  same  character;  they  are  varieties  of  muscular  contraction; 
so  that  sensibility  and  voluntary  motion,  or  muscular  contraction  exe- 
cuted by  the  muscular  system  of  animal  life,  comprise  the  whole  of  the 
life  of  relation.  M.  Magendie  includes  the  voice  and  movements  under 
the  same  head;  but  there  is  convenience  in  separating  them;  and  in 
treating  the  functions  of  locomotility  and  expression  distinctly,  as  has 
been  done  by  M.  Adelon.1 

ANATOMY    OF   THE   MOTORY   APPARATUS. 

The  organs  essentially  concerned  in  this  function  are — the  encepha- 
lon,  spinal  marrow,  nerves,  and  muscles.  The  three  first  of  these  have 
been  sufficiently  described.  The  last,  therefore,  will  alone  engage  us. 

Muscles. 

The  muscles  constitute  the  flesh  of  animals.  They  are  distinguished 
by  their  peculiar  structure  and  composition; — being  formed  of  the  ele- 
mentary or  primary  fibrous  tissue,  already  described.  This  tissue  has 
the  power  of  contracting,  and  thus  of  moving  the  parts  into  which  it 
is  inserted;  hence,  muscles  have  been  termed  active  organs  of  locomo- 
tion, in  contradistinction  to  bones,  tendons,  and  ligaments,  which  are 
passive. 

The  elementary  constituent  of  the  whole  muscular  system  is  this 
primary,  fibrous,  or  muscular  tissue,  the  precise  size  and  intimate  texture 
of  which  have  been  the  occasion  of  innumerable  researches ;  and,  as 
most  of  them  have  been  of  a  microscopic  character,  they  are  highly 
discrepant,  as  a  brief  history  will  exhibit. 

Leeuwenhoek2  asserts,  that  some  thousands  of  the  ultimate  filaments 
are  required  to  form  the  smallest  fibre  visible  to  the  naked  eye.  He 
describes  these  fibres  as  serpentine  and  cylindrical;  and  affirms,  that  they 
lie  parallel  to  each  other,  and  are  of  the  same  shape  in  all  animals, 
but  differ  greatly  in  size.  Their  size,  however,  bears  no  proportion  to 
that  of  the  animal  to  which  they  belong.  Muys3  affirmed,  that  every 
apparent  fibre  is  composed  of  three  kinds  of  fibrils,  each  progressively 

1  Pbysiologie  de  THomme,  2de  edit.,  ii.  1  &  204,  Paris,  1829. 

2  Arcaha  Naturae,  p.  43. 

3  Investigatio  fabricas  quas  in  partibus  rausculos  componentibus  exstat,  .p.  274,  Lugd.  Bat.. 
1841. 


MUSCLES. 


363 


smaller  than  the  other;  and  that  those  of  the  medium  size,  although 
not  larger  than  the  ninth  part  of  a  very  delicate  hair,  are  composed  of 
one  hundred  filaments.  He  supposed  the  ultimate  filament  to  be  always 
of  the  same  size.  Prochaska1  says,  that  the  ultimate  fibre  or  filament 
is  discernible,  and  that  its  thickness  is  about  the  ^th  part  of  the  dia- 
meter of  the  red  globules  of  the  blood ;  and  MM.  PreVost  and  Dumas,2 
from  the  result  of  their  microscopic  observations,  afiirm,  that  16,000 
fibres  may  be  contained  in  a  cylindrical  nerve,  one  millimeter  or  0-039 
of  an  inch,  in  diameter.  The  microscopic  examinations  of  Mr.  Skey,3 
which  have  been  confirmed  and  developed  by  subsequent  observers,  led 
him  to  infer,  that  there  is  a  distinction  between  the  muscular  fibres  of 
animal  and  organic  life;  the  former  having,  in  man,  an  average  diameter 
of  ^Jffth  °f  an  incn-  Each  of  these  muscular  fibres  is  -divisible  into 
bands  or  fibrillse,  and  each  of  these  is  again  subdivisible  into  about  100 
tubular  filaments,  arranged  parallel  to  each  other:  the  diameter  of  each 
filament  is  yg^oir^1  Part  of  an  inch,  or  about  a  third  part  of  that  of  a 
blood-globule.  The  muscles  of  organic  life  he  found  to  be  composed, 
not  of  fibres  similar  to  those  described,  but  of  filaments  only;  these 
filaments  being  interwoven,  and  forming  a  kind  of  untraceable  net- work. 
The  fibres  of  the  heart  appeared  to  possess  a  somewhat  compound  cha- 
racter of  texture :  the  muscles  of  the  pharynx  exhibited  the  character 
of  those  of  animal  life,  whilst  those  of  the  oesophagus,  stomach,  intes- 
tines, and  arterial  system  possessed  the  character  of  those  of  organic 


Fig.  144. 


Fig.  145. 


Non-striated  Muscular  Fibre. 

At  6,  in  its  natural  state.    At  a,  showing   the  4.  A  muscular  fibre  of  organic  life,  with  two 

nuclei  after  the  action  of  acetic  acid.  of  its  nuclei ;  taken  from  the  urinary  bladder,  and 

magnified  600  diameters.    5.  Muscular  fibre  of  or- 
ganic life  from  the  stomach,  magnified  the  same. 

life.     He  was^  unable  to  determine  the  exact  nature  of  the  muscular 
fibres  of  the  iris.     At  the  present  day,  muscular  tissue  is  universally 

1  De  Carne  Muscular!,  p.  25,  Vienn.,  1778. 

2  Annales  de  Chimie,  tom.xviii.;  Magendie's  Journal  de  Physiologic,  torn.  iii. 

3  Transactions  of  the  Royal  Society,  for  1836. 


364  MUSCULAR  MOTION. 

divided  into  two  kinds  ;  —  the  one  forming  the  muscles  of  animal  life, 
the  other  the  muscles  of  organic  life.  The  former,  called  also  striated 
and  striped  muscles  (see  Fig.  147),  embrace  all  the  voluntary  muscles, 
as  well  as  the  heart,  the  muscular  tissue  of  the  pharynx  and  upper  por- 
tion of  the  oesophagus  :  the  latter,  called  also  non-striated  or  unstriped 
muscles,  constitute  the  proper  contractile  coats  of  the  digestive  tube 
from  the  middle  of  the  oesophagus  to  the  external  sphincter  ani,  as  well 
as  those  of  the  urinary  bladder,  trachea  and  bronchia,  excretory  ducts, 
gall  bladder,  vesiculse  seminales,  pregnant  uterus  and  Fallopian  tubes; 
arteries,  and  —  to  a  less  degree  —  of  the  veins. 

The  intimate  structure  of  the  filaments  has  given  rise  to  extraordi- 
nary contrariety  of  sentiment;  —  some,  as  Santorini,  Heister,  Cowper,1 
Vieussens,  Mascagni,2  Prochaska,3  Borelli,4  John  Bernouilli,  &c.,  believ- 
ing them  to  be  hollow;  others,  as  Sir  A.  Carlisle,5  and  Fontana,6  solid; 
some  thinking  them  straight;  others  zigzag,  spiral,  or  waved;  some 
jointed;  others  knotted,  &c.  &c.7  Borelli  and  J.  Bernouilli  announced, 
that  each  fibre  consists  of  a  series  of  hollow  vesicles,  filled  with  a  kind 
of  spongy  substance  or  marrow;  —  the  shape  of  the  vesicles  being,  ac- 
cording to  the  former,  rhomboidal,  —  according  to  the  latter,  spheroidal. 
Deidier  conceived  it  to  be  a  fasciculus,  composed  of  an  artery,  vein,  and 
lymphatic,  enveloped  by  a  nervous  membrane,  and  held  together  by 
nervous  filaments:  —  Prochaska,  to  consist  of  bloodvessels  turned  spi- 
rally around  an  axis  of  gelatinous  or  fibrinous  substance,  into  the  in- 
terior of  which  the  blood  rushed  at  the  time  of  contraction.  He  says, 
that  the  visible  fibres  are  not  cylindrical,  as  they  had  been  described 
by  many  observers,  but  of  a  polyhedral  shape  ;  and  that  they  are  gene- 
rally flattened,  or  thicker  in  one  direction  than  in  the  other.  All  are 
not  of  the  same  diameter:  they  differ  in  different  animals,  and  in  dif- 
ferent parts  of  the  same  animal;  and  are  smaller  in  young  subjects. 
The  filaments  or  ultimate  fibres,  which  can  only  be  seen  with  the  micro- 
scope, have  the  same  shape  as  the  visible  fibres  :  they  are,  however, 
always'  of  the  same  magnitude.  Sir  A.  Carlisle,8  —  whose  opinions,  on 
many  subjects  at  least,  are  not  entitled  to  much  weight  —  describes  the 
ultimate  fibre  as  a  solid  cylinder,  the  covering  of  which  is  a  reticular 
membrane,  and  the  contained  part  a  pulpy  substance,  regularly  granu- 
lated, and  of  very  little  cohesive  power  when  dead.  The  extreme 
branches  of  the  bloodvessels  and  nerves,  he  says,  are  seen  ramifying 
on  the  surface  of  the  membrane  enclosing  the  pulp,  but  cannot  be  traced 
into  the  substance  of  the  fibre.  Mr.  Bauer9  and  MM.  Provost  and 
Dumas10  differed  essentially  from  the  observers  already  mentioned. 
Mr.  Bauer  found,  that  the  muscular  fibre  was  composed  of  a  series  of 
globules,  arranged  in  straight  lines;  the  size  of  the  globule  being 


1  Myotomia  Reformata,  Lond.,  1724.  a  Prodrome,  p.  97. 

3  Oper.  Minor.,  P.  i.  198. 

4  De  Motu  Animalium  ;  addit.  Johan.  Bernouilli,  M.  D.,  Meditationes  Mathematic.  Mus- 
culorum,  Lugd.  Bat.,  1710. 

s  Phil.  Trans,  for  1805,  p.  6.  6  Sur  les  Poisons,  ii.  228. 

7  Elliotson's  Physiology,  p.  476.  8  Op.  citatv 

9  Sir  E.  Home,  Lectures  on  Comp.  Anat.,  v.  240,  Lond.,  1828. 

10  Appendix  to  Edwards,  De  1'Influence  des  Agens  Physiques  sur  la  Vie,  Paris,  1824. 


MUSCLES.  365 

part  of  an  inch  in  diameter ;  whilst  M.  Easpail1  considers,  that  the  inti- 
mate structure  of  the  muscular  tissue,  when  it  is  in  its  most  simple  state, 
consists  of  a  bundle  of  cylinders,  intimately  agglutinated  together,  and 
disposed,  in  a  very  loose  spiral  form  around  the  ideal  axis  of  the  group. 
These  tubes  are  filled  with  a  substance  not  wholly  miscible  with  water, 
and  may  be  regarded  as  elongated  vesicles,  united  at  each  end  to  other 
vesicles  of  a  similar  character. 

When  a  muscular  fibre  is  seen  through  an  ordinary  microscope,  it 
appears  to  be  composed  of  longitudinal  filaments,  each  consisting  of  a 
string  of  globules,  about  g^Wtn  of  an  inch  in  diameter.  "But  with  a 
better  instrument,"  says  Mr.  Mayo,2  "such  as  that  which  Mr.  Lister 
possesses,  the  delusion  vanishes,  and  the  parallel  lines,  which  traverse 
the  fibre,  appear  perfectly  cle(an  and  even.  Mr.  Lister  politely  gave 
me  an  opportunity  of  examining  this  appearance,  which  was  discovered 
by  himself  and  Dr.  Hodgkin." 

Fig.  146.  Fig.  147. 


Striated  Muscular  Fibres. 

Fig.  146. — A.  A  small  portion  of  muscle,  natural  size.  B.  The  same  magnified  5  diameters,  of  larger 
and  smaller  fasciculi,  seen  in  a  transverse  section. 

Fig.  147. — A  few  muscular  fibres,  being  part  of  a  small  fasciculus,  highly  magnified,  showing  the 
transverse  stria?,  a.  End  view  of  b  6,  fibres  j  c.  A  fibre  split  into  its  fibrillae. 

The  researches  of  Mr.  Bowman3  and  others  are  as  follows.  When 
the  smallest  fibre,  that  can  be  seen  by  the  naked  eye,  is  examined  by 
the  microscope,  it  is  found  to  consist  of  a  number  of  cylindrical  fibres 
lying  parallel  to  each  other,  and  closely  bound  together.  These  fibres 
present  striae — one  set  of  which  is  longitudinal,  the  other  transverse. 
When  the  fibres  are  separated  from  each  other,  and  examined  more 
closely,  they  may  be  resolved  into  fibrillse,  which,  so  far  as  at  present 
known,  are  the  ultimate  elements  of  muscular  structure.  They  are 
represented  in  Figure  153.  The  fibrillse  are  bound  together  by 

1  Chimie  Organique,  &c.,  p.  211,  Paris,  1833. 

2  Outlines  of  Human  Physiology,  chap.  iii.  3d  edit.,  London,  1833. 

3  Philosophical  Transactions  for   1840;  art.  Muscle,  Cyclop,  of  Anat.  and  Physiol.,  Part 
xxiv.,  p.  507,  July,  1842 ;  and  Todd  and  Bowman's  Physiological  Anatomy  and  Physiology 
of  Man,  Part  i.,  Lond.,  1843. 


366 


MUSCULAR  MOTION. 


delicate  tubular  sheath  or  sarcolemma,    which  may   be    distinctly 

when  the  two  ends  of  a  fibre  are 


Fig.  148. 


seen, 


twi 
Bowman.) 


Fig.  149. 


drawn  apart.  The  contained  fibrillse 
will  rupture,  whilst  the  sheath  remains 
entire,  as  represented  in  Fig.  148. 
During  the  act  of  contraction,  it  is  also 
sometimes  observed  to  rise  up  in  wrin- 
kles, upon  the  surface  of  the  fibre,  as  in 
Fig.  166.  It  is  distinct  from  the  cellu- 

Fragments  of  an  Elementary  Fibre  of  lar  tissue  that   binds   the  fibres  into  fas- 

the  Skate,  held  together  by  the  untora   c[cu\i*  (]oes  not  appear  to  be  perforated 

but    twisted    Sarcolemma.      (Todd    &  .\r  , 

by  nerves  or  capillary  vessels;  ana  evi- 
,  dently  has  no  share  in 

the  contraction  of  the 
fibre.  Although  com- 
monly described  as  cy- 
lindrical, these  fibres 
would  seem  to  be  rather 
of  a  polygonal  form, 
their  sides  being  flat- 
tened against  those  of 
the  adjoining  fibres. 
Their  size  varies  greatly 
in  different  classes  of 
animals,  and  even  in 
the  same  animal,  and 
the  same  mus,cle.  Mr. 
Bowman  found  them  to 
be,  in  the  human  male, 
from  5J7  to  TJ3  of  an 
inch;  in  the  female, 
from  g-Jg  to  ^ J?,  and  it 
has  been  estimated,  that  each  fibre  may  be 
composed  of  from  500  to  800  fibrillse.  Il- 
lustration, Fig.  149,  representing  a  trans- 
verse section  of  the  fibres  from  the  pectoral 
muscle  of  a  teal;  and  Fig.  150,  a  transverse 
section  of  the  ultimate  fibres  of  the  biceps, 
exhibit  well  the  irregular  shape  and  size, 
and  the  cut  extremities  of  fibrils  that  go  to 
the  constitution  of  the  fibre.  Under  the 
microscope  each  fibre  exhibits  a  close  alter- 
nation of  light  and  dark  lines  crossing  it 
transversely,  which  are  presumed  to  be 
owing  to  the  arrangement  of  beaded  fibrillae, 
as  shown  in  Fig.  151.  The  beaded  enlargements  of  the  fibrillse  seem 
to  adhere  closely  to  each  other,  so  that  when  the  extremities  of  a  fibre 
are  drawn  apart,  it  not  unfrequently  happens,  that  the  disks  formed  by 
them  separate. 

It  has  keen  affirmed,  that  the  primitive  component  segments  of  the 


Transverse  Section  of  Fibres  from  the  Pectoral  Muscle  of  a 
Teal. 


Fig.  150. 


Transverse  Section  of  Ultimate  Fi- 
bres of  Biceps.     (Bowman.) 


MUSCLES. 


367 


Fig.  151. 


Fig.  152. 


Fragment  of  Muscular 
Fibre  from  macerated  heart 
of  Ox,  showing  formation 
of  striag  by  aggregation  of 
beaded  fibrillae.  (Bowman.) 


Portion  of  Human  Muscular  Fibre,  separating  into  disks,  by 
cleavage  in  direction  of  transverse  striae.     (Bowman.) 


fibrillge  are  the  ultimate  elements  of  the  fibre;  these  segments  being 
connected  longitudinally,  so  as  to  constitute  the  fibrillae,  the  distinct- 
ness of  which  is  marked,  even  in  the  complete  fibre,  by  longitudinal 
striae ;  whilst  they  also  adhere  laterally,  so  as  to  form  disks,  the  par- 
tial separation  of  which  gives  origin  to  the  transverse  striae. 

The  views  of  histologists  on 

the  whole  of  this  subject  have  Fig.  153. 

until  recently  been  sufficiently 
discrepant.  Dr.  Martin  Bar- 
ry1 revived  a  view  of  Dol- 
linger,  but  which  has  met  with 
little  favour,  and  certainly 
needs  demonstration,  that  the 
blood  corpuscle  is  the  imme- 
diate agent  in  the  construc- 
tion of  many  tissues,  particu- 
larly the  muscular,  the  ele- 
mentary fibre  of  which — called 

by  him  Spiml.fibre — may  even  Fragments  of  Striated  Elementary  Fibres,  showing  a 
be  detected  in  the  nucleus  Of  Cleavage  in  Opposite  Directions.—  Magnified  300  di- 

the  corpuscle.     Mr.  Bowman2 

•U  fC  J     J/L         il~  - '  Longitudmal  cleavage.     The  longitudinal  and  trans- 

haS  amrmed,  that  the  mUSCU-  verse  lines  both  seen.  Some  longitudinal  lines  darker  and 
lar  fibre  *l™-«™»  T^no^f a  ™!der  than  t.he  rest>  and  not  continuous  from  end  to  end  : 


"hnt  if  ic  htr  * 
,  DUt  It  IS   Dy  a 

alone,     that     the     fibrillse    are 

j         m,  . 

ODtamed.        Hiey  CIO   not  eXISt 

in   ik/i  -fiKv.^         TT«  -fV,*. 
1  me  nore.        ±16  lar- 

tVinf     if     r^r»os» 

t  iat  it   occa- 


presents,     this  results  from  partial  separation  of  the  fibrillce.    6.  Fi- 
UDOn  and  within  it,  lonffitudi-    bril,lae>   separated  from   one  another   by  violence   at   the 
r,     ,  '  y>.  broken  end  of  the  fibre,  and  marked  by  transverse  lines 

nal  (lark  ImeS,   along  Which  it     equal  in  width  to  those  on  the   fibre.    "7,  8  represent  two 
•11     ,  M    11  -p.*.  :~i        appearances  commonly  presented  by  the  separated  single 

Will     generally    Split     Up     mtO     fibrill®.     (More  highly  magnified.)     At  7,  the  borders  and 

transverse  lines  are  all  perfectly  rectilinear,  and  the  in- 
cluded  spaces  perfectly  rectangular.  At  8,  the  borders  are 
scall°Ped,  the  spaces  bead-like.  When  most  distinct  and 
definite,  the  fibrilla  presents  the  former  of  these  appear- 
ances.—  2.  Transverse  cleavage.  The  longitudinal  lines 
are  scarcely  visible.  3.  Incomplete  fracture  following  the 
opposite  surfaces  of  a  disk,  which  stretches  across  the  in- 
terval  and  retains  the  two  fragments  in  connexion.  The 

edge  and  surface  of  this  disk  a»  seen     be  minutely  gra. 


happens    that  no  dis-    nular,  the  granules  corresponding  in  size  to  the  thickness 
of  the  disk,  and  to  the  distance  between  the  faint  longitu- 
Whatever  IS  Shown  tO     dinal  lines.    4.  Another  disk  nearly  detached.    5.  Detached 

this  longitudinal  cleavage;  but  ^1^'  sh°wing  the  sarc°us  ele" 


1  Philosophical  Transactions,  for  1842,  Parti,  p.  89. 

a  Art.  Muscle,  Cyclopedia  of  Anat.  and  Physiology,  July,  1842,  p.  508,  and  Physiological 
Anatomy  and  Physiology  of  Man,  Part  i.,  Lond.,  1843. 


368  MUSCULAR  MOTION. 

that,  on  the  contrary,  violence  causes  a  separation  along  the  transverse 
dark  lines,  which  always  intersect  the  fibre  in  a  plane  perpendicular  to 
its  axis.  By  such  a  cleavage,  disks  and  not  fibrillse  are  obtained;  and 
this  cleavage  is  as  material  as,  although  less  frequent  than,  the  former. 
Hence,  he  esteems  it  as  proper  to  say,  that  the  fibre  is  a  pile  of  disks, 
as  that  it  is  a  bundle  of  fibrillae;  that  it  is,  in  fact,  neither  one  nor  the 
other;  but  a  mass  in  the  structure  of  which  there  is  an  intimation  of 
the  existence  of  both,  and  a  tendency  to  cleave  in  the  two  directions. 
If  there  were  a  general  disintegration  along  all  the  lines  in  both  direc- 
tions, there  would  result  a  series  of  particles,  which  might  be  termed 
primitive  particles  or  sarcous  elements,  the  union  of  which  would  con- 
stitute the  mass  of  the  fibre;  these  elementary  particles  being  arranged 
and  united  together  in  the  two  directions. 

Gerber1  is  disposed  to  consider,  that  the  "cross-streaking"  fre- 
quently depends  on  the  presence  of  a  wrinkled  fascicular  sheath; 
"for  when,"  he  says,  "the  more  superficial  fibres  chance  to  be  removed, 
and  the  deeper  ones  exposed,  these  appear  cylindrical,  and  the  bundle 
at  the  part  is  longitudinally  streaked.  At  the  extremity  of  a  torn  fas- 
ciculus, too,  the  peripheral  fibres  often  appear  so  distinctly  marked  off 
from  the  internal  and  more  pulpy  substance,  that  the  existence  of  a 
more  compact  transversely  streaked  sheath  can  scarcely  be  called  in 
question."  Dr.  Goddard2  is  of  opinion,  from  his  own  observations,  that 
the  transverse  striae  seem  to  be  produced  by  a  delicate  thread  of  areolar 
tissue  wound  spirally  around  the  ultimate  fibrils,  so  as  to  hold  them  in  a 
bundle ;  whilst  Dr.  Will3  thinks  that  they  are  owing  to  the  fibrils,  which, 
in  their  natural  relaxed  state,  are  uniform  and  cylindrical,  being  thrown 
in  contraction  into  undulations  or  zigzag  flexures ;  and  Valentin,4  who  has 
long  described  the  relaxed  muscular  fibre  as  a  uniform  cylinder,  con- 
firms, generally,  Dr.  Will's  account,  although  he  cannot  determine, 
whether  the  striated  appearance  of  the  fibrils  be  owing  to  their  becoming 
varicose,  or  to  zigzag  flexures  induced  by  contraction.  He  also  main- 
tains the  view,  long  professed  by  him,  that  the  fibres  and  fasciculi  in 
the  fully  contracted  state,  are  bent  in  zigzag  lines,  with  angles  of  from 
80°  to  120°.  The  zigzag  arrangement  of  fibres  having  the  appear- 
ance of  "series  of  rhomboidal  pinnulse,  which  immediately  disappear 
as  soon  as  the  muscle  ceases  to  act,"  was  observed  by  Hales,5  in  the 
abdominal  muscles  of  the  frog. 

Mr.  Erasmus  Wilson,6  by  resorting  to  peculiar  methods  of  manipu- 
lation, and  employing  a  microscope  of  more  than  ordinary  power, 
believes  that  he  has  succeeded  in  discovering  the  real  structure  of  the 
ultimate  muscular  fibril  in  a  specimen  taken  from  the  arm  of  a  strong 
healthy  man  immediately  after  amputation.  He  finds  each  fibril  to  be 
composed  of  minute  cells  disposed  in  a  linear  series,  flattened  at  their 
surfaces  of  apposition,  and  so  compressed  in  the  longitudinal  direction 

1  Elements  of  General  and  Minute  Anatomy,  by  Gulliver,  p.  251. 

2  Wilson's  Anatomist's  Vade  Mecum,  by  Goddard,  Amer.  edit.,  p.  142,  Philad.,  1843. 

3  Mullet's  Archiv.,  1843,  Heft  iv. 

4  Lehrbuch  der  Physiologic  des  Menschen,  ii.  33,  Braunschweig,  1844. 

5  Statical  Essays,  ii.  61,  Lond.,  1733. 

«  Proceedings  of  the  Royal  Society,  June  20,  1844. 


Fis-  154- 


Mass  of  Ultimate  Fi- 


MUSCLES.  369 

as  to  have  no  marginal  indentation  on  the  surface; 
thus  constituting  a  uniform  cylinder  divided  into 
minute  subdivisions  by  transverse  septa,  which  are 
formed  by  the  adherent  surfaces  of  contiguous  cells. 
The  diameter  of  the  fibril,  in  the  state  of  relaxation, 
is  the  20,000th  part  of  an  inch.  The  cells  are  filled 
with  a  transparent  substance,  to  which  Mr.  Wilson 
gives  the  name  myoline^  and  which  differs  in  its  re- 
fractive density  in  different  cells.  In  four  consecu- 
tive cells,  the  myoline  is  of  greater  density  than 
in  the  four  succeeding  cells,  and  this  alternation  is 
repeated  throughout  the  whole  course  of  the  fibril,  bres  from  the  Pectoraiis 
In  consequence  of  all  the  fibrils  composing  the  ulti-  ^°\tf  ^hi^^onuS" 
mate  fasciculus  having  the  same  structure ;  and  the  These  fibres  have  been 
cells,  which  are  in  lateral  juxtaposition,  containing  JSSri^acS*  ^nd'Their 
myoline  of  the  same  density,  they  act  similarly  on  "numerous  corpuscles, 
light,  and  the  whole  presents  to  the  eye  of  the  mi-  I™*  sLT'prese^fng 
croscopic  observer  a  succession  of  striae  or  bands,  nucieoli,"  are  shown. 
dark  and  luminous  alternately,  and  transverse  to 
the  direction  of  the  fasciculus;  an  appearance  which  has  been  noticed 
by  previous  observers,  but  the  cause  of  which,  according  to  Mr.  Wilson, 
had  not  been  before  ascertained.  A  dark  stria  may  occasionally  ap- 
pear as  a  luminous  one,  and  conversely,  when  viewed  by  light  trans- 
mitted at  different  degrees  of  obliquity.  The  structure  here  described, 
Mr.  Wilson  remarks,  reduces  the  muscular  fibre 
to  the  simple  type  of  organization  exhibited  in 
the  combination  of  a  series  of  cells,  associating 
it  with  other  tissues  of  cell  formation;  and  may 
probably,  he  thinks,  open  new  sources  of  expla- 
nation of  the  immediate  agency  of  muscular 
action, — a  power  which,  as  he  properly  ob- 
serves, is  involved  in  the  deepest  mystery. 

One  of  the  most  recent  views  that  have  been 
published,  is  that  of  Dr.  Sharpey1  and  Dr. 
Carpenter,2  announced  about  the  same  time; 
according  to  which,  each  of  the  alternate  light 
and  dark  particles  of  which  the  fibril  is  com- 
posed, has  a  quadrilateral  and  generally  a  rec- 
tangular form.  Each  bright  particle  or  space 
is  marked  across  its  centre  by  a  fine,  dark, 
transverse  line  or  shadow,  by  which  the  space 
is  divided  into  two  equal  parts;  and,  at  times, 
a  bright  border  is  perceptible  on  either  side  of 
the  fibril,  so  that  each  of  the  rectangular  dark 
bodies  seems  to  be  surrounded  by  a  bright  area, 
having  a  similar  quadrangular  outline,  as  if 


Fig.  155. 


a  An  apparently  single  fibril. 
b-  Longitudinal  segment  of  a 

fibre  consisting   of  a  number  of 

fibrils  connected  together. 


1  Human  Anatomy,  by  Jones  Quain,  M.  D.,  edited  by  Quain  &  Sharpey,  Amer.  edit.,  by 
Leidy,  i.  316,  Philad.,  1849. 

a  Elements  of  Physiology,  Amer.  edit.,  p.  206,  Philad.,  1846. 

VOL.  i.  —  24 


370  MUSCULAR  MOTION. 

the  pellucid  substance  inclosed  it  >on  all  sides; — appearances  which 
have  been  considered  to  show,  that  the  elementary  particles  of  which 
the  fibril  is  composed  are  little  masses  of  pellucid  substance,  possibly 
nucleated  cells,  presenting  a  rectangular  outline,  and  appearing  dark 
in  the  centre. 

The  ultimate  fibres  or  filaments,  when  united  in  bundles,  form  fas- 
ciculi or  lacerti;  and  these,  by  their  aggregation,  constitute  the  various 
muscles.  Each  fibre,  each  lacertus,  and  each  muscle,  is  surrounded  by 
a  sheath  of  areolar  tissue,  which  enables  them  to  move  readily  upon 
each  other,  and  preserves  them  in  situ.  The  fibres  are  not  the  same 
at  the  extremities  as  they  are  at  the  middle.  The  latter  only  consist 
of  the  proper  muscular  tissue;  the  extremities  being  formed  of  areolar 
tissue.  If  we  examine  a  muscle,  we  find,  that  the  proper  muscular 
fibres  become  gradually  fewer,  and  at  length  cease  to  be  perceptible  as 
they  approach  the  tendon  at  one  or  other  extremity.  In  this  way,  the 
areolar  membrane,  which  surrounds  every  fibre,  becomes  freed  from 
the  muscular  tissue;  its  divisions  approximate,  and  become  closely 
united  and  condensed,  so  as  to  form  the  cord  or  tendon,  which,  of 
course,  holds  a  relation  to  each  fibre  of  the  muscle;  and  when  they  all 
contract,  the  whole  force  is  exerted  upon  it.  The  microscopic  obser- 
vations of  Mr.  Bowman  exhibited  to  him,  that  the  component  fibres  of 
the  tendinous  structure  are  arranged  with  great  regularity,  parallel  to 

Fig.  156. 


Attachment  of  Tendon  to  Muscular  Fibre,  in  Skate.     (Bowman.) 

each  other,  and  are  attached  to  the  end  of  the  sarcolemma,  which  termi- 
nates abruptly,  as  in  Figs.  148  &  156;  which  shows  the  attachment  of 
the  tendon  to  the  muscular  fibre  in  the  skate.  Dr.  Leidy1  observed  that 
the  filaments  of  areolar  tissue,  which  form  the  sheaths  of  the  muscular 
fasciculi,  proceed,  for  the  most  part,  in  a  diagonally  crossing  manner 
around  the  fasciculi,  occasionally  passing  in  between  the  fibres  and 
intermingling  with  fine  filaments  of  elastic  tissue  which  exist  in  this 
situation.  The  sheaths  are  also  connected  together  by  filaments  from 
them,  which  pursue  the  same  diagonally  crossing  course.  The  fila- 
ments of  the  areolar  sheaths  become  more  or  less  straight  at  the  extre- 

1  Proceedings  of  the  Academy  of  Natural  Sciences  of  Philadelphia,  vol.  iv.,  No.  6,  1848; 
and  Quain's  Anatomy,  by  Quain  &  Sharpey,  Amer.  edit.,  by  Leidy,  i.  319,  Philadelphia, 
1849.  •  ' 


MUSCLES.  371 

mities  of  the  muscular  fasciculi,  and  combine  with  the  fibrous  filaments 
originating  there  to  form  the  tendinous  connexion  of  the  muscle. 

The  close  union  that  exists  between  the  muscle  and  its  tendon  for- 
merly gave  occasion  to  the  belief,  that  the  latter  is  only  the  former  con- 
densed. An  examination  of  some  of  the  physical  and  vital  properties 
of  the  two  will  show,  that  they  differ  as  essentially  as  any  two  of  the 
constituents  of  the  body  that  could  be  selected.  The  tendon  consists 
chiefly  of  gelatin,  and  does  not  exhibit  the  same  irritability ;  whilst  the 
muscle  is  formed  essentially  of  fibrin  ;  and  contracts  under  the  will, 
as  well  as  on  the  application  of  certain  mechanical  and  chemical  irri- 
tants. The  differences,  in  short,  that  exist  between  the  two,  are  such 
as  distinguish  the  primary  fibrous  and  areolar  tissues ;  yet  the  opinion 
of  their  identity  prevailed  in  antiquity ;  was  embraced  by  Boerhaave 
and  his  school,  and,  as  Dr.  Bostock1  observes,  was  so  generally  admitted 
even  in  the  middle  of  the  last  century,  that  Haller2  and  Sabatier3 
scarcely  ventured  to  give  a  decided  opposition  to  it. 

Similar  remarks  are  applicable  to  the  notion  of  Dr.   Cullen,4  that 
muscles  are  only  the  moving  extremities  of  nerves.     The  fibres  of  the 
muscle  were  supposed  by  him  to  be  continuous  with  those  of  the  nerve ; 
to    be,    indeed,    the   same    substance,    but 
changed   in   structure;    so  that  when   the  Fig.  157. 

nerve  is  converted  into  muscle,  it  loses  the 
power  of  communicating  feeling,  and  ac- 
quires that  of  producing  motion. 

Every  muscle  and  every  fibre  of  a  muscle 
is  probably  supplied  with  bloodvessels,  lym- 
phatics, and  nerves.  These  cannot  be 
traced  into  the  ultimate  filament ;  but,  as 
this  must  be  possessed  of  life  and  be  con- 
tractile under  the  will,  it  must  receive  Capillary  Net- work  of  Muscle. 
through  the  bloodvessels  and  nerves  the 

appropriate  influences.  MM.  Dumas  and  Prevost,5  and  Mr.  Bow- 
man,— as  has  been  remarked, — affirm,  that  the  microscope  shows,  that 
neither  the  one  nor  the  other  terminates  in  the  muscle.  The  vessels 
merely  traverse  the  organs  ; — the  arteries  terminating  in  corresponding 
veins  ;  so  that  the  nutrition  of  muscles  is  effected  by  the  transudation 
of  plastic  materials  through  the  parietes  of  the  artery,  in  the  same  man- 
ner probably  as  various  other  parts, — teeth,  hair,  cartilages,  for  exam- 
ple,— are  nourished.  A  similar  distribution  is  assigned  by  them  to  the 
nerves.  All  the  branches,  they  assert,  enter  the  muscle  in  a  direction 
perpendicular  to  that  of  the  fibres  composing  it ;  and  their  final  ramifi- 
cations, instead  of  terminating  in  the  muscular  fibres,  surround  them 
loopwise,  and  return  to  the  trunk  that  furnished  them,  or  anastomose 
with  some  neighbouring  trunk.  In  their  view,  each  nervous  filament, 
distributed  to  the  muscles,  sets  out  from  the  anterior  column  of  the 

1  An  Elementary  System  of  Physiology,  3d  edit.,  p.  84,  London,  1836. 

2  Elem.  Physiol.,  ii.  1,  18.  3  Traite  complet  d'Anatomie,  i.  242,  Paris,  1791. 
*  Institutions  of  Medicine,  §§  29,  94  ;  or  Works  of  William  Cullen,  M.D.,  by  John  Thorn 

son,  M.D.,  i.  pp.  15,  68,  Edinb.  and  Lond.,  1827. 
6  Magendie's  Journal  de  Physiologic,  torn.  iii. 


372 


MUSCULAR  MOTION. 


Loop-like  termination  of  the  Nerves 
in  voluntary  muscle.— After    Burdach. 

(Todd  and  Bowman.) 


158<  spinal  marrow,  forming  part  of  a  nerv- 

ous trunk  ;  turns  around  one  or  more, 
muscular  fibres,  and  returns  along  the 
same  or  a  neighbouring  trunk  to  the 
posterior  column  of  the  marrow. 

The  red  colour  of  muscles  is  usually 
ascribed  to  the  blood  distributed  to 
them,  as  it  may  be  removed  by  repeated 
washing  and  maceration  in  water  or 
alcohol,  without  the  texture  of  the  mus- 
cle being  modified.  By  some,  it  has 
been  thought,  that  a  quantity  of  red 
blood  remains  attached  to  the  fibres, 
and  is  extravasated  from  the  vessel :  by 
others,  it  is  presumed  with  more  proba- 
bility to  be  contained  in  the  vessels,  and 
according  to  Mulder,1  who  considers 
the  red  colour  to  be  wholly  due  to  the 
blood  in  the  capillary  system  of  the 
muscles,  when  they  are  injected  with 
water,  every  muscle  is  colourless.  Bi- 
chat2  conceived,  that  the  colour  is  de- 
pendent upon  some  foreign  substance 
combined  with  the  fibre;  and  he  grounded 
his  opinion  upon  the  circumstance  that,  in  the  same  animal,  some  of  the 
muscles  are  always  much  redder  than  others,  and  yet  they  do  not  appear 
to  have  a  greater  quantity  of  blood  sent  to  them ;  and  also,  that  in  dif- 
ferent classes  of  animals  the  colour  of  the  muscles  does  not  appear  to 
correspond  with  the  quantity  of  red  blood  circulating  through  their 
vessels.  The  fact,  however,  that  when  muscles  have  been  long  in  a  state 
of  inaction  they  become  pale  ;  and  that,  on  the  other  hand,  the  colour 
becomes  deeper  when  they  are  exercised,  is  additional  evidence,  that 
their  colour  is  dependent  upon  the  blood  they  receive,  which  is  found 
to  diminish  or  increase  in  quantity,  according  to  the  degree  of  inactivity 
or  exertion. 

Muscles  differ,  like  the  primary  fibre,  at  their  extremities  and  centre ; 
the  former  being  composed  of  condensed  areolar  membrane  ;  the  latter 
of  the  muscular  or  fibrous  tissue.  The  centre  of  a  muscle  is  usually 
called  its  venter  or  belly ;  and  the  areolar  texture  at  the  extremities  is 
variously  termed; — that  from  which  it  appears  to  arise  being  called  the 
head  or  origin;  and  that  into  which  it  is  inserted  the  tail,  termination 
or  insertion.  These  terms  are  not  sufficiently  discriminative.  We  shall 
find,  that  a  muscle  is  capable  of  acting  in  both  directions ;  so  that  the 
head  and  the  tail — the  origin  and  insertion — may  reciprocally  change 
places.  In  ordinary  language,  however,  the  extremity  at  which  the 
albugineous  tissue  (if  we  adopt  Chaussier's  nomenclature),  assumes  a 
rounded  form,  so  as  to  constitute  a  cord  or  tendon,  is  called  the  inser- 


1  The  Chemistry  of  Vegetable  and  Animal  Physiology,  translated  by  Fromberg,  &c.,  p. 
589,  Edinburgh  and  Lond.,  1849.  a  Anat.  General.,  ii.  327,  Paris,  1818. 


COMPOSITION  OF  MUSCLES. 


373 


tion.  When  this  tissue  is  expanded  into  a  membrane  it  is  termed  an 
aponeurosis ;  and  in  this  state  it  exists  at  the  head  or  origin  of  the 
muscle  ;  so  that  by  tendon  and  aponeurosis  the  muscles  are  inserted 
into  the  parts,  which  they  are  destined  to  move,  if  we  except  those  that 
are  inserted  into  the  skin. 

Fig.  159.  * 


Compound  Ventriform  Muscle. 

Muscles  are  divided  into  simple  and  compound.  The  simple  are 
those  whose  fibres  have  a  simi- 
lar course  and  arrangement.  Fig.  160. 
They  may  be  either  flat  or 
ventriform,  radiated  or  penni- 
form.  The  compound  arise 
from  different  parts ;  their 
origins  are,  consequently,  by 
distinct  fasciculi,  or  they  may 
terminate  by  distinct  inser- 
tions. Fig.  159,  which  is  a 
representation  of  the  biceps — 
a  flexor  muscle  of  the  forearm 
— is  one  of  these.  It  has,  as 
its  name  imports,  two  heads  running  into  one  belly.  It  is,  also,  an 
example  of  a  ventriform  muscle. 

In  the  pectoralis  major,  Fig.  160,  we  have  an  example  of  the  radi- 
ated muscle,  or  of  one  in  which  the  fibres  converge  toward  their  tendi- 
nous insertion. 

In  the  penniform  muscle,  the  fibres  run  in  a  parallel  direction,  but 
are  all  inserted  obliquely  into  the  tendon,  like  the  feathers  of  a  quill. 
Fig.  161  is  a  representation  of  a  double  penniform  muscle.  Muscles 
may,  also,  be  complicated:  that  is,  with  one  belly,  and  several  tendons 
having  the  fibres  variously  inserted  into  them  ;  or  having  several  bellies 
with  the  tendons  interlaced. 

Fig.  161. 


Penniform  Muscle. 


Double  Penniform  Muscle. 


They  are,  again,  partitioned  into  the  long,  broad,  and  short.  The 
long  muscles  are  situate  chiefly  on  the  limbs,  and  are  concerned  in 
locomotion.  The  broad  generally  form  the  parietes  of  cavities :  they 
are  not  so  much  enveloped  as  the  long  by  strong  fibrous  aponeuroses 


374  MUSCULAR  MOTION. 

or  fascise,  owing  to  their  being  obviously  less  liable  to  displacement ; 
and  the  short  are  situate  in  parts,  where  considerable  force  is  required, 
and  but  little  motion ;  so  that  their  fibres  are  very  numerous. 

The  number  of  muscles,  varies,  of  course,  in  different  animals,  in 
proportion  to  the  extent  and  variety  of  motion  they  are  called  upon 
to  execute.  In  man,  it  is  differently  estimated  by  anatomists;  some 
describing  several  distinct'  muscles  under  one  name ;  and  others  di- 
viding into  many  what  ought  to  belong  to  one.  According  to  the 
arrangement  of  M.  Chaussier,  three  hundred  and  sixty-eight  distinct 
muscles  are  admitted ;  but  others  reckon  as  many  as  four  hundred  and 
fifty. 

When  muscles  are  subjected  to  analysis,  they  are  found  to  consist  of 
fibrin;  osmazome  ;  jelly;  albumen;  phosphates  of  soda,  ammonia,  and 
lime ;  carbonate  of  lime ;  chloride  of  sodium ;  phosphate,  and  lactate 
of  soda;  and,  according  to  Fourcroy  and  Vauquelin,1  sulphur  and 
potassa  are  present.  The  great  constituents  of  the  pure  muscular 
tissue  are, — fibrin,  and  probably  osmazome; — the  gelatin  met  with 
being  ascribable  to  the  areolar  membrane  that  envelopes  the  muscular 
fibres  and  lacerti.  The  membranous  structures  of  young  animals  con- 
tain a  much  greater  quantity  of  jelly  than  those  of  the  adult;  and  it 
is  probably  on  this  account,  that  the  flesh  of  the  former  is  more  gela- 
tinous ;  not  because  the  muscular  fibre  contains  more  gelatin.  M.  The- 
nard  assigns  the  muscles,  on  final  analysis,  the  following  constituents : — 
fibrin ;  albumen ;  osmazome  ;  fat ;  substances  capable  of  passing  to  the 
state  of  gelatin ;  acid  (lactic),  and  different  salts :  kreatin  and  krea- 
tinin  have  likewise  been  found  in  them.  They  have  also  been  ana- 
lyzed by  Berzelius  and  Braconnot2  and  others.  It  must  be  borne  in 
mind,  however,  as  M.  Raspail3  has  properly  remarked,  that  all  these 
are  the  results  of  the  analysis  of  muscle,  as  we  meet  with  it.  The 
analysis  of  muscular  fibre  has  yet  to  be  accomplished.  In  this,  too, 
and  every  analogous  case,  the  analysis  only  affords  us  evidence  of  the 
constituents  of  dead  animal  matter ;  and  some  of  the  products  may 
even  have  been  formed  by  new  affinities  resulting  from  the  operations 
of  the  analyst.  They  can  afford  but  an  imperfect  judgment  of  the  con- 
stitution of  the  living  substance.  These  remarks  are  especially  appli- 
cable to  the  efforts  at  determining  the  composition  of  muscle  by  ulti- 
mate analysis.  Mulder,4  indeed,  affirms,  that  this  is  impracticable — 
"  for  in  this  process  we  burn  a  mixture  of  various  substances,  a  very 
complicated  tissue  of  muscular  fibres,  ligamentary  tissue,  coats  of 
bloodvessels  and  nerves.  If,  therefore,  Playfair  and  Bockmann  have 
found  the  composition  of  muscle  to  be  identical  with  that  of  blood, — 
which  is  a  mixture  of  various  substances,  containing  some  that  are  en- 
tirely different  from  those  of  muscle,  and  in  which  again  others  are 
wanting  that  are  present  in  the  latter, — then  this  may  be  considered  as 

1  Annales  de  Chimie,  Ivi.  43. 

a  Miiller's  Handbuch  der  Physiologie,  Baly's  translation,  Part  i.  p.  369,  Lond.,  1837  ;  and 
Dr.  T.  Thomson,  Chemistry  of  Animal  Bodies,  p.  273,  Edinb.,  1843. 

3  Op.  citat.,  p.  214. 

4  The  Chemistry  of  Vegetable  and  Animal  Physiology,  by  Fromberg,  &c.,  p.  589.  Edinb. 
and  Lond.,  1849. 


COMPOSITION  OF  MUSCLES.  375 

a  proof  that  it  is  impossible  to  find  out  essential  differences  by  means 
of  ultimate  analysis :" — and  he  adds — "  Nothing  has  ever  surprised  me 
more  than  the  assertions  now  so  frequently  repeated,  that  muscle  and 
blood  are  identical  in  composition — two  substances  which  present,  in 
fact,  no  other  point  of  resemblance,  except  this,  that  they  both  con- 
tain protein  compounds.  But  if  we  proceeded  upon  this  principle,  we 
should  be  induced  at  present  to  apply  the  term  identity  to  a  great  num- 
ber of  substances  indeed." 

Muscular  structure  is  liable,  under  particular  circumstances,  to  a 
singular  kind  of  conversion,  to  which  it  may  be  well  to  advert.  When, 
about  the  latter  part  of  the  last  century,  it  was  determined,  for  pur- 
poses of  salubrity,  to  remove  the  bodies  from  the  churchyard  of  Les 
Innocens  at  Paris1 — which  had  been  the  cemetery  for  a  considerable 
part  of  the  population  of  Paris  for  centuries  ;  the  whole  area,  occupy- 
ing about  seven  thousand  square  yards,  was  found  converted  into  a 
mass,  consisting  chiefly  of  animal  manner,  and  raising  the  soil  several 
feet  above  the  natural  level.  On  opening  the  ground,  to  remove  the 
prodigious  collection  of  dead  bodies,  they  proved  to  be  strangely  al- 
tered in  their  nature  and  appearance.  What  had  constituted  the  soft 
parts  of  the  body  was  converted  into  an  unctuous  matter,  of  a  gray 
colour,  and  peculiar,  but  not  highly  offensive,  smell.  According  to 
their  position  in  the  pits, — for  the  bodies  were  deposited  in  pits  or 
trenches,  about  thirty  feet  deep,  each  capable  of  holding  from  twelve 
hundred  to  fifteen  hundred, — and  according  to  the  length  of  time  they 
had  been  deposited,  this  transformation  had  occurred  to  a  greater  or 
less  extent.  It  was  found  to  be  most  complete  in  those  that  were  near- 
est the  centre  of  the  pits,  and  when  they  had  been  buried  about  three 
years.  In  such  case,  every  part,  except  the  bones,  hair  and  nails, 
seemed  to  have  lost  its  properties,  and  to  be  converted  into  gras  des 
cimetieres,  which  was  found  to  be  a  saponaceous  compound,  consisting 
of  ammonia,  united  to  adipocire, — a  substance,  as  its  name  imports, 
possessing  properties  intermediate  between  those  of  fat  and  wax. 
When  the  adipocire  was  freed  from  the  ammonia,  and  obtained  in  a 
state  of  purity,  it  was  found  to  resemble  strongly  spermaceti,  both  in 
physical  and  chemical  qualities.  It  was  afterwards  discovered,  that 
the  conversion  of  muscular  flesh  into  adipocire  might  be  caused  by  other 
means.  Simple  immersion,  in  cold  water,  especially  in  a  running 
stream,  was  found  by  Dr.  Gibbes2  to  produce  the  conversion  more  speed- 
ily than  inhumation.  It  can  be  caused,  too,  still  more  rapidly  by  the 
action  of  dilute  nitric  acid. 

The  chemical  is  not  the  only  interest  attached  to  this  substance.  It 
has  been  adduced  in  a  court  of  justice  for  the  purpose  of  enabling 
some  judgment  to  be  formed  regarding  the  time  that  a  body  may 
have  been  immersed  in  the  water.  It  is  probable  that  this  must  differ 
greatly  according  to  various  circumstances; — as  the  period  that  elapsed 
between  the  death  of  the  individual,  and  the  act  of  immersion;  the 
conditions  of  the  fluid  as  to  rest  or  motion,  temperature,  &c. ;  and  the 

1  Thouret,  Journal  de  Physique,  xxxviii.  255. 
3  Philosophical  Transactions  for  1794  and  1795. 


376  MUSCULAR  MOTION. 

temperature  of  the  atmosphere ;  so  that  any  effort  to  fix  a  time  for 
such  conversion  must  be  liable  to  much  inconclusiveness.  Yet  the  opin- 
ion of  a  medical  practitioner  on  the  subject  has  been  the  foundation  of 
a  juridical  decision.  At  the  Lent  assizes,  holden  at  Warwick,  Eng- 
land, in  the  year  1805,  the  following  case  came  before  the  court.  A 
gentleman,  who  was  insolvent,  left  his  home  with  the  intention, — as 
was  presumed  from  his  previous  conduct  and  conversation, — of  de- 
stroying himself.  Five  weeks  and  four  days  after  that  period,  his  body 
was  found  floating  down  a  river.  The  face  was  disfigured  by  putrefac- 
tion, and  the  hair  separated  from  the  scalp  on  the  slightest  pull ;  but 
the  other  parts  of  the  body  were  firm  and  white,  without  any  putrefac- 
tive appearance.  On  examining  the  body,  it  was  found  that  several 
parts  were  converted  into  adipocire.  A  commission  of  bankruptcy 
having  been  taken  out  against  the  deceased  a  few  days  after  he  left 
home,  it  became  an  important  question  to  the  interest  of  his  family  to 
ascertain  whether  or  not  he  was  living  at  that  period.  From  the 
changes  sustained  by  the  body,  it  was  presumed,  that  he  had  drowned 
himself  on  the  day  he  left  home;  and  to  corroborate  the  presumption, 
the  evidence  of  Dr.  Gibbes  was  requested,  who,  from  his  experiments 
on  this  subject,  it  was  thought,  was  better  acquainted  with  it  than  any 
other  person.  Dr.  Gibbes  stated  on  the  trial,  that  he  had  procured  a 
small  quantity  of  this  fatty  matter,  by  immersing  muscular  parts  of 
animals  in  water  for  a  month,  and  that  it  required  five  or  six  weeks  to 
form  it  in  any  large  quantity.  Upon  this  evidence,  the  jury  were  of 
opinion,  that  the  deceased  was  not  alive  at  the  time  the  commission  was 
taken  out,  and  the  bankruptcy  was  accordingly  superseded!1 

Bones. 

The  bones  are  the  hardest  parts  of  the  animal  frame ;  and  serve  as 
a  base  of  support  and  attachment  to  the  soft  parts.  They  constitute 
the  framework  of  the  body,  and  determine  its  general  shape.  The 
principal  functions  they  fulfil  are, — to  form  defensive  cavities  for  the 
most  important  organs  of  the  body, — the  encephalon,  spinal-marrow, 
&c. — and  to  act  as  so  many  levers  for  transmitting  the  weight  of  the 
body  to  the  soil,  and  for  the  different  locomotive  and  partial  movements. 
To  them  are  attached  the  different  muscles,  concerned  in  those  func- 
tions. In  man  and  the  higher  classes  of  animals,  the  bones  are,  as  a 
general  rule,  within  the  body;  his  skeleton  is,  consequently,  said  to  be 
internal.  In  the  Crustacea,  the  testaceous  mollusca,  and  certain  in- 
sects, the  skeleton  is  external;  the  whole  of  the  soft  parts  being  con- 
tained within  it.  The  lobster  and  crab  are  familiar  instances  of  this 
arrangement. 

The  stature  of  the  human  skeleton  is  various,  and  may  be  taken,  on 
the  average,  perhaps, — in  -those  of  European  descent, — at  about  five 
feet  seven  and  a  half  inches.2  We  find,  however,  examples  of  con- 
siderable variation  from  this  average.  A  skeleton  of  an  Irish  giant, 

1  Male,  Epitome  of  Forensic  Medicine,  in  Cooper's  Tracts  on  Medical  Jurisprudence, 
Philad.,  1919. 

a  Quetelet,  Sur  THomme,  &c.,  Paris,  1835;  or  translation  by  Dr.  Knox,  p. 64, Edinb.,  1842. 


BONES.  377 

in  the  museum  of  the  Royal  College  of  Surgeons  of  London,  measures 
eight  feet  four  inches.  On  the  other  hand,  Bebe,  the  dwarf  of  Stanislaus, 
King  of  Poland,  was  only  thirty-three  inches  high ;  and  a  Polish  noble- 
man, Boruwlaski,  is  said  to  have  measured  twenty-eight  French  inches, 
at  twenty-two  years  of  age.  Mr.  Mathews,  the  comedian,  states,  how- 
ever, that  he  measured  him  late  in  life  and  found  that  his  height  was  three 
feet  three  inches ;  and  that  he  had  undoubtedly  grown  an  inch  a  short 
time  before  he  was  eighty-one,  when  he  measured  three  feet  four.1  He 
had  a  sister,  whose  height  was  twenty-one  inches.2  Sir  George  Simp- 
son,3 in  one  of  the  villages  of  Siberia,  saw  a  dwarf,  about  forty  years 
of  age,  thickset,  with  a  large  head,  and  barely  two  feet  and  a  half  high. 
"Eor  his  inches,  however,"  says  Sir  George,  "he  was  a  person  of  great 
importance,  being  the  wise  man  of  the  place,  and  the  great  arbiter  in 
all  disputes,  whether  of  love  or  of  business."  The  celebrated  dwarf 
called  General  Tom  Thumb,  was  seen  by  the  author  in  1847.  He  was 
then  said  to  be  fifteen  years  old;  weighed  at  the  Mint  twenty  pounds 
and  two  ounces,  and  was  twenty-eight  inches  high.  His  intellect  was 
evidently  limited,  childlike. 

The  bones  may  be  divided  into  short,  broad,  or  flat,  and  long.  Short 
bones  are  met  with  in  parts  of  the  body,  which  require  to  be  both  solid 
and  movable: — in  the  hands  and  feet,  for  example;  and  in  the  spine. 
Flat  or  broad  bones  form  the  parietes  of  cavities,  and  aid  materially  in 
the  movements  and  attitudes,  by  affording  an  extensive  surface  for  the 
attachment  of  muscle.  Long  bones  are  chiefly  intended  for  locomo- 
tion ;  and  are  met  with  only  in  the  extremities.  The  shape  of  the  body 
or  shaft  and  of  the  extremities  of  a  bone,  merits  attention.  The  shaft 
or  middle  portion  is  the  smallest  in  diameter,  and  is  usually  cylindrical. 
The  extremities,  on  the  other  hand,  are  expanded;  a  circumstance, 
which  not  only  adds  to  the  solidity  of  the  articulations,  but  diminishes 
the  obliquity  of  the  insertion  of  the  tendons,  passing  over  them,  into 
the  bones.  In  their  interior  is  a  medullary  canal  or  cavity,  which  con- 
tains the  medulla,  marrow  or  pith: — a  secretion,  whose  office  will  be  a 
theme  for  after  inquiry.  One  great  advantage  of  this  canal  is,  that  it 
makes  the  bone  a  hollow  cylinder,  and  thus  diminishes  its  weight.  On 
many  of  the  bones,  prominences  and  cavities  are  perceptible.  The 
eminences  bear  the  generic  name  of  apophyses  or  processes.  Their 
great  use  is  to  cause  the  tendons  to  be  inserted  at  a  much  greater  angle 
into  the  bones  they  have  to  move.  It  may  be  seen,  hereafter,  that  the 
nearer  such  insertion  is  to  the  perpendicular  to  the  lever,  the  greater 
will  be  the  effect  produced. 

The  cavities  are  of  various  kinds.  Some  are  articular:  others  for 
the  insertion,  reception,  or  transmission  of  parts.  Those  of  insertion 
and  reception  afford  space  for  attachment  of  muscles;  those  of  trans- 
mission, &c.,  are  frequently  incrusted  with  cartilage;  converted  into 
canals  by  means  of  ligament,  and  furnished  with  a  synovial  membrane, 

1  A  Continuation  of  the  Memoirs  of  Charles  Mathews,  Comedian,  by  Mrs.  Mathews, 
Amer.  edit,  i.  165,  Philad.,  1839. 

8  Lectures  on  Physiology,  Zoology,  &c.,  by  W.  Lawrence,  p.  434,  Lond.,  1819. 

3  An  Overland  Journey  round  the  World,  Amer.  edit.,  Part  ii.  p.  203,  Philad.,  1847. 


378  MUSCULAR  MOTION. 

which  lubricates  them;  and  facilitates  the  play  of  the  tendons,  for  the 
passage  of  which  they  are  destined. 

The  mechanical  structure  of  bone  is  a  laminated  framework  incrusted 
by  an  earthy  substance,  and  penetrated  by  exhalant  and  absorbent 
vessels,  arteries,  veins  and  nerves.  M.  Herissant1  appears  to  have  been 
one  of  the  first  who  stated,  that  bone  is  essentially  composed  of  two 
substances: — the  one  a  cartilaginous  basis  or  parenchyma,  giving  form 
to  the  part; — the  other  a  peculiar  earthy  matter  deposited  on  this  basis, 
and  communicating  to  it  hardness.  These  two  constituents  can  be  readily 
demonstrated ;  the  first,  by  digesting  the  bone  in  dilute  chlorohydric 
acid,  which  dissolves  the  earthy  part,  without  acting  on  the  animal 
matter;  and  the  second,  by  burning  the  bone  until  all  the  animal  mat- 
ter is  consumed,  whilst  the  earthy  is  left  untouched. 

If  we'  take  a  long  bone  and  divide  it  longitudinally,  we  find,  that  it 
is  composed  of  three  different  substances,  all  of  which  may,  however, 
be  regarded  as  the  same  osseous  tissue  in  various  degrees  of  condensa- 
tion. These  are, — the  hard  or  compact  substance ;  the  spongy  or  areolar; 
and  the  reticulated.  The  first  is  in  the  most  condensed  form;  it  exists 
at  the  exterior  of  the  bone,  and  constitutes  almost  the  whole  of  the 
shaft.  The  second  is  seen  towards  the  extremities  of  a  long  bone, 
and  in  almost  the  whole  of  the  short  bones.  In  it,  the  laminae  are  less 
close,  and  have  a  cancellated  appearance, — the  cellules  bearing  the 
name  of  cancelli.  The  reticulated  substance  is  a  still  looser  formation ; 
the  laminae  being  situate  at  a  considerable  distance;  and  the  space 
between  filled  up  with  a  series  of  membranous  cells,  which  lodge  the 
marrow.  The  marginal  figures  represent  a  longitudinal  and  a  trans- 
verse section  of  the  same  bone,  in  which  this  arrangement  is  well 
exhibited. 

We  have  seen  the  advantages  of  the  expanded  extremities  of  long 
bones,  as  regards  the  insertion  of  muscles;  but  it  is  obvious,  that  if 
these  portions  of  the  bone  had  consisted  of  the  heavy  compact  tissue, 
the  increased  weight  would  have  destroyed  the  advantages,  that  would 
otherwise  have  accrued;  whilst,  if  the  shaft  of  the  bone,  exposed,  as  it 
is,  to  external  violence,  had  consisted  of  the  spongy  tissue  only,  it  would 
not  have  offered  the  necessary  resistance.  It  is,  therefore,  formed 
almost  entirely  of  the  compact  tissue;  so  that  a  section  of  one  inch,  taken 
from  the  body  of  the  bone,  will  not  differ  essentially  in  weight  from  an 
inch  taken  from  the  extremity.  Nor  does  the  cavity  within  the  bones 
dimmish  their  strength,  as  might  at  first  sight  be  presumed.  By  en- 
larging the  circumference,  the  contrary  effect  is  produced ;  for  we  shall 
see,  in  the  mechanical  proem  to  the  particular  movements,  that  of  two 
hollow  columns,  formed  of  an  equal  quantity  of  matter  and  of  the  same 
height,  that,  which  has  the  larger  cavity,  is  actually  the  stronger.  A 
very  important  use  of  the  cancellated  or  spongy  texture  of  the  bones 
was  suggested  by  a  distinguished  individual  of  this  country,  to  whom 
surgical  science,  in  particular,  has  been  largely  indebted.  Dr.  Physick2 
asserts,  that  it  serves  to  diminish,  and,  in  many  cases,  to  prevent,  con- 

1  Memoir,  de  1'Academ.  des  Sciences  de  Paris,  pour  1758,  p.  322. 
3  Homer,  Special  and  General  Anatomy,  &c.,  5th  edit.,  Philad.,  1843. 


ANALYSIS  OF  BONES. 


379 


cussion  of  the  brain,  and  of  other  viscera,  in  Fis-  162- 

falls  and  blows.  The  demonstration,  which 
he  gives  of  this,  is  simple  and  satisfactory. 
If  we  suspend  a  series  of  six  ivory  balls  by 
threads;  raise  the  ball  at  one  extremity  of 
the  series,  and  allow  it  to  fall  on  the  next  to 
it,  the  farthest  ball  in  the  series  is  impelled 
to  a  distance  which  corresponds  with  the 
momentum  communicated  by  the  first  ball 
to  the  second.  But  if  we  substitute,  for  the 
middle  ball  of  the  series,  a  ball  made  of 
the  cellular  structure  of  bone,  almost  the 
whole  of  the  momentum  is  lost  in  this 
osseous  structure;  especially,  if  it  be  pre- 
viously filled  with  tallow  or  well  soaked  in 
water,  so  as  to  bring  it  to  a  closer  approxi- 
mation to  the  living  condition. 

Bones  consist  of  earthy  salts,  and  animal 
matter,  intimately  blended.  The  latter  is 
chiefly  cartilage,  gelatin,  and  the  peculiar 
fatty  matter — the  marrow.  On  reducing 

bones  to  powder,  and  digesting  them  in  water,  Sections  of  a  Bone, 

the  fat  rises  and  swims  upon  the  surface  ;      1,2.  Longitudinal  section  of  the  ex- 
and  the  gelatin  is  dissolved.     According  to  'Transverse  section  of  the  body. 
the  analysis  of  Berzelius,  102  parts  of  dry 

human  bones  consist  of  animal  matter,  33'3;  basic  phosphate  of  lime, 
51-04;  carbonate  of  lime,  11-30;  fluoride  of  calcium,  2;  phosphate  of 
magnesia,  1/16;  soda,  chloride  of  sodium,  and  water,  1/2.  It  has  been 
much  doubted,  however,  whether  fluoride  of  calcium  is  contained  in 
recent  bones ;  whilst  it  is  admitted  to  have  been  defected  in  fossil  bones. 
According  to  Dr.  Daubeny,1  it  exists  in  the  former,  in  about  a  quarter 
of  the  proportion  in  which  it  is  present  in  the  latter;  but  the  propor- 
tions in  different  specimens  of  both  kinds  are  variable.  Dr.  Daubeny 
ascribes  the  failure  of  those  who  have  not  detected  fluorine  except  in 
fossil  bones  and  teeth,  to  the  tenacity  with  which  it  is  retained  by 
animal  matter ;  and  to  its  being  carried  off  with  the  carbonic  acid 
evolved  at  the  same  time,  too  rapidly  to  act  upon  glass  exposed  to  it. 
He,  therefore,  before  submitting  the  bones  to  the  action  of  strong  sul- 
phuric acid,  burns  away  all  the  animal  matters;  removes  the  carbonic 
acid  by  dissolving  them  in  chlorohydric  acid;  then  throws  down  the 
earthy  phosphates  by  caustic  ammonia,  and  dries  them. 

MM.  Fourcroy  and  Vauquelin  found  in  bones  oxides  of  iron  and 
manganese,  silica,  and  albumen.  Mr.  Hatchett  detected,  also,  a  small 
quantity  of  sulphate  of  lime.  Schreger  gives  the  following  as  the  pro- 
portions of  the  animal  and  earthy  parts: 


Animal  matter 
Earthy  matter 


95-68 


95-02 


Aged. 
12-20 
84-10 

96-30 


1  Philosophical  Magazine,  Aug.,  1844, 


380  MUSCULAR  MOTION. 

The  following  are  the  average  proportions,  according  to  Lehmann,1 
from  his  own  analyses,  and  those  of  two  other  observers. 

Sebastian.  Lehmann.  Frerichs. 

Compact  Bone.        Spongy  Bone. 

Organic       .         .       63'66  32-28  31'2  37-82 

Earthy         .         .       63-34  67-72  68'8  62-18 

Dr.  Stark2  affirms,  from  the  results  of  his  experiments,  that  the 
mean  proportion  of  animal  matter  in  the  bones  of  all  vertebrate  animals 
is  33*91;  of  earthy  66*09;  the  mean  proportion  in  the  bones  of  man 
33*39  of  animal  matter;  66*61  of  earthy. 

The  bones  are  enveloped  by  a  dense  fibrous  membrane,  termed,  in 
the  abstract,  periosteum ;  but  assuming  different  names  according  to 
the  part  it  covers.  On  the  skull,  it  is  called  pericranium:  and  its 
extensions  over  the  cartilages  of  prolongation  are  called  perichondrium. 
The  chief  uses  of  this  expansion  are,  to  support  the  vessels  in  their 
passage  to  and  from  the  bone,  and  to  assist  in  its  formation ;  for  we 
find,  that  if  the  periosteum  be  removed  from  a  bone,  it  becomes  dead 
at  the  surface  previously  covered  by  the  membrane,  and  exfoliates.  In 
the  foetus,  it  adds  materially  to  the  strength  of  bone,  prior  to  the 
completion  of  ossification.  In  the  long  bones,  ossification  commences 
at  particular  points ;  one  generally  in  the  shaft,  and  others  at  the 
different  articular  and  other  processes.  These  ossified  portions  are, 
for  some  time,  separated  from  each  other  by  the  animal  matter,  which 
alone  composes  the  intermediate  portions  of  the  bone ;  and,  without 
this  fibrous  envelope,  they  would  be  too  feeble,  perhaps,  to  resist  the 
strains  to  which  they  are  exposed.  The  periosteum,  moreover,  affords 
a  convenient  insertion  for  muscles  destined  to  act  upon  bones ;  and 
enables  them  to  slide  more  readily  when  contracting :  hence  friction  is 
avoided. 

The  cavity  of  lon^  bones  is  lined  by  a  membrane — called  medullary 
membrane  or  internal  periosteum — which  is  supplied  with  numerous 
vessels ;  adheres  to  the  internal  surface  of  bone,  and  is  not  only  con- 
cerned in  its  nutrition,  but  in  the  secretion  of  the  marrow,  and  likewise 
of  a  kind  of  oily  matter,  which  differs  from  marrow  in  being  more 
fluid,  and  is  contained  in  cells  formed  by  the  spongy  substance,  and  in 
areolae  of  the  compact  substance.  This  is  called  oil  of  bones. 

Marrow  is  considered  to  be  lodged  in  membranous  cells,  formed  by  an 
extension  of  the  internal  periosteum ;  whilst,  according  to  Mr.  Howship,3 
oil  of  bones  is  probably  deposited  in  longitudinal  canals — Haversian 
canals — which  traverse  the  solid  substance  of  the  bone,  and  through 
which  its  vessels  are  transmitted.  If  a  thin  transverse  section  of  long 
bone  be  examined  under  a  high  magnifying  power,  the  bony  matter  is 
observed  to  be  arranged  in  concentric  circles  around  the  orifices  of  the 
canals  as  in  Fig.  164.  These  circles  are  marked  by  a  number  of  stel- 
lated dark  spots  formerly  termed  osseous  corpuscles;  but  as  they  are 
minute  cavities  in  the  bony  substance,  now  more  appropriately  called 
lacunse.  From  these,  fine  pores  or  tubes,  termed  canaliculi,  proceed, 

1  Schmidt's  Jahrbncher,  No.  vi.,  1843. 

2  Edinburgh  Medical  and  Surgical  Journal,  April,  1845,  p.  313. 
MedicoChirurg.  Transact.,  vii.  393. 


ANALYSIS  OF  BONES. 


381 


which  traverse  the  substance  of  the  ttpe,  and 
communicate  irregularly  with  each  other.  All 
the  different  lacunae  communicate  by  means  of 
the  canaliculi  with  the  Haversian  canals ;  so 
that  fluid  may  pass  to  every  part  of  the  osseous 
substance,  and  thus  convey  fluid  for  nutrition. 
They  open,  likewise,  into  the  great  medullary 
canal,  and  into  the  cavities  of  the  cancellated 
texture.  Blood  corpuscles  cannot  pass  along 
them,  as  their  largest  diameter  has  not  seemed 
to  be  more  than  from  l-20000th  to  l-14000th 
of  an  inch ;  and  the  smallest  not  more  than 
from  l-60000th  to  l-40000th. 

The  nature  and  fancied  uses  of  marrow  and 
oil  of  bones  will  be  considered  elsewhere. 

The  bones,  periosteum,  and  marrow  are,  in 
the  sound  state,  amongst  the  insensible  parts  of 
the  frame.  They  are  certainly  not  sensible  to 
ordinary  irritants ;  but,  when  morbid,  exhibit 
intense  sensibility.  This  applies,  at  least,  to 
bones  and  the  periosteum ;  the  sensibility,  which 
has  been  ascribed  to  the  marrow,  in  disease, 
being  probably  owing  to  that  of  the  prolonga- 
tions of  the  membrane  in  which  it  is  contained. 

Fig.  164. 


Fig.  163. 


Haversian  Canals,  seen  on  a 
Longitudinal  Section  of  the 
Compact  Tissue  of  the  Shaft 
of  one  of  the  Long  Bones. 

1.  Arterial  canal.  2.  Venous 
canal.  3.  Dilatation  of  another 
venous  canal. 


Transverse  Section  of  Compact  Tissue  of  Humerus  magnified  about  150  diameters. 

Three  of  the  Haversian  canals  are  seen,  with  their  concentric  rings;  also  the  corpuscles  or  lacunas, 
With  the  canaliculi  extending  from  them  across  the  direction  of  the  lamellae.  The  Haversian  apertures 
had  got  filled  with  debris  in  grinding  down  the  section,  and  therefore  appear  black  in  the  figure,  which 
represents  the  object  as  viewed  with  transmitted  light. 

The  number  of  the  bones  in  the  body  is  usually  estimated  at  two 
hundred  and  forty,  exclusive  of  the  sesamoid,  which  are  always  found 


882  MUSCULAR  MOTION. 

in  pairs  at  the  roots  of  the  thiu^b  and  great  toe ;  between  the  tendons 
of  the  flexor  muscles  and  joints;  and,  occasionally,  at  the  roots  of  the 
fingers  and  small  toes. 

The  bones  are  connected  by  means  of  articulations  or  joints,  which 
differ  materially%om  each  other.  To  all  the  varieties,  names  are  ap- 
propriated, which  form  a  difficult  task  for  the  memory  of  the  anatomical 
student.  Technically,  every  part  at  which  two  bones  meet,  and  are 
connected,  is  called  an  articulation,  whether  any  degree  of  motion 
exists  or  not.  This,  indeed,  is  the  foundation  of  the  division  that  pre- 
vails at  the  present  day, — the  articulations  being  separable  into  two 
classes  ;  the  immovable  or  synarthroses ;  and  the  movable  or  diarthroses. 
Synarthroses  are  variously  termed,  according  to  their  shape.  When 
the  articular  surfaces  are  dovetailed  into  each  other,  the  joint  is  called 
a  suture.  This  is  the  articulation  that  prevails  in  the  bones  of  the 
skull.  Harmony  is  when  the  edges  of  bones  are  even,  and  merely 
touch ;  as  in  the  bones  of  the  head  in  quadrupeds  and  birds.  When  a 
pit  in  one  bone  receives  the  projecting  extremity  of  another,  we  have 
a  case  of  gomphosis.  It  is  exhibited  in  the  union  between  the  teeth 
and  their  sockets.  Lastly,  schindylesis  is  when  the  lamina  of  one  bone 
is  received  into  a  groove  of  another ;  as  in  the  articulation  of  the 
vomer,  which  separates  the  nasal  fossae  from  each  other.  The  movable 
articulations  comprise  two  orders : — amphiarthroses,  in  which  the  two 
bones  are  intimately  united  by  an  intermediate  substance,  of  a  soft 
and  flexible  character,  as  in  the  junction  of  the  vertebrae  with  each 
other;  and  diarthroses,  properly  so  called.  The  last  admit  of  three 
subdivisions — enarthroses  or  ball  and  socket  joints;  the  condyloid,  in 
which,  owing  to  the  head  being  oval,  the  movements  are  not  as  easy  in 
all  directions  as  when  it  is  spherical ;  and  the  ginglymoid  or  ginglymus, 
in  which  the  motion  can  occur  in  only  one  direction,  as  in  a  hinge. 
The  farther  subdivision  of  the  joints  belongs  more  to  anatomy  than 
to  physiology. 

The  articular  surfaces  of  bones  never  come  into  immediate  contact. 
They  are  tipped  with  a  firm,  highly  elastic  substance,  called  cartilage  ; 
which,  by  its  smoothness,  enables  the  bones  to  move  easily  upon  each 
other ;  and  may  have  some  influence  in  deadening  shocks,  and  defending 
the  bones,  which  it  covers.  The  arrangement  of  cartilage  varies  ac- 
cording to  the  shape  of  the  extremity  of  the  bone.  If  it  be  spherical, 
the  cartilage  is  thick  at  the  centre,  and  gradually  diminishes  towards 
the  circumference.  In  the  cavity,  the  reverse  is  the  case  ;  the  cartilage 
is  thin  at  the  centre,  and  becomes  thicker  towards  the  circumference ; 
whilst  on  a  trochlea  or  pulley  its  thickness  is  nearly  every  where  alike. 

An  admirable  provision  against  displacement  of  bones  at  the  articu- 
lations is  seen  in  the  ligaments.  These,  by  the  French  anatomists,  are 
distinguished  into  two  kinds — fibrous  capsules,  and  ligaments  properly 
so  called.  The  former  are  a  kind  of  cylindrical  sac,  formed  of  a  firm, 
fibrous  membrane ;  open  at  each  extremity,  by  which  they  closely 
embrace  the  articular  ends  of  bones ;  and  loose,  when  the  joint  admits 
of  much  motion.  In  this  way,  the  articulation  is  completely  enclosed : 
they  generally  bear  the  name  of  capsular  ligaments.  The  ligaments, 
properly  so  called,  are  bands  of  the  same  kind  of  tissue,  which  extend 


PHYSIOLOGY  OF  MUSCULAR  MOTION.  383 

from  one  bone  to  another ;  by  their  rq^tance  preserving  the  bones  in 
situ;  and  by  their  suppleness  admitting  the  necessary  motion. 

The  interior  of  all  these  articulations  is  lubricated  by  a  viscid  fluid, 
called  synovia.  This  is  secreted  by  a  peculiar  membrane  of  a  serous 
nature  ;  and  its  use  is  to  diminish  friction,  and,  aMhe  same  time,  to 
favour  adhesion.  The  mode  in  which  it  is  secreted,  and  its  chief  pro- 
perties and  uses,  will  be  the  subject  of  future  inquiry. 

In  certain  of  the  movable  articulations,  fibro-cartilaginous  substances, 
frequently  called  inter  articular  cartilages,  are  found  between  the  articu- 
lar surfaces,  and  not  adherent  to  either.  These  have  been  supposed  to 
form  a  kind  of  cushion,  which,  by  yielding  to  pressure,  and  returning 
upon  themselves,  may  protect  the  joints  to  which  they  belong ;  and, 
accordingly,  it  is  asserted,  that  they  are  met  with  in  joints,  which  have 
to  sustain  the  greatest  pressure  ;  but  M.  Magendie1  properly  remarks, 
that  they  do  not  exist  in  the  hip  or  ankle-joint,  which  have  constantly  to 
support  the  strongest  pressure.  The  use,  which  he  suggests,  is  more 
specious; — that  they  may  favour  the  extent  of  motion,  and  prevent 
displacement. 

The  stability  of  the  joints  is  likewise  aided  by  the  manner  in  which 
muscles  or  tendons  pass  over  them.  These  are  contained  in  an  aponeu- 
rotic  sheath,  to  prevent  their  displacement ;  and  thus  the  whole  limb 
becomes  well  protected,  and  dislocation  unfrequent,  even  in  those  joints, 
as  that  of  the  shoulder,  which,  as  regards  their  osseous  arrangement, 
ought  to  be  very  liable  to  displacement. 

It  has  been  suggested  by  Weber,  that  the  head  of  the  thigh-bone  is 
retained  in  situ,  not  by  the  power  of  the  muscles  or  ligaments,  but  by 
the  pressure  of  the  surrounding  atmosphere  ;  and  Lauer,2  who  repeated 
Weber's  experiments  under  the  directions  of  Fricke,  of  Hamburg,  is  of 
opinion,  that  atmospheric  pressure  must  be  classed  among  the  means  by 
which  the  lower  extremity  is  kept  in  apposition  with  the  trunk  of  the 
body. 

PHYSIOLOGY   OF   MUSCULAR   MOTION. 

By  voluntary  motion  or  that  effected  by  the  muscular  system  of  ani- 
mal life,  we  mean  contraction  of  the  muscles  under  the  influence  of 
volition  or  will.  This  influence  is  propagated  along  the  nerves  to  the 
muscles,  which  are  excited  by  it  to  contraction.  The  encepJialon,  spi- 
nal marrow,  nerves,  and  'muscles  are,  therefore,  organs  of  voluntary 
muscular  contraction. 

Volition  is  a  function  of  the  encephalon,  and  might  have  been  with 
much  propriety  included  under  the  physiology  of  the  intellectual  and 
moral  acts ;  but  as  it  is  so  intimately  concerned  with  muscular  motion, 
it  was  judged  advisable  to  defer  its  consideration.  That  in  man  and 
the  higher  animals,  it  is  a  product  of  encephalic  action  is  proved  by 
many  facts.  If  the  brain  be  injured  in  any  manner; — by  fracture  of  the 
skull,  or  by  effusion  of  blood,  producing  apoplectic  pressure  ; — or  if  it  be 
deprived  of  its  functions  by  a  strong  dose  of  any  narcotic  substance ; — 

1  Precis  Elementaire,  2de  edit.,i.  292,  Paris,  1823. 

8  Zeitschrift  fur  die  gesammte  Medicin,  Band  ii.  Heft  3. 


384  MUSCULAR  MOTION. 

or  if,  again,  it  be  in  a  state  of  Jtest,  as  in  sleep  ; — volition  is  no  longer 
exerted  ;  and  voluntary  motion  is  impracticable.  This  is  the  cause  why 
the  erect  attitude  cannot  be  maintained  during  sleep  ;  and  why  the  head 
falls  forward  upon  the  chest,  when  somnolency  is  to  such  an  extent  as 
to  deprive  the  esfcisor  muscles  of  the  back  and  head  of  their  stimulus 
to  activity.1  That  an  emanation  from  the  encephalon  is  necessary  is 
likewise  proved  by  the  effect  of  tying,  cutting,  compressing,  or  stupefy- 
ing a  nerve  proceeding  to  a  muscle ;  it  matters  not  that  the  will  may 
act ;  the  muscle  does  not  receive  the  excitation,  and  no  motion  is  pro- 
duced ;  a  fact  which  proves,  that  nerves  are  the  channels  of  communi- 
cation between  the  brain  and  the  muscles.  If,  again,  we  destroy  the 
medulla  oblongata  and  medulla  spinalis,  we  abolish  all  muscular  mo- 
tion, notwithstanding  the  brain  may  will,  and  the  muscles  be  in  a  state 
of  physical  integrity  ;  because  we  have  destroyed  the  parts  whence  the 
nerves  proceed.  In  like  manner,  by  successively  slicing  away  the 
medulla  spinalis  from  its  base  to  the  occiput,  we  paralyse,  in  succession, 
every  muscle  of  the  body  that  receives  its  nerves  from  the  spinal  marrow. 

Experiments  of  physiologists  have  confirmed  the  view,  that  the  ence- 
phalon is  the  chief  seat  of  volition.  When  it  has  been  sliced  away  to  a 
certain  extent,  the  animal  has  been  thrown  into  a  state  of  stupor, 
attended  with  loss  of  sensibility,  power  of  locomotion,  and  especially 
spontaneous  motion ;  and  in  writing,  dancing,  speaking,  &c.,  we  have 
indisputable  evidence  of  its  direction  by  the  intellect.  It  is  not  so  clear, 
that  the  seat  of  volition  is  restricted  to  the  encephalon.  There  are 
actions  of  the  yet  living  trunk,  which  appear  to  show,  that  an  obscure 
volition  may  be  exerted  even  after  the  brain  has  been  separated  from 
the  rest  of  the  body ;  and  acephalous  children  have  not  only  moved 
perceptibly  when  in  utero,  but  at  birth.  Without  referring  to  the  low- 
est classes  of  animals,  which  execute  voluntary  motions  for  a  long  time 
after  they  have  been  bisected,  every  one  must  have  noticed  the  motions 
of  decapitated  fowls,  which  continue  for  a  time,  to  run  and  leap,  and 
apparently,  to  suffer  uneasiness  in  the  incised  part. 

The  feats  of  the  Emperor  Commodus  are  elucidative  of  this  matter. 
Herodian  relates,  that  he  was  in  the  habit  of  shooting  at  the  ostrich,  as 
it  ran  across  the  circus,  with  an  arrow  having  a  cutting  edge  ;  and, 
even  when  the  shaft  was  true  to  its  destination,  and  the  head  was  sev- 
ered from  the  body,  it  usually  ran  several  yards  before  it  dropped. 
Kaauw  Boerhaave — nephew  of  the  celebrated  Hermann,  himself  an  emi- 
nent medical  teacher  at  St.  Petersburg — asserts  that  he  saw  a  cock, 
thus  decapitated,  run  a  distance  of  twenty-three  feet.  Cases  are  also 
recorded  of  men  walking  a  few  steps  after  decapitation,  striking  their 
breasts,  &c.  ;  but  they  can  scarcely  be  regarded  as  authentic.2  In 
countries  where  judicial  execution  consists  in  decapitation  by  the  sword, 
sufficient  opportunities  must  have  presented  themselves  for  testing  this 
question;  but  no  zealous  Naturforscher  appears  to  have  been  pre- 

1  Adelon,art.  Encephale  (Physiol.)  in  Dict.de  Med.,  vii.  516,  Paris,  1823;  and  Physiol.  de 
l'Homme,ii.25,  2de  edit,  Paris,  1829. 

2  Adelon,  op.  citat.,  ii.  28 ;  and  Dr.  J.  R.  Coxe,  in  Dunglison's  Amer.  Med.  Intelligencer, 
for  May  15,  1837. 


SEAT  OF  VOLITION.  385 

sent  to  record  them.      Similar  opportunities  have  likewise  occurred 
under  the  operations  of  the  guillotine. 

M.  Legallois,1  in  some  experiments,  which  he  instituted,  for  the  pur- 
pose of  determining  the  nervous  influence  on  the  heart,  &c.,  found  that 
rabbits,  which  he  had  deprived  of  their  heads  and  hinder  extremities, 
but  still  kept  alive  by  artificial  respiration,  moved  their  fore  paws  when- 
ever he  stimulated  them  by  plucking  their  hairs. 

With  regard  to  complete  acephali,  or  those  foetuses  which  are  totally 
devoid  of  encephalon, — although  they  may  vegetate  in  utero,  they  ex- 
pire after  birth,  owing  to  their  being  devoid  of  the  medulla  oblongata  in 
which  is  the  nervous  system  of  respiration.  Monsters  have  been  born 
without  the  brain,  but  with  part  of  the  encephalon.  These  have  been 
called,  by  way  of  distinction,  anencepliali  or  hemicephali.  Where  the 
medulla  oblongata  exists,  they  possess  the  nervous  system  of  the  senses, 
and  of  respiration,  and  are,  consequently,  able  to  live  for  a  time  after 
birth,  and  to  exert  certain  muscular  movements,  as  sucking,  moving  the 
limbs,  evacuating  the  excretions,  &c.  M.  Adelon  asserts,  that  none  of 
these  facts  ought  to  shake  the  proposition, — that  in  the  superior  animals, 
and  consequently  in  man,  the  medulla  spinalis  and  nerves  are  merely 
the  conductors  of  volition  or  the  locomotive  will;  and  that  volition  is 
produced  in  the  encephalon  alone.  His  arguments  on  this  point  are 
not,  however,  characterized  by  that  ingenuousness  and  freedom  from 
sophism,  for  which  his  physiological  disquisitions  are  generally  distin- 
guished. "First  of  all,"  he  observes,  "the  fact  of  the  progression  and 
motions  of  men  and  quadrupeds  after  decapitation  is  manifestly  apo- 
cryphal; and  even  if  we  admit,  that  certain  animals  still  execute  certain 
movements  after  decapitation,  are  such  evidently  regular  and  ordained  ? 
And,  supposing  them  to  be  so,  may  not  this  have  arisen  from  the  con- 
formation of  the  parts,  or  from  habits  contracted  by  the  organs?  This 
last  appears  to  us  most  probable ;  for  if,  from  any  cause  whatever,  the 
muscles  of  a  part  contract,  they  cause  the  part  to  execute  such  motions 
as  the  joints,  entering  into  its  composition,  require;  and  which  may, 
therefore,  be  similar  to  those  produced  by  the  will."  He  further  at- 
tempts to  deny  the  facts  related  of  the  lower  classes  of  animals,  and 
asserts,  that  "they  are  not  evinced  in  the  experiments  instituted  in  our 
day."  The  cases,  recorded  to  prove  the  defective  sensibility  of  the  lower 
tribes  of  animated  nature,  are,  however,  as  has  been  elsewhere  shown, 
incontestable. — The  trunk  of  the  wasp  attempts  to  sting  after  the  head 
has  been  removed;  and  an  experiment  made  on  the  rattlesnake  by  Dr. 
Harlan,2  in  the  presence  of  Capt.  Basil  Hall,  certainly  demonstrates 
something  like  design  in  the  headless  trunk ;  and  the  cases,  already  re- 
ferred to,  on  the  authority  of  Drs.  Le  Conte  and  Dowler,  exhibit  almost 
miraculous  phenomena  of  the  kind  in  the  decapitated  alligator.3 

Our  conclusion  ought  probably  to  be,  from  all  these  cases, — that 
volition  is  chiefly  seated  in  the  encephalon,  but  that  an  obscure  action 
of  the  kind  may  originate,  perhaps,  farther  down  the  cerebro-spinal 

1  GEuvres,  Paris,  1824.  2  Medical  and  Physical  Researches,  Philad.,  1835. 

3  See  p.  307. 

VOL.  i. — 25 


386  MUSCULAR  MOTION. 

axis.  This  conclusion,  of  course,  applies  only  to  the  higher  classes  of 
animals;  for  we  have  seen,  that  the  polypus  is  capable  of  division  into 
several  portions,  so  as  to  constitute  as  many  distinct  beings;  and  it  is 
probable,  that  the  principal  seat  of  volition  may  extend  much  lower 
down  in  the  inferior  tribes  of  created  beings. 

Successful  attempts  have  been  made  to  discover,  whether  the  whole 
brain  is  concerned  in  volition,  or  only  a  part.  Portions  have  been  dis- 
organized by  disease,  and  yet  the  person  has  not  been  deprived  of 
motion;  at  other  times,  as  in  paralysis,  the  faculty  has  been  impaired; 
and  again,  considerable  quantities  of  brain  have  been  lost,  owing  to 
accidents  (in  one  case  the  author  knew  nineteen  tea-spoonfuls),  with 
equal  immunity  as  regards  the  function  in  question.  Experiments, 
executed  on  this  subject,  go  still  farther  to  confirm  the  idea,  that  voli- 
tion is  not  seated  exclusively  in  the  encephalon.  MM.  Rolando  and 
Flourens1  performed  several,  with  the  view  of  detecting  the  seat  of  the 
locomotive  will,  or  of  that  which  presides  over  the  general  movements 
of  station  and  progression ;  and  they  were  led  to  fix  upon  the  cerebral 
lobes.  Animals,  from  which  these  were  removed,  were  thrown  into  a 
sleepy,  lethargic  condition;  were  devoid  of  sensation  and  spontaneous 
motion,  and  moved  only  when  provoked.  On  the  other  hand,  M.  Magen- 
die2  affirms,  that  the  cerebral  hemispheres  may  be  cut  deeply  in  different 
parts  of  their  upper  surface,  without  any  evident  alteration  in  the 
movements.  Even  their  total  removal,  if  it  did  not  implicate  the  cor- 
pora striata,  he  found  to  produce  no  greater  effect ;  or,  at  least,  none 
but  what  might  be  easily  referred  to  the  suffering  induced  by  such  an 
experiment.  The  results,  however,  were  not  alike  in  all  classes  of  ver- 
tebrated  animals.  Those  mentioned  were  observed  on  quadrupeds,  and 
particularly  dogs,  cats,  rabbits,  Guinea-pigs,  hedgehogs,  and  squirrels. 
In  birds,  the  removal  or  destruction  of  the  hemispheres — the  optic  tu- 
bercles remaining  untouched — was  often  followed  by  the  state  of  stupor 
and  immobility  described  by  MM.  Rolando  and  Flourens;  but,  in 
numerous  cases,  the  birds  ran,  leaped,  and  swam,  after  the  hemispheres 
had  been  removed,  the  sight  alone  appearing  to  be  destroyed.  In  rep- 
tiles and  fish,  the  removal  of  the  hemispheres  seemed  to  exert  little 
effect  upon  their  motions.  Carps  swam  with  agility;  frogs  leaped  and 
swam  as  if  uninjured ;  and  their  sight  did  not  appear  to  be  affected. 
Magendie3  properly  concludes,  from  these  experiments,  that  the  spon- 
taneity of  the  movements  does  not  belong  exclusively  to  the  hemi- 
spheres ;  that  in  certain  birds,  as  the  pigeon,  adult  rook,  &c.,  this  seems 
to  be  the  case;  but  not  so  in  other  birds.  To  mammalia,  reptiles,  and 
fish, — at  least  such  of  them  as  were  the  subjects  of  experiment, — his 
conclusion  is,  however,  applicable. 

Of  the  nature  of  the  action  of  the  brain  in  producing  volition  we 
know  nothing.  It  is  only  in  the  prosecution  of  direct  experiments  on 
the  encephalon  that  we  can  have  an  opportunity  of  seeing  it  during  the 
execution  of  the  function ;  but  the  process  is  too  minute  to  admit  of 
observation.  Our  knowledge  is  confined  to  the  fact,  that  the  encephalon 
acts,  and  that  some  influence  is  projected  from  it  along  the  muscles, 

1  Op.  citat.  *  Precis  Elementaire.  3  Ibid.,  i.  336. 


NERVOUS  CENTRE  OF  MUSCULAR  CONTRACTION.  387 

which  excites  them  to  action ;  and  accurately  regulates  the  extent  and 
velocity  of  muscular  contraction.  Yet  volition  is  not  the  sole  excitant 
of  such  contraction.  If  we  irritate  any  part  of  the  encephalon  or 
spinal  marrow,  or  any  of  the  nerves  proceeding  from  them,  muscular 
movements  are  excited;  but  they  are  not  regulated  as  when  under  the 
influence  of  volition.  The  whole  class  of  involuntary  motions,  or  rather 
of  those  executed  by  the  muscular  system  of  organic  life,  is  of  this 
kind,  including  the  action  of  many  of  the  most  important  organs, — 
heart,  intestines,  blood-vessels,  &c.  The  involuntary  muscles  equally 
require  a  stimulus  to  excite  them  into  action ;  but,  as  their  name 
imports,  they  are  removed  from  the  influence  of  volition.  In  certain 
diseased  conditions,  we  find,  that  all  the  voluntary  muscles  assume  in- 
voluntary motions ;  but  this  is  owing  to  the  ordinary  volition  being 
interfered  with,  and  to  some  direct  or  indirect  stimulation  affecting  the 
parts  of  the  cerebro-spinal  axis  concerned  in  muscular  contraction;  or, 
if  the  effect  be  local,  to  some  stimulation  of  the  nerve  proceeding  from 
the  axis  to  the  part.  Of  this  kind  of  general  involuntary  contraction 
of  voluntary  muscles,  we  have  a  common  example  in  the  convulsions  of 
children ;  and  one  of  the  partial  kind,  in  cramp  or  spasm. 

The  will,  then,  is  the  great  but  not  the  sole  regulator  of  the  supply 
of  voluntary  nervous  influence.  This  is  confirmed  by  experiment.  If 
a  portion  of  the  spinal  marrow  be  divided,  so  as  to  separate  it  from  all 
communication  with  the  encephalon,  the  muscles  cannot  be  affected  by 
the  will ;  but  they  contract  on  irritating  the  part  of  the  spinal  marrow, 
from  which  its  nerves  proceed.  It  has,  hence,  been  presumed  by  some 
physiologists,  that  volition  is  only  the  exciting  and  regulating  cause  of 
the  nervous  influx;  and  that  the  latter  is  the  immediate  agent  in  pro- 
ducing contraction;  and  they  affirm,  that  as,  in  the  sensations,  the  im- 
pression is  made  on  the  nerve,  and  perception  effected  in  the  brain, — so, 
in  muscular  motion,  volition  is  the  act  of  the  encephalon,  and  the  nerv- 
ous influx  to  a  part  corresponds  to  the  act  of  impression. 

With  regard  to  the  seat  of  this  nervous  centre  of  muscular  contrac- 
tion, much  discrepancy  has  existed  amongst  modern  physiologists.  It 
manifestly  is  not  in  the  whole  encephalon,  as  certain  portions  of  it  may 
be  irritated  in  the  living  animal  without  exciting  convulsions.  Parts 
of  it,  again,  may  be  removed  without  preventing  the  remainder  from 
exciting  muscular  contraction  when  irritated.  In  the  experiments  of 
M.  Flourens,  the  cerebral  lobes  were  taken  away,  yet  the  animals,  when 
stimulated,  were  susceptible  of  motion;  and,  whenever  the  medulla 
oblongata  was  irritated,  convulsions  were  produced.  Its  seat  is  not, 
therefore,  in  the  whole  encephalon.  M.  Rolando  refers  it  to  the  cere- 
bellum. He  asserts,  that  on  removing  the  cerebellum  of  living  animals, 
without  implicating  any  other  part  of  the  encephalon,  they  preserved 
their  sensibility  and  consciousness,  but  were  deprived  of  the  power  of 
motion.  This  occurred  to  a  greater  extent  in  proportion  to  the  severity 
of  the  injury  inflicted  on  the  cerebellum.  If  the  injury  was  slight,  the 
loss  of  power  was  slight;  and  conversely.  Impressed  with  the  resem- 
blance between  the  cerebellum  of  birds  and  the  galvanic  apparatus  of 
the  torpedo ;  and  taking  into  consideration  the  lamellated  structure  of 
the  cerebellum,  which,  according  to  him,  resembles  a  voltaic  pile;  and 


MUSCULAR  MOTION. 

the  results  of  his  experiments,  which  showed,  that  the  movements 
diminished  in  proportion  to  the  injury  done  to  the  cerebellum,  Rolando 
drew  the  inference,  that  this  part  of  the  encephalon  is  an  electro-motive 
apparatus  for  the  secretion  of  a  fluid  analogous  to  the  galvanic.  This 
fluid  is,  according  to  him,  transmitted  along  the  nerves  to  the  muscles, 
and  excites  them  to  contraction.  The  parts  of  the  encephalon  con- 
cerned in  volition  would,  in  this  view,  regulate  the  quantity  in  which 
the  motive  fluid  is  secreted ;  and  govern  the  motions ;  whilst  the  medulla 
oblongata,  which,  when  alone  irritated,  always  occasions  convulsions, 
would  put  the  encephalic  extremity  of  the  conducting  nerves  in  direct 
or  indirect  communication  with  the  locomotive  apparatus. 

This  ingenious  and  simple  theory  is,  however,  far  from  being  corro- 
borated, by  the  fact,  mentioned  by  M.  Magendie,1  that  he  is  annually  in 
the  habit  of  exhibiting  to  his  class  animals  deprived  of  cerebellum, 
which  are  capable  of  executing  regular  movements.  For  example,  he 
has  seen  the  hedgehog  and  Guinea-pig,  deprived  not  only  of  brain  but 
of  cerebellum,  rub  the  nose  with  its  paw,  when  a  bottle  of  strong  acetic 
acid  was  held  to  it ;  and  he  remarks,  that  a  single  positive  fact  of  the 
kind  is  worth  all  the  negative  facts  that  could  be  adduced.  He  farther 
observes,  that  there  could  be  no  doubt  of  the  entire  removal  of  the 
brain  in  his  experiments.  The  experiments  of  Magendie  are,  however, 
equally  adverse  to  the  hypothesis  of  M.  Flourens,  that  the  cerebellum 
is  the  regulator  or  balancer  of  the  movements.  Some  anatomical  ob- 
servations by  Mr.  Solly2  would  seem  to  show,  that  there  is  a  direct 
communication  between  the  motor  tract  of  the  spinal  marrow  and  the 
cerebellum.  The  corpora  pyramidalia  have  been  generally  supposed 
to  be  formed  by  the  entire  mass  of  the  anterior  or  motor  columns  of  the 
spinal  cord,  but  Mr.  Solly  shows,  that  not  more  than  one-half  of  the 
anterior  column  enters  into  the  composition  of  these  bodies ;  and  that 
another  portion,  which  he  terms  "  antero-lateral  column,"  when  traced 
on  each  side  in  its  progress  upwards,  is  found  to  cross  the  cord  below 
the  corpora  olivaria,  forming,  after  mutual  decussation,  the  surface  of 
the  corpora  restiformia;  and  being  ultimately  continuous  with  the  cere- 
bellum. 

Others,  again,  have  estimated  the  encephalon  to  be  the  sole  organ 
of  volition,  and  have  referred  the  nervous  action,  which  produces  the 
" locomotive  influx,"  as  it  is  termed,  exclusively  to  the  spinal  marrow; 
and  hence  they  have  termed  the  spinal  marrow,  and  the  nerves  issuing 
from  it,  the  "nervous  system  of  locomotion."  It  is  manifest,  however, 
that  the  encephalon  must  participate  with  the  medulla  spinalis  in  this 
function ;  inasmuch  as  not  only  does  direct  irritation  of  several  parts 
of  the  former  excite  convulsions,  but  we  see  them  frequently  as  a  con- 
sequence of  disease  of  the  encephalon;  yet,  as  has  been  remarked, 
there  is  some  reason  for  believing,  that,  in  the  upper  classes  of  animals, 
an  obscure  volition  may  be  exercised  for  a  time,  even  when  the  ence- 
phalon is  separated  from  the  body.  It  need  scarcely  be  said,  that  we 

1  Precis,  &c.,  i.  340. 

7-  Transactions  of  the  Royal  Society  for  1836  ;  and  Solly  on  the  Brain,  Araer.  edit.,  Phila., 
1848. 


ENCEPHALIC  SEAT  OF  MUSCULAR  MOTION. 

are  as  ignorant  of  the  character  of  this  influx,  as  we  are  of  that  of  the 
nervous  phenomena  in  general. 

The  parts  of  the  encephalon  and  spinal  marrow,  concerned  in  mus- 
cular motion,  are  very  distinct  from  those  that  receive  the  impressions 
of  external  bodies.  The  function  of  sensibility  is  comprised  in  the 
medulla  oblongata  and  in  the  posterior  column  of  the  spine,  whilst  the 
encephalic  organs  of  muscular  motion  appear  to  be  the  corpora  striata, 
the  thalami  nervorum  opticorum,  at  their  lower  part;  the  crura  cerebri; 
the  pons  Varolii;  the  peduncles  of  the  cerebellum;  the  lateral  parts  of 
the  medulla  oblongata,  and  the  anterior  column  of  the  medulla  spi- 
nalis.  This  is  proved  by  direct  experiment,  as  will  be  shown  presently; 
and,  in  addition  to  this,  pathology  furnishes  us  with  numerous  examples 
of  their  distinctness.  In  various  cases  of  hemiplegia  or  palsy  of  one 
side  of  the  body, — which  is  of  encephalic  origin, — we  find  motion 
almost  lost ;  yet  sensibility  may  be  slightly  or  not  at  all  affected ;  and, 
on  the  other  hand,  instances  of  loss  of  sensation  have  been  met  with, 
in  which  the  power  of  voluntary  motion  has  continued.  Modern  dis- 
coveries in  the  system  of  vertebral  nerves  exhibit  how  this  may  hap- 
pen. A  considerable  space  may  exist  between  the  roots  of  a  nerve, 
one  of  which  shall  be  destined  for  sensation,  the  other  for  motion ;  yet 
both  may  pass  out  enveloped  in  one  sheath ; — the  same  nervous  cord 
thus  conveying  the  two  irradiations,  if  they  may  be  so  termed.  Ac- 
cording to  Sir  Charles  Bell's  system  the  spinal  column  is  divided  into 
three  tracts;  the  anterior  for  motion;  the  posterior  for  sensibility; 
and  the  two  are  kept  separate  and  united  by  the  third — the  column  for 
respiration.  The  existence  of  the  last  column  is  now  admitted  by  few.1 

The  experiments  performed  by  the  French  physiologists  especially, — 
for  the  purpose  of  discovering  the  precise  parts  of  the  encephalon  con- 
cerned in  muscular  motion,  have  attracted  great  and  absorbing  interest. 
We  wish  it  could  be  said,  that  the  results  have  been  such  as  to  afford 
determinate  notions  on  the  subject.  According  to  those  of  M.  Flou- 
rens,  the  cerebral  lobes  preside  over  volition,  and  the  medulla  oblon- 
gata over  the  locomotive  influx  :  to  the  latter  organ  he  assigns,  also, 
sensibility.  We  have  seen,  that  the  results  of  his  experiments  have 
been  contested;  and  with  them,  of  course,  his  deductions.  The  facts 
and  arguments,  already  stated,  throw  doubts  on  all  except  the  last  pro- 
position, which  refers  sensibility  to  the  medulla  oblongata;  and  even  it 
is  not  restricted  to  that  organ,  or  group  of  organs,  whichsoever  it  may 
be  considered. 

MM.  Foville  and  Pinel  Grand- Champ2  have  affirmed  that  the  cere- 
bellum is  the  seat  of  sensibility.  To  this  conclusion  they  were  led  by 
the  remarks  they  had  made,  in  the  course  of  their  practice,  that  the 
cases  of  paralysis  of  sensibility,  which  fell  under  their  notice,  suc- 
ceeded more  especially  to  morbid  conditions  of  the  encephalon.  In 
this  view  they  conceive  themselves  supported  by  the  discovery  of 
columns  in  the  spinal  marrow  destined  for  particular  functions  ;  and, 
as  the  posterior  column  is  found  to  be  the  column  of  sensibility,  and 
the  cerebellum  seems  to  be  formed  from  this  column,  they  think  it 
ought  to  be  possessed  of  the  same  functions.  M.  Adelon3  remarks,  that 

1  See  page  89.  3  Sur  le  Systeme  Nerveux,  Paris,  1820.  3  Op.  citat.,  ii.  38. 


390  MUSCULAR  MOTION. 

Willis  professed  a  similar  notion,  and  that  he  considered  the  cerebral 
lobes  to  be  the  point  of  departure  for  the  movements,  and  the  cere- 
bellum the  seat  of  sensibility.  In  his  first  volume,  however,  he  had 
cited  more  correctly  the  views  of  Willis.  "  Willis  says  positively," 
he  remarks,  "  that  the  corpora  striata  are  the  seat  of  perception; 
the  medullary  mass  of  the  brain,  that  of  memory  and  imagination; 
the  corpus  callosum,  that  of  reflection  ;  and  the  cerebellum,  the  source 
of  the  motive  spirits."  Willis,  in  truth,  regarded  the  cerebellum  as 
supplying  animal  spirits  to  the  nerves  of  involuntary  functions,  as  the 
heart,  intestinal  canal,  &c.  The  opinions  of  Foville  and  Pinel  Grand- 
Champ  are,  however,  subverted  by  the  experiments  of  Rolando, 
Flourens,  and  Magendie,  which  show,  that  sensation  continues,  not- 
withstanding serious  injury  to,  and  even  entire  removal  of,  the  cere- 
bellum. 

By  other  physiologists,  the  two  functions  have  been  assigned  re- 
spectively to  the  cineritious  xand  medullary  parts  of  the  brain ;  some 
asserting,  that  the  seat  of  sensibility  is  more  especially  in  the  latter, 
and  the  motive  force  in  the  former.  According  to  Treviranus,  the 
more  medullary  matter  an  animal  has  in  its  brain  and  spinal  marrow, 
in  proportion  to  the  cineritious,  the  greater  will  be  its  sensibility.  To 
this,  however,  M.  Desmoulins1  properly  objects,  that  in  many  animals, 
the  spinal  marrow  is  composed  exclusively  of  medullary  matter  [?]  ;  and 
consequently  they  ought  not  only  to  be  the  most  sensible  of  all,  but  to 
be  wholly  devoid  of  the  power  of  motion.  Others,  again,  as  MM. 
Foville  and  Pinel  Grand- Champ  have  reversed  the  matter;  assigning 
sensibility  to  the  cineritious  substance,  and  motility  to  the  medullary. 
From  these  conflicting  opinions,  it  is  obviously  impossible  to  sift  any- 
thing categorical;  except  that  we  are  ignorant  of  the  special  seat  of 
these  functions.  A  part  of  the  discrepancy,  in  the  results,  must  be 
ascribed  to  organic  differences  in  the  animals  which  were  the  subjects 
of  the  experiments.  This  was  strikingly  exemplified  in  those  instituted 
by  M.  Magendie,  which  have  been  cited.  Similar  contrariety  exists 
in  the  experiments  and  hypotheses,  regarding  the  particular  parts  of 
the  encephalon,  that  are  concerned  in  determinate  movements  of  the 
body.  The  results  of  many  of  those  are,  indeed,  so  strange,  that  did 
they  not  rest  on  eminent  authority  they  might  be  classed  among  the 
romantic. 

It  has  been  already  remarked,  that  Rolando  considered  the  cerebel- 
lum to  be  an  electro-motive  apparatus,  producing  the  whole  of  the  gal- 
vanic fluid  necessary  for  the  motions.  M.  Flourens,  on  the  other  hand, 
from  similar  experiments,  independently  performed,  and  without  any 
knowledge  of  those  of  Rolando,  affirmed  it  to  be  the  regulator  and 
balancer  of  the  locomotive  movements ;  and  he  asserted,  that,  when 
removed  from  an  animal,  it  could  neither  maintain  the  erect  attitude, 
nor  execute  any  movement  of  locomotion;  nor,  although  possessing  all 
its  sensations,  could  it  fly  from  danger  it  saw  menacing  it.  The  same 
view  has  been  advocated  by  M.  Bouillaud,  who  has  detailed  eighteen 
experiments,  in  which  he  cauterized  the  cerebellum,  and  found  that,  in 

1  Anatomie  des  Systemes  Nerveux,&c.,  Paris,  1825. 


ENCEPHALIC  SEAT  OF  MUSCULAR  MOTION.  391 

all,  the  functions  of  equilibration  and  progression  were  disordered.  The 
experiments  of  M.  Magendie1  on  this  subject,  are  pregnant  with  import- 
ant novelty.  We  have  already  referred  to  those  that  concern  the  cere- 
bral hemispheres  and  cerebellum  as  the  encephalic  organs  of  the  general 
movements,  in  the  mode  suggested  by  MM.  Rolando  and  Flourens,  and 
others.  M.  Magendie  affirms,  in  addition,  "  that  there  exist,  in  the 
brain,  four  spontaneous  impulses  or  forces,  which  are  situate  at  the 
extremity  of  two  lines,  cutting  each  other  at  right  angles  ;  the  one 
impelling  forwards  ;  the  second  backwards  ;  the  third  from  right  to  left, 
causing  the  body  to  rotate ;  and  the  fourth  from  left  to  right,  occasion- 
ing a  similar  movement  of  rotation."  The  first  of  these  impulses  he 
fixes  in  the  cerebellum  and  medulla  oblongata  ;  the  second  in  the  cor- 
pora striata ;  and  the  third  and  fourth  in  each  of  the  peduncles  of  the 
cerebellum. 

1.  Forward  Impulse. — It  has  often  been  observed  by  those  who  have 
made  experiments  on  the  cerebellum,  that  injuries  of  it  cause  animals 
to  recoil  manifestly  against  their  will.     M.  Magendie2  asserts,  that  he 
has  frequently  seen  them,  when  wounded  in  the  cerebellum,  make  an 
attempt  to  advance,  but  be  immediately  compelled  to  run  back  ;  and  he 
says  that  he  kept  a  duck  for  eight  days,  the  greater  part  of  whose  cere- 
bellum he  had  removed,  which  did  not  move  forwards  during  the  whole 
of  that  time,  except  when   placed  on  water.     Pigeons,   into  whose 
cerebella  he  thrust  pins,  constantly  walked  and  flew  backwards,  for 
more  than  a  month  afterwards.    Hence,  he  concludes,  that  there  exists, 
either  in  the  cerebellum   or  medulla  oblongata,  a  force  of  impulsion, 
which  tends  to  cause  animals  to  go  forward.     He  thinks  it  not  impro- 
bable, that  this  force  exists  in  man ;  and  states  that  Dr.  Laurent,  of 
Versailles,  exhibited  to  him,  and  to  the  Academie  Royale  de  Medecine, 
a  young  girl,  who,  in  the  attacks  of  a  nervous  disease,  was  obliged  to 
recoil  so  rapidly,  that  she  was  incapable  of  avoiding  bodies  or  pits 
behind  her ;  and  was,  consequently,  exposed  to  serious  falls  and  bruises. 
This  force,  he  affirms,  exists  only  in  the  mammalia  and  birds  ; — certain 
fish  and  reptiles,  on  which  he  experimented,  appearing  to  be  unaffected 
by  the  entire  loss  of  the  cerebellum. 

2.  Backward  Impulse. — M.  Magendie  found,3  when  the  corpora  stri- 
ata were  removed,  that  the  animal  darted  forward  with  great  rapidity  ; 
and,  if  stopped,  still  maintained  the  attitude  of  running.  This  was  particu- 
larly remarked  in  young  rabbits ;  the  animals  appearing  to  be  impelled 
forward  by  an  inward  and  irresistible  power,  and  passing  over  obstacles 
without  noticing  them.     These  effects  were  not  found  to  take  place, 
unless  the  white,  radiated  part  of  the  corpora  striata  was  cut :  if  the 
gray  was  alone  divided,  no  modification  was  produced  in  the  movements. 
If  only  one  of  the  corpora  was  removed,  the  rabbit  remained  master  of 
its  movements,  directed  them  in  different  ways,  and  stopped  when  it 
chose  ;  but,  immediately  after  the  removal  of  the  other,  all  regulating 
power  over  the  motions  appeared  to  cease,  and  it  was  irresistibly  im- 
pelled forwards.     In  the  disease  of  the  horse,  called,  by  the  French, 

,  the  animal  is  often  capable  of  walking,  trotting,  and  gallop- 

Op.  citat.,  i.  345.  2  p^cis,  i.  341.  3  Op.  cit.,  i.  337. 


392  MUSCULAR  MOTION. 

ing  forward  with  rapidity;  but  he  does  not  back ;  and  frequently  it  is 
impracticable  to  arrest  his  motion  forwards.  M.  Magendie1  asserts,  that 
he  has  opened  several  horses  that  died  in  this  condition  ;  and  found,  in 
all,  a  collection  of  fluid  in  the  lateral  ventricles,  which  had  produced  a 
morbid  change  on  the  surface  of  the  corpora  striata,  and  must  have 
exerted  a  degree  of  compression  on  them. 

Similar  pathological  cases  occur  in  man.  M.  Magendie  relates  the 
case  of  a  person,  who  became  melancholic,  and  lost  all  power  over  his 
movements  ;  continually  executing  the  most  irregular  and  fantastic 
antics ;  and  frequently  compelled  to  walk  exclusively  forwards  or  back- 
wards until  stopped  by  some  obstacle.  In  this  case,  recovery  occurred ; 
and,  accordingly,  there  was  no  opportunity  for  investigating  the  ence- 
phalic cause.  M.  Itard  describes  two  cases,  in  which  the  patients  were 
impelled,  in  paroxysms,  to  run  straight  forward,  without  the  power  of 
changing  their  course,  even  when  a  river  or  precipice  was  before  them. 
A  case  is  related  by  M.  Piedagnel,2  which  is  more  to  the  purpose  as  an 
opportunity  occurred  for  post  mortem  examination.  The  subject  of  it 
also  was  irresistibly  impelled  to  constant  motion.  "  At  the  time  of  the 
greatest  stupor,"  says  M.  Piedagnel,  "he  suddenly  arose;  walked 
about  in  an  agitated  manner ;  made  several  turns  in  his  chamber,  and 
did  not  stop  until  fatigued.  On  another  occasion,  the  room  did  not 
satisfy  him  ;  he  went  out,  and  walked  as  long  as  his  strength  would 
permit.  He  remained  out  about  two  hours,  and  was  brought  back  on  a 
litter."  M.  Piedagnel  adds,  "that  he  seemed  impelled  by  an  insur- 
mountable force,"  which  kept  him  in  motion,  until  his  powers  failed 
him.  On  dissection,  several  tubercles  were  found  in  the  right  cerebral 
hemisphere,  especially  at-  its  anterior  part ;  and  at  the  side  of  the  cor- 
pora striata.  These  had  produced  much  morbid  alteration  in  that  hemi- 
sphere ;  and  had,  at  the  same  time,  greatly  pressed  on  the  other.  From 
these  facts,  M.  Magendie  infers  it  to  be  extremely  probable,  that,  in 
the  mammalia  and  in  man,  a  force  of  impulsion  always  exists,  which 
tends  to  impel  backwards,  and  is,  consequently,  the  antagonist  to  the 
force  seated  in  the  cerebellum. 

3.  Lateral  Impulse. — If  the  peduncles  of  the  cerebellum — crura 
cerebelli — be  divided  in  a  living  animal,  it  immediately  begins  to  turn 
round,  as  if  impelled  by  some  considerable  force.  The  rotation  or  cir- 
cumgyration is  made  in  the  direction  of  the  divided  peduncle — M. 
Longet  says,  in  the  opposite  direction — and,  at  times,  with  such  rapidity, 
that  the  animal  makes  as  many  as  sixty  revolutions  in  a  minute.  The 
same  kind  of  effect  is  produced  by  any  vertical  section  of  the  cerebellum, 
which  implicates  from  before  to  behind  the  whole  substance  of  the  me- 
dullary arch  formed  by  that  organ  above  the  fourth  ventricle ;  but  the 
movement  is  more  rapid,  the  nearer  the  section  is  to  the  origin  of  the 
peduncles ;  in  other  words  to  their  point  of  junction  with  the  pons  Varolii. 
M.  Magendie3  affirms,  that  he  has  seen  this  movement  continue  eight 
days  without  stopping,  and  apparently  without  any  suffering.  When 
an  impediment  was  placed  in  the  way,  the  motion  was  arrested ;  and, 

1  Op.  cit.,  i.  338. 

2  Magendie,  Journal  de  Physiologic,  torn,  iii.;  and  Precis  Elementaire,  i.  338. 

3  Precis,  &c.,  i.  343. 


ENCEPHALIC  SEAT  OF  MUSCULAR  MOTION. 


393 


under  such  circumstances,  the  animal  frequently  remained  with  its  paws 
in  the  air,  and  ate  in  this  attitude.  What  he  conceives  to  have  been 
one  of  his  most  singular  experiments  was, — the  effect  of  the  division 
of  the  cerebellum  into  two  lateral  and  equal  halves :  the  animal  ap- 
peared to  be  alternately  impelled  to  right  and  left,  without  retaining 
any  fixed  position:  if  he  made  a  turn  or  two  on  one  side,  he  soon 
changed  his  motion  and  made  as  many  on  the  other.  M.  Serres1 — who 
is  well  known  as  a  writer  on  the  comparative  anatomy  of  the  brain,  and 
must  have  had  unusual  opportunities  for  observation  at  the  Hospital  La 
Pitie  to  which  he  was  attached — gives  the  case  of  an  apoplectic,  who 
presented,  amongst  other  symptoms,  the  singular  phenomenon  of  turn- 
ing round,  like  the  animals  in  those  experiments;  and,  on  dissection,  an 
apoplectic  effusion  was  found  in  that  part  of  the  encephalon.  On  di- 
viding the  pons  Varolii  vertically,  from  before  to  behind,  M.  Magendie2 
found,  that  the  same  rotary  movement  was  produced :  when  the  section 
was  to  the  left  of  the  median  line,  the  rotation  was  to  the  left,  and  con- 
versely; but  he  could  never  succeed  in  making  the  section  accurately 
on  the  median  line.  From  these  facts  he  concludes,  that  there  are  two 
forces,  which  are  equilibrious  by  passing  across  the  circle  formed  by  the 
pons  Varolii  and  cerebellum.  To  put  this  beyond  all  question,  he  cut 
one  peduncle,  when  the  animal  immediately  rolled  in  one  direction;  but 
on  cutting  the  other  or  the  one  on  the  opposite  side,  the  movement 
ceased,  and  the  animal  lost  the  power  of  keeping  itself  erect,  and  of 
walking. 

From  the  results  of  all  his  experiments,  M.  Magendie  infers,  that  an 
animal  is  a  kind  of  automatic  machine,  wound  up  for  the  performance 
of  certain  motions,  but  incapable 
of  producing  any  other.  The 
figure  of  the  base  of  the  brain 
in  the  margin,  will  explain,  more 
directly,  the  impulses  described 
by  this  physiologist.  The  cor- 
pora striata  are  situate  in  each 
hemisphere,  but  their  united 
impulses  may  be  represented  by 
the  arrow  A;  the  impulse  seated 
in  the  cerebellum,  by  the  arrow 
B  ;  and  those  in  each  peduncle 
of  the  cerebellum,  p,  p,  by  the 
arrows  C  and  D  respectively. 
When  the  impulse  backwards  is 
from  any  cause  destroyed,  the 
animal  is  given  up  to  the  forward 
impulse,  or  that  represented  by 
the  arrow  B;  and  conversely. 
In  like  manner,  the  destruction 
of  one  lateral  impulse  leaves  the 
other  without  an  antagonist,  and 


Fig.  165. 


Direction  of  Encephalic  Impulses,  according  to 
M 


1  Magendie's  Journ.  de  Physiol.,  iv.  405. 


[agendie. 
3  Precis,  &c.,  p.  344. 


394  MUSCULAR  MOTION. 

the  animal  moves  in  the  direction  of  the  arrow  placed  over  the  seat  of 
the  impulsion  that  remains.  In  a  state  of  health,  all  these  impulsions 
being  nicely  antagonized,  they  are  subjected  to  the  influence  of  volition ; 
but  in  disease  they  may  be  so  modified  as  to  be  entirely  withdrawn 
from  its  control. 

These  four  are  not  the  only  movements  excited  by  particular  injuries 
done  to  the  nervous  system.  M.  Magendie1  states,  that  a  circular  mov£- 
ment  to  the  right  or  left,  similar  to  that  of  horses  in  a  circus,  was  caused 
by  the  division  of  the  medulla  oblongata,  to  the  outer  side  of  the  cor- 
pora pyramidalia  anteriora.  When  the  section  was  made  on  the  right 
side,  the  animal  turned,  in  this  fashion,  to  the  right;  and  to  the  left,  if 
the  section  was  made  on  that  side. 

Pathology  has,  likewise,  indicated  the  brain  as  the  seat  of  different 
bodily  movements.  Diseases  of  the  encephalon  have  been  found  not 
only  to  cause  irregular  movements  or  convulsions,  but,  also,  paralysis 
of  a  part  of  the  body,  leaving  the  rest  untouched.  Hence  it  has  been 
concluded,  that  every  motion  of  every  part  has  its  starting  point  in 
some  portion  of  the  brain.  The  ancients  were  well  aware,  that  in  cases 
of  hemiplegia,  the  encephalic  cause  of  the  affection  is  found  in  the 
opposite  hemisphere.  Attempts  have  been  made  to  decide  upon  the 
precise  part  of  the  encephalon  in  which  the  decussation  takes  place. 
Many  have  conceived  it  to  be  in  the  commissures ;  but  the  greater  num- 
ber, perhaps,  have  referred  it  to  the  corpora  pyramidalia.  These,  the 
researches  of  Gall  and  Spurzheim2  and  others,  had  pointed  out  as  de- 
cussating at  the  anterior  surface  of  the  marrow,  and  as  being  apparently 
continuous  with  the  radiated  fibres  of  the  corpora  striata;  and  an 
opinion  has  prevailed,  that  the  paralysis  is  of  the  same  side  as  the 
encephalic  affection,  or  of  the  opposite,  according  as  the  affected  part  of 
the  brain  is  a  continuation  of  fasciculi,  which  do  not  decussate — of  the 
corpora  olivaria,  for  example — or  of  the  corpora  pyramidalia,  which  do. 
M.  Serres,3  however,  affirms,  that  affections  of  the  cerebellum,  pons 
Varolii,  and  tubercula  quadrigemina,  exert  their  effects  upon  the  oppo- 
site side  of  the  body,  and  he  supports  his  statement  by  pathological 
cases  and  direct  experiment.  M.  Magendie4  divided  one  pyramid  from 
the  fourth  ventricle;  yet  no  sensible  effect  was  produced  on  the  move- 
ments ;  certainly,  there  was  no  paralysis,  either  of  the  affected  or  oppo- 
site side:  he  then  divided  both  pyramids  about  the  middle,  and  no 
apparent  derangement  occurred  in  the  motions — a  slight  difficulty  in 
progression  being  alone  observable.  The  section  of  the  posterior  pyra- 
mids was  equally  devoid  of  perceptible  influence  on  the  general  move- 
ments; and  to  cause  paralysis  of  one  half  the  body,  it  was  necessary 
to  divide  the  half  of  the  medulla  oblongata,  when  the  corresponding 
side  became, — not  immovable,  for  it  was  affected  by  irregular  move- 
ments ;  and  not  insensible,  for  the  animal  moved  its  limbs  when  they 
were  pinched, — but  incapable  of  executing  the  determinations  of  the 
will. 

These  views  are  not  exactly  in  accordance  with  the  general  idea, 

'  Precis,  &c.,  p.  345. 

3  Recherches  sur  le  Systeme  Nerveux,  &c.,  sect,  vi.,  Paris,  1809. 

9  Anatomie  Compares  du  Cerveau,  Paris,  1824.  4  Op.  cit. 


ENCEPHALIC  SEAT  OF  MUSCULAR  MOTION.  395 

that  disease,  confined  to  one  hemisphere  of  the  brain,  or  cerebellum, 
and  to  one  side  of  the  mesial  plane  in  the  tuber  annulare,  constantly 
affects  the  opposite  side ;  whilst  disease,  confined  to  one  of  the  lateral 
columns  of  the  medulla  oblongata  and  medulla  spinalis,  affects  the 
corresponding  side  of  the  muscular  system  ; — the  encephalon  having 
a  crossed, — the  medulla  a  direct  effect.1  The  crossing  of  the  fibres  at 
the  anterior  surface  of  the  marrow  would  not,  however,  account  for 
the  loss  of  sensation  in  hemiplegia.  Mr.  Hilton2  has  examined  care- 
fully the  continuation  upwards  of  the  anterior  and  posterior  columns 
of  the  spinal  marrow  into  the  medulla  oblongata,  and  found,  that  the 
decussation  at  the  upper  part  of  the  marrow  belongs  in  part  to  the 
column  for  motion,  and  in  part  to  the  column  for  sensation;  and 
farther,  that  the  decussation  is  only  partial  with  respect  to  either  of 
the  columns. 

The  result  of  the  examination  of  morbid  cases  has  induced  some 
physiologists  to  proceed  still  farther  in  their  location  of  the  encephalic 
organs  of  muscular  motion ;  and  to  attempt  an  explanation  of  para- 
plegia, or  cases  in  which  one  half  the  body,  under  the  transverse  bi- 
section, is  paralyzed.  MM.  Serres,  Foville,  and  Pinel  Grand-Champ 
assert,  that  the  anterior  radiated  portion  of  the  corpora  striata  presides 
over  the  movements  of  the  lower  limbs ;  and  the  optic  thalami  over 
those  of  the  upper ;  and  that  according  as  the  extravasation  of  blood, 
in  a  case  of  apoplexy,  occurs  in  one  of  these  parts,  or  in  all,  the  para- 
lysis is  confined  to  the  lower  or  to  the  upper  limbs,  or  extends  over  the 
whole  body.  In  1768,  M.  Saucerotte3  presented  a  prize  memoir  to 
the  Academic  Royale  de  Chirurgie,  of  Paris,  in  which  a  similar  view 
was  expressed.  He  had  concluded,  from  experiments,  that  affections 
of  the  anterior  parts  of  the  encephalon  paralyse  the  lower  limbs,  whilst 
those  of  the  posterior  parts  paralyse  the  upper.  M.  Chopart, — in  a 
prize  essay,  crowned  in  1769,  and  contained  in  the  same  volume  with 
the  last — refers  to  the  results  of  experiments  by  M.  Petit,  of  Namur, 
which  appeared  to  show,  that  paralysis  of  the  opposite  half  of  the 
body  was  not  induced  by  injury  of  the  cerebral  hemisphere,  unless  the 
corpora  striata  were  cut  or  removed.  The  experiments  by  Saucerotte 
were  repeated  by  M.  Foville,  and  are  detailed  in  a  memoir,  crowned 
by  the  Academie  Royale  de  Medecine,  of  Paris,  in  1826.  They  were 
attended  with  like  results.  In  cats  and  rabbits,  he  cauterized,  in  some, 
the  anterior  part  of  the  encephalon  ;  in  others,  the  posterior :  in  every 
one  of  the  former,  paralysis  of  the  posterior,  and  in  the  latter,  of 
the  anterior  extremities  succeeded.  Having  in  one  animal  mutilated 
the  whole  of  the  right  hemisphere,  and  only  the  anterior  part  of  the 
left,  he  found  that  the  animal  was  paralysed  in  the  hinder  extremities, 
and  in  the  paw  of  the  left  fore-leg;  but  that  the  paw  of  the  right  re- 
mained active.4 

1  Lectures  on  the  Nervous  System  and  its  Diseases,  by  Marshall  Hall,  M.D.,  &c.,  Lond., 
1836,  p.  34,  or  Amer.  edit.,  Philacl.,  1836. 

2  Proceedings  of  the  Royal  Society,  No.  34,  for  1837-8;  also,  Solly  on  the  Brain,  p.  145, 
Lond.,  1836;  and  Dr.  John  Reid,  Edinb  Med.  and  Surg.  Journ.,  Jan.,  1841,  p.  12. 

3  Prix  de  1'Academie  Royale  de  Chirurgie,  vol.  iv.  p.  373,  Paris,  1819. 

4  Adelon,  Physiologic  de  1'Homme,  edit,  cit.,  ii.  44. 


396  MUSCULAR  MOTION. 

Lastly,  the  motions  of  the  tongue  or  of  articulation  are  sometimes 
alone  affected  in  apoplexy.  The  seat  of  this  variety^  of  muscular 
motion  has  been  attempted  to  be  deduced  from  pathological  facts.  M. 
Foville  places  it  in  the  cornu  ammonis  and  temporal  lobe ;  and  M. 
Bouillaud1  in  the  anterior  lobe  of  the  brain,  in  the  medullary  substance, 
— the  cineritious  being  concerned,  he  conceives,  in  the  intellectual  part 
of  speech. 

It  is  sufficiently  obvious,  from  the  whole  of  the  preceding  detail, 
that  the  mind  must  still  remain  in  doubt,  regarding  the  precise  part  of 
the  encephalon  engaged  in  the  functions  of  muscular  motion.  The 
experiments  of  M.  Magendie  are,  perhaps,  more  than  any  others,  en- 
titled to  consideration.  They  appear  to  have  been  instituted  without 
any  particular  bias;  to  subserve  no  particular  theory;  and  are  supported 
by  pathological  facts  furnished  by  others.  He  is,  withal,  a  practised 
experimenter,  and  one  to  whom  physiology  has  been  largely  indebted. 
His  vivisections  have  been  more  numerous,  perhaps,  than  those  of  any 
other  individual.  His  investigations,  however,  on  this  subject  clearly 
show,  that  owing  to  the  different  morphology  of  animals,  we  cannot 
draw  as  extensive  analogical  deductions  from  comparative  anatomy  and 
physiology  as  might  be  anticipated.  The  greatest  source  of  discre- 
pancy, indeed,  between  his  experiments  and  those  of  MM.  Rolando  and 
Elourens,  appears  to  have  been  the  employment  of  different  animals. 
Where  the  same  animals  were  the  subjects  of  the  vivisections,  the 
results  were  in  accordance.  The  experiments  demand  careful  repe- 
tition, accompanied  by  watchful  and  assiduous  observation  of  patho- 
logical phenomena  ;  and,  until  this  is  effected,  we  can,  perhaps,  scarcely 
feel  justified  in  deducing,  from  all  these  experiments  and  investigations, 
more  than  the  general  propositions  regarding  the  influence  of  the 
cerebro-spinal  axis  on  muscular  motion,  which  we  have  enunciated.  .It 
has  been  already  shown,  however,  that  strong  evidence  may  be  adduced 
in  favour  of  the  view  of  M.  Flourens,  that  the  cerebellum  is  the  regu- 
lator or  co-ordinator  of  the  muscular  movements,2  and  it  is  the  one  now 
embraced  by  the  generality  of  physiologists ;  although  it  must  be  ad- 
mitted, with  M.  Longet,3  that  "  the  precise  determination  of  the  uses 
of  the  cerebellum  is  one  of  the  most  embarrassing  problems  in  physi- 
ology." 

The  nerves,  it  has  been  shown,  are  the  agents  for  conducting  the 
locomotive  influence  to  the  muscles.  At  one  time,  it  was  universally 
believed,  that  the  same  nerve  conveys  both  sensation  and  volition;  but 
the  pathological  cases,  that  not  unfrequently  occurred,  in  which  either 
sensation  or  voluntary  motion  was  lost,  without  the  other  being  neces- 
sarily implicated;  and,  of  late  years,  the  beautiful  additions  to  our 
knowledge  of  the  spinal  nerves,  for  which  we  are  mainly  indebted  to  Sir 
Charles  Bell,4  and  M.  Magendie,5  have  satisfied  the  most  sceptical,  that 

1  Magendie's  Journal  de  Physiologic,  torn,  x.;  also,  Belhomme,  Archiv.  General,  de  Mede- 
cine,  Mai,  1845. 

2  Longet,  Anatomie  et  Physiologie  du  Systeme  Nerveux,  i.  703,  Paris,  1842. 

3  Traite  de  Physiologie,  ii.  272,  Paris,  1850. 

4  The  Nervous  System,  &c.,  3d  edit.,  Lond.,  1837,  and  Narrative  of  the  Discoveries  of  Sir 
Charles  Bell  in  the  Nervous  System,  by  A.  Shaw,  London,  1839. 

5  Precis  Elementaire,  &c.,  2de  edit.,  i.  216. 


NERVES  OF  MOTION.  397 

there  are  separate  nerves  for  the  two  functions,  although  they  may  be 
enveloped  in  the  same  neurilemma  or  nervous  sheath;  and  may  consti- 
tute one  nervous  cord.  We  have  more  than  once  asserted,  that  the 
posterior  part  of  the  spinal  marrow,  with  the  nerves  proceeding  from, 
it,  has  been  considered  to  be  chiefly  concerned  in  the  function  of  sen- 
sibility; and  the  anterior  column,  and  the  nerves  connected  with  it,  to 
be  inservient  to  muscular  motion;  whilst  a  third  intervening  column, 
in  the  opinion  of  Sir  Charles  Bell,  is  the  source  of  all  the  respiratory 
nerves,  and  of  the  various  movements  connected  with  respiration  and 
expression.  It  is  proper,  here  again,  to  observe,  that  although  these 
two  distinguished  physiologists  agree  in  their  assignment  of  function  to 
the  anterior  and  posterior  columns  of  the  spinal  marrow,  Bellingeri1 
has  deduced  very  different  inferences  from  like  experiments.  He 
asserts,  that  having  divided,  on  living  animals,  either  the  anterior  roots 
of  the  spinal  nerves,  and  the  anterior  column  of  the  medulla  spinalis — 
or  the  posterior  roots  of  these  nerves,  and  the  posterior  column  of  the 
marrow,  he  did  not  occasion,  in  the  former  case,  paralysis  of  motion, 
and  in  the  latter,  loss  of  sensation ;  but  only,  in  the  one,  the  loss  of  all 
movements  of  flexion;  and  in  the  other,  of  those  of  extension.  In  his 
view,  the  brain  and  its  prolongations, — crura  cerebri,  corpora  pyra- 
midalia,  anterior  column  of  the  spinal  marrow,  and  the  nerves  con- 
nected with  it,  preside  over  the  movements  of  flexion;  and,  on  the 
contrary,  the  cerebellum  and  its  extensions,  as  the  posterior  column  of 
the  medulla  spinalis,  and  the  nerves  connected  with  it,  preside  over 
those  of  extension:  he  infers,  in  other  words,  that  there  is  an  antago- 
nism between  these  sets  of  nerves.  The  primd  facie  evidence  is  against 
the  accuracy  of  Bellingeri's  experiments.  The  weight  of  authority 
in  opposition  to  him  is,  in  the  first  place,  preponderant;  and  in  the 
second  place,  it  seems  highly  improbable,  that  distinct  nerves  should 
be  employed  for  the  same  kind  of  muscular  action.  Moreover,  in 
experiments  on  the  frog,  Professor  Miiller  established  the  correctness 
of  the  views  of  Bell.  It  seems,  that  the  different  physiologists,  who 
engaged  in  the  inquiry  before  he  did,  employed  warm-blooded  animals 
in  their  experiments,  and  he  imagines,  that  the  pain,  resulting  from 
the  necessarily  extensive  wounds,  may  have  had  such  an  effect  on  the 
nervous  system  as  to  modify,  and  perhaps  even  counteract,  the  results. 
Muller  employed  the  frog,  whose  sensibility  is  less  acute,  and  tenacity 
of  life  greater.  If  the  spinal  marrow  of  this  animal  be  exposed,  and 
the  posterior  roots  of  the  nerves  of  the  lower  extremities  be  cut,  not 
the  least  motion  is  perceptible  when  the  divided  roots  are  touched  by 
mechanical  means,  or  galvanism.  But  if  the  anterior  roots  be  touched, 
the  most  active  movements  are  instantly  observed.  These  experiments, 
Miiller2  remarks,  are  so  readily  made,  and  the  evidence  they  afford  is 
so  palpable,  that  they  leave  no  doubt  as  to  the  correctness  of  the  views 
of  Sir  Charles  Bell. 

1  Exper.  Physiol.  in  Mecl.  Spinal.  August,  Taurin.,  1825;  Ragionamenti,  Sperienze,  &c., 
comprovanti  I'Antagonismo  Nervoso,  &o.  Torino,  1833;  and  an  Analysis  of  tbe  same,  in 
Edinb.  Med.  and  Surg.  Journ.,  Jan.,  1835,  p.  160. 

3  Elements  of  Physiology,  by  Baly,  p.  644,Lond.,  1838. 


398  MUSCULAR  MOTION. 

Experiments,  by  M.  Magendie,  and  by  Dr.  Kronenberg,1  of  Moscow, 
have  shown,  that  a  portion  of  the  fibres  of  the  sensitive  roots  extends 
to  the  point  of  union  between  them  and  the  anterior  roots,  and  is  re- 
flected to  the  anterior  column  of  the  spinal  marrow; — the  return  or 
reflection  of  the  fibres  taking  place  near  the  junction  of  the  two  roots. 
This  arrangement  of  the  fibres  accounts  for  the  fact,  often  noticed  by 
physiologists,  that  some  degree  of  sensibility  appears  to  be  manifested, 
in  experiments  on  animals,  when  the  motor  roots  of  the  nerves  are 
irritated.  The  sensibility  of  the  portio  dura,  a  motor  nerve,  has  been 
long  known,  and  properly  ascribed  to  its  receiving  filaments  of  the  fifth 
pair.  Motions  can  be  excited  by  irritating  the  posterior  root,  which 
are  owing  to  its  connexion  with  the  spinal  cord.  This  irritation  does 
not  act  immediately  upon  the  muscles  through  the  trunk  of  the  nerve, 
which  the  posterior  root  contributes  to  form;  but  it  excites  a  motor 
impulse  in  the  spinal  cord,  which  is  propagated  through  the  anterior 
roots  to  the  periphery  of  the  system. 

In  the  ordinary  case  of  the  action  of  a  voluntary  striped  or  striated 
muscle,  the  nervous  influence,  emanating  from  some  part  of  the  cerebro- 
spinal  axis,  under  the  guidance  of  volition,  proceeds  along  the  nerves 
with  the  rapidity  of  lightning,  and  excites  the  muscle  to  contraction. 
The  muscle,  which  was  before  smooth,  becomes  rugous;  the  belly  more 
tumid;  the  ends  approximate,  and  the  whole  organ  is  rendered  thicker, 
firmer,  and  shorter.  The  researches  of  Mr.  Bowman2  have  shown,  that 
in  the  state  of  contraction  the  transverse  striae,  before  described  as  ex- 
isting in  each  fibre,  approach  each  other;  whilst  its  diameter  is  increased; 
hence  the  solid  parts  are  more  closely  approximated,  and  the  fluid  which 
previously  existed  between  them  is  pressed  out  so  as  to  form  bullae  in 
the  sarcolemma,  as  represented  in  Fig.  166,  from  Mr.  Bowman.  The 

Fig.  166. 


Muscular  Fibre  of  Dytiscus  in  contraction.     (Bowman.) 

marginal  representations,  Fig.  167,  of  the  muscular  fibre  of  the  skate, 
at  rest  and  in  contraction,  are  also  from  Mr.  Bowman.  It  is  proper  to 
remark,  however,  that  these  representations  are  of  muscular  fibres 
when  in  an  unnatural  condition, — separated,  that  is,  from  the  rest  of  the 
economy,  and  it  cannot  be  considered  established,  that  contraction  ex- 
cited by  the  agency  of  the  nerves  is  accomplished  in  precisely  the  same 
manner. 

With  regard  to  the   degree  of  contraction  or  shortening,  which  a 
muscle  experiences,  some  difference  of  sentiment  has  prevailed.     Ber- 

1  Muller's  Archiv.,  Heft  v.  1839. 

3  Art.  Muscular  Motion,  in  Cyclop,  of  Anat.  and  Physiol.,Part  xxiv.  p.  525,  London,  July, 
1842;  and  Philosophical  Transactions  for  1840-1841. 


STATE  OF  MUSCLES  IN  ACTION. 


399 


Muscular  Fibre  of  Skate. 

In  a  state  of  rest  (1),  and  in  three 
i  of  contraction  (2, 3, 


nouilli  and  Keill1  estimated  it  at  one-third  of  Fig.  167. 

the  length;  and  Dumas2  carried  it  still  higher. 
It  must,  of  course,  be  proportionate  to  the 
length  of  the  fibres, — being  greater,  the  longer 
the  fibres.  It  has,  also,  been  a  subject  of  ex- 
periment and  speculation,  whether  the  bulk 
and  the  specific  gravity  of  a  muscle  be  aug- 
mented during  contraction.  Borelli3  and  Sir 
Anthony  Carlisle4  affirm,  that  its  bulk  is  in- 
creased. In  the  experiments  of  the  latter, 
the  arm  was  immersed  in  a  jar  of  water,  with 
which  a  barometrical  tube  was  connected;  and 
when  the  muscles  were  made  to  contract 
strongly,  the  level  of  the  water  in  the  tube 
was  raised.  Glisson,  however,  from  the  same 
experiment,  deduced  opposite  conclusions; 
Swammerdam  and  Ermann5  appear  to  be  of 
their  opinion;  but  Sir  Gilbert  Blane,6  Mr. 
Mayo,7  Barzellotti,8  MM.  Dumas  and  PreVost,9 
and  Valentin,10  during  the  most  careful  ex- 
periments could  see  no  variation  in  the  level 
of  the  fluid;  and,  consequently,  do  not  believe, 
that  the  size  of  a  muscle  is  modified  by  con- 
traction. Sir  Gilbert  enclosed  a  living  eel  in  Jj[ 
a  glass  vessel  filled  with  water,  the  neck  of 
which  was  drawn  out  into  a  fine  tube;  he  then,  by  means  of  a  wire 
introduced  into  the  vessel,  irritated  the  tail  of  the  animal,  so  as  to  ex- 
cite strong  contraction,  during  which  he  noticed,  that  the  water  in  the 
vessel  remained  stationary.  He,  likewise,  compared  the  two  sides  of  a 
fish,  one  of  which  had  been  crimped,  and  thus  brought  into  a  state  of 
strong  contraction; — the  other  left  in  its  natural  condition:  their  specific 
gravity  was  the  same.  The  experiment  of  Barzellotti  was  the  following. 
He  suspended,  in  a  glass  vessel,  the  posterior  half  of  a  frog;  filled  the 
jar  with  water,  and  closed  it  with  a  stopper,  traversed  by  a  narrow, 
graduated  tube.  The  muscle  was  then  made  to  contract  by  means  of 
galvanism,  but  in  no  case  was  the  level  of  the  liquid  in  the  tube  changed. 
It  may,  then,  be  concluded,  that  the  bulk  of  a  muscle  is  not  much,  if 
at  all,  greater  when  contracted  than  when  relaxed.  Professor  E.  Weber, 
who  repeated  the  experiments  of  Ermann,  detected  an  increase  of  bulk, 
but  it  was  exceedingly  small.11 

1  Tentamina-Medico-Physica,  Lond.,  1718. 

2  Principes  de  Physiologie,  &c.,  2de  edit.,  Paris,  1806. 

3  De  Motu  Animaliurn.  addit.  J.  Bernouillii,  Medit.  Mathem.  Muscul.,  L.  B.  1710. 

4  Philos.  Transact,  for  1805,  pp.  22,  23.  *  Gilbert's  Annalen,  p.  40,  1812. 

6  A  Lecture  on  Muscular  Motion,  &c.,  Lond.,  1778';  and  Select  Dissertations,  &c.,  p.  239. 

7  Anatomical  and  Physiological  Commentaries,  i.  12;  and  Outlines  of  Human  Physiology, 
3d  edit.,  p.  35,  Lond.,  1833. 

8  Esame  di  alcune  moderne  Teorie  intorno  alia  Causa  prossima  della  Contrazione  mos- 
colare,  Siena,  1796.  9  Op.  citat,  and  Magendie,  Precis,  &c.,  i.  222. 

10  Lehrbuch  der  Physiologie  des  Menschen,  s.  42,  Braunschweig,  1844;  and  Grundriss 
der  Physiologie,  s.  218,  Braunschweig,  1846. 

11  Art.  Muskelbewegung,  in  Wagner's  Handworterbuch  der  Physiologie,  15te  Lieferung,  s. 
52  und  121,  Braunschweig,  1846. 


400  MUSCULAR  MOTION. 

During  contraction,  the  muscle  is  sometimes  so  rigid  and  elastic  as 
to  be  capable  of  vibration  when  struck.  The  ordinary  firm  state  is  well 
exhibited  by  the  masseter,  when  the  jaws  are  forcibly  closed ;  and  some 
men  possess  the  power  of  producing  sonorous  vibrations  by  striking  the 
contracted  biceps  with  a  metallic  rod. 

It  has  been  a  matter  of  dispute  whether  the  quantity  of  blood  circu- 
lating in  a  muscle  is  diminished  during  contraction.  At  one  time,  it 
was  universally  believed,  that  such  diminution  existed,  and  that  it  ac- 
counted for  the  diminished  size  of  the  muscle  during  contraction.  This 
last  allegation  we  have  shown  to  be  inaccurate;  and  no  correct  deduc- 
tion can,  consequently,  be  drawn  from  it.  Sir  Anthony  Carlisle1 
adopted  the  opinion,  that  the  muscles  become  pale  during  contraction; 
but  he  offers  no  proof  of  it.  The  probability  is,  that  he  implicitly 
obeyed,  in  this  respect,  the  dicta  of  his  precursors,  without  observing 
the  incongruity  of  such  a  supposition  with  his  idea,  that  the  absolute 
size  of  the  muscle  is  augmented  during  contraction.  The  truth  is,  we 
have  no  evidence,  that  the  colour  of  a  muscle,  or  the  quantity  of  blood 
circulating  in  it,  is  altered  during  contraction.  Bichat,2  who  adopted 
the  opinion,  that  the  blood  is  forced  out  during  this  state,  relies  chiefly 
upon  the  fact,  known  to  every  one,  that  in  the  operation  of  blood-letting 
from  the  arm  the  flow  of  blood  is  augmented  by  working  the  muscles; 
but  the  additional  quantity  expelled  is  properly  ascribed  by  Dr.  Bos- 
tock3  to  the  compression  of  the  large  venous  trunks  by  the  swelling 
out  of  the  bellies  of  the  muscles.  The  prevalent  belief,  amongst  phy- 
siologists of  the  present  day,  is,  that  there  is  no  change  of  colour  in 
the  muscle  during  contraction. 

When  the  extremities  of  a  muscle  are  made  to  approximate,  the 
belly,  of  course,  swells  out;  and  would  probably  expand  to  such  an 
extent,  that  the  fasciculi,  of  which  it  is  composed,  would  separate  from 
each  other,  were  it  not  for  the  areolar  membrane  and  aponeuroses, 
with  which  they  and  the  whole  muscle  are  enveloped. 

The  phenomena  attendant  upon  the  relaxation  of  a  muscle  are  the 
reverse  of  those  that  accompany  its  contraction.  The  belly  loses  its 
rugous  character;  becomes  soft,  and  the  swelling  subsides;  the  ends 
recede,  and  the  organ  is  as  it  was  prior  to  contraction.  It  is  obvious, 
however,  that  after  a  part,  as  the  arm,  has  been  bent  by  the  contrac- 
tion of  appropriate  muscles,  simple  relaxation  would  not  be  sufficient 
to  restore  it  to  its  original  position;  for  although  the  relaxation  of  a 
muscle  has  been  regarded  by  Bichat  and  others  to  be,  in  part  at  least, 
an  active  effort;  and  to  consist  in  something  more  than  the  mere  ces- 
sation of  contraction,  the  evidence  in  favour  of  the  view  is  extremely 
feeble  and  unsatisfactory.  The  arrangement  of  the  muscular  system 
is,  in  this,  as  in  every  other  respect,  admirable,  and  affords  signal  evi- 
dence of  Omnipotent  agency.  The  arm,  as  in  the  case  selected  above, 
has  not  only  muscles  to  bend,  but  also  to  extend  it;  and,  accordingly, 
when  it  has  been  bent,  and  it  becomes  necessary  to  extend  it,  the  flexor 
muscles  are  relaxed  and  rest,  while  the  extensors  are  thrown  into 

1  Op.  citat,  p.  27.  a  Anat.  General.,  torn.  iii.  §  2. 

3  Physiology,  3d  edit.,  94,  Lond.,  1 836. 


PHENOMENA  OF  MUSCULAR  CONTRACTION.  401 

action.  This  disposition  of  antagonist  muscles  prevails  in  almost  every 
part  of  the  frame,  and  will  require  notice  presently. 

Muscles  are  not,  however,  the  sole  agents  in  replacing  parts.  Many 
elastic  textures  exist,  which,  when  put  upon  the  stretch  by  muscular 
contraction,  have  a  tendency  to  return  to  their  former  condition,  as 
soon  as  the  extending  cause  is  removed.  Of  this  a  good  example 
occurs  in  the  cartilages  of  prolongation,  which  unite  the  ribs  to  the 
sternum.  During  inspiration,  these  elastic  bodies  are  extended;  and, 
by  returning  upon  themselves,  they  become  active  agents  of  expiration, 
and  tend  to  restore  the  chest  to  its  unexpanded  state. 

The  production  of  the  phenomena  of  muscular  contraction  is,  so  far 
as  is  known,  unlike  any  physical  process  with  which  we  are  acquainted. 
It  has,  therefore,  been  considered  essentially  organic  and  vital ;  and, 
like  other  operations  of  the  kind,  will  probably  ever  elude  our  researches. 
Yet  here,  as  on  every  obscure  subject,  hypotheses  have  been  innumera- 
ble; varying  according  to  the  fashionable  systems  of  the  day,  or  the 
views  of  the  propounder.  They,  who  formerly  believed  that  the  mus- 
cular fibre  is  hollow,  or  vesicular,  ascribed  its  contraction  to  distension 
by  the  influx  of  "animal  spirits"  or  of  blood;  and  relaxation  to  the 
withdrawal  of  those.  Such  were  the  hypotheses  of  Borelli,1  Stuart,2 
and  others.  Independently,  however,  of  the  objection  to  these  views, 
that  we  have  no  positive  evidence  of  the  existence  of  such  vesicles,  it 
is  obvious,  that  the  explanation  is  defective,  inasmuch  as  we  have  still  to 
look  to  the  cause  that  produces  this  mechanical  influence.  Again, 
how  are  we  to  account,  under  this  hypothesis,  for  the  surprising  efforts 
of  strength  executed  by  muscles?  The  mechanical  influence  of  animal 
or  other  spirits — granting  for  a  moment  their  existence — might  develope 
a  certain  degree  of  force ;  but  how  can  we  conceive  them  able,  as  in  the 
case  of  the  muscles  inserted  into  the  foot,  to  develope  such  a  force  as 
to  project  the  body  from  the  ground?  In  all  these  cases,  a  new  force 
is  generated  in  the  brain;  and  this,  by  acting  on  the  muscular  fibre,  is 
the  efficient  cause  of  the  contraction.  Moreover,  what  an  inconceivable 
amount  of  fluids  would  be  necessary  to  produce  the  contraction  of  the 
various  muscles,  that  are  constantly  in  action;  and  what,  it  has  been 
asked,  becomes  of  these  fluids  when  relaxation  succeeds  to  contraction? 
Some  have  affirmed,  that  they  are  absorbed  by  the  venous  radicles; 
others,  that  they  run  off  by  the  tendons;  and  others,  again,  that  they 
become  neutralized  in  the  muscle,  and  communicate  to  it  the  greater 
size  it  attains  under  exercise.  These  fantasies  are  too  abortive  to 
require  comment. 

When  chemical  hypotheses  were  in  fashion  in  medicine,  physiology 
participated  in  them  largely.  At  one-  time  it  was  imagined,  that  an 
effervescence  was  excited  in  the  muscle  by  the  union  of  two  substances, 
one  of  which  was  of  an  acid,  the  other  of  an  alkaline  nature.  Willis, 
Mayow,  Keill,3  Bellini,4  &c.,  supported  opinions  of  this  kind;  some 
ascribing  the  effervescence  to  a  union  of  the  nervous  fluid  with  the  arte- 

1  De  Motu  Animalium,  Lugd.  Bat.,  1710. 
3  De  Structura  et  Motu  Musculari,  Lond.,  1738. 

3  Tentamin.  Medico-Physic.,  No.  v.,  Lond.,  1718.  •*  Bostock,  op.  cit.,  p.  111. 

VOL.  I. — 26 


402  MUSCULAR  MOTION. 

rial  blood;  others  to  a  union  of  the  particles  of  the  muscular  fibre  with 
the  nervous  fluid;  and  others,  to  the  disengagement  of  an  elastic  gas, 
primitively  contained  in  the  blood,  and  separated  from  it  by  the  nerv- 
ous spirits.  It  would,  however,  be  unprofitable,  as  well  as  uninterest- 
ing, to  repeat  the  different  absurdities  of  this  period — so  prolific  in 
physical  obscurities.  Medicine  has  generally  kept  pace  with  physics, 
and  where  the  latter  science  has  been  dark  and  enigmatical,  the  former 
has  been  so  likewise.  In  physiology,  this  is  especially  apparent;  most 
of  the  natural  philosophers  of  eminence  having  applied  their  doctrines 
in  physics  to  the  explanation  of  the  different  functions  of  the  human 
frame.  Newton,  Leibnitz,  and  Des  Cartes,  were  all  speculative  physi- 
ologists. The  discovery  of  electricity  gave  occasion  to  its  application 
to  the  topic  in  question;  and  it  was  imagined,  that  the  fibres  of  the 
muscle  might  be  disposed  in  such  a  manner  as  to  form  a  kind  of  battery, 
capable  of  producing  contraction  by  its  explosions;  and  after  the  dis- 
covery of  galvanic  electricity,  Valli1  attempted  to  explain  muscular 
contraction,  by  supposing  that  the  muscles  have  an  arrangement  simi- 
lar to  that  of  the  galvanic  pile.  Haller2  endeavoured  to  resolve  the 
problem  by  his  celebrated  doctrine  of  irritability,  which  will  engage 
attention  hereafter.  He  conceived,  that  the  muscles  possess,  what  he 
calls,  a  vis  insita;  and  that  their  contraction  is  owing  to  the  action  of 
this  force,  excited  by  a  stimulus,  which  stimulus  is  the  nervous  influx 
directed  by  volition.  This,  although  a  true  doctrine  we  think,  sheds  no 
new  light  on  the  mysterious  process.  It  is,  in  fact,  cutting  the  Gor- 
dian  knot.  We  should  still  have  to  explain  the  precise  mode  of  action 
of  the  vis  insita:3  but  that  it  is  not  in  any  way  derived  from  the  nerv- 
ous system  will  be  shown  when  treating  of  LIFE. 

The  hypothesis  of  Prochaska4  is  entirely  futile.  He  gratuitously 
presumes,  that  minute  ramifications  of  arteries  are  every  where  con- 
nected with  the  ultimate  muscular  filaments,  twining  around  them,  and 
crossing  them  in  all  directions.  When  these  vessels  are  rendered 
turgid  by  an  influx  of  blood, — by  passing  among  the  filaments,  they 
must,  he  conceives,  bend  the  latter  into  a  serpentine  shape,  and  thus 
diminish  their  length,  and  that  of  the  muscle  likewise.  Sir  Gilbert 
Blane,5  again,  throws  out  a  conjecture — deduced  from  experiments,  in 
which  he  found  that  the  actual  bulk  of  a  muscle  is  not  changed  during 
contraction,  but  that  it  gains  in  thickness  exactly  what  it  loses  in 
length ; — that  this  may  be  owing  to  the  muscle  being  composed  of 
particles  of  an  oblong  shape ;  and  that  when  the  muscle  is  contracted, 
the  long  diameter  of  the  particle  is  removed  from  a  perpendicular  to  a 
transverse  direction.  But  the  same  objection  applies  to  this  as  to  other 
hypotheses  on  the  subject;  that  it  is  entirely  gratuitous, — resting  on 
no  histological  observation  whatever. 

Two  views  have  been,  perhaps,  the  most  prevalent ;  one  which  con- 
siders muscular  contraction  to  be  a  kind  of  combustion  ;  another  that  it 

1  Experiments  in  Animal  Electricity,  Lond.,  1793. 

2  Element.  Physiol.,  xi.  214;  and  Oper.  Minor.,  torn.  i. 

»  M.  Hall,  art.  Irritability,  Cyclop,  of  Anat.  and  Physiol.,  July,  1840. 
*  De  Came  Musculari,  §  ii.,  Vienn.,  1778. 
6  Op.  citat. 


ELECTRICAL  THEORY  OF  MUSCULAR  CONTRACTION.  403 

is  produced  by  electricity.  The  former,  which  was  originally  propounded 
by  Girtanner,1  and  zealously  embraced  by  Dr.  Beddoes,  who  was  more 
celebrated  for  his  enthusiasm  than  for  the  solidity  of  his  opinions,  has 
now  few  supporters.  This  hypothesis  supposes,  that  muscular  contrac- 
tion depends  upon  the  combustion  of  the  combustible  elements  of  the 
muscle,  hydrogen  and  carbon,  by  the  oxygen  of  the  arterial  blood;  the 
combustion  being  produced  by  the  nervous  influx,  which  acts  in  the  man- 
ner of  an  electric  spark ; — at  least,  such  is  the  view  adopted  by  M. 
Richerand,2  one  of  the  most  fanciful  of  physiological  speculators.  Of 
course,  we  have  neither  direct  nor  analogical  evidence  of  any  such  com- 
bustion, which,  if  it  existed  at  all,  ought  to  be  sufficient,  in  a  short  space 
of  time,  to  entirely  consume  the  organs  that  furnish  the  elements. 
The  idea  is  as  unfounded  as  numerous  others  that  have  been  enter- 
tained, and  is  worthy  only  of  particular  notice,  from  its  being  professed 
in  one  of  the  well-known  works  on  physiological  science. 

The  second  hypothesis  refers  muscular  contraction  to  electricity. 
Attention  has  been  already  directed  to  the  electroid  or  galvanoid  cha- 
racter of  the  nervous  agency ;  and  we  have  some  striking  examples  on 
record  of  the  analogous  effects  produced  by  the  physical  and  the  vital 
fluid  on  the  phenomena  under  consideration.  It  has  been  long  known, 
that  when  nerves  and  muscles  are  exposed  in  a  living  animal,  and 
brought  into  contact,  contractions  or  convulsions  occur  in  the  latter. 
Galvani3  was  the  first  to  point  this  out.  He  decapitated  a  living  frog; 
removed  the  fore-paws,  and  quickly  skinned  it.  The  spine  was  divided, 
so  as  to  leave  the  spinal  marrow  communicating  only  with  the  hinder 
extremities  by  means  of  the  lumbar  nerves.  He  then  took,  in  one  hand, 
one  of  the  thighs  of  the  animal,  and  the  vertebral  column  in  the  other, 
and  bent  the  limb  until  the  crural  muscles  touched  the  lumbar  nerves. 
At  the  moment  of  contact  the  muscles  were  strongly  convulsed.  The 
experiment  was  repeated  by  Volta,4  Aldini,5  Pfaff,6  Humboldt,7  and 
others  ;  and  with  like  results.  Aldini8  caused  convulsions  in  the  mus- 
cles by  the  contact  of  those  organs  with  nerves,  not  only  in  the  same 
frog,  but  in  two  different  frogs.  He  adds,  that  he  remarked  them 
when  he  put  the  nerves  of  a  frog  in  connexion  with  the  muscular  flesh 
of  an  ox  recently  killed.  Humboldt  made  numerous  experiments  of 
this  kind  on  frogs,  and  found  convulsions  supervene  when  he  placed 
upon  a  dry  plate  of  glass  a  posterior  extremity  whose  crural  nerves  had 
been  exposed,  and  touched  the  nerves  and  muscles  with  a  piece  of  raw 
muscular  flesh,  insulated  at  the  extremity  of  a  stick  of  sealing-wax. 
Convulsions  likewise  occurred,  when,  instead  of  one  piece  of  flesh,  he 
used  three  different  pieces  to  form  the  chain,  one  of  which  touched  the 
nerve  ;  the  other  the  thigh,  and  the  third  the  two  others.  The  expe- 
riments were  repeated  by  Ritter  with  similar  results ;  but  they  were 

'  Journal  de  Physique,  xxxvii.  139.  2  Elements  of  Physiology,  §  163. 

3  Mem.  sull'  Elettricita  Animate,  Bologn.,  1797. 

4  Memoria  sull' Elettricita  Animale,  1782. 

6  Essai  Theoretique  et  Experiment,  sur  le  Galvanisme,  Paris,  1804. 
Ueber  thierische  Electricitat  und  Reizbarkeit,  Leipz.,  1795. 

7  Versuche  iiber  die  gereizte  Muskel  und  Nervenfaser,  Posen  und  Berlin,  1797. 

8  Traite  cornplet  de  Physiologic  de  1'Homme,  par  Tiedemann,  traduit  par  Jourdan,p.  559, 
Paris,  1837. 


404  MUSCULAR  MOTION. 

only  found  to  succeed,  when  the  frogs  were  in  full  vital  activity, — espe- 
cially in  spring,  after  pairing  ;  when  the  animal  was  of  sufficient  size, 
and  its  preparation  for  the  experiment  had  been  rapidly  effected. 

From  all  these  experiments  it  might  be  inferred,  that  parts  of  an  ani- 
mal may  form  galvanic  chains,  and  produce  a  galvanic  effect,  which, 
independently  of  any  mechanical  excitation,  may  give  rise  to  the  con- 
traction of  muscles.  This  excitation  of  electricity  in  chains  of  animal 
parts,  M.  Tiedemann  thinks,  ought  not  to  be  esteemed  a  vital  act.  Its 
effects  only — the  contractions  excited  in  the  muscles — are  dependent  on 
the  vital  condition  of  the  muscles  and  nerves.  He  considers,  that  elec- 
tricity, excited  in  chains  of  heterogeneous  animal  parts,  may  be  modi- 
fied and  augmented  by  the  organic  or  living  forces  ;  and  that,  more- 
over, in  certain  animals,  organs  exist,  the  arrangement  of  which  is  such 
as  to  excite  electricity  during  their  vital  action  as  in  the  different  kinds 
of  electrical  fishes  ;  but  in  some  experiments,  instituted  by  M.  Edwards,1 
the  effects  above  referred  to  were  produced  by  touching  a  denuded 
nerve  with  a  slender  rod  of  silver,  copper,  zinc,  lead,  iron,  gold,  tin,  or 
platinum,  and  drawing  it  along  the  nerve  for  the  space  of  from  a  quar- 
ter to  a  third  of  an  inch.  He  took  care  to  employ  metals  of  the  great- 
est purity,  as  they  were  furnished  him  by  the  assayers  of  the  mint. 
But  it  was  not  even  necessary  that  the  rod  should  be  metallic  :  he  suc- 
ceeded with  glass  or  horn.  All  metals,  however,  did  not  produce 
equally  vigorous  contractions.  Iron  and  zinc  were  far  less  effective 
than  the  others  ;  but  no  accurate  scale  could  be  formed  of  their  respect- 
ive powers. 

Much  difference  is  found  to  exist,  when  electricity  is  employed,  ac- 
cording as  the  nerve  is  insulated  or  not ;  for  as  the  muscular  fibre  is  a 
good  conductor  of  electricity,  if  the  nerve  be  not  insulated,  the  electri- 
city is  communicated  to  both  nerve  and  muscle,  and  its  effect  is  conse- 
quently diminished.  It  became,  therefore,  interesting  to  M.  Edwards 
to  discover,  whether  any  difference  would  be  observable,  when  one  metal 
only  was  used,  whether  the  nerve  was  insulated  or  not.  In  the  expe- 
riments above  referred  to,  the  nerve  was  insulated  by  passing  a  strip  of 
oiled  silk  beneath  it.  A  comparison  was  now  instituted  between  an 
animal  thus  prepared,  and  another  whose  nerves  instead  of  being  insu- 
lated, rested  on  the  subjacent  flesh.  He  made  use  of  small  rods,  with 
which  he  easily  excited  contractions  when  he  drew  them  from  above  to 
below  along  the  denuded  portion  of  nerve  that  was  supported  by  the 
oiled  silk  ;  but  he  was  unable  to  cause  them  when  he  passed  the  rod 
along  the  nerve  of  the  other  animal  which  was  not  insulated.  His 
experiments  were  then  made  on  two  nerves  of  the  same  animal ;  an.d  he 
found  that  after  having  vainly  attempted  to  produce  contractions  by 
the  contact  of  a  nerve  resting  upon  muscle,  they  could  still  be  induced 
if  the  oiled  silk  were  had  recourse  to;  and  he  was  able  to  command  their 
alternate  appearance  and  disappearance  by  using  a  non-conductor  or  a 
conductor  for  the  support  of  the  nerve.  Somewhat  surprised  at  these 
results,  M.  Edwards  was  stimulated  to  the  investigation,  —  whether 

1  Appendix  to  Edwards  on  the  Influence  of  Physical  Agents  on  Life, — Hodgkin  and 
Fishers  translation,  Lond.,  1832. 


ELECTRICAL  THEORY  OF  MUSCULAR  CONTRACTION.  405 

some  degree  of  contraction  might  not  be  excited  by  touching  the  unin- 
sulated nerve,  and  having  remarked,  that  contractions  were  most  con- 
stantly produced  in  the  insulated  nerve  by  a  quick  and  light  touch,  he 
adopted  this  method  on  an  animal  whose  nerve  was  not  insulated,  and 
frequently  obtained  slight  contractions.  All  his  experiments  on  this 
subject  seemed  to  prove,  that,  cseteris  paribus,  muscular  contractions, 
produced  by  the  contact  of  a  solid  body  with  a  nerve,  are  much  less 
considerable,  or  even  wholly  wanting,  when  the  nerve,  in  place  of  being 
insulated,  is  in  communication  with  a  good  conductor ;  and  it  would 
seem  to  follow,  as  a  legitimate  conclusion,  that  these  contractions  are 
dependent  on  electricity ;  facts,  which  it  is  well  to  bear  in  mind,  in  all 
experiments  on  animals  where  feeble  electrical  influences  are  employed.1 
Galvanic  electricity,  it  will  be  seen  hereafter,  is  one  of  the  great 
tests  of  muscular  irritability,  and  is  capable  of  occasioning  contractions 
for  some  time  after  the  death  of  the  animal,  as  well  as  of  maintaining, 
for  a  time,  many  of  the  phenomena  peculiar  to  life.  This  is  the  reason 
why  muscular  contraction,  excited  by  this  nervous,  electroid  fluid,  has 
been  regarded  as  an  electrical  phenomenon.  Much  discrepancy  has, 
however,  arisen  amongst  the  partisans  of  this  opinion  regarding  its 
modus  operandi.  Rolando,  we  have  seen,  assimilates  the  cerebellum  to 
an  electro-motive  apparatus,  which  furnishes  the  fluid  that  excites  the 
muscles  to  contraction.  Some  have  compared  the  spinal  column  to  a 
voltaic  pile,  and  have  supposed  the  contraction  of  a  muscle  to  be  owing 
to  an  electric  or  galvanic  shock.  The  views  of  MM.  Dumas  and  Prevost2 
are  amongst  the  most  striking.  By  a  microscope,  magnifying  ten  or 
twelve  diameters,  they  first  of  'all  examined  the  manner  in  which  the 
nerves  are  arranged  in  a  muscle;  and  found,  as  has  been  already  ob- 
served, that  their  ramifications  always  enter  the  muscle  in  a  direction 
perpendicular  to  its  fibres.  They  satisfied  themselves,  that  none  of  the 
nerves  really  terminate  in  the  muscle ;  but  that  the  final  ramifications 
embrace  the  fibres  like  a  noose,  and  return  to  the  trunk  that  furnishes 
them,  or  to  one  in  its  vicinity, — the  nerve  setting  out  from  the  anterior 
column  of  the  spinal  marrow,  and  returning  to  the  posterior.  On  farther 
examining  the  muscles  at  the  time  of  their  contraction,  the  parallel 
fibres  composing  them  were  found,  under  the  microscope,  to  bend  in  a 
zigzag  manner,  and  to  exhibit  a  number  of  regular  undulations;  such 
flexions  forming  angles,  which  varied  according  to  the  degree  of  con- 
traction, but  were  never  under  fifty  degrees.  The  flexions,  too,  always 
occurred  at  the  same  parts  of  the  fibre,  and  to  them  the  shortening  of 
the  muscle  was  owing,  as  MM.  Dumas  and  Prevost  proved  by  calculat- 
ing the  angles.  The  angular  points  were  always  found  to  correspond 
to  the  parts  where  the  small  nervous  filaments  enter  or  pass  from  the 
muscles.  (See  page  371.)  They  therefore  believed,  that  these  filaments, 
by  their  approximation,  induce  contraction  of  the  muscular  fibre;  and 
this  approximation  they  ascribed  to  a  galvanic  current  running  through 
them ;  which,  as  the  fibres  are  parallel  and  in  proximity,  they  thought, 
ought  to  cause  them  to  attract  each  other,  according  to  the  law 

1  Coldstream,  art.  Animal  Electricity,  in   Cyclop.  Anat.  and   Physiol.,  P.  ix.  p.  93,  Jan., 
1837;  and  J.  Miiller,  Elements  of  Physiology,  by  Baly,  p.  261,  London,  1838. 

2  Journal  de  Physiologic,  torn.  iii.  301 ;  and  Magendie,  Precis,  i.  220. 


406  MUSCULAR  MOTION. 

Jaid  down  by  M.  Ampere,  that  two  currents  attract  each  other  when 
they  move  in  the  same  direction.  The  living  muscles  are,  consequently, 
regarded  by  them  as  galvanometers,  and  galvanometers  of  an  extremely 
sensible  kind,  on  account  of  the  very  minute  distance  and  tenuity  of 
the  nervous  filaments.  They  moreover  affirm,  that,  by  anatomical  ar- 
rangement, the  nerve  is  fixed  in  the  muscle  in  the  very  position  required 
for  the  proper  performance  of  its  function;  and  they  esteem  the  fatty 
matter,  which  envelopes  the  nervous  fibres,  and  which  was  discovered 
by  M.  Yauquelin,  as  a  means  of  insulation  for  preventing  the  electric 
fluid  from  passing  from  one  fibre  to  another. 

Soon  after  hearing  of  M.  Ampere's  discovery  of  the  attraction  of  elec- 
trical currents,  it  occurred  to  Dr.  Roget,1  that  it  might  be  possible  to 
render  the  attraction  between  the  successive  and  parallel  turns  of  heli- 
acal or  spiral  wires  very  sensible,  if  the  wires  were  sufficiently  flexible 
and  elastic ;  and,  with  the  assistance  of  Dr.  Faraday,  his  conjecture 
was  put  to  the  test  of  experiment  in  the  laboratory  of  the  Royal  Insti- 
tution of  London.  A  slender  harpsichord- wire,  bent  into  a  helix,  being 
placed  in  the  voltaic  circuit,  instantly  shortened  itself  whenever  the 
electric  stream  was  sent  through  it;  but  recovered  its  former  dimensions 
the  moment  the  current  was  intermitted.  From  this  experiment  it  was 
supposed,  that  possibly  some  analogy  might  hereafter  be  found  to  exist 
between  the  phenomenon  and  the  contraction  of  muscular  fibre. 

The  views  of  MM.  Dumas  and  Prevost  were  altogether  denied  by 
M.  Raspail,2  on  the  ground,  that  it  is  impossible  to  distinguish,  by  the 
best  microscope,  the  ultimate  muscular  fibre  from  the  small  nervous 
fibrils  by  which  those  gentlemen  consider  them  to  be  surrounded  loop- 
wise.  He  farther  affirmed,  that  the  zigzag  form  is  the  necessary  result 
of  the  method  in  which  they  performed  their  experiments,  and  is 
produced  by  the  muscular  fibre  adhering  to  the  glass  on  which  it  was 
placed.  His  own  idea,  founded  on  numerous  observations,  is,  that  the 
contraction  of  the  fibre  in  length  is  always  occasioned  by  its  extension 
in  breadth  under  the  influence  of  the  vital  principle.  Independently, 
however,  of  M.  Raspail's  objection,  the  circumstance,  that,  in  this  mode 
of  viewing  the  subject,  the  muscle  itself  is  passive,  and  the  nerve  alone 
active,  is  a  stumbling-block  in  the  way  of  the  views  of  MM.  Dumas  and 
Prevost,  and  of  Dr.  Roget.  It  is  proper,  too,  to  remark,  that  M.  Person3 
was  unable  to  detect  any  longitudinal  galvanic  currents  in  the  nerves 
by  the  most  sensible  galvanometer ;  and  that  other  stimuli  besides 
galvanism  are  capable  of  exciting  the  muscular  fibre  to  contraction. 
This  we  daily  see  in  experiments  on  the  frog,  by  dropping  salt  on  the  de- 
nuded muscle.  Prof.  Miiller4  hence  infers,  that  a  nerve  of  motion,  dur- 
ing life,  and  whilst  its  excitability  or  irritability  continues,  is  so  circum- 
stanced, that  whatever  suddenly  changes  the  relative  condition  of  its 
molecules  excites  a  contraction  at  the  remote  end  of  the  muscle,  and 

1  Electro-Magnetism,  p.  59,  in  2d  vol.  of  Nat.  Philosophy,  Library  of  Useful  Knowledge, 
London,  1832. 

3  Chimie  Organique,  p.  212,  Paris,  1833. 

3  Journal  de  Physiologie,  torn.  x.  Paris,  1830. 

4  Art.  Electricitiit  (thierische)  in  Ericyclopad.  Worterb.  der  Medicin.  Wissensch.,  x.  545, 
Berlin,  1834. 


ELECTRICAL  THEORY  OF  MUSCULAR  CONTRACTION.  407 

that  electrical,  chemical,  and  mechanical  irritants  are,  in  this  respect, 
similarly  situate. 

Interesting  electro-physiological  researches  have  been  made  by  Pro- 
fessor Matteucci  of  Pisa,  from  which  he  has  deduced  the  following 
results.  First.  Muscle  is  a  better  conductor  of  electricity  than  nerve; 
and  nerve  conducts  better  than  brain.  The  conducting  power  of 
muscle  may  be  taken  as  four  times  greater  than  that  of  brain  or  nerve. 
Secondly.  In  the  muscles  of  living  animals,  as  well  as  of  those  recently 
killed,  an  electric  current  exists,  which  is  directed  from  the  interior  of 
each  muscle  to  its  surface.  The  duration  of  this  muscular  current 
corresponds  with  that  of  contractility ;  in  cold-blooded  animals,  there- 
fore, it  is  greatest :  in  mammalia  and  birds  very  brief.  Temperature 
has  a  considerable  influence  on  the  intensity  of  the  current, — a  small 
amount  of  electricity  being  developed  in  a  cold  medium ;  a  larger  one 
when  the  medium  is  moderately  warm.  Any  circumstance  that  enfeebles 
the  frogs  (the  animals  experimented  on)  and  deranges  their  general 
nutrition,  diminishes  the  power  of  the  muscles  to  generate  electricity, 
as  it  likewise  impairs  the  contractile  force.  The  muscular  current 
appears  to  be  quite  independent  of  the  nervous  system.  It  is  unin- 
fluenced by  narcotic  poisons  in  moderate  doses,  but  is  destroyed  by 
large  doses,  such  as  would  kill  the  animal.  The  developement  of  this 
muscular  current  seems  evidently  to  depend  on  the  chemical  action 
constantly  taking  place  as  an  effect  of  the  changes  accompanying  nutri- 
tion. Thirdly.  In  frogs  an  electric  current  exists,  which  is  distinct 
from  the  muscular  current.  It  proceeds  from  the  feet  to  the  head, 
and  is  peculiar  to  batrachian  reptiles.  Fourthly.  Singular  results  are 
obtained  by  applying  electricity  in  various  ways  to  nerves.  On  making 
experiments  on  the  sciatic  nerves  of  rabbits,  he  found  that  on  closing 
the  circuit  of  the  direct  electric  current,  or  the  current  passing  from 
the  brain  to  the  nerves,  contractions  in  the  muscles  of  the  posterior 
limbs  were  produced ;  whilst  opening  this  circuit  was  followed  by  marked 
signs  of  pain,  with  contraction  of  the  muscles  of  the  back,  and  feeble 
contractions  of  the  posterior  limbs.  On  closing  the  circuit  of  the  inverse 
current,  or  that  directed  from  the  nerves  to  the  brain,  signs  of  pain, 
contractions  of  the  muscles  of  the  back,  and  feeble  contractions  of  the 
posterior  limbs  were  produced.  On  opening  it,  contractions  of  the  pos- 
terior limbs  followed.1 

With  regard  to  the  hypotheses  which  ascribe  muscular  contractility 
to  the  chemical  composition  of  the  fibre,  and  that  which  maintains,  that 
the  property  is  dependent  upon  the  mechanical  structure  of  the  fibre, 
they  are  undeserving  of  citation,  notwithstanding  the  respectability  of 
the  individuals  who  have  written  and  experimented  on  the  subject. 
They  merely  seem  to  show,  that  here,  as  in  every  case,  a  certain  che- 
mical and  mechanical  constitution  is  necessary,  in  order  that  the  vital 
operation,  peculiar  to  the  part,  may  be  accomplished. 

But  not  only  is  it  necessary,  that  the  muscle  shall  possess  a  proper 

1  For  an  account  of  Matteucci's  researches,  see  Todd  and  Bowman,  Physiological  Ana- 
tomy and  Physiology  of  Man,  vol.  i.,  Lond.,  1845,  and,  especially,  Matteucci,  Lectures  on  the 
Physical  Phenomena  of  Living  Beings,  by  Pereira,  Amer.  edit.,  pp.  176  and  224,  Philad., 
1848. 


408  MUSCULAR  MOTION. 

physical  organization,  it  must,  likewise,  be  endowed  with  a  property 
essentially  vital ;  in  other  words,  with  irritability  or  contractility.  The 
cause  of  the  ordinary  contraction  of  muscles  is,  doubtlesss  the  nervous 
influx ;  but  if  we  materially  alter  the  condition  of  the  muscle,  although 
the  nervous  influx  may  be  properly  transmitted  to  it,  there  will  be  no 
contraction.  This  applies  to  the  living  animal;  but  not  apparently  to 
the  dead;  for  Valentin1  found,  that  after  tying  the  femoral  artery  or 
vein,  or  dividing  the  sciatic  nerve  in  frogs,  the  full  strength  of  the 
muscle  remained  unaltered  for  several  days, — in  one  case  for  twelve. 
We  moreover  find,  that  after  a  muscle  has  acted  for  some  time,  it  be- 
comes fatigued,  notwithstanding  volition  may  regularly  direct  the  nerv- 
ous influx  to  it ;  and  that  it  requires  repose,  before  it  is  again  capable 
of  executing  its  functions. 

In  the  upper  classes  of  animals,  contractility  remains  for  some  time 
after  dissolution;  in  the  lower,  especially  in  the  amphibia,  the  period 
during  which  it  is  evinced  on  the  application  of  appropriate  stimuli  is 
much  greater.  From  experiments  on  the  bodies  of  executed  criminals, 
M.  Nysten  found  that  irritability  ceased  in  the  following  order  of  parts. 
The  left  ventricle  of  the  heart  first;  the  intestinal  canal  at  the  end  of 
forty-five  or  fifty-five  minutes;  the  urinary  bladder  at  nearly  the  same 
time;  the  right  ventricle  after  the  lapse  of  an  hour;  the  oesophagus  at 
the  end  of  an  hour  and  a  half;  the  iris  a  quarter  of  an  hour  later;  the 
muscles  of  animal  life  somewhat  later;  and  lastly,  the  auricles  of  the 
heart,  especially  the  right,  which,  in  one  instance,  under  the  influence 
of  galvanism,  contracted  sixteen  and  a  half  hours  after  death.  These 
results  are  singular;  and  the  experiments  merit  repetition.  It  is,  in- 
deed, strange,  that  muscles  of  organic  life,  apparently  circumstanced  so 
much  alike,  should  vary  so  greatly  in  the  length  of  time  during  which 
they  retain  their  irritability. 

One  of  the  most  interesting  of  the  many  experiments  that  have  been 
made  on  the  bodies  of  criminals  recently  deceased,  for  the  purpose  of 
exhibiting  the  effects  of  galvanism  on  muscular  irritability,  is  detailed 
by  Dr.  Ure.2  The  subject  was  a  murderer,  named  Clydesdale;  a  middle- 
sized  athletic  man,  about  thirty  years  of  age.  He  was  suspended  from 
the  gallows  nearly  an  hour,  and  made  no  convulsive  struggle  after  he 
dropped.  He  was  taken  to  the  theatre  of  the  Glasgow  University  about 
ten  minutes  after  he  was  cut  down.  His  face  had  a  perfectly  natural 
aspect,  being  neither  livid  nor  tumefied ;  and  there  was  no  dislocation 
of  the  neck.  In  the  first  experiment,  a  large  incision  was  made  into 
the  nape  of  the  neck,  close  below  the  occiput,  and  the  spinal  marrow 
was  brought  into  view.  A  considerable  incision  was  made,  at  the  same 
time,  into  the  left  hip,  through  the  glutaeus  maximus  muscle,  so  as  to 
expose  the  sciatic  nerve;3  and  a  small  cut  was  made  in  the  heel;  from 

1  Lehrbuch  der  Physiologie  des  Menschen,  ii.  176-92,  Braunschweig,  1844. 

2  Art.  Galvanism,  in  Diet,  of  Chemistry,  Hare  and  Bache;s  Amer.  edit.,  Philad.,  1821. 

8  It  is  not  indispensable,  in  these  experiments,  to  expose  the  nerve.  The  author  has  long 
known,  that,  in  the  case  of  the  frog,  it  is  needless ;  and,  in  his  experiments,  he  has  been  in  the 
habit  of  acting  under  this  knowledge.  The  experiments  made  on  three  criminals, — two  of 
whom  were  executed  at  Philadelphia,  and  the  third  at  Lancaster,  Pennsylvania — showed, 
indeed,  that  the  effect  was  even  greater  when  the  nerves  were  not  exposed.  It  was  found, 
too,  to  be  more  marked  when  the  current  was  transmitted  from  the  peripheral  extremity  of 


ACTION  OF  GALVANISM  ON  MUSCLES.  409 

neither  of  which  any  blood  flowed.  A  pointed  rod,  connected  with  one 
end  of  a  galvanic  battery,  of  two  hundred  and  seventy  pairs  of  four- 
inch  plates,  was  now  placed  in  contact  with  the  spinal  marrow,  whilst 
another  rod,  connected  with  the  other  end,  was  applied  to  the  sciatic 
nerve.  Every  muscle  of  the  body  was  immediately  agitated  with  con- 
vulsive movements,  resembling  a  violent  shuddering  from  cold.  The 
left  side  was  most  powerfully  convulsed  at  each  renewal  of  the  electric 
contact.  On  removing  the  second  rod  from  the  hip  to  the  heel,  the 
knee  being  previously  bent,  the  leg  was  thrown  out  with  such  violence 
as  nearly  to  overturn  one  of  the  assistants,  who  in  vain  attempted  to 
prevent  its  extension. 

In  the  next  experiment,  the  left  phrenic  nerve  was  exposed  at  the 
outer  edge  of  the  sterno-thyroideus  muscle.  As  this  nerve  is  distributed 
to  the  diaphragm,  and  communicates  with  the  heart  through  the  pneu- 
mogastric  nerves,  it  was  expected  that,  by  transmitting  the  galvanic 
fluid  along  it,  the  respiratory  process  might  be  renewed.  Accordingly, 
a  small  incision  having  been  made  under  the  cartilage  of  the  seventh 
rib,  the  point  of  one  rod  was  brought  into  contact  with  the  great  head 
of  the  diaphragm,  whilst  that  of  the  other  was  applied  to  the  phrenic 
nerve  in  the  neck.  The  diaphragm,  which  is  a  main  agent  in  respira- 
tion, was  instantly  contracted,  but  with  less  force  than  was  expected. 
"Satisfied,"  says  Dr.  Ure,  "from  ample  experience  on  the  living  body, 
that  more  powerful  effects  can  be  produced  in  galvanic  excitation  by 
leaving  the  extreme  communicating  rods  in  close  contact  with  the  parts 
to  be  operated  on,  while  the  electric  chain  or  circuit  is  completed  by 
running  the  end  of  the  wires  along  the  top  of  the  plates  in  the  last 
trough  of  either  pole,  the  other  wire  being  steadily  immersed  in  the 
last  cell  of  the  opposite  pole,  I  had  immediate  recourse  to  this  method. 
The  success  of  it  was  truly  wonderful.  Full,  nay  laborious  breathing 
instantly  commenced.  The  chest  heaved  and  fell;  the  belly  was  pro- 
truded and  again  collapsed,  with  the  relaxing  and  retiring  diaphragm. 
This  process  was  continued,  without  interruption,  as  long  as  I  continued 
the  electric  discharges.  In  the  judgment  of  many  scientific  gentlemen 
who  witnessed  the  scene,  this  respiratory  experiment  was  perhaps  the 
most  striking  ever  made  with  a  philosophical  apparatus.  Let  it  also  be 
remembered,  that  for  full  half  an  hour  before  this  period,  the  body  had 
been  well-nigh  drained  of  its  blood,  and  the  spinal  marrow  severely 
lacerated.  No  pulsation  could  be  perceived,  meanwhile,  at  the  heart  or 
wrist;  but  it  may  be  supposed,  that  but  for  the  evacuation  of  the  blood, — 
the  essential  stimulus  of  that  organ, — this  phenomenon  might  also  haVe 
occurred." 

In  a  third  experiment,  the  supra-orbital  nerve  was  laid  bare  in  the 
forehead.  The  one  conducting  rod  being  applied  to  it,  and  the  other 
to  the  heel,  most  extraordinary  grimaces  were  exhibited.  Every  muscle 
in  the  face  was  simultaneously  thrown  into  fearful  action.  "  Kage, 
horror,  despair,  anguish,  and  ghastly  smiles,  united  their  hideous  ex- 
pression in  the  murderer's  face,  surpassing  far  the  wildest  representa- 

a  nerve  towards  its  centre.  See  Bell's  Select  Medical  Library,  for  Oct.,  1839 ;  Amer.  Journ. 
of  Med.  Sciences,  May,  1840,  p.  13;  and  Medical  Examiner,  Jan.  23d  and  30th,  1841. 


410  MUSCULAR  MOTION. 

tion  of  a  Fuseli  or  of  a  Kean."  At  this  period,  several  of  the  spectators 
were  forced  to  leave  the  room  from  terror  or  sickness ;  and  one  gentle- 
man fainted. 

The  last  experiment  consisted  in  transmitting  the  electric  power  from 
the  spinal  marrow  to  the  ulnar  nerve  as  it  passes  by  the  internal  con- 
dyle  at  the  elbow;  when  the  fingers  moved  nimbly,  like  those  of  a  violin 
performer;  and  an  assistant  who  tried  to  close  the  fist,  found  the  hand 
open  forcibly  in  spite  of  every  effort  to  prevent  it.  When  one  rod  was 
applied  to  a  slight  incision  in  the  tip  of  the  forefinger,  the  fist  being 
previously  clenched,  the  finger  was  instantly  extended;  and  from  the 
convulsive  agitation  of  the  arm,  he  seemed  to  point  to  the  different 
spectators,  some  of  whom  thought  he  had  come  to  life. 

The  experiments  of  Dr.  Ure  have  been  several  times  repeated  in  this 
country  on  the  bodies  of  criminals,  and  with  analogous  results.1 

What  important  reflections  are  suggested  by  the  perusal  of  such 
cases !  The  great  resemblance  between  the  galvanic  and  the  nervous 
fluids,  and  the  absorbing  idea,  to  the  philanthropist,  that  galvanism 
might  be  found  successful  in  resuscitating  the  apparently  dead,  in  cases 
where  other  means  may  have  failed!  Unfortunately,  it  can  rarely 
happen,  that  the  means  will  be  at  hand,  so  as  to  be  available ;  and, 
moreover,  when  the  heart  has  ceased  to  beat  for  a  few  minutes,  it  is 
generally  impracticable  to  cause  it  to  resume  its  functions. 

An  experiment,  described  by  Dr.  George  Fordyce,2  exhibits  the 
power  of  contractility  resident  in  the  tissue.  He  slightly  scratched, 
with  a  needle,  the  inside  of  a  heart  removed  from  the  body,  when  it 
contracted  so  strongly  as  to  force  the  point  of  the  needle  deep  into  its 
substance.  This  experiment  has  been  often  cited  for  the  purpose  of 
showing,  that  the  mechanical  effect,  in  such  cases,  is  infinitely  greater 
than  the  mechanical  cause  producing  it ;  and  hence,  as  we  have  endea- 
voured already  to  show,  that  all  mechanical  explanations  must  be  in- 
sufficient to  account  for  the  phenomena  of  muscular  contraction:  we 
are  compelled,  indeed,  to  infer,  that  a  new  force  must  always  be  gene- 
rated. 

In  the  year  1806,  a  cause  was  tried  before  the  Court  of  Exchequer 
in  England,  in  which  a  better  knowledge  of  the  properties  of  muscle 
might  have  led  to  a  different  result.3  According  to  the  English  law, 
where  a  man  marries  a  woman  seised  of  an  estate  of  inheritance,  and 
has,  by  her,  issue  born  alive,  which  was  capable  of  inheriting  her 
estate, — in  such  case  he  shall,  on  the  death  of  his  wife,  hold  the  lands 
for  his  life  as  tenant  ~by  the  courtesy  of  England.  It  has,  consequently, 
been  a  point  of  moment  for  the  husband  to  show,  that  the  child  was 
born  alive;  and  the  law  authorities  have,  with  singular  infelicity, 
attempted  to  define  what  shall  be  regarded  evidences  of  this  condition. 
According  to  Blackstone,4  "it  must  be  born  alive.  Some  have  had  a 
notion  that  it  must  be  heard  to  cry,  but  that  is  a  mistake.  Crying, 

'  Dunbar,  in  Baltimore  Mecl.  and  Surg.  Journal,  i.  245,  Bait.,  1833,  and  the  Journals  re- 
ferred to  in  the  preceding  pages. 
8  Philos.  Transact,  for  1788,  p.  25. 

3  Taylor,  Medical  Jurisprudence,  Amer.  edit.,  by  R.  E.  Griffith,  p.  480,Philad.,  1845. 

4  Commentaries,  B.  ii.  127. 


MUSCULAR  SENSE.  411 

indeed,  is  the  strongest  evidence  of  its  being  born  alive,  but  it  is  not 
the  only  evidence."  According  to  Coke,1  "if  it  be  born  alive  it  is  suf- 
ficient, though  it  be  not  heard  to  cry,  for  peradventure  it  may  be  born 
dumb.2  It  must  be  proved  that  the  issue  was  alive ;  for  mortuus  exitus 
non  est  exitus;  so  that  the  crying  is  but  a  proof  that  the  child  was  born 
alive;  and  so  is  motion,  stirring,  and  the  like."  This  latitudinarian 
definition  has  given  occasion  to  erroneous  decisions,  as  in  the  trial 
alluded  to,  in  which  the  jury  agreed  that  the  child  was  born  alive; 
because,  although,  when  immersed  in  a  warm  bath  immediately  after 
birth,  it  did  not  "cry,  or  move,  or  show  any  symptoms  of  life;"  yet, 
according  to  the  testimony  of  two  females, — the  nurse  and  the  cook, — 
there  twice  appeared  a  twitching  and  tremulous  motion  of  the  lips;  and 
this  was  sufficient  to  make  it  fall  under  Lord  Coke's  definition.  It  is 
manifest,  that,  granting  such  motion  to  have  actually  occurred,  it  was 
of  itself  totally  insufficient  to  establish  the  existence  of  somatic  life. 
We  have  seen,  that  on  the  application  of  stimuli,  the  muscles  of  a  body 
may  be  thrown  into  contraction  for  two  hours  after  the  cessation  of 
respiration  and  circulation  or  after  somatic  death.  Instead,  therefore, 
of  referring  the  irritability  to  the  existence,  at  the  time,  of  somatic  life, 
it  must  be  regarded  simply  as  an  evidence  of  the  persistence  of  mole- 
cular life  in  parts  that  had  previously  and  recently  formed  part  of  a 
living  whole. 

The  contraction  of  a  muscle  is  followed  by  its  relaxation  ; — the  fibres 
returning  to  their  former  condition.  This  appears  to  be  a  passive  state; 
and  to  result  from  the  suppression  of  the  nervous  influx  by  the  will ; — 
in  other  words,  from  the  simple  cessation  of  contraction.  Some  have, 
however,  regarded  both  states  to  be  active,  but  without  proof.  Barthez3 
maintains,  that  the  relaxation  of  a  muscle  is  produced  by  a  nervous 
action  the  reverse  of  that  which  occasions  its  contraction  ; — the  will  re- 
laxing the  muscles  as  well  as  contracting  them.  The  muscle  is  the  only 
part  susceptible  of  contraction.  The  tendon  conveys  the  force  deve- 
loped by  it,  passively  to  the  lever,  which  has  to  be  moved. 

It  has  been  ascertained  by  MM.  Becquerel  and  Breschet,4  that  a 
muscle  during  contraction  augments  in  temperature.  This  increase  is 
usually  more  than  one  degree  of  Fahrenheit ;  but  at  times  when  the 
exertion  has  been  continued  for  five  minutes, — as  in  the  case  of  the 
biceps  of  the  arm,  in  sawing  wood, — it  has  been  double  that  amount.5 

Lastly,  a  sensation  instructs  the  mind  that  a  muscle  has  contracted, 
and  this  has  given  rise  to  the  notion  of  a  muscular  sense,  and  a  sensa- 
tion of  motion : — M uskelsinn,  Bewegungssinn  or  muscular 
sense  of  Gruithuisen,  Lenhossek,6  Brown,7  Sir  C.  Bell,8  and  other 

1  Institutes,  30,  a. 

3  It  need  scarcely  be  said  that  the  deaf-dumb  cry  at  the  moment  of  birth  the  same  as 
other  children.  The  natural  cry  is  effected  by  them  as  well  as  by  the  infant  that  possesses 
all  its  senses.  It  is  the  acquired  voice,  alone,  which  they  are  incapable  of  attaining. 

3  Nouveaux  Elemens  de  la  Science  de  1'Homme,  Paris,  1806. 

<  Archiv.  du  Museum,  torn.  i.  p.  402,  and  Annales  des  Sciences  Naturelles,  nouv.  serie, 
iii.  272. 

6  See  on  this  subject  Helmholtz,  in  Miiller's  Archiv.,  H.  ii.  s.  144,  Berlin,  1848. 

6  Rudolphi,  Grundriss  der  Physiologic,  2te  Band,  Iste  Abtheil.,  s.  318,  Berlin,  1823. 

7  Lectures  on  Moral  Philosophy. 

s  The  Hand,  &c.,  Amer.  edit.,  p.  145,  Philad.,  1833. 


412  MUSCULAR  MOTION. 

writers.  It  appears  to  be  an  internal  sensation,  produced  by  the 
muscle  pressing  on  the  sensible  parts  surrounding  it,  which  convey  the 
sensation  to  the  brain.  It  is  by  this  muscular  sense  that  the  brain 
learns  to  adapt  the  effort  to  the  effect  to  be  produced.  Without  it  no 
precision  could  exist  in  the  movements  of  the  muscles,  and  every  manual 
effort — whether  of  the  artist  or  the  mechanic — would  be  confused  and 
disorderly.  The  step,  too,  would  be  unsteady  and  insecure.  "In 
chewing  our  food,"  s^ys  Dr.  A.  Combe,1  "in  turning  the  eyes  towards 
an  object  looked  at,  in  raising  the  hand  to  the  mouth,  and,  in  fact,  in 
every  variety  of  muscular  movement  which  we  perform,  we  are  guided 
by  the  muscular  sense  in  proportioning  the  effect  to  the  resistance  to 
be  overcome;  and  where  this  harmony  is  destroyed  by  disease,  the 
extent  of  the  service  rendered  us  becomes  more  apparent.  The  shake 
of  the  arm  and  hand  which  we  see  in  drunkards,  and  their  consequent 
incapability  of  carrying  the  morsel  directly  to  the  mouth,  are  examples 
of  what  would  be  of  daily  occurrence,  unless  we  were  directed  and 
assisted  by  a  muscular  sense."  It  enables  us  to  form  ideas  of  force  and 
resistance,  by  conveying  to  our  minds  a  distinct  idea  of  the  effort  re- 
quired. 

The  force  or  intensity  of  muscular  contraction  is  dependent  upon  two 
causes, — the  physical  condition  of  the  muscle,  and  the  energy  of  the 
brain.  A  muscle,  which  is  composed  of  large,  firm  fibres,  will  con- 
tract,— the  energy  of  the  brain  being  equal, — more  forcibly  than  one 
with  delicate,  loose  fibres.  Volition  generally  determines  the  degree  of 
power  developed  by  the  voluntary  motions;  and  is  accurately  regulated 
so  as  to  raise  a  weight  of  one  pound  or  one  hundred.  We  notice 
astonishing  efforts  of  strength  in  those  that  are  labouring,  at  the  time, 
under  strong  cerebral  excitement;  mania,  rage,  delirium,  &c.  In  such 
cases,  the  delicate  muscles  of  the  female  are  capable  of  contracting 
with  a  force  far  transcending  that  of  the  healthy  male.  The  power  of 
muscular  contraction  is,  therefore,  in  a  compound  ratio  with  the 
strength  of  the  organization  of  the  muscle,  and  the  degree  of  excitation 
of  the  brain.  When  both  are  considerable,  the  feats  of  strength  sur- 
pass belief;  and  where  both  are  small,  the  results  are  insignificant. 
The  extensors  of  the  knee  and  foot  occasionally  contract  with  so  much 
violence  as  to  fracture  the  patella  and  tendo  Achillis,  respectively. 
The  force,  developed  in  the  calf  of  the  leg,  must  be  great,  when  a  per- 
son stands  on  tiptoe  with  a  burden  on  his  head  or  shoulders;  or  when 
he  projects  his  body  from  the  soil,  as  in  leaping.  Rudolphi2  asserts, 
that  he  has  seen  a  horse,  which  fractured  its  under-jaw  by  biting  a 
piece  of  iron. 

It  has  been  a  question,  whether  the  power  of  a  muscle  is  greater  or 
less  at  different  degrees  of  contraction,  the  same  stimulus  being  applied. 
To  determine  this,  Schwann3  invented  an  apparatus,  which  should  accu- 
rately measure  the  length  of  the  muscle,  and  the  weight  it  would  balance 
by  its  contraction ;  and,  from  his  experiments  it  appeared,  that  a  uniform 

1  Principles  of  Physiology,  5th  edit.,  p.  131,  Edinb.,  1836. 

3  Op.  cit.,  p.  303. 

3  J.  Miiller,  Physiology,  p.  903. 


FORCE  OF  MUSCULAR  CONTRACTION.  413 

increase  of  force  is  attended  with  a  nearly  uniform  increase  in  the 
length  of  the  muscle.  The  explanation  of  this  by  Dr.  Carpenter1  is 
probably  correct ; — that,  as  the  observations  of  Mr.  Bowman  have 
clearly  shown,  there  must  be  a  considerable  displacement  of  the  con- 
stituents of  every  fibre  during  contraction,  it  is  easy  to  understand, 
that  the  greater  the  contraction  the  more  difficult  must  any  farther 
contraction  become.  "If,  between  a  magnet  and  a  piece  of  iron 
attracted  by  it,  there  were  interposed  a  spongy  elastic  tissue,  the  iron 
would  cease  to  approach  the  magnet  at  a  point,  at  which  the  attraction 
of  the  magnet  would  be  balanced  by  the  force  needed  to  compress  still 
farther  the  intermediate  substance." 

We  have  a  number  of  feats  of  surprising  strength  on  record,  several 
of  which  have  been  collected  by  Sir  David  Brewster.2  Of  these,  the 
cases  of  John  Charles  Van  Eckeberg,  who  travelled  through  Europe 
under  the  appellation  of  Samson,  and  of  Thomas  Topham,  are  the 
most  authentic  and  extraordinary.  Dr.  Desaguliers  saw  Topham,  by 
the  strength  of  his  fingers,  roll  up  a  very  strong  and  large  pewter  dish. 
He  broke  seven  or  eight  short  and  strong  pieces  of  tobacco-pipe  with 
the  force  of  his  middle  finger,  having  laid  them  on  his  first  and  third 
fingers.  Having  thrust  under  his  garter  the  bowl  of  a  strong  tobacco- 
pipe,  his  leg  being  bent,  he  broke  it  to  pieces  by  the  tendons  of  his 
hams  without  altering  the  flexure  of  his  knee.  He  broke  another  such 
bowl  between  his  first  and  second  fingers,  by  pressing  his  fingers  to- 
gether sideways.  He  lifted  a  table  six  feet  long — which  had  half  a 
hundred  weight  hanging  at  the  end  of  it — with  his  teeth,  and  held  it 
in  a  horizontal  position  for  a  considerable  time,  the  feet  of  the  table 
resting  against  his  knees.  He  took  an  iron  kitchen  poker,  about  a 
yard  long,  and  three  inches  in  circumference,  and,  holding  it  in  his 
right  hand,  he  struck  upon  his  bare  left  arm,  between  the  elbow  and 
wrist,  till  he  bent  the  poker  nearly  to  a  right  angle.  He  took  such 
another  poker,  and  holding  the  ends  of  it  in  his  hands,  and  the  middle 
against  the  back  of  his  neck,  he  brought  both  ends  of  it  together  before 
him  ;  and  afterwards  pulled  it  nearly  straight  again.  He  broke  a  rope 
about  two  inches  in  circumference,  which  was  in  part  wound  about  a 
cylinder  of  four  inches  in  diameter,  having  fastened  the  other  end  of 
it  to  straps  that  went  over  his  shoulders.  Lastly,  he  lifted  a  rolling- 
stone,  eight  hundred  pounds  in  weight,  with  his  hands  only,  standing 
in  a  frame  above  it,  and  taking  hold  of  a  chain  that  was  fastened  to  it. 

An  equally  remarkable  example  is  given  by  a  recent  well-known 
traveller3  as  having  been  witnessed  by  him  in  Paris.  In  the  Place  du 
Carrousel,  a  large  coarse  French  woman  made  the  following  exhibition 
in  the  presence  of  a  great  crowd  of  spectators.  A  rough  block  of 
stone,  weighing  more  than  three  hundred  pounds,  and  which  two  men 
could  barely  lift  from  the  ground,  was  fastened  round  with  several  turns 
of  rope.  The  long  black  hair  of  the  woman,  which  was  divided  into 
seven  traces,  tightly  platted  and  fastened  at  the  end,  was  then  brought 

»  Human  Physiology,  §  394,  Lond.,  1842. 

2  Letters  on  Natural  Magic,  Amer.  edit.,  p.  222,  New  York,  1832. 

a  J.  S.  Buckingham,  Travels  in  France,  Piedmont,  &c.,  ii.  63,  Lond.,  1849 


414  MUSCULAR  MOTION. 

down,  and  attached  to  these  ropes,  whilst  the  woman  herself  bent  her 
head  back  towards  the  stone  for  the  purpose  of  admitting  of  the  traces 
being  fastened.  When  this  was  done,  she  slowly  rose  to  her  erect 
position,  lifting  the  stone  entirely  from  the  ground,  its  weight  being 
borne  by  the  seven  traces  of  her  hair,  and  the  pressure  resting  wholly 
on  her  scalp.  She  then  began  to  turn  herself  slowly  round,  swinging 
the  stone  just  fastened  to  her  hair,  until,  by  the  progressively  increas- 
ing motion,  she  twirled  round  as  rapidly  as  the  spinning  dervishes,  or 
an  opera  dancer  in  a  pirouette,  but  for  a  longer  period, — the  stone  all 
this  while  going  out  farther  and  farther  from  her  person  till  it  swung 
round  almost  horizontally,  and  with  a  velocity  that  made  it  fearful  to 
look  upon,  relaxing  gradually  from  the  highest  point  of  motion  till  it 
rested  at  her  feet.  It  was  then  loosened  from  the  hair  and  the  cords ; 
and  her  next  feat  was  to  place  two  rush-bottomed  chairs  at  a  distance 
of  about  four  feet  and  a  half  from  each  other,  when  she  placed  her 
head  on  one,  and  her  heels  on  the  other,  thus  lying  horizontally  between 
the  two,  without  any  support  for  her  back  or  loins  in  the  centre,  and 
neither  her  head  nor  her  heels  being  more  than  six  inches  from  the 
outer  edge  of  the  chairs.  Whilst  in  this  condition,  two  men  were  invited 
to  come  from  the  crowd  and  lift  up  the  stone,  so  as  to  place  it  on  her 
stomach.  Two  persons  came  from  amongst  the  bystanders,  and  one  of 
them  not  being  a  strong  man,  they  were  unable  to  lift  it,  when  a  third 
came  to  their  assistance  ;  but  not  till  after  at  least  twenty  persons  had 
tried  to  lift  the  stone  a  little  from  the  ground,  to  be  assured  it  was  not 
hollow,  and  that  there  was  no  deception,  and  each  had  failed  to  lift  it  half 
an  inch  from  where  it  stood.  The  three  men,  however,  raised  it  up, 
and  placed  it  on  the  woman's  stomach,  as  she  lay  in  this  horizontal 
position ;  when  another  person,  at  her  request,  placed  a  smaller  stone 
on  the  large  one,  and  with  a  heavy  iron  sledge-hammer  broke  it  into 
twenty  pieces.  All  this  occupied  about  a  quarter  of  an  hour,  during 
the  whole  of  which  time  the  woman  evinced  no  appearance  of  shrinking ; 
and  in  conversing  with  her  after  she  rose  there  was  not  the  slightest 
evidence  of  any  inconvenience  being  felt  by  her  from  the  exertion. 

That  much  depends  upon  physical  organization,  as  regards  the  force 
of  muscular  contraction,  is  evinced  by  the  fact  of  the  great  difference 
in  the  various  races  of  mankind.  On  our  own  continent,  numerous 
opportunities  have  occurred  for  witnessing  the  inferiority,  in  strength, 
of  the  aborigines  to  the  white  settlers.  Pe'ron1  took  with  him,  in  his 
voyage  round  the  world,  one  of  Regnier's  dynamometers,  which  indicate 
the  relative  force  of  men  and  animals.  He  directed  his  attention  to 
the  strength  of  the  arms  and  loins,  making  trial  on  several  individuals 
of  different  nations  ;  twelve  natives  of  Van  Diemen's  Land ;  seventeen 
of  New  Holland ;  fifty-six  of  the  island  of  Timor ;  seventeen  Frenchmen 
belonging  to  the  expedition,  and  fourteen  Englishmen  in  the  colony  of 
New  South  Wales.  The  following  was  the  mean  result : — 

1  Voyage,  &c.,  torn.  i.  chap.  xx.  p.  446;  and  t.  ii.  p.  461;  and  Lawrence's  Lectures  on 
Physiology,  &c.,  p.  404,  Lond.,  1819. 


DURATION  OF  MUSCULAR  CONTRACTION.  415 


Of  the  Arms.  Of  the  Loins. 

Kilogrammes.1          Myriagr,ammes. 

1.  Van  Diemen's  Land,         •  50-6 

2.  New  Holland,              .                          •  -      50-8  10-2 

3.  Timor,      -                           ....  58-7  11-6 

4.  French,            -                           -                          •  69-2  15-2 

5.  English, 71-4  16-3 

The  highest  numbers,  in  the  first  and  second  divisions,  were  respect- 
ively 60  and  62 ;  the  lowest  in  the  fifth,  63 ;  in  the  highest  83,  for  the 
strength  of  the  arms.  In  the  power  of  the  loins,  the  highest  amongst 
the  New  Hollanders  was  13;  the  lowest  of  the  English,  12-7.2 

The  force  of  muscular  contraction  is  also  largely  increased  by  the 
proper  exercise  of  the  muscles.  Hence  the  utility  of  the  ancient  gym- 
nasia. In  early  times,  muscular  energy  commanded  respect  and  admira- 
tion. It  was  the  safeguard  of  individuals  and  families,  and  the  protection 
of  nations;  and  it  was  esteemed  a  matter  of  national  policy  to  encou- 
rage its  acquisition.  In  modern  times,  the  invention  of  gunpowder 
having  altered  the  system  of  warfare,  and  given  to  skill  the  superiority 
which  strength  communicated  in  personal  combats,  institutions  for  the 
developement  of  the  muscular  system  have  been  abandoned,  until  of 
comparatively  late  years.  They  afford  us  striking  examples  of  the  value 
of  muscular  exertion,  not  only  in  giving  energy  and  pliancy  to  the  frame, 
but  as  a  means  of  preserving  health. 

The  mean  effect  of  the  labour  of  an  active  man,  working  to  the 
greatest  possible  advantage,  and  without  impediment,  is  usually  esti- 
mated to  be  sufficient  to  raise  ten  pounds,  ten  feet  in  a  second  for  ten 
hours  in  a  day;  or  to  raise  one  hundred  pounds,  which  is  the  weight  of 
twelve  wine  gallons  of  water,  one  foot  in  a  second,  or  thirty-six  thou- 
sand feet  in  a  day;  or  three  millions,  six  hundred  thousand  pounds,  or 
four  hundred  and  thirty-two  thousand  gallons,  one  foot  in  a  day.  Dr. 
Desaguliers  affirms,  that  the  weakest  men  who  are  in  health,  and  not 
too  fat,  lift  about  one  hundred  and  twenty-five  pounds ;  and  the  strong- 
est of  ordinary  men  four  hundred  pounds.  Topham  lifted  eight  hun- 
dred. The  daily  work  of  a  horse  is  estimated  to  be  equal  to  that  of 
five  or  six  men. 

In  insects,  the  force  of  muscular  contraction  appears  to  be  greater  in 
proportion  to  their  size  than  in  any  other  animals.  The  Lucanus  cer- 
vus  or  Stag  Beetle  has  been  known  to  gnaw  a  hole  of  an  inch  diameter 
in  the  side  of  an  iron  canister  in  which  it  had  been  confined,  and  many 
striking  examples  of  a  similar  kind  are  given  hereafter  under  the  head 
of  FLYING. 

In  the  duration  of  muscular  contraction  we  notice  considerable  dif- 
ference between  the  voluntary  and  involuntary  muscles;  the  latter  being 
much  more  rapid  and  alternating.  The  same  remark  applies  to  the 

1  The  approximate  value  of  a  kilogramme  is  about  two  pounds  avoirdupois : — of  a  myria- 
gramme  about  twenty. 

a  See  Quetelet,  Sur  THomme,  &c.,  Paris,  1835,  or  English  edit.,  by  Dr.  R.  Knox,  p.  67,  Edin- 
burgh, 1842.  Prof.  Forbes,  of  Edinburgh,  in  London  and  Edinburgh  Phil.  Magazine,  for 
March,  1837,  p.  197;  and  in  Dunglison's  American  Med.  Intelligencer,  for  May  15,  1837, 
p.  74;  in  which  are  detailed  experiments  on  the  weight,  height,  and  strength  of  above  eight 
hundred  individuals,  natives  of  England,  Scotland,  Ireland,  and  Belgium. 


416  MUSCULAR  MOTION. 

voluntary  muscles,  when  excited  by  another  stimulus  than  that  of  the 
will.  Contraction,  excited  by  volition,  can  be  maintained  for  a  con- 
siderable time:  of  this  we  have  examples  in  bearing  a  burden;  the  act 
of  standing;  holding  the  arm  extended  from  the  body,  &c.  In  all  these 
cases,  the  contractility  of  the  muscles  is  sooner  or  later  exhausted; 
fatigue  is  experienced;  and  it  becomes  necessary  to  give  them  rest;  the 
power  of  contractility,  however,  is  soon  resumed,  and  they  can  be  again 
put  in  action.  This  law  of  intermission  in  muscular  action  appears 
absolute; — relaxation  being  followed  by  contraction,  in  every  organ, 
from  the  commencement  of  life  until  its  final  cessation.  The  inter- 
mission, has,  indeed,  by  many  physiologists,  been  held  to  prevail — to  a 
slight  extent  only,  it  is  true — during  what  we  are  in  the  habit  of  con- 
sidering continuous,  muscular  contraction.  In  proof  of  this,  they  cite 
the  fact,  that  when  we  put  the  tip  of  the  finger  into  the  meatus  audi- 
torius  externus,  we  hear  a  kind  of  buzzing  or  humming,  which  does  not 
occur  when  an  inert  body  is  introduced.1  There  are,  however,  other 
actions  going  on  in  the  finger  besides  muscular  contraction ;  and  the 
buzzing  might,  with  as  much  propriety,  be  referred  to  the  noise  made 
by  the  progression  of  fluids  in  the  vessels,  as  to  the  oscillations  of  mus- 
cular contraction  and  relaxation.  We  know  not,  in  truth,  whence  the 
sound  immediately  proceeds. 

In  the  velocity  of  muscular  contraction,  much  difference  exists,  accord- 
ing to  the  stimulus  which  sets  it  in  action.  If  we  apply  galvanism  to 
a  muscle,  we  find  the  contractions  at  first  exceedingly  rapid;  but  they 
become  progressively  feebler,  and  require  a  stronger  stimulus,  until 
their  irritability  appears  to  be  exhausted.  Irritating  the  nerve  in  these 
cases  is  found  to  produce  a  greater  effect,  than  when  the  stimulus  is 
applied  directly  to  the  muscle.  The  velocity  of  voluntary  contraction 
is,  of  course,  variable,  being  regulated  entirely  by  the  will.  We  have, 
in  various  classes  of  the  animal  kingdom,  remarkable  instances  of  this 
velocity.  The  motions  of  the  racer,  greyhound,  practised  runner,  the 
fingers  in  playing  on  musical  instruments — as  the  violin,  flute,  piano- 
forte,— and  in  writing;  of  the  voice  in  enunciation,  and  of  the  upper 
and  lower  limbs  in  striking,  leaping,  and  kicking,  convey  a  general 
notion  of  this  rapidity  of  contraction;  and  how  nicely,  in  many  cases, 
it  must  be  regulated  by  volition.  The  fleetest  race-horse  on  record  was 
capable  of  going,  for  a  short  distance,  at  the  rate  of  a  mile  per  minute; 
yet  this  is  trifling,  when  compared  with  the  velocity  of  certain  birds, 
which  can,  with  facility,  wheel  round  and  round  the  most  rapid  racer  in 
circles  of  immense  diameters, — and  with  that  of  numerous  small  insects, 
which  accompany  us,  with  apparent  facility,  when  we  travel  with  great 
rapidity,  even  against  the  wind. 

It  has  frequently  excited  surprise,  how  the  migratory  birds  can  sup- 
port themselves  so  long  upon  the  wing  as  to  reach  the  country  of  their 
migration;  and,  at  the  same  time,  live  without  food  during  their  aerial 
voyage.  The  difficulties  of  the  subject  have  impelled  many  to  deny 
the  fact  of  their  migration,  and  excited  others  to  form  extravagant 
theories  to  account  for  the  preservation  of  the  birds  during  the  winter 

1  Wollaston,  in  Philosoph.  Transact,  for  1810,  p.  2. 


VELOCITY  OF  MUSCULAR  CONTRACTION.  417 

months;  but  if  we  attend  to  their  excessive  velocity,  the  difficulties,  in 
a  great  measure,  vanish.  "Nothing,"  says  Wilson,1  "is  more  common 
in  Pennsylvania  than  to  see  large  flocks  of  the  bluebirds,  in  spring  and 
fall,  passing  at  considerable  heights  in  the  air, — from  the  south  in  the 
former,  from  the  north  in  the  latter  season.  The  Bermudas  are  said  to 
be  six  hundred  miles  from  the  nearest  part  of  the  continent.  This  may 
seem  an  extraordinary  flight  for  so  small  a  bird ;  but  it  is  a  fact  that  it 
is  performed.  If  we  suppose  the  bluebird  to  fly  only  at  the  rate  of  a 
mile  a  minute,  which  is  less  than  I  have  actually  ascertained  them  to 
do  over  land,  ten  or  twelve  hours  would  be  sufficient  to  accomplish  the 
journey."  Montagu,  a  celebrated  ornithologist,  estimates  the  rapidity 
with  which  hawks  and  many  other  birds  occasionally  fly  to  be  not  less 
than  one  hundred  and  fifty  miles  an  hour ;  and  that  one  hundred  miles 
per  hour  is  certainly  not  beyond  a  fair  computation  for  the  continuance 
of  their  migration.  Major  Cartwright,  on  the  coast  of  Labrador,  found 
by  repeated  observations,  that  the  flight  of  the  eider  duck  is  at  the  rate 
of  ninety  miles  an  hour;  yet  it  has  not  been  esteemed  very  remarkable 
for  its  swiftness.  Sir  George  Cayley  computes  the  rate  of  flight  of  the 
common  crow  at  nearly  twenty-five  miles  an  hour.  Spallanzani  found 
that  of  the  swallow  about  ninety-two  miles  an  hour;  and  he  conjectures, 
that  the  velocity  of  the  swift  is  nearly  three  times  greater.  A  falcon 
belonging  to  Henry  IV.  of  France  escaped  from  Fontainbleau,  and  was 
in  twenty-four  hours  afterwards  at  Malta, — a  distance  computed  to  be  not 
less  than  one  thousand  three  hundred  and  fifty  miles,  making  a  velocity 
of  nearly  fifty-seven  miles  an  hour,  supposing  the  falcon  to  have  been 
on  the  wing  the  whole  time ;  but,  as  such  birds  never  fly  by  night,  if 
we  allow  the  day  to  have  been  at  the  longest,  his  flight  was  perhaps  at 
the  rate  of  seventy-five  miles  per  hour.  It  is  not  probable,  however,  as 
Montagu  observes,  that  it  had  either  so  many  hours  of  light  in  the 
twenty-four  to  perform  its  journey,  or  that  it  was  retaken  at  the  moment 
of  its  arrival.2  A  society  of  pigeon-fanciers  from  Antwerp  despatched 
ninety  pigeons  from  Paris,  the  first  of  which  returned  in  four  hours  and 
a  half,  at  a  rate  of  nearly  fifty  miles  an  hour.  Out  of  one  hundred  and 
ten  pigeons,  carried  from  Brussels  to  London  in  the  summer  of  1830, 
and  let  fly  from  London  on  July  19th,  at  a  quarter  before  nine  A.M., 
one  reached  Antwerp,  one  hundred  and  eighty-six  miles  distant,  at 
eighteen  minutes  past  two,  or  in  five  and  a  half  hours, — being  at  the 
rate  of  nearly  thirty-four  miles  an  hour.  In  another  case,  one  went 
from  London  to  Maestricht,  two  hundred  and  sixty  miles,  in  six  and  a 
quarter  hours.  In  January,  1831,  two  pigeons,  carried  from  Liskeard 
to  London,  were  let  loose  in  London.  One  reached  Liskeard,  two  hun- 
dred and  twenty  miles  distant,  in  six  hours ;  the  other  in  a  quarter  of 
an  hour  more.3  There  is  an  instance  of  the  migratory  or  passenger 
pigeon — Oolumbamigratoria  of  Wilson — having  been  shot  in  Fifeshire, 
in  Scotland.  It  was  the  first  ever  seen  in  Great  Britain,  and  had  been 
forced  over,  it  was  imagined,  by  unusually  strong  westerly  gales.4 

1  American  Ornithology,  ii.  178. 

2  Fleming's  Philosophy  of  Zoology,  ii.  42,  Edinb.,  1822. 

3  Turner's  History  of  the  World,  Amer.  edit.,  i.  259,  New  York,  1832. 
*  New  Monthly  Magazine  for  1826. 

VOL.  I.— 27 


418  MUSCULAR  MOTION. 

The  velocity  of  the  contraction  of  the  muscles  of  the  wings,  in  these 
rapid  nights,  is  incalculable.  The  possible  velocity,  in  any  case,  must 
be  greatly  dependent  upon  habit.  Nothing  can  be  more  awkward  than 
the  first  attempts  at  writing,  drawing,  playing  on  musical  instruments, 
or  performing  any  mechanical  process  in  the  arts ;  and  what  a  con- 
trast is  afforded  by  the  astonishing  celerity,  which  practice  never  fails 
to  confer,  in  any  one  of  those  varieties  of  muscular  contraction  !  In 
running,  leaping,  wrestling,  dancing,  or  any  other  motion  of  the  body, 
one  person  can  execute  with  facility  what  another,  with  equally  favour- 
able original  powers,  cannot  effect,  because  he  has  not  previously  and  fre- 
quently made  the  attempt.  Prize-fighting  affords  an  instance  of  this 
kind  of  muscular  velocity  and  precision  acquired  by  habit, — the  prac- 
tised boxer  being  able  to  inflict  his  blow  and  return  his  arm  to  the 
guard  so  quickly  as  almost  to  elude  the  sight.  By  considering  the  mus- 
cular motions,  employed  in  transporting  the  body  of  the  fleetest  horse, 
Haller  concluded,  that  the  elevation  of  the  leg  must  have  been  performed 
in  7*0 th  of  a  second.  He  calculates,  that  the  rectus  femoris, — the  large 
muscle  which  is  attached  to  the  knee-pan  and  extends  the  leg, — is  short- 
ened three  inches  in  the  ^th  of  a  second  in  the  most  rapid  movements 
of  man.  But,  he  adds,  the  quickest  motions  are  executed  by  the  mus- 
cles concerned  in  the  articulation  of  the  voice.  He  himself,  in  one 
experiment,  pronounced  fifteen  hundred  letters  in  a  minute  ;  and  as  the 
relaxation  of  a  muscle  occupies  as  much  time  as  its  contraction,  the  con- 
traction of  a  muscle,  in  pronouncing  one  of  these  letters,  must  have  been 
executed  in  g^^th  part  of  a  minute;  and  in  much  less  time  in  some 
letters,  which  require  repeated  contractions  of  the  same  muscle  or  mus- 
cles as  r.  If  the  tremors,  that  occur  in  the  pronunciation  of  this  let- 
ter, be  estimated  at  ten,  the  muscles  concerned  in  it  must  have  con- 
tracted in  Haller's  experiment,  in  3^3  otn  Part  °f  a  minute.1  It  has 
been  calculated,  that  all  the  tones  of  which  the  human  voice  is  capable 
are  produced  by  a  variation  of  not  more  than  one-fifth  of  an  inch  in  the 
length  of  the  vocal  cords  ;  and  that  in  man  the  variation  required  to 
pass  from  one  interval  to  another  will  not  be  more  than  y^^th  of  an 
inch.  These  cases  are,  however,  far  exceeded  by  the  rapidity  of  the 
vibrations  of  the  wings  of  insects,  which  can  be  estimated  from  the  musi- 
cal tone  they  induce,  experiment  having  shown  the  number  of  vibrations 
required  to  produce  any  given  note.  The  vibrations  of  their  wings 
have  thus  been  found  to  amount  to  several  thousands  per  second. 

It  has  been  the  opinion  of  many  physiologists  and  metaphysicians, 
that  muscular  contraction  is  only  directed  by  volition  within  certain 
limits  of  velocity;  and  that  when  it  exceeds  a  certain  velocity  it  depends 
upon  habit.  The  effects  of  volition  have,  in  this  respect,  been  divided 
into  the  immediate  and  remote.  Of  the  first  we  have  examples  in  the 
formation  of  certain  vocal  and  articulate  sounds ;  and  in  certain  mo- 
tions of  the  joints,  as  in  the  production  of  voice,  speech,  and  locomo- 
tion. In  the  second,  those  actions  are  included  which  we  conceive  to 
be  within  our  power,  but  in  which  we  think  of  the  end  to  be  obtained, 
without  attending  to  the  mechanical  means.  "  In  learning  a  language, 

1  Elementa  Physiologic,  &c.,  lib.  xi.  2,  Lausan.,  1757-1766. 


ELEMENTARY  PRINCIPLES  OF  MECHANICS.  419 

for  example,"  says  Dr.  Bostock,1  "we  begin  by  imitating  the  pronun- 
ciation of  the  words,  and  use  a  direct  effort  to  put  the  organs  of  speech 
in  the  proper  form.  By  degrees,  however,  we  become  familiar  with 
this  part  of  the  operation,  and  think  only  of  the  words  that  are  to  be 
employed,  or  even  the  meaning  that  is  to  be  conveyed  by  them.  In 
learning  music,  we  begin  by  imitating  particular  motions  of  the  fingers, 
but  at  length  the  fingers  are  disregarded,  and  we  only  consider  what 
sounds  will  follow  from  certain  notes,  without  thinking  of  the  mechani- 
cal way  in  which  the  notes  are  produced."  In  these,  however,  and  in 
all  other  cases  that  can  be  brought  forward,  it  is  difficult  to  conceive 
how  the  effect  can  be  produced  without  the  agency  of  volition, — obscure 
it  is  true,  but  still  in  action.  The  case  of  reading  is  often  assumed,  as 
confirming  the  view  that  invokes  habit ;  yet,  if  a  letter  be  inverted,  we 
immediately  detect  it ;  and  although,  by  habit,  we  may  have  acquired 
extreme  facility  in  playing  the  notes  of  a  rapid  musical  movement,  no 
doubt,  we  think,  ought  to  exist,  that  an  effort  of  volition  is  exerted  on 
each  note  composing  it, — inasmuch  as  there  is  no  natural  sequence  of 
sounds;  and  hence  there  appears  no  cogent.reason,  why  one  should  follow 
rather  than  another,  unless  a  controlling  effort  of  the  will  were  exerted. 
With  regard  to  the  extent  of  muscular  contraction,  this  must  of  course 
be  partly  regulated  by  volition ;  but  it  is  also  greatly  owing  to  the  length 
of  the  muscular  fibres.  The  greater  the  length,  of  course  the  greater 
the  decurtation  during  contraction.  We  shall  see,  likewise,  that  this 
depends  upon  the  kind  of  lever,  which  the  bone  forms,  and  the  dis- 
tance at  which  the  muscle  is  inserted  from  the  joint  or  fulcrum. 

Before  passing  to  the  examination  of  special  movements,  it  will  be 
necessary  to  consider  briefly  certain  elementary  principles  of  mechanics, 
most  of  which  are  materially  concerned  in  every  explanation,  and  with- 
out some  knowledge  of  which  such  explanation  would,  of  course,  be 
obscure  or  unintelligible.  Were  we,  as  M.  Magendie2  has  remarked,  to 
investigate  narrowly  every  motion  of  the  body,  we  should  find  the  ap- 
plicability of  almost  all  the  laws  of  mechanics  to  them. 

If  we  take  a  rod  of  wood  or  metal,  of  uniform  matter  throughout, 
and  support  it  at  the  middle,  either  like  the  beam  of  a  balance,  or  on 
a  pointed  body,  we  find,  that  the  two  ends  accurately  F.  r  16g 
balance  each  other;  and  if  we  add  weights  at  corre- 
sponding parts  of  each  arm  of  the  beam,  that  is,  at  parts 
equidistant  from  the  point  of  suspension,  the  balance 
will  still  be  maintained.  The  point  by  which  the  beam 
is  suspended,  or  at  which  it  is  equilibrious,  is  called  its 
centre  of  gravity;  and,  in  every  mass  of  matter,  there 
is  a  point  of  this  kind,  about  which  all  the  parts  balance 
or  are  equilibrious;  or,  in  other  words,  they  have  all  a 
centre  of  gravity  or  inertia.  The  centre  ofgravity,  in 
a  mass  of  regular  form  and  uniform  substance,  as  in  the 
parallelograms,  Figs.  168  and  169,  is  easily  determined, 
inasmuch  as  it  must  necessarily  occupy  the  centre  c ;  but 
in  bodies  that  are  irregular,  either  as  regards  density  or  Centre  of  Gravity 

1  Physiology,  edit,  cit.,  p.  774,  Lond.,  1836.  a  Precis,  &c.,  edit,  cit,  i.  276. 


420 


MUSCULAR  MOTION. 


Fig.  169. 


Centre  of  Gravity. 


Fig.  170. 


form,  it  has  to  be  determined  by  rules  of  calculation,  to  be  found  in  all 
works  on  physics;  but  which  it  is  unnecessary  to  adduce  here. 

The  nearer  the  centre  of  gravity  is  to  the  soil  on  which  the  body- 
rests,  the  more  stable  is  the  equilibrium.  In  order  that  the  Figures 
168  and  169  shall  be  overturned  from  left  to  right, 
the  whole  mass  must  turn  upon  e  as  upon  a  pivot; 
the  centre  of  gravity  describing  the  curve  c  b,  and 
the  whole  mass  being  lifted  in  the  same  degree.  In 
Fig.  168,  the  curve  is  nearly  horizontal,  owing  to  the 
narrowness  of  the  base  and  the  height  of  the  centre 
of  gravity.  In  Fig.  169,  on  the  other  hand,  whose 
base  is  broad  and  the  centre  of  gravity  low,  the 
curve  rises  considerably;  the  resistance  to  overturn- 
ing is  consequently  nearly  equal  to  the  whole  weight 
of  the  body,  and  the  equilibrium  necessarily  firm. 
The  condition  of  equilibrium  of  a  body  resting  upon  a  plane  is  such, 
that  a  perpendicular,  let  fall  from  the  centre  of  gravity,  shall  fall  within 
the  points  by  which  it  touches  the  plane.  This  per- 
pendicular is  called  vertical  line  or  line  of  direction, 
being  that  in  which  it  tends  naturally  to  descend  to 
the  earth;  and  the  space  comprised  between  the  points 
by  which  the  body  touches  the  soil  is  called  base  of 
sustentation.  We  can  now  understand,  why  a  wagon, 
loaded  with  heavy  goods,  may  pass  with  safety  along 
a  sloping  road;  whilst,  if  it  be  loaded  to  a  greater 
height  with  a  lighter  substance,  it  may  be  readily 
overturned.  When  the  wagon  is  loaded  with  metal, 
the  centre  of  gravity  is  low,  as  at  c,  Fig.  170;  the 
vertical  line  c  p  falls  considerably  within  the  base  of 
sustentation ;  and  the  centre  describes  a  rising  path; 
but  in  the  other  case  the  centre  is  thrown  higher,  to  a;  and  the  vertical 
line  falls  very  near  the  wheel,  or  on  the  outside  of  it,  and  consequently 
of  the  base,  whilst  the  centre  describes  a  falling  path. 

Of  two  hollow  columns,  formed  of  an  equal  quantity  of  the  same 
matter,  and  of  the  same  height,  that  which  has  the  largest  cavity  will 
be  the  stronger ;  and  of  two  columns  of  the  same  diameter,  but  of  dif- 
ferent heights,  the  higher  will  be  the  weaker. 

All  bodies  tend  to  continue  in  the  state  of  motion  or  of  rest,  so  as 
to  render  force  necessary  to  change  their  state.  This  property  is  called 
the  inertia  of  motion,  or  of  rest,  as  the  case  may  be.  When  a  carriage 
is  about  to  be  moved  by  horses,  considerable  effort  is  necessary  to  over- 
come the  inertia  of  rest;  but  if  it  moves  with  velocity,  effort  is  required 
to  arrest  it,  or  to  overcome  the  inertia  of  motion.  We  can  thus  under- 
stand why,  if  a  horse  start  unexpectedly,  it  is  apt  to  get  rid  of  its 
burden;  and  why  an  unpractised  rider  is  projected  over  his  horse's  head 
if  it  stops  suddenly.  In  the  former  case,  the  inertia  of  rest  is  the 
cause  of  his  being  thrown ;  in  the  latter,  the  inertia  of  motion.  The 
danger  of  attempting  to  leap  from  a  carriage,  when  the  horses  have 
taken  fright,  is  thus  rendered  apparent.  The  traveller  has  acquired 
the  same  velocity  as  the  vehicle ;  and  if  he  leaps  from  it,  he  is  thrown 


Condition  of  Equi- 
librium. 


ELEMENTARY  PRINCIPLES  OP  MECHANICS. 


421 


to  the  ground  with  that  velocity;  thus  incurring  an  almost  certain  injury 
to  avoid  one  remotely  contingent. 

The  force,  momentum,  or  quantity  of  motion  in  a  body  is  measured 
by  the  velocity,  multiplied  into  the  quantity  of  matter.  A  cannon-ball, 
for  example,  may  be  rolled  so  gently  against  a  man's  leg,  as  not  even  to 
bruise  it;  but  if  it  be  projected  by  means  of  gunpowder,  it  may  mow 
down  a  dense  column  of  men,  or  penetrate  the  most  solid  substance. 
If  a  man  be  running,  and  strike  against  another  who  is  standing,  a 
certain  shock  is  received  by  both ;  but  if  both  be  running  in  opposite 
directions  with  the  same  velocity,  the  shock  will  be  doubled. 

The  subject  of  the  direction  of  forces  applies  to  most  cases  of  mus- 
cular movement.  Where  only  one  force  acts  upon  a  body,  the  body 
proceeds  in  the  direction  in  which  the  force  is  exerted,  as  in  the  case 
of  a  bullet  fired  from  a  gun ;  but  if  two  or  more  forces  act  upon  it  at 
the  same  time,  the  direction  of  its  motion  will  be  a  middle  course  be- 
tween the  direction  of  the  separate  forces.  This  course  is  called  the 
resulting  direction,  that  is,  resulting  from  the 
composition  of  the  forces.  Let  us  suppose  two  Fig.  171. 

forces  a  T  and  b  T  in  Fig.  171,  acting  upon 
the  body  T,  which  may  be  regarded  as  the  ten- 
don of  a  muscle,  and  the  two  forces  as  the 
power  developed  by  muscular  fibres  holding 
the  same  situation;  the  result  will  be  the  same, 
whether  they  act  together  or  in  succession. 
For  example,  if  the  force  a  T  is  sufficient  to 
draw  T  to  a,  and  immediately  afterwards  the 
force  b  T  be  exerted  upon  it,  the  tendon  will 
be  at  c,  the  place  towards  which  it  would  be 
drawn  by  the  simultaneous  action  of  the  two  Composition  of  Forces. 
forces  or  fibres.  If,  therefore,  we  complete 

the  figure,  by  drawing  a  c  equal  and  parallel  to  T  b,  and  c  b  equal  and 
parallel  to  a  T,  we  have  the  parallelogram  of  forces,  as  it  is  called,  of 
which  the  diagonal  shows  the  resultant  of  the  forces, 
and  the  course  of  the  body  on  which  they  act.     In 
the  case,  assumed  in  Fig.  171,  the  forces  are  equal. 
If  not,  the  parallelogram  may  result  as  in  Fig.  173; 
in  which  T  c  will,  again,  be  the  resultant  of  the 
forces  a  T  and  T  b,  or  we  may  have  the  arrangement 
in  Fig.  172. 

By  these  parallelograms,  we  are  enabled,  also,  to 
resolve  the  resultant   into   its   component   forces. 
Suppose,  for  example,  we  desire  to  know  the  quan- 
tity of  force  in  the  resultant,  T  c,  Fig.  171,  which  is 
capable  of  acting  in  the  directions  T  a  and  T  b;  it 
is  only  necessary  to   draw,  from  the  point  c,  c  a 
parallel  to  T  b,  and  c  b  parallel  to  T  a  ;  and  the  lines  Composition  of  Forces. 
T  a  and  T  b,  cut  off  by  these,  will  be  the  forces  into 
which  it  may  be  resolved.    The  same  applies  to  Figs.  172  and  173,  and 
to  every  other  of  the  kind. 

Friction  is  the  resistance  necessary  to  be  overcome  in  making  one 


422 


MUSCULAR  MOTION. 


body  slide  over  another;    and  adhesion  the  force,  which  unites  two 

polished  bodies  when  applied   to 

Fig- 173.  each   other,  —  a   force,   which   is 

measured  by  the  perpendicular  ef- 
fort necessary  for  separating  the 
two  bodies.  The  more  polished  the 
surfaces  in  contact,  the  greater  is 
the  adhesion,  and  the  less  the  fric- 
tion; so  that  where  the  object  is 
merely  to  facilitate  the  sliding  of 
one  surface  over  another,  it  will  be 
always  advantageous  to  make  the 


Composition  of  Forces. 


Fig.  174. 


Lever  of  the  first  kind. 


surfaces  polished,  or  to  put  a  liquid  between  them. 

A  beam  or  rod  of  any  kind,  resting  at  one  part  on  a  prop  or  support, 
which  thus  becomes  its  centre  of  motion,  is  a  lever;     The  ten  inch 

beam,  PW,  Fig.  174, 
is  a  lever,  of  which  F 
may  be  considered 
the  prop  or fulcrum  ; 
P,  the  part  at  which 
the  power  is  applied, 
and  W,  the  point  of 
application  of  the 
weight  or  resistance. 

In  every  lever  we  distinguish  three  points ; — the  fulcrum,  power,  and 
resistance;  and,  according  to  the  relative  position  of  these  points,  the 
lever  is  said  to  be  of  the  first,  second,  or  third  kind.  In  a  lever  of  the 
first  kind,  the  fulcrum  is  between  the  resistance  and  power,  as  in  Fig. 
174 ;  F  being  the  fulcrum  on  which  the  beam  rests  and  turns ;  P,  the 
power;  and  W,  the  weight  or  resistance.  We  have  numerous  familiar 
examples  of  this  lever; — the  crowbar  in  elevating  a  weight;  the  handle 
of  a  pump  ;  a  pair  of  scales ;  a  steelyard,  &c.  A  lever  of  the  second 

kind  has  the  resist- 
ance W,  Fig.  175, 
between  the  power 
P  and  the  fulcrum 
F;  the  fulcrum  and 
power  occupying 
each  one  extremity. 
The  rudder  of  a  ship, 
a  wheelbarrow,  and 
nut-crackers,  are  varieties  of  this  kind  of  lever.  In  a  lever  of  the  third 
kind,  the  power  P  is  between  the  resistance  W,  and  the  fulcrum  F,  Fig. 
176;  the  resistance  and  the  fulcrum  occupying  each  one  extremity  of 
the  lever.  In  the  last  two  levers,  the  weight  and  the  power  change 
places.  Tongs  and  shears  are  levers  of  this  kind ;  also,  a  long  ladder 
raised  against  a  wall  by  the  efforts  of  a  man:  here  the  fulcrum  is  at  the 
part  of  the  ladder  which  rests  on  the  ground;  the  power  is  exerted  by 
the  man ;  and  the  resistance  is  the  ladder  above  him. 


Fig.  175. 


Lever  of  the  second  kind. 


ELEMENTARY  PRINCIPLES  OF  MECHANICS.  423 

In  all  levers  are  distinguished, — the  arm  of  the  power  and  the  arm 
of  the  resistance.  The 

former  is  the  distance  Fig.  176 

comprised  between  the 
power  and  the  ful- 
crum, P  F,  Figs.  174, 
175,  and  176;  and 
the  latter  is  the  dis- 
tance W  F,  or  that 

between     the    weight    ^  rw 

and       the       fulcrum.  * 

When,  in  the  lever  of  .  LeVer  of  the  third  kind, 

the  first  kind,  the  ful- 
crum occupies  the  middle,  the  lever  is  said  to  have  equal  arms ;  but  if 
it  be  nearer  the  power  or  the  resistance,  it  is  said  to  be  a  lever  with 
unequal  arms. 

The  length  of  the  arm  of  the  lever  gives  more  or  less  advantage  to 
the  power,  or  the  resistance,  as  the  case  may  be.  In  a  lever  of  the 
first  kind,  with  equal  arms,  complete  equilibrium  would  exist,  provided 
the  beam  were  alike  in  every  other  respect.  But  if  the  arm  of  the 
power  be  longer  than  that  of  the  resistance,  the  resistance  is  to  the 
power  as  the  length  of  the  arm  of  the  power  is  to  that  of  the  arm  of 
the  resistance;  so  that  if  the  former  be  double  or  triple  the  latter,  the 
power  need  only  be  'one-half  or  one-third  of  the  resistance,  in  order 
that  the  two  forces  may  be  in  equilibrium.  A  reference  to  the  figures 
will  exhibit  this  in  a  clear  light.  The  three  levers  are  all  presumed 
to  be  of  equal  substance  throughout,  and  to  be  ten  inches,  or  ten  feet, 
in  length.  The  arm  of  the  power,  in  Fig.  174,  is  the  distance  P  F, 
equal  to  eight  of  those  divisions ;  whilst  that  of  the  resistance  is  W  F, 
equal  to  two  of  them.  The  advantage  of  the  former  over  the  latter  is, 
consequently,  in  the  proportion  of  eight  to  two,  or  as  four  to  one ;  in 
other  words,  the  power  need  only  be  one-fourth  of  the  resistance,  in 
order  that  the-  two  forces  may  be  equilibrious.  In  the  lever  of  the 
second  kind,  the  proportion  of  the  arm  P  F  of  the  power  is  to  that  of 
the  resistance,  W  F/  as  ten—the  whole  length  of  the  lever — to  two  ; 
or  five  to  one ;  whilst,  in  the  lever  of  the  third  kind,  it  is  as  two  to 
ten,  or  as  one  to  five;  in  other  words,  to  be  equilibrious,  the  power 
must  be  five  times  greater  than  the  resistance.  We  see,  therefore, 
that  in  the  lever  of  the  second  kind,  the  arm  of  the  power  must  neces- 
sarily be  longer  than  that  of  the  resistance,  since  the  power  and  the 
fulcrum  are  separated  from  each  other  by  the  whole  length  of  the 
lever ;  hence  this  kind  of  lever  must  always  be  advantageous  to  the 
power;  whilst  the  lever  of  the  third  kind,  for  like  reasons,  must  always 
be  unfavourable  to  it,  seeing  that  the  arm  of  the  resistance  is  the 
whole  length  of  the  lever,  and,  therefore,  necessarily  greater  than  that 
of  the  power. 

It  can  now  be  understood  why  a  lever  of  the  first  kind  should  be 
most  favourable  for  equilibrium;  one  of  the  second  for  overcoming  re-, 
sistance ;  and  one  of  the  third  for  rapidity  and  extent  of  motion :  for 
whilst,  in  Fig.  176,  the  power  is  moving  through  the  minute  arc  at  P, 


424  MUSCULAR  MOTION. 

in  order  .that  the  lever  may  assume  the  position  indicated  by  the 
dotted  lines  F  w,  the  weight  or  resistance  is  moving  through  the  much 
more  considerable  space  W  w. 

The  direction  in  which  the  power  is  inserted  into  the  lever  likewise 
demands  notice.  When  perpendicular  to  the  lever,  it  acts  with  the 
greatest  advantage, — the  whole  of  the  force  developed  being  employed 
in  surmounting  the  resistance ;  whilst  if  inserted  obliquely  a  part  of 
the  force  is  employed  in  tending  to  move  the  lever  in  its  own  direc- 
tion; and  this  part  is  destroyed  by  the  resistance  of  the  fulcrum. 

Lastly:  the  general  principles  of  equilibrium  in  levers  consist  in 
this ; — that  whatever  may  be  the  direction  in  which  the  power  and  re- 
sistance are  acting,  they  must  always  be  to  one  another  inversely  as 
the  perpendiculars  drawn  from  the  fulcrum  to  their  lines  of  direction. 
In  Fig.  176,  for  example,  the  line  of  direction  of  the  upper  weight  is 
W  w\  that  of  the  power  P  p',  and,  to  keep  the  lever  in  equilibrium  in 
this  position,  the  forces  must  be  to  one  another  inversely  as  F  w  to  F  p. 

In  applying  these  mechanical  principles  to  the  illustration  of  muscu- 
lar motion,  we  must,  in  the  first  place,  regard  each  movable  bone  as  a 
lever,  whose  fulcrum  or  centre  of  motion  is  in  its  joint ;  the  power  at 
the  insertion  of  the  muscle ;  and  the  resistance  in  its  own  weight  and 
that  of  the  parts  which  it  supports.  In  different  parts  of  the  skeleton 
we  find  the  three  kinds  of  levers.  Each  of  the  vertebrae  of  the  back 
forms,  with  the  one  immediately  beneath  it,  a  lever  of  the  first  kind, — 
the  fulcrum  being  seated  in  the  middle  of  the  under  surface  of  the 
body  of  the  vertebra.  The  foot,  when  we  stand  upon  the  toe,  is  a 
lever  of  the  second  kind, — the  fulcrum  being  in  the  part  of  the  toes 
resting  upon  the  soil ;  the  power  in  the  muscles  inserted  into  the  heel, 
and  the  resistance  in  the  ankle-joint,  on  which  the  whole  weight  of  the 
body  rests.  Of  levers  of  the  third  kind  we  have  numerous  instances ; 
of  which  the  deltoid,  to  be  described  presently,  is  one.  In  this,  as  in 
other  cases,  the  applicability  of  the  principle,  laid  down  regarding  the 
arms  of  the  lever,,  &c.,  is  seen,  and  we  find,  that,  in  the  generality  of 
cases,  the  power  is  inserted  into  the  lever  so  near  to  the  fulcrum,  that 
considerable  force  must  be  exerted  to  raise  an  inconsiderable  weight ; — 
that  so  far,  consequently,  mechanical  disadvantage  results;  but  such 
disadvantage  enters  into  the  economy  of  nature,  and  is  attended 
with  so  many  valuable  concomitants  as  to  compensate  richly  for  the 
expense  of  power.  Some  of  these  causes,  that  tend  to  diminish  the 
effect  of  the  forces,  we  shall  first  consider,  and  afterwards  attempt  to 
show  the  advantages  resulting  from  these  and  similar  arrangements  in 
effecting  the  wonderful,  complicate  operations  of  the  muscular  system. 
In  elucidation  of  this  subject,  we  may  take,  with  Haller,1  the  case  of 
the  deltoid — the  large  muscle,  which  constitutes  the  fleshy  mass  on  the 
top  of  the  arm,  and  whose  office  it  is  to  raise  the  upper  extremity. 
Let  W  F,  Fig.  177,  represent  the  os  humeri,  with  a  weight  W  at  the 
elbow,  to  be  raised  by  the  deltoid  D.  The  fulcrum  F  is  necessarily, 
in  this  case,  in  the  shoulder  joint;  and  the  muscle  D  is  inserted  much 

1  Elementa  Physiologiee,  lib.  xi.  2. 


APPLICATION  OP  MECHANICAL  PRINCIPLES. 


425 


Fig.  177. 


nearer  to  the  fulcrum  than  to  the  end  of  the  bone  on  which  the  weight 
rests;  the  arm  of  the  power  P  F, — (supposing,  for  a  moment,  that  it 
is  acting  at  this  part  with  every  advantage,  which  we  shall  see  pre- 
sently it  is  not,) — is,  consequently, 
much  shorter  than  that  of  the  resist- 
ance W  F,  which,  as  in  all  levers  of 
the  third  kind,  occupies  the  whole 
length  of  the  lever.  In  estimating 
the  effect  from  this  cause  alone  upon 
the  power  to  be  exerted  by  the  del- 
toid, we  may  suppose,  that  the  arm 
of  the  power  is  to  that  of  the  resist- 
ance as  1  to  3 ; — the  deltoid  being 
inserted  into  the  humerus  about  one- 
third  down.  Now,  if  we  raise  a 
weight  of  fifty-five  pounds  in  this  way,  and  add  five  pounds  for  the 
weight  of  the  limb — (which  may  be  conceived  to  act  entirely  at  the 
end  of  the  bone) — the  power,  which  the  deltoid  must  exert  to  produce 
the  effect,  is  equal  not  to  sixty  pounds,  but  to  three  times  sixty  or  one 
hundred  and  eighty  pounds. 

Fig.  178. 


Action  of  the  Deltoid. 


Action  of  the  Deltoid. 
A.  The  scapula.    B.  The  os  humeri .    C.  The  deltoid. 

Figures  177  and  178  exhibit  the  disadvantages  of  the  deltoid,  so  far 
as  regards  the  place  of  its  insertion  into  the  lever;  but  many  muscles 
have  insertions  much  less  favourable  than  it.  The  biceps,  D,  for  exam- 
ple, in  Fig.  179, — the  muscle  which  bends  the  forearm  on  the  arm, — is 
attached  to  the  forearm  ten  times  nearer  the  elbow-joint  or  fulcrum 
than  to  the  extremity  of  the  lever ;  and  if  we  apply  the  argument  to 
it, — supposing  the  weight  of  the  globe,  in  the  palm  of  the  hand,  to  be 
fifty-five  pounds  and  the  weight  of  the  lirnb  five  pounds, — it  would 
have  to  act  with  a  force  equal  to  sixty  times  ten,  or  six  hundred  pounds, 
to  raise  the  weight. 

Muscles,  again,  are  attached  to  the  bones  at  unfavourable  angles. 
If  they  were  inserted  at  right  angles  in  the  direction  P  P,  Fig.  177, 
the  whole  power  would  be  effectually  applied  in  moving  the  limb.  On 
the  other  hand,  if  the  muscle  were  parallel  to  the  bone,  the  resistance 
would  be  infinite,  and  no  effect  could  result.  In  the  animal  it  rarely 


426 


MUSCULAR  MOTION. 


happens,  that  the  muscle  is  inserted  at  the  most  favourable  angle:  it  is 
generally  much  smaller  than  a  right  angle.     Reverting  to  the  deltoid, 
this  muscle  is  inserted  into  the  humerus  at  an  angle  of  about  ten  de- 
Fig.  179. 


Action  of  the  Biceps. 

A.  The  os  humeri.     B.  The  ulna.      C.  The  radius.     D.  The  biceps. 

into  the  radius. 


E.  Insertion  of  the  biceps 


grees.  Now,  a  power  acting  obliquely  upon  a  lever,  is  to  one  acting 
perpendicularly,  as  the  sine  of  inclination,  represented  by  the  dotted 
line  F  s,  Fig.  177,  to  the  whole  sine  P  P.  In  the  case  of  the  deltoid, 
the  proportion  is  as  1,736,482  to  10,000,000.  Wherefore,  if  the 
muscle  had  to  contract  with  a  force  of  one  hundred  and  eighty  pounds, 
owing  to  the  disadvantage  of  its  insertion  near  the  fulcrum,  it  would 
have,  from  the  two  causes  combined,  to  exert  a  force  equal  to  1,058 
pounds. 

Again,  the  direction  in  which  the  fibres  are  inserted  into  the  tendon 
has  great  influence  on  the  power  developed  by  the  muscle.  There  are 
few  straight  muscles,  in  which  all  the  fibres  have  the  same  direction  as 

the  tendon.  Fig.  180  will  exhibit  the 
loss  of  power,  which  the  fibres  must 
sustain  in  proportion  to  the  angle  of 
insertion.  The  fibre  t  F  would,  of 
course,  exert  its  whole  force  upon  the 
tendon,  whilst  the  fibre  t  90°,  by  its 
contraction,  would  merely  displace  the 
tendon.  Now,  the  force  exerted  is, 
in  such  case,  to  the  effective  force, — 
that  is,  to  that  which  acts  in  moving 
the  limb, — as  the  whole  sine  £  F  is  to 
the  sines  of  the  angles  at  which  the 
fibres  join  the  tendon  represented  by 
the  dotted  lines.  Borelli  and  Sturm 
have  calculated  these  proportions  as 

follows:— At  an  angle  of  30°,  they  are  as  100  to  87;  at  45°  as  100  to 
70;  at  26°  as  100  to  89;  at  14°  as  100  to  97;  and  at  8°  as  100  to  99. 
The  largest  angle,  formed  by  the  outer  fibres  of  the  deltoid,  is  esti- 
mated by  Haller  at  30°:  the  smallest  about  8°.     If  this  disadvantage 


Fig.  180. 


70' 


Insertion  of  Fibres  into  Tendon. 


APPLICATION  OF  MECHANICAL  PRINCIPLES.  427 

be  taken  into  account,  the  deltoid  will  have  to  contract  with  a  force 
equal  to  1,284  pounds,  to  raise  fifty-five  pounds  at  the  elbow.  It  is 
farther  contended  by  Borelli,  Sturm,  and  Haller,  that  the  force  of  the 
muscle,  as  estimated  in  the  preceding  calculations,  must  be  doubled, 
seeing  that  it  has  to  exert  as  much  force  in  resisting  the  bone  which 
affords  a  fixed  point  at  one  extremity,  as  in  elevating  the  weight  at  the 
other.  This  estimate,  if  admitted,  would  elevate  the  force,  to  be  exerted 
by  the  deltoid  in  raising  the  fifty  pounds,  to  2,568  pounds.  Lastly : 
Much  force  is  spent  when  a  muscle  passes  over  many  joints;  antagonist 
muscles  must,  likewise,  exert  an  influence  of  the  kind,  consuming  a  cer- 
tain portion  of  the  force  developed  in  the  contraction  of  the  muscle. 

On  the  other  hand,  there  are  arrangements  that  augment  the  power 
developed  by  muscles  ; — as  the  thick  articular  extremities  of  bones;  the 
patella  and  sesamoid  bones  in  general ;  all  of  which  enlarge  the  angle, 
at  which  the  tendon  is  inserted  into  the  bone  or  lever.  The  projecting 
processes  for  muscular  attachments,  as  the  trochanters,  protuberance 
of  the  os  calcis,  spinous  processes  of  the  vertebrae,  &c.,  augment  the 
arm  of  the  lever,  and  are  thus  inservient  to  a  like  valuable  purpose. 
The  smoothness  of  the  articular  surfaces  of  bones, — tipped,  as  they  are, 
with  cartilage, — and  the  synovia,  which  lubricates  the  joints,  by  dimin- 
ishing friction,  as  well  as  the  bursae  mucosae,  which  are  interposed  wher- 
ever there  is  much  pressure  or  friction,  also  aids  the  power.  Trochleae  or 
pulleys  act  only  in  directing  the  force,  without  augmenting  its  amount ; 
and  the  same  may  be  said  of  the  bony  canals  and  tendinous  sheaths,  by 
which  the  tendons  of  the  muscles,  especially  those  passing  to  the  fingers 
and  toes,  are  kept  in  their  proper  course.  Still,  it  must  be  admitted, 
that,  as  regards  the  effort  to  be  exerted  by  muscles,  it  must,  in  almost 
all  cases,  be  much  greater  than  the  resistance  to  be  overcome.  The 
very  fact  of  the  lever  of  the  third  kind  being  that  which  prevails  in  our 
movements  shows  this.  The  mere  mechanician  has  conceived  this  to  be 
an  unwise  construction:  and  that  there  is  a  needless  expense  of  force 
for  the  attainment  of  a  determinate  end.  In  all  cases  we  find,  that  the 
expense  of  power  has  been  but  little  regarded  in  the  construction  of  the 
frame  ;  nor  is  it  necessary  that  it  should  have  been.  It  must  be  recol- 
lected, that  the  contraction  of  the  muscle  is  under  the  nervous  influ- 
ence, and  that,  within  certain  limits,  the  force,  to  be  employed,  is  regu- 
lated by  the  influx  sent  by  it  into  the  muscle.  The  great  object  in  the 
formation  of  the  body  appears  to  have  been — to  unite  symmetry  and 
convenience  with  the  attainment  of  great  velocity  and  extent  of  motion, 
so  that  whilst  the  power  is  moving  through  a  small  space,  the  weight 
or  resistance  shall  move  rapidly  through  one  more  extensive.  We  have 
seen  that,  in  these  respects,  the  lever  of  the  third  kind  is  most  fitting. 
With  the  others  less  power  might  be  required  ;  but  there  would  be  less 
extent  of  motion  and  velocity,  whilst  the  symmetry  and  convenience  of 
the  body  would  be  destroyed.  Suppose,  for  example,  that  in  Fig.  179, 
the  biceps — instead  of  being  inserted  at  E,  near  the  elbow — had  passed 
on  to  the  wrist, — or,  to  simplify  the  matter,  to  the  extremity  of  the 
member;  it  would  assuredly  have  acted  with  more  force — the  lever 
having  been  changed  into  one  of  the  second  kind, — but  the  hand  would 
have  lost  that  velocity  and  extent  of  motion,  which  are  so  important  to 


428 


MUSCULAR  MOTION. 


Fig.  181.  it ;  and  the  course  of  the  mus- 

cle would  have  been  so  modi- 
fied as  to  convert  the  conve- 
nient and  symmetrical  mem- 
ber into  a  cumbrous,  webbed 
instrument,  badly  adapted  for 
the  multitudinous  purposes  to 
which  it  has  to  be  applied. 

The  same  effect  results,  as 
Sir  Charles  Bell1  has  remark- 
ed, from  the  course  of  ten- 
dons and  their  confinement  by 
sheaths,  strengthened  by  liga- 
ments. If  the  tendon  A,  Fig. 
181,  took  the  shortest  course 
to  its  termination  at  B,  it 

would  draw  up  the  toe  with  more  force ;  but  the  toe  would  lose  its 

velocity  of  movement. 

To  favour  this  velocity,  we  find  that  the  majority  of  muscles  are  in- 
serted obliquely  into 

Fig.  182. 

f~^  'C^  ~W  f 

\jr  _lli  J~|_ 

iimiminirR 


Tendon  of  the  Great  Toe. 


their  levers,  and  the 
fibres  into  the  ten- 
dons. By  this  ar- 


Action  of  Intercostal  Muscles. 


rangement,  as  we 
have  proved,  consi- 
derable loss  of  power 
results;  but  in  the 
majority  of  cases, 
the  motion  is  effected 
by  a  less  degree  of 
decurtation  than  if 
the  muscles  were  straight.  Let  A  B  and  C  D,  Figs.  182  and  183,  be 
parts  of  two  ribs  that  are  parallel,  and  continue  parallel  till  brought 
into  contact  by  the  action  of  the  straight  muscle  E  F  ;  or  by  that  of  the 
oblique  muscles  F  Gr  and  F  H.  Now  it  is  obvious,  that  when  the  point 

E  comes  in  contact 

Fis- 183-  with  F,  the  length 

of  the  straight  mus- 
cle E  F  must  be 
null;  whilst  that  of 
the  oblique  muscles 
will  only  have  expe- 
rienced a  decurta- 
tion equal  to  Gr  g 
and  H  A,  Fig.  182 ; 
and  to  F  g  and  F  h, 
Fig.  183.  It  is 
clear,  also,  that,  in  these  cases,  the  straight  muscles  can  never  so  con- 


J.-1. 


Action  of  Intercostal  Muscles. 


Animal  Mechanics,  Library  of  Useful  Knowledge,  p.  27,  Lond.,  1829. 


APPLICATION  OF  MECHANICAL  PRINCIPLES. 


429 


Fig.  184. 


Action  of  Intercostals. 


tract  as  to  admit  of  a  close  approximation  of  the  ribs ;  whilst  the 
oblique  muscles  will  admit  of  this  to  a  much  greater  extent.  We  can, 
therefore,  understand,  why  the  intercostal  muscles  pass  obliquely  from 
one  rib  to  another,  as  at  D  and  B  C,  Fig.  184,  instead  of  in  a  direction 
perpendicular  to  the  two  ribs  as  at  A. 

There  are  cases,  however,  in  which  a  straight  muscle  may  pass 
between  two  parallel  ribs,  and  carry  them  through  a  given  space,  with 
less  decurtation  of  fibres,  than  any  oblique  muscle,  which  has  the  same 
origin;  but  is  inserted  at  a  greater 
distance  from  the  centre  of  motion, 
and  acts  through  the  medium  of  a 
longer  lever.  Moreover,  a  mus- 
cle, with  a  less  degree  of  obliquity, 
may  be  so  situate  as  to  carry  the 
bones  through  a  given  space,  with 
a  less  decurtation  of  fibres  than 
any  other  muscle  having  the  same 
origin  but  a  much  greater  de- 
gree of  obliquity.  Suppose  A  B  and  C  D,  Fig.  185,  to  be  two 
parallel  ribs,  of  which  A  B  is  movable  about  A  as  a  centre  ;  and  sup- 
pose it  to  be  brought 
by  the  action  of  the  Fig.  185. 

straight  muscle  E  F,  j?  O- 

and  of  the  oblique 
muscles  E  G  and  E 
H,  into  the  position 
A/.  The  points  of 
insertion  of  the  mus- 
cles will  now  be  at  a, 
c,  and  e,  after  having 
traversed  the  spaces 
F  a,  G  c,  and  H  e. 
If  we  now,  from  the  point  E,  as  a  centre,  describe  the  arcs  c  b  and  e  d; 
the  spaces  d  H  and  b  G  will  indicate  the  degree  of  decurtation,  which 
the  oblique  muscles  have  experienced,  and  a  F  that  of  the  straight  mus- 
cle. This  figure  also  shows,  that  when  the  muscles  change  the  relative 
position  of  any  two  bones,  they  at  the  same  time  change  the  direction 
of  their  own  action,  and  vary  their  lever.  When  the  rib  A  B  is  brought 
into  the  position  A/,  the  muscles  E  G  and  E  H,  by  being  brought 
down  to  c  and  6,  have  assumed  the  positions  E  c  and  E  e;  and  have,  con- 
sequently, changed  their  length,  situation,  obliquity,  and  leverage. 

Again,  of  the  muscles,  which  are  attached  to  ribs  that  are  parallel, 
equally  movable,  and  situate  at  right  angles  to  the  spine,  those  which 
pass  perpendicularly  from  one  rib  to  the  other  will  act  upon  each  with 
equal  leverage;  and  each  will  approach  the  other  with  the  same  velo- 
city; whilst  those  that  pass  obliquely  from  one  to  the  other,  will  .make 
them  approach  with  different  velocities; — a  principle  which  is  strikingly 
applicable  to  the  intercostal  muscles.  Let  us  suppose  A  B  and  C  D, 
Fig.  186,  to  be  two  parallel  ribs,  articulated  with  the  spine  at  A  and 
C,  and  equally  movable  on  these  centres  of  motion.  Let  D  B  repre- 


:o 


Action  of  Intercostals. 


430 


MUSCULAR  MOTION. 


Action  of  Intercostals. 


?86-  sent  a  straight  mus- 

cle, passing  directly 
from  the  one  rib  to 
the  other;  and  D  E 
an  oblique  muscle. 
The  levers  of  D  B, 
according  to  the 
mechanical  princi- 
ples laid  down,  will 
be  AB  and  CD, per- 
pendiculars drawn 
from  the  centres  of 

motion  to  the  line  of  direction  of  the  power.  These  levers  being  pa- 
rallel are  of  course  equal;  but  the  levers  of  D  E  will  be  C  F  and  A  Gr, 
— also  perpendiculars  drawn  from  the  centres  of  motion  to  the  line  of 

direction   of  the   power. 

Fig- 187.  These   levers   are  of  dif- 

ferent lengths;  and,  ac- 
cordingly, the  muscle 
must  act  with  different 
degrees  of  force  on  the 
two  ribs;,  so  that  it  will 
cause  C  D,  on  which  it 
acts  with  the  longest 
lever,  to,  approach  A  B 
faster  than  it  makes  the 
latter  approach  the  for- 
mer,— in  the  ratio  of  C 
F  to  A  C,  or  with  three 
times  the  velocity. 
Action  of  Biceps.  In  all  muscular  mo- 

tions, the   levers  of  the 

power  and  resistance  are  undergoing  variations;  so  that  the  degree 
of  power,  necessary  to  be  developed  in  one  position  of  the  member, 
may  be  much  less  than  in  another.  The  case  of  the  biceps  already 
referred  to,  elucidates  this.  Let  E  C,  Fig.  187,  represent  the  os 
humeri;  E  A  the  forearm;  E  the  elbow-joint;  W,  a  weight  or  resist- 
ance hung  at  the  wrist,  and  D  the  biceps  muscle,  inserted  at  b,  a 
tenth  of  the  distance  down  the  forearm.  It  is  manifest,  that  the  force, 
necessary  for  bending  the  arm,  must  be  much  greater  when  it  is  in  the 
position  A  E  than  in  that  of  E  a.  The  lever  of  the  resistance,  in  the 
former  case,  is  the  whole  length  of  the  forearm;  or,  in  other  words,  the 
perpendicular  drawn  from  the  fulcrum  to  the  line  of  direction  of  the 
weight  W;  but,  when  the  arm  is  raised  to  #,  the  lever  of  the  resistance 
is  no  longer  E  A,  but  E  H:  but  not  only  is  the  lever  of  the  resistance 
shortened;  that  of  the  power  is  augmented.  The  lever  of  the  biceps, 
when  the  forearm  is  horizontal,  is  the  dotted  perpendicular  drawn  from 
the  fulcrum  at  the  elbow  to  the  line  of  direction  of  the  muscle;  but 
when  the  forearm  is  bent  to  the  position  E  $,  the  disposition  of  the 
muscle  is  also  modified.  It  assumes  the  position  occupied  by  the  dotted 


APPLICATION  OF  MECHANICAL  PRINCIPLES. 


431 


Fig.  188. 


line,  which  is  farther  distant  from  the  fulcrum ;  and  the  lever  of  the 
power  is  consequently  increased.  In  this  case,  then,  of  the  action  of  the 
biceps,  in  proportion  as  we  raise  the  arm,  the  mechanical  disadvantages 
become  less  and  less;  the  lever  of  the  power  increasing,  whilst  that  of 
the  resistance  diminishes. 

In  many  of  the  changes  of  position  of  a  body,  whilst  a  bone  is  turn- 
ing upon  its  centre  of  motion,  the  centre  itself  is  often  describing  a 
curve  at  the  same  time.  In  Fig.  188,  let  A 
B  represent  the  foot,  B  C  the  tibia,  C  D  the 
thigh-bone,  and  D  E  the  trunk;  and  let  us 
suppose  it  is  required  to  bring  the  body  to 
the  erect  position  B  F ;  so  that  B  C  shall  cor- 
respond to  B  G,  0  D  to  (1 1,  and  D  E  to  I 
F.  The  point  C  will  describe  the  curve  C  G; 
and,  whilst  it  is  accomplishing  this,  the  point 
D  is  likewise  moving ;  so  that  the  latter,  in- 
stead of  describing  the  curve  D  H,  which  it 
would  do,  were  the  centre  of  motion  C  fixed, 
proceeds  along  the  curve  D  I:  the  point  E, 
again,  is  subjected  to  the  like  influence;  and 
instead  of  describing  the  curve  E  K,  which  it 
would  do  if  the  centre  D  were  fixed,. rises 
along  E  F. 

The  motions  produced  by  the  muscles  may 
be  either  simple  or  compound.  The  simple 
muscles  admit  of  variety ;  some  being  straight, 
composed  of  parallel  fasciculi ;  others  reflected 
in  their  course,  and  others,  again,  are  circu- 
lar. In  the  straight  muscles,  each  fibre,  by 
its  contraction,  draws  the  tendon  in  its  own 
direction;  and  the  effect  of  the  whole  is  to 
bring  it  towards  the  centre  of  the  muscle.  In  a  long  muscle,  the 
whole  contractile  effort  is  concentrated  on  the  tendon,  in  consequence 
of  the  course  of  the  fibres  being  parallel  to  that  of  the  tendon.  In 
most  of  the  broad  muscles,  on  the  other  hand,  as  the  attachments  at 
both  extremities  are  usually  at  different  points,  all  the  fibres  do  not 
concur  in  one  effort.  Different  sets  of  fibres  may  have  a  very  different 
action  from  others,  and  are  capable  of  being  thrown  separately  into  con- 
traction. The  ordinary  direction  in  which  a  muscle  acts  is  from  its  ten- 
dinous, back  to  its  aponeurotic,  attachment, — that  is,  from  the  movable 
to  the  more  fixed  part ;  and,  in  a  straight  muscle,  this  direction  can  be 
accurately  appreciated.  It  must  be  borne  in  mind,  however,  that  the 
muscle  can  act  in  an  inverse  direction  also. 

When  the  whole  of  the  fibres  composing  a  broad  muscle  are  brought 
to  act  on  the  tendon,  as  in  the  case  of  the  deltoid,  we  find,  by  the  com- 
position of  forces,  that  the  middle  line  of  direction  must  be  taken  for 
the  purpose  of  estimating  their  line  of  action.  A  part,  however,  may 
act  and  carry  the  arm  upwards  and  outwards ;  whilst  the  opposite  fibres 
may  move  it  upwards  and  inwards. 

Where  a  muscle  is  reflected,  like  the  superior  oblique  of  the  eye,  ai^cl 


Combined  Muscular  Movements 
in  Rising. 


432  MUSCULAR  MOTION. 

the  peronei  muscles, — the  line  of  motion  will  be  from  the  insertion  to 
the  point  of  reflection;  precisely  as  a  rope  passing  over  a  pulley  raises 
the  weight  in  a  line  drawn  from  the  weight  to  the  pulley. 

The  circular  muscles,  which  have  no  precise  origin  or  insertion,  are 
inservient  to  the  contraction  of  the  apertures  around  which  they  are 
placed. 

In  executing  the  complex  movements  of  any  part  of  the  frame,  a 
combination  of  the  action  of  the  different  muscles  attached  to  the  part, 
generally  occurs, — rendering  the  process  one  of  a  complicated  charac- 
ter. This,  if  no  other  cause  existed,  would  render  it  extremely  difficult 
to  calculate  the  precise  degree  of  force,  which  particular  muscles,  alone 
or  in  combination,  are  capable  of  exerting.  The  mathematical  physi- 
ologists made  multifarious  attempts  in  this  direction;  but  their  con- 
clusions were  discrepant.  When  we  bear  in  mind,  that  the  force,  capa- 
ble of  being  exerted  by  any  muscle,  is  dependent  upon  the  proper 
organization  of  the  muscle,  and  likewise  upon  the  degree  of  energy  of 
the  brain,  it  will  be  apparent,  that  all  attempts  of  the  kind  must  be 
futile.  We  can  determine  with  nicety  the  effect  of  which  the  parts  are 
capable,  supposing  them  inanimate  structures.  We  can  calculate  the 
disadvantages,  caused  by  the  insertion  of  the  power  near  the  fulcrum; 
by  the  obliquity  of  the  line  of  action  of  the  power,  &c. ;  but  we  have 
not  the  slightest  data  for  estimating  the  effect  produced  by  the  nervous 
influx, — by  that  mysterious  process,  which  generates  a  new  force,  and 
infuses  it  into  the  muscles,  in  a  manner  so  unlike  that  in  which  the 
ordinary  mechanical  powers  are  exerted.  The  data  necessary  for  such 
a  calculation  would  be  the  precise  influx  from  the  brain, — the  irrita- 
bility of  the  muscle, — the  mechanical  influences,  dependent  on  the 
straight  or  oblique  direction  of  the  fibres  composing  it,  as  regards  the 
tendon, — the  perpendicular  or  oblique  direction  in  which  the  tendon  is 
attached  to  the  bone, — the  particular  variety  of  lever, — the  length  of 
the  arm  of  the  power  and  that  of  the  resistance, — the  loss  sustained 
from  friction,  and  the  diminution  of  such  loss  caused  by  the  cartilages 
that  tip  the  bones,  and  by  the  synovia,  &c. — data,  which  it  is  impossi- 
ble to  attain;  and  hence  the  solution  of  the  problem  is  impracticable.  : 

One  great  source  of  the  combination  of  muscular  motions  is  the 
necessity  for  rendering  one  of  the  attachments  fixed,  in  order  that  the 
full  force  may  be  developed  on  the  other.  In  but  few  of  the  muscles 
is  the  part,  whence  the  muscle  originates,  steady.  To  these  few,  the 
muscles  of  the  eye,  which  arise  from  the  inner  part  of  the  orbit  and 
pass  forward  to  be  inserted  into  the  organ,  belong.  To  show  how  dis- 
tant muscles  may  be  concerned  in  this  fixation  of  one  end  of  a  muscle, 
when  it  is  excited  to  the  developement  of  plenary  power,  we  may  take 
the  case  of  the  deltoid,  which  arises  from  the  scapula  and  clavicle,  and 
is  inserted  into  the  os  humeri :  but  the  scapula  and  clavicle,  themselves, 
are  not  entirely  fixed ;  and,  accordingly,  if  the  deltoid  were  to  contract 
alone,  it  would  draw  down  the  scapula  and  clavicle,  as  well  as  elevate 
the  humerus.  If,  therefore,  it  be  important  to  produce  the  latter  effect 
only,  the  scapula  and  clavicle  must  be  fixed  by  appropriate  muscles; 
as  by  the  rhomboidei,  trapezius,  &c.  These  muscles,  however,  arise 
from,  various  vertebrae  of  the  neck,  which  are  themselves  movable.  It 


PREPONDERANCE  OF  FLEXORS.  433 

becomes  necessary,  therefore,  that  the  neck  should  be  fixed  by  its 
extensors,  which  arise  from  the  lumbar  and  dorsal  regions.  By  the 
united  action  of  all  these  muscles,  the  deltoid  is  able  to  exert  its  full 
effect  in  elevating  the  humerus.  But  the  deltoid,  like  other  muscles, 
is  capable  of  acting  inversely;  as  in  the  case  of  a  person  lying  on  the 
ground,  and  attempting  to  raise  himself  by  laying  hold  of  any  object 
above  him.  The  hand  and  forearm  are  thus  rendered  firm,  and  the 
deltoid  now  contracts  from  origin  to  insertion,  and,  consequently,  ele- 
vates the  scapula  and  clavicle.  Again,  if  a  person,  in  the  recumbent 
posture,  endeavours  to  bend  the  head  forwards,  the  recti  muscles  of  the 
abdomen  are  firmly  contracted  for  the  purpose  of  fixing  the  sternum, 
whence  the  sterno-cleido-mastoidei  muscles  in  part  arise,  which  can 
then  exert  their  full  power  in  bending  the  neck  forwards.  These 
instances  will  be  sufficient  to  exemplify  the  mode  in  which  muscular 
motions  are  combined.  The  same  principle  prevails  over  the  whole 
body ;  and  where  a  greater  number  of  parts  has  to  be  moved,  the  case 
must,  necessarily,  be  more  complex. 

When  a  part,  movable  in  various  directions,  is  drawn  towards  any 
point,  it  must  be  rendered  steady,  and  be  prevented  from  deviating,  by 
the  muscles  on  each  side ;  and  the  extent  of  its  motion  may  be  partly 
regulated  by  the  action  of  antagonist  muscles.  Supposing,  for  instance, 
that  the  head  is  inclined  forwards,  there  must  be  muscles  not  only  to 
move  it  in  that  direction,  but  also  to  prevent  it  from  inclining  to  the 
right  or  left,  and  to  limit  the  motion  forwards ;  although  doubt  may 
arise,  whether  this  be  not  entirely  effected  by  the  nervous  influx  sent 
by  volition  to  the  flexors  of  the  head.  Hence,  some  anatomists  have 
considered,  that  there  must,  in  these  cases,  be  movers,  directors,  and 
moderators. 

In  sleep,  the  muscles  are  perhaps  in  the  most  complete  state  of  re- 
laxation; and,  accordingly,  this  condition  has  been  invoked,  as  affording 
evidence  of  the  comparative  preponderance  of  particular  antagonizing 
muscles, — flexors  and  extensors,  for  example.  In  perfect  sleep,  when 
no  volition  is  exercised  over  the  muscles,  the  body  reposes  in  a  state  of 
semiflexion, — which  seems  to  show,  that  the  flexor  muscles  have  slightly 
the  advantage  over  the  extensors.  M.  Richerand1  has  assigned  the  fol- 
lowing reasons  for  this  preponderance.  First.  The  number  of  flexors  is 
greater  than  that  of  extensors.  Secondly.  The  fibres,  composing  them, 
are  more  numerous  and  longer: — take,  for  example,  the  sartorius,  gra- 
cilis,  semi-tendinosus,  semi-membranosus,  and  biceps,  which  are  flexors 
of  the  leg,  and  the  rectus  and  triceps  cruris,  which  are  its  extensors. 
Thirdly.  Their  insertion  is  nearer  the  resistance  and  farther  from  the 
centre  of  motion,  which  adds  to  their  force.  Fourthly.  Their  insertion 
into  the  bones  is  at  a  larger  angle,  and  nearer  the  perpendicular ;  and 
Fifthly.  Their  arrangement  is  such,  that  the  continuation  of  the  move- 
ment of  flexion  renders  them  perpendicular  to  the  bones  to  be  moved. 
The  explanation,  afforded  by  M.  Richerand,  applies,  on  the  whole,  to 
the  case  he  has  selected;  but  there  are  many  exceptions  to  it.  The 

1  Recueil  des  Memoires  de  la  Societe  Medicate  de  Paris,  an  vii.  (1799),  and  Elemens  de 
Physiologic,  13eme  edit.,  par  M.  Berard,  aine;  edit.  Beige,  p.  253,  §  clx.,  Bruxelles,  1837. 

VOL.  i.— 28 


434 


MUSCI/LAK  MOTION. 


extensors  of  the  thigh,  foot,  and  jaw,  are  decidedly  predominant ;  and, 
according  to  M.  Adelon,1  experiments,  instituted  by  Regnier  with  his 
dynamometer,  make  the  extensors  some  kilogrammes  more  powerful 
than  the  flexors.  In  our  various  attitudes,  the  movements  of  the  flexors 
certainly  prevail  largely;  but  as  the  power  of  contraction  is  regulated 
by  volition,  it  is  unnecessary  to  inquire,  whether  there  be  any  physical 
predominance  in  the  flexors  over  the  extensors,  as  has  been  attempted 
by  M.  Richerand.  We  have  already  seen,  that  we  can  in  no  way  attain 
a  knowledge  of  the  degree  of  force,  which  any  one  muscle  of  the  body 
is  capable  of  developing. 


TABLE  OF  THE  MUSCLES, 


ARRANGED  AFTER  THE  MANNER  OF  DR.  BARCLAY,  ACCORDING  TO 
THEIR  ACTIONS. 


Forwards  by 
Platysma  myoides, 
Sterno-mastoideus, 
Kectus  anticus  major, 
"  "      minor, 

Assisted  (when  the  lower  jaw 

is  fixed}  by 
Mylo-hyoideus, 
Genio-hyoideus, 
Genio-hyo-glossus, 
Digastric!. 

Forwards  by 
Platysma  myoides, 
Sterno-mastoideus, 
Digastricus, 
Mylo-hyoideus, 
Genio-hyoideus, 
Genio-hyo-glossus, 
Omo-hyoidei, 
Sterno-hyoidei, 
Thyro-hyoidei, 
Rectus  anticus  minor, 
Longus  colli. 


THE  HEAD  IS  MOVED 

Backwards  by 
Part  of  trapezius, 
Splenius  capitis, 
Complexus, 
Trachelo-mastoideus, 
Rectus  posticus  major, 
"  "        minor, 

Obliquus  capitis  superior. 


THE  1TECK  IS  MOVED 

Backwards  by 
Part  of  trapezius, 
Rhomboideus  minor, 
Serratus  posticus  superior, 
Splenius  capitis, 

"      colli, 
Complexus, 
Trachelo-mastoideus, 
Transversalis  colli, 
Inter-spinales  colli, 
Semi-spinales  colli, 
Rectus  posticus  major, 
"  "        minor, 

Obliquus  capitis  superior, 
"  "      inferior, 

Scaleni  postici, 
Levator  scapulae. 


To  either  side  by 
Platysma  myoides, 
Sterno-mastoideus, 
Part  of  trapezius, 
Splenius  capitis, 

"      colli, 

Trachelo-mastoideus, 
Complexus. 


Laterally  by 

Various  combinations  of  those 
muscles  which  separately 
move  it  forwards  and 
backwards,  assisted  by  the 
scaleni,  inter-transversales, 
and  recti  laterales. 


Forwards  by 
Rectus  abdominis, 
Pyramidalis, 

Obliquus  externus  abdominis, 
Obliquus  internus, 
Psoas  magnus, 
«      parvus, 

Assisted  (when  the  arms  are 
carried  forwards)  by 

Pectoralis  major, 

"         minor, 

Serratus  magnus. 


THE  TRUNK  IS  MOVED 

Backwards  by 
Trapezius, 
Rhomboideus  major, 
Latissimus  dorsi, 
Serratus  posticus  superior, 
"  "        inferior, 

Sacro-lumbalis, 
Longissimus  dorsi, 
Spinales  dorsi, 
Semi-spinales  dorsi, 
MuUifidus  spinae, 
Inter-transversales  dorsi  et 
lumborum. 


1  Physiologic  de  I'Homme,  2de  edit.,  ii.  117,  Paris,  1829  ; 
des  Sciences  Medicales. 


Laterally  by 
Obliquus  externus, 
"        internus, 
Quadratus  lumborum, 
Longissimus  dorsi, 
Sacro-lumbalis, 
Serrati  postici, 
Latissimus  dorsi. 


and  art.  Dynamometre,  in  Diet. 


TABLE  OP  MUSCLES. 


435 


THE  SCAPULA  IS  MOVED 

Upwards  by  Downwards  by  Forwards  by  Backwards  by 

Trapezius,  Lower  part  of  trape-    Pectoralis  minor,  Part  of  trapezius, 

Levator  scapulae,  zius,  Serratus  magnus.  Rhomboidei, 

Rhomboidei.  Latissimus  dorsi,  Latissimus  dorsi. 

Pectoralis  minor. 


THE  HUMEHUS  IS  MOVED 


Forwards  by 
Part  of  deltoid, 
Part  of  pectoralis  ma- 
jor, 

Assisted  in  some  cir- 
cumstances by 
Biceps, 
Coraco-brachialis. 


Backwards  by 
Part  of  deltoid, 
Teres  major, 
"      minor, 

Long  head  of  triceps, 
Latissimus  dorsi. 


Inwards  by 
Part  of  pectoralis  ma- 

T  J°r'  . 
Latissimus  dorsi. 


Rotated  inwards  by 
Subscapularis, 

Assisted    occasionally 

by 

Pectoralis  major, 
Latissimus  and  teres 
major. 

Outwards  by 
Supra-spinatus, 
Infra-spinatus, 
Teres  minor. 


Forwards  by 
Biceps, 

Brachialis  anticus, 
Pronator  teres, 

Assisted  by 
Flexor  carpi  radialis, 

"       sublimis, 

"      ulnaris, 
Supinator  longus. 


THE  FOREARM  IS  MOVED 

Backwards  by  Rotated  inwards  by 

Pronator  teres, 


Triceps, 
Anconeus. 


Flexor  carpi  radialis, 
Palmaris  longus, 
Flexor  sublimis, 
Pronator  quadratus. 

Outwards  by 
Biceps, 

Supinator  brevis, 
Extensor  secundi  inter- 

nodii. 


Forwards  by 
Flexor  carpi  radialis, 
Palmaris  longus, 
Flexor  sublimis, 
"      carpi  ulnaris, 
"      profundus, 
"      longus  pollicis. 


THE  CARPUS 

Backwards  by 

Extensor  carpi  radialis 
longior, 

Extensor  carpi  radialis 
brevior, 

Extensor  secundi  in- 
ternodii, 

Indicator, 

Extensor  communis 
digitorum, 

Extensor  proprius  pol- 
licis. 


IS    MOVED 

Outwards  by 
Flexor  carpi  radialis, 
Extensor  carpi  radialis 

longior, 
Extensor  carpi  radialis 

brevior, 
Extensor  ossis   meta- 

carpi, 
Extensor  primi  inter- 

nodii. 


THE  THUMB   IS  MOVED 


Inwards      and     for-     Outwards    and    back-     Upwards     and    for- 


wards,     across 

palm,  by 

Opponens  pollicis, 
Flexor  brevis, 
"      longus. 


the 


wards 


wards,   away  from, 
the  other  fingers,  by 
Abductor, 


Extensor  ossis   meta- 

carpi  pollicis. 
Extensor  primi  inter-    Assisted  by  part  of  the 

nodii,  Flexor  brevis. 

Extensor  secundi    m- 

ternodii. 

THE  FINGERS  ARE  MOVED 


Inwards  by 
Flexor  sublimis, 
"      carpi  ulnaris, 
"      profundus, 
Extensor      communis 

digitorum, 

Extensor    minimi    di- 
giti, 
Extensor  carpi  ulnaris. 


Backwards  and  in- 
wards, to  the  other 
fingers,  by 

Adductor, 

Extensor  primi  inter- 
nodii, 

Extensor  secundi  in- 
ternodii. 


Forwards,  or  flexed,    Backwards, 
by  tended, 

Flexor  sublimis,  Extensor  communis, 

"      profundus, 

Lumbricales, 

Interossei, 

Flexor     brevis    digiti 
minimi, 

Abductor  digiti  mini- 
mi. 


minimi  digiti, 
Indicator. 


Outwards,    to    radial  Inwards  by 

border,  by 

Abductor  indicis.  Abductor  digiti  mini- 

"      digiti  minimi,        mi, 


Interossei. 


Interossei. 


436 


MUSCULAE  MOTION. 


THE  THIGH  18  MOVED 


Forwards  by 
Psoas  magnus, 
Iliacus, 

Tensor  vaginae  femo- 
ris, 

Pectineus, 
Adductor  longus, 
"        brevis. 


Backwards  by 
Gluteus  maximus, 
Part  of  gluteus  me- 

dius, 

Pyriformis, 
Obturator  internus, 
Part  of  adductor  mag- 
nus, 

Long  head  of  biceps, 
Semi-tendinosus, 
Semi-membranosus . 


Inwards  by 

Psoas  magnus, 

Iliacus, 

Pectineus, 

Gracilis, 

Adductor  longus, 
"  brevis, 
"  magnus, 

Obturator  externus, 

Quadratus  femoris. 


Outwards  by 
Tensor  vaginae  femo- 
ris, 

Gluteus  maximus, 
"      medius, 
"      minimus, 
Pyriformis. 


THE  THIGH  IS   ROTATED 


Inwards  by 
Tensor  vaginae  femo- 
ris, 

Part  of  gluteus    me- 
dius, 

And,  when  the  leg  is 

extended,  by 
Sartorius, 
Semi-tendinosus. 


Outwar 
Gluteus  maximus, 
Part  of  gluteus  medius, 
Pyriformis, 
Gemellus  superior, 
Obturator  internus, 
Gemellus  inferior, 
Quadratus  femoris, 
Obturator  externus, 
Psoas  magnus, 
Iliacus, 

Adductor  longus, 
"        brevis, 
"        magnus, 
Biceps  cruris,  slightly. 


THE  LEG  IS  MOVED 

Backwards,  or  flexed,  by  Extended  by 


Forwards,  or 


Tibialis  anticus, 
Extensor  proprius  pol- 

licis, 
Extensor  longus  digi- 

torum, 
Peroneus  tertius. 


Semi-tendinosus, 

Biceps, 

Sem  i-membranosus, 

Gracilis, 

Sartorius, 

Popliteus. 


Rectus, 
Crureus, 
Vastus  externus, 
"      internus. 


THE  FOOT  IS    MOVED 


Backwards,  or  extend- 
ed, by 

Gastrocnemius, 
Plantaris, 
Soleus, 
Flexor     longus     digi- 

torum, 

Flexor  longus  pollicis, 
Tibialis  posticus, 
Peroneus  longus, 
"        brevis. 


Inclined  inwards  by 

Extensor  proprius  pol- 
licis, 

Flexor  longus  digi- 
torum, 

Flexor  longus  pollicis, 

Tibialis  posticus. 


Outwards  by 

Peroneus  longus, 
"        brevis, 
Extensor  longus  digi- 

torum, 
Peroneus  tertius. 


THE  TOES  ARE  MOVED 

Forwards,  or  extend-      Inclined  inwards  by 
ed,by 

Extensor  longus  digi-    Abductor  pollicis, 
torum, 

Extensor  proprius  pol- 
licis, 

Extensor  brevis  digi- 
torum. 


Interossei. 


Outwards  by 

Adductor  pollicis, 

"      digiti  minimi, 
Interossei.1 


Backwards,  or  flexed, 
by 

Abductor  pollicis, 

Flexor     brevis     digi- 
torum, 

Abductor   minimi   di- 
giti, 

Flexor  longus  pollicis, 
"      digitorum, 
"       accessorius, 

Lumbricales, 

Flexor  brevis  pollicis, 

Adductor  pollicis, 

Flexor  brevis  minimi 
digiti, 

Interossei. 

1  Quain's  Human  Anatomy,  by  Quain  and  Sharpey,  Amer.  edit,  by  Leidy,  i.  465,  Phila- 
delphia, 1849. 


ATTITUDES — STANDING.  437 


ATTITUDES. 

The  attitudes,  which  man  is  capable  of  assuming,  are  of  different 
kinds.  They  may,  however,  be  reduced  to  two  classes — the  active  and 
the  passive;  the  former  including  those  that  require  a  muscular  effort; 
and  the  latter  comprising  only  one  variety, — that  in  which  the  body  is 
extended  horizontally  on  the  soil,  and  no  effort  needed  to  maintain  its 
position. 

We  shall  begin  with  the  most  ordinary  attitude ; — that  of  standing 
on  both  feet.  This  requires  considerable  muscular  effort  to  preserve 
equilibrium.  The  base  of  sustentation — the  space  comprised  between 
the  feet  plus  that  occupied  by  the  feet  themselves — is  small ;  whilst  the 
centre  of  gravity  is  high.  The  body,  again,  does  not  consist  simply 
of  one  bone,  but  of  many;  all  of  which  have  to  be  kept  steady  by 
muscular  effort;  and  it  is  necessary,  Jhat  the  vertical  line  shall  fall 
within  the  base  of  sustentation,  in  order  that  equilibrium  may  be  pre- 
served. 

That  standing  is  the  effect  of  the  action  of  the  different  extensors 
is  proved  by  the  fact,  that  if  an  animal  be  killed  suddenly,  or  stunned, 
so  that  volition  is  no  longer  exerted  over  the  extensors,  it  immediately 
falls  forward. 

The  head,  which  is  intimately  united  with  the  atlas  or  first  vertebra 
of  the  neck,  forms  with  it  a  lever  of  the  first  kind;  the  fulcrum  being 
in  the  articulation  of  the  lateral  parts  of  the  atlas  and  vertebra  dentata; 
whilst  the  power  and  the  resistance  occupy  the  extremities  of  the  lever; 
and  are  situate — the  one  at  the  face,  the  other  at  the  occiput.  The  ful- 
crum being  nearer  the  occiput  than  to  the  anterior  part  of  the  face,  the 
head  has  a  tendency  to  fall  forwards.  This  can  be  readily  seen  by  sup- 
porting a  skull  on  the  condyles;  yet  Mr.  Abernethy1  affirms,  that  "the 
condyles  are  placed  so  exactly  parallel  in  the  centre  of  gravity,  that 
when  we  sit  upright,  and  go  to  sleep  in  that  posture,  the  weight  of  the 
head  has  a  tendency  to  preponderate  equally  in  every  direction,  as  we 
see  in  those  who  are  dozing  in  a  carriage"!  In  the  living  subject,  the 
preponderance  anteriorly  is  not  so  great  as  it  is  in  the  skeleton,  because 
the  greater  part  of  the  encephalon  is  lodged  in  the  posterior  portion; 
but  the  fact,  that  when  we  go  to  sleep  in  the  upright  position  the  head 
drops  forward  is  sufficient  evidence  that  it  exists;  and  that  in  the  waking 
state  the  head  is  kept  in  equilibrium  on  the  vertebral  column  by  the 
contraction  of  the  extensor  muscles  of  the  head,  which  are  situate  at 
the  back  part  of  the  neck,  and  inserted  into  the  head; — as  the  splenius, 
complexus,  trapezius,  and  posterior  recti.  These  muscles  are  inserted 
perpendicularly  into  the  lever  or  bone  to  be  moved, — an  advantage, 
and  some  compensation  for  the  shortness  of  the  arm  of  the  lever  by 
which  they  act. 

In  quadrupeds,  the  head  not  being  in  equilibrium  on  the  spine  these 
muscles  are  large  and  strong;  the  spinous  and  transverse  processes  of 
the  vertebrae  and  the  occipital  depressions  are  larger;  and,  in  addition, 

1  Physiological  Lectures,  exhibiting  a  general  view  of  Mr.  Hunter's  Physiology,  &c., 
Lect.  3,  2d  edit.,  p.  115,  London,  1822. 


438 


MUSCULAR  MOTION. 


.they  have  a  strong  ligament — posterior  cervical  or  ligamentum  nuclise. 
(N,  Fig.  189,) — which  extends  from  the  spinous  processes  of  the  ver- 
tebrae to  the  occiput,  and  aids  in  supporting  the  head. 


Fig.  189. 


Ligamentum  Nuchae. 

The  vertebral  column  supports  the  head,  and  transmits  the  weight 
to  its  lower  extremity.  The  tendency  of  the  column  is  to  bear  for- 
wards ; — the  upper  limbs,  neck,  thorax  with  its  contents,  the  greater 
part  of  the  contents  of  the  abdomen,  and  the  head  itself,  by  reason  of 
its  tendency  to  fall  forwards,  either  directly  or  indirectly  exert  their 
weight  upon  it.  Hence  the  necessity  for  its  great  firmness  and  solidity, 
which  are  readily  appreciated,  if  we  examine  the  mode  of  junction  of 
the  different  vertebrae,  with  the  strong,  ligamentous  bands  connecting 
them,  the  whole  having  the  form  of  a  pyramid,  whose  base  rests  upon 
the  sacrum,  with  three  curvatures  in  opposite  directions,  which  give  it 
more  resistance  than  if  it  were  straight,  and  enable  it  to  support  very 
heavy  burdens  in  addition  to  the  weight  of  the  organs  pressing  upon 
it.  (Fig.  5,  p.  77.)  The  tendency  of  the  spine  to  fall  forward  is  resisted 
by  the  extensor  muscles,  which  fill  the  vertebral  fossae  or  gutters — sacro- 
lumbalis,  longissimus  dorsi,  multifidus  spinae,  &c. — and  pass  from  the 

sacrum  to  the  lower  vertebrae  of  the  spine, 
and  from  the  lower  to  the  upper.  Each 
vertebra,  in  this  action,  constitutes  a  lever 
of  the  first  kind ;  the  fulcrum  of  which  is  in 
the  intervertebral  cartilage;  the  power  in 
the  ribs,  and  other  parts  that  draw  the  body 
forwards ;  and  the  resistance  in  the  muscles 
attached  to  the  spinous  and  transverse  pro- 
cesses. 

The  vertebral  column,  regarded  as  a 
whole,  may  be  considered  a  lever  of  the 
third  kind ;  the  fulcrum  of  which  is  in  the 

Lateral  View  of  a  Dorsal  Vertebra.  uni<>n  between  the  last  lumbar  vertebra  and 
i.  Body.  G.  spinous  process.  7.  sacrum,  the  power  in  the  parts  drawing  the 
Extremity  of  transverse  process,  s.  spine  forward,   and  the  resistance  in    the 

Superior  articular  processes.    9.  In-  1  r>    ,  i        i        i  T       •  ,  i 

ferior  articular  processes.  mUSCleS  of   the    back.        It    IS    On    the 


Fig.  190. 


ATTITUDES — STANDING.  439 

part  of  the  lever  that  the  power  acts  most  forcibly;  and  it  is  there  that 
the  pyramid  is  thicker,  and  that  the  spinous  and  transverse  processes 
are  larger,  and  more  horizontal.  We  can  accordingly  comprehend  why 
fatigue  should  be  experienced  in  the  loins  and  sacrum,  when  we  have 
been,  for  a  long  time,  in  the  erect  attitude.  It  need  scarcely  be  said, 
that  the  longer  and  more  horizontal  the  spinous  processes,  the  greater 
will  be  the  arm  of  the  lever ;  and  the  less  the  muscular  force  necessary 
to  produce  a  given  effect. 

The  weight  of  the  whole  of  the  upper  part  of  the  body  is  transmitted 
to  the  pelvis;  which,  resting  upon  the  thigh-bones  as  on  pivots,  repre- 
sents a  lever  of  the  first  kind,  the  fulcrum  being  in  the  ilio-femoral 
articulations;  the  power  and  resistance  situate  before  and  behind.  The 
pelvis  supports  the  weight  of  a  part  of  the  abdominal  viscera;  and  the 
sacrum  that  of  the  vertebral  column,  which,  by  reason  of  its  shape, 
transmits  the  weight  equally  to  the  ossa  femorum,  through  the  medium 
of  the  ossa  ilii.  When  the  pelvis  is,  therefore,  in  equilibrium  on  the 
heads  of  the  thigh-bones,  this  is  owing  to 
many  causes.  The  abdominal  viscera,  Fis-  191- 

pressing  upon  the  anterior  part  of  the 
pelvis,  which  is  naturally  inclined  for- 
wards, tend  to  depress  the  os  pubis ;  whilst 
the  vertebral  column  by  its  weight  tends 
to  press  down  the  sacrum.  As  the  weight 
of  the  latter  is  more  considerable  than 
that  of  the  former,  muscles  would  seem 
to  be  required  to  keep  it  in  equilibrium, 

as  Well  as  Others  passing  from  the   femur      Lateral  View  of  a  Lumbar  Vertebra. 

to  be  inserted  into  the  os  pubis,  by  the  i.Body.  5.  spmous process.  6.  Trans- 
contraction  of  which  the  excess  of  weight  ISftit^SSSS^SST 
of  the  vertebral  column  may  be  counter- 
balanced. Such  muscles  do  exist;  but,  as  M.  Magendie1  remarks,  they 
are  not  the  great  agents  in  producing  the  equilibrium  of  the  pelvis  on  the 
thigh-bones ;  for  the  pelvis,  instead  of  having  a  tendency  to  be  depressed 
posteriorly,  would  appear  to  bear  forwards,  inasmuch  as  the  muscles, 
that  resist  the  tendency  which  the  spine  itself  has  to  bear  forwards, 
have  their  fixed  point  on  the  pelvis;  and  consequently  exert  a  consider- 
able effort  to  draw  it  upwards.  The  strong  glutsei  muscles,  which  form 
the  nates,  and  are  inserted  into  the  os  femoris,  are  the  great  agents  of 
the  equipoise;  and  as  the  hip-joint  is  nearer  the  pubis  than  it  is  to  the 
sacrum,  these  muscles  act  with  a  greater  leverage. 

The  thigh-bones  transmit  the  weight  of  the  trunk  to  the  tibia  ;  and 
here  we  see  the  advantage  of  the  neck  of  the  thigh-bone,  which,  as 
represented  in  Fig.  192,  B,  joins  the  shaft  at  a  considerable  angle. 
The  trochanters  I)  and  C  are  for  muscular  attachments;  and  are,  of 
course,  advantageous  to  the  muscles,  which  are  inserted  into  them. 
The  cervix  femoris  directs  the  head  of  the  bone,  A,  obliquely  upwards 
and  inwards,  so  that,  whilst  it  supports  the  vertical  pressure  of  the 
pelvis,  it  resists  the  separation  of  the  ilia,  which  the  pressure  of  the 
sacrum,  with  its  superincumbent  weight,  has  a  tendency  to  produce. 

1  Precis,  &c.,  edit,  cit.,  i.  296. 


440 


MUSCULAR  MOTION. 


D 


Upper  Portion  of  Thigh 
Bone. 


Fig.  192.  But  another  and  important  advantage  is  that  of 

affording  additional  strength  in  adventitious  cir- 
cumstances. When  we  are  standing  perfectly 
erect,  the  necks  of  the  thigh-bones  are  very  oblique, 
compared  with  the  line  of  direction  of  the  body; 
but  if  we  are  thrown  forcibly  to  one  side,  the  line 
of  direction  of  gravitation  corresponds  more  nearly 
with  that  of  the  neck  of  the  thigh-bone,  and  frac- 
ture is  rarely  produced  in  this  manner.  The  most 
common  cause  of  fracture  of  the  neck  of  the  thigh- 
bone is  slipping  from  a  curbstone,  or  any  slight 
elevation,  with  one  foot,  upon  a  firm  substance 
beneath ;  and  the  fracture  in  such  case,  is  general- 
ly transverse.  The  advantage  of  this  arrangement 
of  the  neck  of  the  thigh-bone  has  been  compared 
not  inaptly  to  that  resulting  from  the  dishing  of  a 
wheel ;  or  the  oblique  position  of  the  spokes  from 
the  nave  outward  to  the  felly,  which  strengthens 
the  wheel  against  the  strains  produced  by  its  sink- 
ing with  force  into  a  rut  or  other  hollow.1  The 
femur  transmits  the  weight  of  the  body  to  the 
large  bone  of  the  leg — the  tibia ;  but,  from  the  mode  in  which  the  pel- 
vis presses  upon  it,  its  lower  extremity  has  a  tendency  to  bear  forwards. 
This  is  prevented  by  the  action  of  the  extensors  of  the  leg — rectus  and 
triceps  cruris — whose  power  is  augmented  by  the  presence  of  the  patella 
— a  sesamoid  bone,  seated  behind  their  tendon.  The  muscles  of  the 
posterior  part  of  the  leg,  which  are  attached  to  the  condyles  of  the 
thigh-bone,  aid  also  in  preserving  the  equilibrium. 

The  tibia  is-  the  sole  agent  for  the  transmission  of  the  superincumbent 
weight  to  the  foot.  Its  upper  extremity  has,  however,  a  tendency  to 
bear  forwards  like  the  lower  part  of  the  os  femoris.  This  is  prevented 
by  the  contraction  of  the  gastrocnemii,  tibialis  posticus,  and  other  mus- 
cles on  the  posterior  part  of  the  leg. 

The  foot  sustains  the  whole  weight  of  the  body ;  and  its  shape  and 
structure  are  well  adapted  for  the  purpose.  The  sole  has  some  extent, 
which  contributes  to  the  firmness  of  the  erect  attitude.  The  skin  and 
epidermis  are  thick ;  and  beneath  the  skin  is  a  thick,  adipous  stratum,  in 
greater  quantity  at  the  parts  of  the  foot  which  come  in  contact  with 
the  soil.  This  fat  forms  a  kind  of  elastic  cushion,  adapted  for  deaden- 
ing or  diminishing  the  effect  of  pressure.  The  whole  of  the  sole  of  the 
foot  does  not  come  in  contact  with  the  ground.  The  weight  is  trans- 
mitted by  the  heel,  the  outer  margin,  the  part  corresponding  to  the 
anterior  extremity  of  the  metatarsal  bones,  and  the  extremities  or  pulps 
of  the  toes.  The  tibia  transmits  the  weight  to  the  astragalus  ;  and 
from  this  bone  it  is  distributed  to  the  others  that  compose  the  foot ; 
but  the  heel  conveys  the  largest  share.  When  the  foot  rests  upon  a 
flat  surface,  it  is  entirely  passive  ;  but  when  upon  a  slippery  soil,  the 
flexors  of  the  toes,  especially  of  the  great  toe,  are  firmly  contracted,  so 


1  See  Fig.  170;  al 
Lond.,  1829. 


Sir  C.  Bell,  Animal  Mechanics,  p.  21,  Library  of  Useful  Knowledge, 


ATTITUDES — ON  THE  KNEES,  ETC.  441 

as  to  fix  the  shoe,  as  far  as  possible,  and  render  the  attitude  more  sta- 
ble. The  use  of  shoes  interferes  largely  with  the  exercise  of  the  toes, 
which,  in  the  savage,  are  capable  of  diversified  and  considerable  action. 

The  use  of  the  fibula  is,  to  serve  the  purpose  of  a  clasp,  as  its  name 
imports.  The  tibia  exerts  its  pressure  chiefly  towards  the  inner  part 
of  the  foot,  and,  consequently,  were  it  not  for  the  fibula,  which  passes 
down  below  the  articulation,  dislocation  outwards  would  be  constantly 
menacing  us.  The  fibula  has  no  participation  in  the  transmission  of 
the  weight  to  the  ground. 

The  conditions  for  equilibrium,  as  applicable  to  man,  have  been 
already  indicated.  If  the  base  of  susteritation  be  rendered  extensive  in 
any  one  direction,  as  by  widely  separating  the  feet,  the  attitude  is  more 
firm  in  one  direction,  but  less  so  in  the  other.  It  is  as  firm  as  possible 
in  every  direction,  when  the  feet  are  turned  forwards  parallel  to  each 
other,  and  are  separated  by  a  space  equal  to  the  length  of  one.  What- 
ever diminishes  the  base  of  sustentation,  diminishes,  in  like  proportion, 
the  stability  of  the  erect  attitude.  Hence  the  difficulty  of  walking  on 
stilts  or  wooden  legs,  on  the  toes,  tight  rope,  &c.  It  seems  that  the 
inhabitants  of  Les  Landes,1  in  the  south-west  of  France,  are  enabled 
by  habit  to  use  stilts  with  singular  facility.  The  sandy  plains,  that  bear 
this  name,  afford  tolerable  pasturage  for  sheep;  but,  during  one  part  of 
the  year,  they  are  half  covered  with  water ;  and  during  the  remainder, 
they  are  very  unfit  walking  ground,  on  account  of  the  deep,  loose  sand, 
and  thick  furze.  The  natives,  in  consequence,  habituate  themselves  to 
the  use  of  stilts  or  wooden  poles,  the  former  of  which  are  put  on  and  off 
as  regularly  as  parts  of  their  dress.  With  these  they  walk  readily  over 
the  loose  sand  or  through  the  water,  with  steps  eight  or  ten  feet  long. 
The  difficulty,  in  this  kind  of  progression,  does  not  arise  solely  from  the 
smallness  of  the  base  of  sustentation,  but  from  the  greater  height  to 
which  the  centre  of  gravity  is  thrown,  which  renders  the  equilibrium 
unstable. 

Standing  on  one  foot  is  necessarily  more  fatiguing,  as  it  requires  the 
strong  and  sustained  contraction  of  the  muscles  that  surround  the  hip- 
joint,  to  keep  the  pelvis  in  equilibrium  on  the  os  femoris;  especially  as 
the  body  has  a  strong  tendency  to  fall  to  the  side  that  is  unsupported. 
The  muscles,  that  prevent  the  trunk  from  falling  in  this  direction,  are 
the  glutsei,  gemelli,  tensor  vaginae  femoris,  pyramidalis,  obturators,  and 
quadratus  femoris.  The  use  of  the  neck  of  the  thigh-bone  and  the 
great  trochanter  is  here  manifest.  The  base  of  sustentation,  in  this 
case,  is  the  space  occupied  by  the  foot  which  is  in  contact  with  the  soil; 
and  it  need  hardly  be  said,  that  if  this  be  still  farther  diminished,  by 
attempting  to  stand  on  the  toes,  the  attitude  cannot  be  sustained. 

In  the  attitude  on  the  knees,  the  centre  of  gravity  is  brought  lower,  - 
but  the  base  of  sustentation  is  smaller  than  on  the  feet.  The  patella 
has  to  bear  the  chief  pressure;  and  as  it  is  not  provided  with  a  fatty 
cushion  such  as  exists  at  the  sole  of  the  foot,  the  position  becomes  pain- 
ful, and  the  surface  soon  abraded.  These  remarks  apply  to  the  case, 
in  which  the  knees  only  come  in  contact  with  the  soil.  When  the  feet 

1  Arnott,  Elements  of  Physics,  3d  Amer.  edit.,  i.  15,  Philad.,  1835. 


442  MUSCULAR  MOTION. 

are  allowed  to  touch  also,  by  the  points  of  the  toes,  the  attitude  is  much 
more  easy  and  firm,  as  the  base  of  sustentation  is  largely  augmented, 
and  comprises  the  space  between  the  knees  and  toes  plus  the  space 
occupied  by  those  parts. 

The  sitting  posture  admits  of  variety,  and  its  physiology  is  easily 
intelligible.  In  every  form  in  which  the  back  is  unsupported,  the 
weight  of  the  body  is  conveyed  to  the  soil  by  the  pelvis;  and  the  broader 
this  base  the  firmer  the  attitude.  When  we  sit  upon  a  stool  without  any 
back,  and  with  the  legs  raised  from  the  ground,  the  whole  of  the  weight 
is  conveyed  by  the  parts  in  contact  with  the  seat;  but  if  the  feet  touch 
the  ground,  the  weight  of  the  lower  extremities  is  transmitted  to  the 
soil  by  the  feet,  whilst  the  pelvis  transmits  that  of  the  upper  part  of 
the  body.  In  both  cases,  if  the  attitude  be  long  maintained,  fatigue  is 
felt  in  the  back,  owing  to  the  continued  action  of  the  extensor  muscles 
in  keeping  the  body  erect.  Sitting  in  an  ordinary  chair  differs  some- 
what, in  a  part  of  the  body  being  supported.  Fatigue  is  felt  in  the 
neck,  which  is  unsupported,  and  requires  the  sustained  contraction  of 
the  extensor  muscles  of  the  head.  To  support  all  the  parts,  as  far  as 
possible,  long-backed  chairs  have  been  introduced,  which  sustain  the 
whole  body  and  head;  and,  when  they  are  provided  with  rockers,  a 
position  approaching  to  the  easiest  of  all  attitudes  can  be  assumed.  To 
produce  a  similar  effect  in  a  common  chair,  the  body  is  often  thrown 
back  until  the  chair  rests  on  its  hinder  legs  only.  When  the  feet  of 
the  individual  are  on  the  ground,  this  position  is  stable ;  the  base  of 
sustentation  being  large,  and  comprised  between  the  legs  of  the  chair 
and  the  feet  of  the  individual,  added  to  the  space  occupied  by  the  parts 
themselves,  that  are  in  contact  with  the  soil ;  but  as  soon  as  he  raises 
his  feet,  the  equilibrium  is  destroyed  from  the  impracticability  of  mak- 
ing the  vertical  line  fall  within  the  base  of  sustentation,  which  is  now 
reduced  to  the  space  occupied  by  the  legs  of  the  chair  plus  the  space 
between  them.  In  all  the  varieties  of  the  sitting  posture,  equilibrium 
is  facilitated  by  the  centre  of  gravity  being  brought  nearer  to  the 
ground. 

Lastly.  The  horizontal  posture  is  the  only  one  that  requires  no  mus- 
cular effort.  Hence  it  is  the  attitude  of  repose,  and  of  the  sick  and 
the  feeble.  The  base  of  sustentation  is  here  extremely  large ;  and  the 
centre  of  gravity  very  low.  Accordingly,  the  attitude  can  be  maintained 
for  a  long  time;  the  only  inconvenience  being  that  which  results  to  the 
skin  from  prolonged  pressure  on  those  parts  that  chiefly  convey  the 
weight  to  the  bed, — as  the  back  of  the  pelvis,  the  region  of  the  great 
trochanter,  &c. — an  inconvenience,  which  attracts  the  attention  of  the 
physician,  more  or  less,  in  all  protracted  and  consuming  maladies. 
The  reason,  why  we  prefer  soft,  elastic  beds,  is  not  simply  to  prevent 
abrasion  of  those  parts  of  the  body  that  are  most  exposed  to  pressure, 
but  to  enable  a  greater  portion  of  the  body  to  transmit  the  weight;  and 
thus  occasion  a  more  equable  partition  of  the  pressure. 

There  are  numerous  other  attitudes,  which  maybe  assumed;  as,  upon 
one  knee,  on  the  head,  astride,  &c. ;  but  they  do  not  need  explanation, — 
their  physiology  being  obvious  after  what  has  been  said. 


MOVEMENTS.  443 


MOVEMENTS. 

The  movements,  of  which  the  body  is  susceptible,  are  of  two  kinds, — • 
partial  and  locomotive;  the  former  simply  changing  the  relative  situa- 
tion of  parts  of  the  body;  the  latter  the  relation  of  the  whole  body 
to  the  soil.  Many  of  the  partial  movements  constitute  an  inherent  part 
of  the  different  functions,  and  are  considered  under  them. 

In  the  erect  attitude,  whilst  the  body  holds  the  same  correspondence 
with  the  soil,  the  position  of  the  upper  parts  of  the  body  may  be  greatly 
varied,  provided  the  vertical  line  falls  within  the  base  of  sustentation. 
Accordingly,  to  produce  this  effect,  if  the  upper  part  of  the  body  be 
inclined  in  one  direction,  the  lower  will  have  to  be  thrown  more  to  the 
opposite. 

The  head  may  be  turned  forwards,  backwards,  or  to  one  side ;  and 
it  is  capable  of  a  rotatory  motion  to  the  right  and  left.  The  three  first 
movements,  when  slight,  occur  in  the  articulation  of  the  occipital  bone 
and  atlas  ;  but  if  to  a  greater  extent,  the  whole  of  the  cervical  vertebrae 
participate.  The  rotatory  motion  is  effected  essentially  in  the  articu- 
lation between  the  first  and  second  vertebrae ;  the  latter  of  which  has 
an  arrangement  admirably  adapting  it  for  this  purpose.  A  toothlike 
or  odontoid  process  arises  from  its  anterior  part,  on  which  the  poste- 
rior surface  of  the  anterior  part  of  the  atlas  or  first  vertebra  turns  as 
on  a  pivot.  This  arrangement  has  obtained  the  second  vertebra  the 
name  vertebra  dentata,  and  its  function,  that  of  axis.  Rotation  to 
the  right  is  effected  by  the  contraction  of  the  left  sterno-mastoid  and 
splenius,  and  of  the  right  complexus, — to  the  left  by  the  action  of  the 
opposite  muscles  of  the  same  name.  The  motions  of  the  head  aid  the 
senses  of  sight,  hearing,  and  smell;  and  are  useful  in  the  production 
of  the  different  vocal  tones,  by  occasioning  elongation  or  decurtation 
of  the  trachea  and  vocal  tube.  They  are,  likewise,  inservient  to  ex- 
pression. 

The  spine,  as  a  whole,  and  each  of  the  vertebrae  composing  it,  are 
capable  of  flexion,  extension,  lateral  inclination,  and  circumduction. 
These  motions  occur  in  the  fibro-cartilages  between  the  vertebrae;  and 
they  are  more  easy  and  extensive,  in  proportion  to  the  thickness  and 
width  of  the  cartilages.  This  is  one  cause  why  the  motions  of  the 
cervical  and  lumbar  portions  of  the  vertebral  column  are  freer  than 
those  of  the  dorsal.  The  inter  vertebral  substances  or  fibro-cartilages 
possess  a  remarkable  degree  of  elasticity.  They  yield  somewhat, 
however,  to  prolonged  pressure ;  and  hence,  after  long  continuance  in 
the  erect  attitude,  our  stature  may  be  sensibly  curtailed.  We  can  thus 
understand,  that  at  night  we  may  be  shorter  than  in  the  morning. 
Buffon  asserts,  that  the  son  of  one  of  his  most  zealous  collaborateurs, 
M.  Gueneau  de  Montbeillard, — a  young  man  of  tall  stature, — lost  an 
inch  and  a  half  after  having  danced  all  night.  The  loss  must  be  partly 
ascribed  to  the  condensation  of  the  adipous  tissue  beneath  the  foot. 
During  the  flexion  of  the  spine,  these  cartilages  are  depressed  on  the 
side  of  the  flexure,  but  they  rise  on  the  other;  and,  by  their  elasticity, 
are  important  agents  in  the  restoration  of  the  body  to  the  erect  posi- 
tion. Where  they  are  thickest  the  greatest  extent  of  motion  is  per- 


444  MUSCULAR  MOTION. 

mitted,  and  this  is  a  cause  why  the  spine  admits  of  the  greatest  mo- 
tion anteriorly.  In  rotation,  the  whole  is  pressed  upon  and  undergoes 
elongation  in  the  direction  of  its  constituent  laminae.  In  old  age,  the 
cartilages  become  shrivelled;  and  this,  with  the  loss  of  muscular  power, 
is  one  of  the  causes  why  old  people  bend  forwards. 

When  we  assume  different  positions  with  the  trunk,  the  centre  of 
motion  of  the  vertebrae  becomes  modified.  If  we  bend  forwards,  it  is 
thrown  on  the  anterior  part  of  the  body  of  the  vertebrae;  if  to  one  side, 
on  the  articulating  processes,  &c.  Each  vertebra,  we  have  seen,  is  a 
lever  of  the  first  kind;  and  as  the  centre  of  motion  becomes  altered 
the  leverage  must  be  so  likewise.  It  is  when  the  body  has  been  bent 
forwards,  and  the  object  is  to  restore  it  to  the  erect  position,  that  the 
power  acts  with  the  greatest  advantage, — the  fulcrum  being  thrown  to 
the  anterior  part  of  the  body  of  the  vertebra,  and  the  arm  of  the  power 
being  the  distance  between  this  point  and  the  extremity  of  the*  spinous 
process  into  which  the  power  is  inserted. 

Each  vertebra  has  but  a  slight  degree  of  motion ;  but  the  sum  of  all 
their  motions  is  considerable,  and  is  estimated  by  .multiplying  the 
single  motion  by  the  number  of  vertebrae.  The  result,  however,  can 
only  be  regarded  as  approximate,  as  the  extent  of  motion,  of  which  the 
different  vertebrae  are  capable,  necessarily  varies.  The  arrangement 
of  the  spinous  processes  of  the  vertebrae — especially  of  the  dorsal — 
prevents  any  considerable  flexion  of  the  body  backwards:  and  when 
we  find  the  tumbler  bending  his  body  back  until  his  head  touches  his 
heels,  it  is  owing  to  the  arrangement  of  the  spine  having  been  modified 
in  early  life  by  constant  efforts  of  the  kind,  until  there  are  no  longer 
obstacles  to  the  movement. 

The  motions  of  the  vertebrae  are  frequently  united  to  those  of  the 
pelvis  on  the  thigh-bones,  so  that  they  seem  to  be  more  extensive  than 
they  really  are.  This  is  the  case  when  we  make  a  low  bow. 

The  motions  of  the  spine  are  inservient  to  those  of  the  head,  and  of 
the  superior  and  inferior  extremities. 

The  upper  limbs  are  capable  of  various  motions;  some  of  which  have 
been  already  described ;  others  will  be  hereafter.  They  are  useful  in 
the  different  attitudes ;  and,  at  times,  by  transmitting  to  the  soil  a  part 
of  the  weight  of  the  body,  and  thus  enlarging  the  base  of  sustentation, 
— as  when  we  employ  a  stick,  rest  on  the  hands  and  knees,  or  support 
the  head  on  one  or  both  elbows.  They  are  of  great  use,  likewise, 
in  preserving  equilibrium  when  we  walk  on  a  very  narrow  base ;  serv- 
ing in  part  the  purpose  of  the  pole  employed  by  the  dancer  on  the 
tight-rope. 

The  lower  extremities  are,  of  course,  locomotive  organs;  but  they 
are  susceptible  of  partial  movements  likewise;  as  when  we  kick  with 
one  foot,  try  the  consistence  of  the  ground,  cross  the  legs,  tread  the 
foot-board  of  a  lathe,  &c. 

Thus  much  for  the  attitudes.  We  shall  now  consider  the  mode  in 
which  the  relation  of  the  body  to  the  soil  is  altered,  comprising  the 
physiology  of  walking,  leaping,  running,  swimming,  flying,  &c.,  which 
constitute  the  different  varieties  of  locomotion  or  progression. 


WALKING.  445 

LOCOMOTIVE  MOVEMENTS.1 

a.    Walking. 

Walking  is  motion  on  a  fixed  surface,  the  centre  of  gravity  being 
alternately  moved  by  one  of  the  extremities  and  sustained  by  the  other, 
without  the  latter  being,  at  any  time,  completely  off  the  ground.  It 
consists  of  a  succession  of  steps,  which  are  effected — in  the  erect  atti- 
tude and  on  a  horizontal  surface — by  bending  one  of  the  thighs  upon 
the  pelvis  and  the  leg  upon  the  thigh,  so  as  to  detach  the  foot  from  the 
ground  by  the  general  decurtation  of  the  limb.  The  flexion  of  the 
limb  is  succeeded  by  its  being  carried  forward ;  the  heel  is  then  brought 
to  the  ground,  and,  successively,  the  whole  of  the  inferior  surface  of 
the  foot.  If  the  bones  of  the  leg  were  perpendicular  to  the  part  which 
first  touches  the  ground,  we  should 
experience  a  jolt ;  but,  instead  of  that,  Fig- 193- 

the  foot  descends  in  an  arc  of  a  circle, 
the  centre  of  which  is  the  point  of  the 
heel. 

In  order  that  the  limb  shall  be  thus 
carried  forward,  the  pelvis  must  have 
described  a  movement  of  rotation  on 
the  head  of  the  thigh-bone  of  the 
limb  that  has  not  been  moved,  and 
must  have  carried  forward  the  cor-  Movement  of  the  Foot  in  Walking, 
responding  side  of  the  body.  As  yet, 

only  one  limb  has  advanced.  The  base  of  sustentation  has  been  modi- 
fied, but  there  has  been  no  progression.  The  limb,  remaining  behind, 
has  now  to  be  raised  and  brought  forward,  so  as  to  pass  the  other,  or  to 
be  on  the  same  line  with  it,  as  the  case  may  be;  and  this  finishes  the 
step.  In  order  to  bring  up  the  limb  that  is  behind,  the  foot  must  be 
successively  detached  from  the  soil,  from  the  heel  to  the  toe.  In  this 
way,  an  elongation  of  the  limb  is  produced,  which  assists  in  advancing 
the  corresponding  side  of  the  trunk,  and  excites  the  rotation  of  the 
pelvis  on  the  head  of  the  thigh-bone  first  carried  forward.  A  succes- 
sion of  these  movements  constitutes  walking;  the  essence  of  which  con- 
sists in  the  heads  of  the  thigh-bones  forming  fixed  points,  on  which  the 
pelvis  turns  alternately,  as  upon  a  pivot,  describing  arcs  of  circles, 
which  are  more  extensive  in  proportion  to  the  size  of  the  steps. 

Walking  in  a  straight  line  requires  that  the  arcs  of  circles  described 
by  the  pelvis,  and  the  extension  of  the  limbs  when  carried  forward, 
shall  be  equal;  otherwise,  the  body  will  be  directed  towards  the  side 
opposite  to  that  of  the  limb  whose  movements  are  more  extensive. 
Without  the  aid  of  vision,  it  would  be  impracticable  for  us  to  make  the 
arcs  equal,  or  to  walk  straight  forward. 

Walking  backwards  differs  somewhat  from  this.     The  step  is  com- 

1  On  the  whole  subject  of  Animal  Motion,  Animal  Dynamics,  Locomotion,  or  Progressive 
Motion  of  Animals,  see  an  elaborate  article  by  J.  Bishop,  in  Cyclopaedia  of  Anatomy  and 
Physiology,  Part  xxiii.  p.  407,  London,  April,  1842,  and  Prof.  E.  Weber,  Art.  Muskelbewe- 
gung,  in  Wagner's  Handworterbuch  der  Physiologic,  I5te  Lieferung,  s.  1,  Braunschweig, 
1846. 


446  MUSCULAR  MOTION. 

menced  by  bending  the  thigh  upon  the  pelvis,  and,  at  the  same  time, 
the  leg  upon  the  thigh.  The  extension  of  the  thigh  on  the  pelvis  suc- 
ceeds, and  the  whole  limb  is  carried  backward;  the  leg  is  afterwards 
extended  upon  the  thigh,  the  point  of  the  foot  is  brought  to  the  ground, 
and  the  remainder  of  its  under  surface  in  succession.  The  other  foot 
is  then  raised  on  its  point,  by  which  the  corresponding  limb  is  elon- 
gated; the  pelvis,  being  pushed  backwards,  makes  a  rotation  on  the 
limb  which  is  behind,  and  is,  by  the  action  of  appropriate  muscles,  car- 
ried on  a  level  with,  or  behind,  the  other,  to  afford  a  new  pivot  in  its 
turn.  Walking  laterally  is  different  from  the  two  last  in  no  arcs  being 
described.  In  this  case,  one  of  the  thighs  is  first  slightly  bent  upon 
the  pelvis,  in  order  to  detach  the  foot  from  the  ground;  the  whole  limb 
is  then  moved  away  by  the  action  of  the  abductors,  and  is  brought 
down  to  the  ground.  The  other  limb  follows. 

If  we  walk  up  hill,  the  fatigue  is  much  augmented;  because  the 
flexion  of  the  limb,  first  carried  forward,  has  to  be  more  considerable; 
and  the  limb,  that  remains  behind,  has  not  only  to  cause  the  pelvis  to 
execute  the  movement  of  rotation,  but  it  has  to  raise  the  whole  weight 
of  the  body,  in  order  to  transport  it  upon  the  limb  which  is  in  advance. 
To  aid  in  throwing  the  weight  forward,  the  body  is  bent  forward,  so 
that  the  centre  of  gravity  may  be  as  favourably  disposed  as  possible ; 
and  the  extensor  muscles  of  the  leg  carried  forward  are  powerfully  con- 
tracted to  raise  the  trunk;  hence,  the  feeling  of  fatigue,  which  we  expe- 
rience in  the  knee  and  anterior  part  of  the  thigh,  on  ascending  a  long 
flight  of  stairs.  Fatigue  is  likewise  felt  in  the  calf  of  the  leg,  on  ac- 
count of  the  strong  efforts  developed  in  extending  the  foot,  and  pro- 
jecting the  body  forward.  Walking  down  hill  is  more  fatiguing  than 
on  level  ground.  In  this  case,  there  is  a  tendency  in  the  body  to  fall 
forward;  great  effort  is,  consequently,  required  to  keep  the  vertical 
line  within  the  base  of  sustentation ;  and,  accordingly,  the  muscles, 
employed  in  the  extension  of  the  head  and  vertebral  column,  experience 
fatigue. 

In  all  these  kinds  of  progression,  the  character  of  the  soil  is  a  mat- 
ter of  importance.  It  must  be  firm  enough  to  afford  support  to  the 
limb  that  presses  upon  it,  otherwise  fatigue  is  experienced,  and  pro- 
gression slow  and  laborious.  This  occurs,  whenever  the  soil  is  too  soft 
or  too  smooth;  the  former  yielding  to  the  foot,  and  the  latter  present- 
ing no  inequalities  to  which  the  foot  can  attach  itself.  The  soil,  too, 
has  some  influence,  in  particular  cases,  by  virtue  of  its  elasticity.  Such, 
at  least,  is  the  opinion  of  Borelli;1  but  Barthez2  thinks,  that  the  influ- 
ence of  the  soil  is  limited  to  the  degree  in  which  it  furnishes  a  firm 
support.  If  the  soil,  again,  be  movable,  as  the  deck  of  a  vessel,  the 
line  of  gravity  is  apt  to  fall  outside  the  base  of  sustentation;  and  to 
avoid  this,  the  base  is  enlarged  by  separating  the  legs  so  as  to  give  a 
characteristic  air  to  the  gait  of  the  mariner ; — and,  lastly,  if  the  base 
be  very  narrow,  as  on  the  tight-rope,  the  steps  are  obliged  to  be  rapid, 
and  the  arms  are  aided  in  modifying  the  centre  of  gravity  as  may  be 
required,  by  the  use  of  a  long  and  heavy  pole. 

1  De  Motu  Animalium,  &c.,  Lugd.  Bat,  1710. 

a  Nouveaux  Elemens  de  la  Science  de  1'Homme,  Paris,  1806. 


LEAPING.  447 

b.  Leaping. 

In  the  action  of  leaping,  the  whole  body  is  raised  from  the  ground ; 
and,  for  a  short  period,  suspended  in  the  air.  It  consists,  essentially, 
in  the  sudden  extension  of  the  limbs,  after  they  have  undergone  an 
unusual  degree  of  flexion.  Leaping  may  be  effected  directly  upwards, 
forwards,  backwards,  or  laterally. 

In  the  ordinary  case  of  the  vertical  leap,  the  head  is  slightly  bent  on 
the  neck;  the  vertebral  column  curved  forwards;  the  pelvis  bent  upon 
the  thigh;  the  thigh  upon  the  leg;  and  the  leg  upon  the  foot;  the  heel 
generally  pressing  lightly  on  the  soil,  or  not  touching  it  at  all.  This 
state  of  general  flexion  is  suddenly  succeeded  by  a  quick  extension  of 
all  the  bent  joints;  so  that  the  different  parts  of  the  body  are  rapidly 
elevated,  with  a  force  surpassing  their  own  gravity,  and  to  an  extent 
dependent  upon  the  force  developed.  In  this  general  muscular  move- 
ment, the  muscles  that  form  the  calf  of  the  leg,  and  are  inserted  into 
the  heel,  have  to  develope  the  greatest  force,  inasmuch  as  they  have  to 
raise  the  whole  body,  and  to  give  it  the  impulse,  which  surmounts  its 
gravity.  They  are,  however,  favourably  circumstanced  for  the  pur- 
pose;— being  remarkably  strong;  inserted  perpendicularly  into  the  heel; 
and  having  the  advantage  of  a  long  arm  of  a  lever.  Figure  188  will 
show,  that  whenever  the  body  is  bent  in  the  position  it  assumes  prelimi- 
nary to  a  leap,  opposite  impulses  must  be  communicated  by  the  restora- 
tion of  the  different  parts  to  the  vertical  line  B  F.  The  leg  B  will  tend 
to  impel  the  body  backwards,  by  following  the  curved  line  C  G.  CD,  on 
the  other  hand,  by -describing  the  curve  D  I,  will  tend  to  impel  it  forward; 
whilst  the  head  and  trunk,  represented  by  the  line  D  E,  will  describe 
the  curve  E  F,  and  give  an  impulse  backward.  Every  vertical  leap 
must,  therefore,  be  a  mean  between  these  different  impulses,  or  rather 
the  backward  and  forward  impulses  must  destroy  or  neutralize  each 
other ;  and  that  which  is  concerned  in  the  elevation  of  the  trunk  be 
alone  effective. 

In  the  forward  leap,  the  movement  of  rotation  of  the  thigh  predomi- 
nates over  the  impulses  backward,  and  the  body  is  projected  forward. 
On  the  other  hand,  the  impulses  of  the  vertebral  column,  and  of  the 
leg  on  the  foot,  prevail  in  the  backward  leap.  The  length  of  the  lower 
limbs  is  favourable  to  the  extent  of  the  leap.  The  forward  leap,  in 
particular,  is  greatly  dependent  upon  the  length  of  the  femur,  in  which 
the  forward  impulse  is  situate.  It  does  not  appear,  that  any  kind  of 
impulse  is  communicated  to  the  body,  at  the  moment  of  leaping,  by 
the  surface  on  which  we  rest,  unless  it  be  very  elastic.  In  this  last 
case,  however,  its  reaction  is  added  to  the  effort  of  the  muscles,  that 
occasion  the  elevation  of  the  body ;  hence,  the  wonderful  leaps  of  the 
performers  in  circuses  and  on  the  tight-rope.  On  the  other  hand,  if 
the  soil  does  not  afford  the  necessary  resistance,  and  yields  to  the  feet, 
leaping  is  almost  or  wholly  impracticable. 

The  upper  extremities  are  not  without  their  use  in  leaping.  They 
are  brought  close  to  the  body,  whilst  the  joints  are  bent,  and  are  sepa- 
rated from  it  at  the  moment  when  the  body  leaves  the  ground.  By 
being  held  firmly  in  this  manner,  they  allow  the  muscles,  that  pass  from 


448  MUSCULAR  MOTION. 

the  os  humeri  to  the  trunk,  to  exert  a  degree  of  traction  upwards,  and 
thus  to  assist  the  extensors  of  the  feet  in  the  projection  of  the  body. 
It  is  with  this  view,  that  the  ancients  employed  their  0,7.*^*$,  or  poisers 
in  leaping;  and  that  the  moderns  use  bricks,  stones,  or  other  solid  heavy 
bodies  with  a  like  intent.  It  is  likewise  manifest,  that  by  steadying 
the  arms,  and  then  moving  them  rapidly  backwards,  a  backward  im- 
pulse may  be  given  to  the  upper  part  of  the  trunk. 

The  effect  of  a  run  before  we  leap  is  to  add  to  the  force  developed 
by  muscular  contraction  that  of  the  impulse  acquired  by  the  body  whilst 
running.  The  leap  is,  under  such  circumstances,  necessarily  more 
extensive. 

Some  of  the  smaller  animals  surprise  us  by  the  extent  of  their  leaps. 
The  jumping  maggot,  found  in  cheese,  erects  itself  upon  its  anus,  forms 
its  body  into  a  circle,  by  bringing  its  head  and  tail  into  contact,  and, 
having  contracted  every  part  as  much  as  possible,  unbends  with  a  sud- 
den jerk,  and  darts  forward  to  an  astonishing  distance.  Small  animals 
leap  much  farther  than  the  larger  in  proportion  to  their  size;  and,  as 
Mr.  Sharon  Turner  has  remarked,1  "exhibit  muscular  powers  still  more 
superior  to  those  of  the  greatest  animals  than  their  comparative  minds." 
He  has  given  amusing  representations  of  this  difference:  for  example, 
Linnaeus  observes,  that  if  an  elephant  were  as  strong  in  proportion  as 
a  stag  beetle,  he  would  be  able  to  tear  up  rocks  and  level  mountains. 
A  cock-chafer  is,  for  its  size,  six  times  as  strong  as  a  horse.2  The  flea 
and  locust  leap  two  hundred  times  their  own  length,  as  if  a  man  should 
leap  three  times  as  high  as  St.  Paul's.3  The  cuckoo-spit  froghopper 
sometimes  leaps  two  or  three  yards,  which  is  more  -than  two  hundred 
and  fifty  times  its  own  length,  as  if  a  man  should  vault  at  once  a  quarter 
of  a  mile.4  Mouffet5  relates,  that  an  English  mechanic  made  a  golden 
chain  as  long  as  a  finger,  with  a  lock  and  key,  which  was  dragged  by 
a  flea;  and  Latreille6  mentions  a  flea  of  moderate  size  dragging  a  silver 
cannon  on  wheels,  that  was  twenty-four  times  its  own  weight.  This 
cannon  was  charged  with  powder  and  fired,  without  the  flea  seeming  to 
be  alarmed. 

c.  Running. 

This  variety  of  progression  consists  of  a  series  of  low  leaps  per- 
formed by  each  leg  in  alternation.  It  differs  from  walking,  in  the  body 
being  projected  forward  at  each  step,  and  in  the  hind-foot  being  raised 
before  the  fore-foot  touches  the  ground.  It  is  more  rapid  than  the 
quickest  walk,  because  the  acquired  velocity  is  preserved  and  increased, 
at  each  bound,  by  a  new  velocity.  Running,  therefore,  cannot  be  in- 
stantaneously suspended,  although  a  stop  may  be  put  to  walking  at  any 
moment. 

In  running,  the  body  is  inclined  forward,  in  order  that  the  centre 
of  gravity  may  be  in  a  proper  position  for  receiving  an  impulse  in  that 

'  Sacred  History  of  the  World,  Amer.  edit.,  p.  372,  New  York,  1832. 

4  Kirby  and  Spence,  Introduction  to  Entomology,  Amer.  edit.,  p.  486,  Philad.,  1846. 

3  Nat.  History  of  Insects,  i.  17.  4  Insect  Transformations,  v.  6,  p.  179 

s  Theatr.  Insect,  275. 

6  Nouv.  Diet.  d'Histoire  Natur.,  xxviii.  249,  and  Kirby,  op.  cit. 


SWIMMING.  449 

direction  from  the  hind-leg ;  and  the  fore-leg  is  rapidly  advanced  to 
keep  the  vertical  line  within  the  base  of  sustentation,  and  thus  prevent 
the  body  from  falling.  There  is,  consequently,  in  running,  a  moment 
in  which  the  body  is  suspended  in  the  air. 

d.  Swimming. 

Although  M.  Magendie1  affirms  that  the  human  body  is,  in  general, 
specifically  heavier  than  water;  and  that  consequently,  if  left  to  itself 
in  a  considerable  quantity  of  that  fluid,  it  would  sink  to  its  lowest  por- 
tion, the  question  respecting  its  specific  gravity  has  not  been  rigorously 
determined;  and  many  eminent  practical  philosophers  have  even  held 
an  opinion  the  reverse  of  that  of  Magendie.  Borelli2  accords  with 
him;  and  a  writer  of  a  later  period,  Mr.  Robertson,3  who  details  a  set 
of  experiments  on  this  subject,  seems  to  have  originally  coincided  with 
him  also.  He  weighed,  however,  ten  different  individuals  in  water, 
comparing  the  weight  with  that  of  the  fluid  displaced  by  their  bodies; 
and  he  affirms,  that,  with  the  exception  of  two,  every  man  was  lighter 
than  his  equal  bulk  of  water,  and  much  more  so  than  his  equal  bulk  of 
sea  water; — "consequently,"  he  says,  "could  persons,  who  fall  into 
water,  have  presence  of  mind  enough  to  avoid  the  fright  usual  on  such 
accidents,  many  might  be  preserved  from  drowning."  In  corrobora- 
tion  of  this  inference,  Mr.  Robertson  relates  a  circumstance  connected 
with  his  own  personal  knowledge.  A  young  gentleman,  thirteen  years 
of  age,  little  acquainted  with  swimming,  fell  overboard  from  a  vessel 
in  a  stormy  sea;  but  having  had  presence  of  mind  enough  to  turn  im- 
mediately upon  his  back,  he  remained  a  full  half  hour,  quietly  floating 
on  the  surface  of  the  water,  until  a  boat  was  lowered  from  the  vessel. 
He  had  used  the  precaution  to  retain  his  breath  whenever  a  wave  broke 
over  him,  until  he  again  emerged. 

A  case  is  given  in  the  Rev.  Mr.  Maude's  Visit  to  Niagara,  in  1803, 
which  is  corroborative  of  Mr.  Robertson's  view  of  this  matter.  The 
author  was  on  board  a  sloop  on  Lake  Champlain,  when  a  boy,  named 
Catlin,  who  was  on  deck  cutting  bread  and  cheese  with  a  knife,  was 
knocked  overboard  by  the  captain  jibbing  the  boom.  He  missed  catch- 
ing hold  of  the  canoe,  which  was  dragging  astern,  and  an  attempt  of 
Mr.  Maude's  servant  to  untie  or  cut  the  rope,  which  fastened  it,  that 
it  might  drift  to  his  assistance,  also  failed.  Catlin  was  known  to  be 
unable  to  swim.  It  was  in  the  night  and  very  dark,  and  it  was  with 
difficulty  that  the  captain,  who  considered  that  there  was  no  hope  of 
saving  his  life,  was  at  last  prevailed  upon  to  go  in  the  canoe  to  attempt 
it.  He  succeeded,  however,  in  picking  the  boy  up,  and  brought  him 
on  board  again  in  about  a  quarter  of  an  hour.  "Catlin's  relation," 
proceeds  Mr.  Maude,  "almost  exceeds  probability.  He  had  heard  my 
exclamation  to  seize  the  canoe,  which  he  was  on  the  point  of  doing, 
when  it  gave  a  sudden  swing  and  baffled  him;  but,  finding  he  could 
support  his  head  above  water,  he  dismissed  all  fear,  expecting  that  the 
canoe  would  come  every  moment  to  his  assistance.  When  he  no  longer 

1  Precis  Elementaire,  i.  333.  a  De  Motu  Animalium,  c.  23,  de  Natat.  Prop.,  217. 

3  Philos.  Transact.,  vol.  1. ;  also,  Dr.  Dalton,  in  Manchester  Memoirs,  vol.  x. 

VOL.  i.— 29 


450  MUSCULAR  MOTION. 

heard  our  cheers  from  the  sloop,  hope  "began  to  fail  him,  and  he  was 
on  the  point  of  resigning  himself  to  a  watery  grave,  when  he  heard  the 
captain's  life-restoring  voice.  On  telling  Catlin  that  we  despaired  of 
his  safety,  as  we  understood  that  he  could  not  swim,  he  replied:  'Nor 
can  I.  I  was  never  before  out  of  my  depth ;  but  I  am  fond  of  bathing, 
and  have  often  seen  lads  what  they  call  tread  the  water;  that's  what  I 
did.'  The  truth  of  this  account  was  made  manifest,  by  the  boy  not 
only  retaining  his  hat  on  his  head,  but  its  being  perfectly  dry;  and 
what  adds  to  the  singularity  of  this  event,  the  boy  never  quitted  his 
grasp  of  the  knife  that  he  was  eating  his  bread  and  cheese  with." 

Mr.  Knight  Spencer  found,  that  he  was  buoyant  on  the  surface  of 
the  sea,  even  when  he  held  stones,  weighing  six  pounds  avoirdupois,  in 
his  hands.  In  the  water,  however,  the  stones  lost  two  pounds  five 
ounces  in  weight,  so  that  he  was  really  freighted  with  no  more  than 
three  pounds  eleven  ounces.  He  himself  weighed  one  hundred  and 
thirty  pounds.1  Dr.  Franklin,2  whilst  he  considered  the  detached 
members  of  the  body,  and  particularly  the  head,  as  of  greater  weight 
than  their  bulk  of  water,  acknowledged  the  body  in  the  aggregate  to 
be  of  less  specific  gravity,  by  reason  of  the  hollowness  of  the  trunk. 
He  thought,  that  a  body  immersed  in  water  would  sink  up  to  the  eyes, 
but  that  if  the  head  were  inclined  back,  so  as  to  be  supported  by  the 
water,  the  mouth  and  nostrils  would  remain  above, — the  body  rising 
one  inch  at  every  inspiration,  and  sinking  one  inch  at  every  expiration; 
and  also,  that  clothes  give  additional  weight  in  the  water,  although, 
in  stepping  out  of  it,  the  case  is  quite  otherwise.  He  concluded,  there- 
fore, that  if  a  person  could  avoid  struggling  and  plunging,  he  might 
remain  in  the  posture  described  with  safety.  That  the  body  is  to  a 
certain  degree  buoyant,  he  refers  to  the  experience  of  every  one  who 
has  ever  attempted  to  reach  the  bottom  of  deep  water, — the  effort  re- 
quired sufficiently  proving  that  something  resists  our  sinking. 

The  truth  would  appear  to  be,  that  there  is  only  a  slight  difference 
between  the  specific  gravity  of  the  human  body  and  that  of  water;  the 
former  being  something  greater,  otherwise  there  would  be  no  reason 
why  the  dead  body  should  sink  to  the  bottom,  as  it  is  known  to  do. 
It  would  seem,  however,  where  the  deposition  of  fat  is  excessive,  the 
body  may  be  of  less  specific  gravity  than  water.3  The  old  notion  was, 
that,  in  the  living  state,  the  specific  gravity  of  the  body  is  decidedly 
less;  but  that,  in  death  from  drowning,  a  quantity  of  water  always 
enters  the  lungs  and  stomach,  and  thus  these  cavities  being  no  longer 
occupied  with  air,  buoyancy  is  lost  and  the  body  sinks.  Nothing  is 
now  better  established  than  that  no  water  gets  into  the  stomach,  ex- 
cept what  is  accidentally  swallowed  during  the  struggling;  and  that 
no  water  must  be  looked  for  in  the  lungs;  a  quantity  of  frothy  mucus 
being  all  that  is  generally  perceptible  there.  Yet,  in  courts  of  justice, 
the  absence  of  water  in  these  situations  has  been  looked  upon  as  evi- 
dence, where  a  body  has  been  found  in  the  water,  that  death  had  not 
occurred  from  drowning;  and  attention  has  consequently  been  directed 

1  Fleming's  Philo?.  of  Zoology,  vol.  i.,  Edinb.,  1822. 

a  Works,  iii.  374,  Philad,,  1808  ;  and  Sparks's  edit.,  vi.  289,  Boston,  1838. 

3  See  vol.  ii.,  under  ADIPOUS  EXHALATION. 


SWIMMING.  451 

to  other  causes,  which  might  have  produced  it;  the  presumption  being, 
that  the  person  had  been  first  killed,  and  then  thrown  into  the  water 
for  the  purpose  of  averting  suspicion. 

Another  erroneous  opinion,  at  one  time  prevalent,  was,  that  if  a 
person  be  thrown  alive  into  water  he  will  sink;  if  dead,  he  will  swim; 
and,  therefore,  it  is  necessary,  that  some  weight  should  be  attached 
to  a  body,  when  committed  to  the  deep,  to  make  it  sink.  All  these 
fallacious  notions  are  dwelt  upon  in  a  case,  full  of  interest  to  all 
jurists,  medical  and  others; — that  of  Spencer  Cowper,  Esq.,  a  member 
of  the  English  bar,  and  afterwards  one  of  the  judges  of  the  Court  of 
Common  Pleas,  who,  with  three  other  individuals,  was  tried  at  Hertford 
Assizes,  in  1699,  for  the  murder  of  Mrs.  Sarah  Stout.1  The  speeches 
of  the  counsel,  with  the  evidence  of  many  of  the  medical  witnesses, 
sufficiently  testify  the  low  condition  of  medico-legal  knowledge  at  that 
period.2  Mr.  Jones — the  counsel  for  the  prosecution — affirmed,  that 
"  when  her  (Mrs.  Stout's)  body  came  to  be  viewed,  it  was  very  much 
wondered  at ;  for,  in  the  first  place,  it  is  contrary  to  nature,  that  any 
persons,  that  drown  themselves,  should  float  upon  the  water."  "  We 
have  sufficient  evidence,"  he  adds,  "that  it  is  a  thing  that  never  was: 
if  persons  go  alive  into  the  water,  then  they  sink;  if  dead,  then  they 
swim."  In  confirmation  of  this  strange  opinion,  two  seamen  were  ex- 
amined, one  of  whom  deposed  as  follows: — "  In  the  year  '89  or  '90,  in 
Beechy  fight,  I  saw  several  thrown  overboard  during  the  engagement, 
but  one  particularly  I  took  notice  of,  that  was  my  friend  and  killed  by 
my  side.  I  saw  him  swim  for  a  considerable  distance  from  the  ship, 
&c.  Likewise  in  another  engagement,  where  a  man  had  both  his  legs 
shot  off  and  died  instantly,  they  threw  over  his  legs;  though  they  sunk, 
I  saw  his  body  float;  likewise  I  have  seen  several  men,  who  have  died 
natural  deaths  at  sea;  they  have,  when  they  have  been  dead,  had  a  con- 
siderable weight  of  ballast  made  fast  to  them  and  so  were  thrown  over- 
board ;  because  we  hold  it  for  a  general  rule  that  all  men  swim  if  they 
be  dead  before  they  come  into  the  water,  and,  on  the  contrary,  I  have 
seen  men  when  they  have  been  drowned,  that  they  have  sunk  as 
soon  as  the  breath  is  out  of  their  bodies,"  &c.  The  weights  are, 
however,  attached  to  the  dead,  when  they  are  thrown  into  the  sea,  not 
for  the  purpose  of  facilitating  their  descent,  but  to  prevent  them  from 
rising,  when  putrefaction  renders  them  buoyant,  by  the  disengagement 
of  air  in  the  splanchnic  cavities.  On  the  same  trial,  Drs.  Coatsworth, 
Burnet,  Nailor,  and  Woodhouse  deposed,  that  when  a  person  is  drowned, 
water  will  be  taken  into  the  stomach  and  lungs ;  and  as  none  was  found 
in  the  case  of  Mrs.  Stout,  they  were  of  opinion,  that  she  came  to  her 
death  by  other  means. 

From  all  that  has  been  said,  it  would  appear,  that  the  great  requisite 
for  safety  to  the  inexperienced  who  may  fall  accidentally  into  the  water 
is  a  firm  and  sufficient  conviction  of  the  fact,  that  the  living  body  natu- 
rally floats,  or  that  it  can  be  easily  made  to  do  so.  This  conviction 
being  acquired,  no  more  than  a  common  share  of  presence  of  mind 

1  Hargrave's  State  Trials,  vol.  v. ;  Beck's  Medical  Jurisprudence,  6th  edit.,  ii.  205, 
Albany,  1838. 

a  Lives  of  the  Lord  Chancellors,  by  Lord  Campbell,  Amer.  edit.,  iv.  240,  Philad.,  1848. 


452  MUSCULAR  MOTION. 

would  seem  to  be  necessary  to  insure,  that  the  portion  of  the  body, 
which  is  the  great  outlet  of  the  respiratory  organs,  shall  be  above  the 
surface. 

The  movements,  adapted  to  the  progression  of  the  body,  are  to  be 
acquired  in  the  same  manner  as  a  child  learns  to  walk ;  proficiency  in 
this,  as  in  every  thing  else,  being  the  result  of  practice. 

Swimming  nearly  resembles  leaping,  except  that  the  effort  in  it  does 
not  take  place  from  a  fixed  surface.  Both  the  upper  and  lower  extre- 
mities participate  in  it.  Whilst  the  former  are  brought  to  a  point 
anterior  to  the  head,  and  form  a  kind  of  cut- water,  the  lower  extremities 
are  drawn  up,  and  suddenly  extended,  as  in  leaping.  The  water,  of 
course,  yields  to  their  impulse ;  but  not  as  rapidly  as  it  is  struck,  and 
hence  the  body  is  projected  forwards.  The  upper  limbs  are  now  sepa- 
rated, and  carried  circularly  and  forcibly  round  to  the  sides  of  the  body, 
by  which  the  impulse  is  maintained;  the  legs  are  in  the  meantime 
drawn  up;  and,  by  a  succession  of  these  movements,  progression  is 
effected — the  hands  and  feet  being  turned  outwards  to  present  as  large 
a  resisting  surface  as  possible.  The  chest  is,  at  the  same  time,  kept 
dilated,  to  augment  the  bulk  of  the  body,  and,  of  course,  to  render  it 
specifically  lighter,  and  the  head  is  raised  above  the  surface  to  admit 
of  respiration.  This  action  is  analogous  to  that  of  the  propulsion  of  a 
boat  by  oars.  The  body  resembles  the  boat ;  and  the  upper  and  lower 
extremities  are  the  oars  or  sculls. 

The  practised  swimmer  can  execute  almost  as  many  movements  in 
the  water  as  he  can  on  land. 

e.  Flying. 

If  the  human  body  sinks  in  the  water,  how  little  can  it  be  susceptible 
of  suspension  in  the  air  by  its  own  unassisted  muscular  powers !  This 
is  a  mode  of  progression  which  is  denied  to  man;  and  accordingly, 
most  of  the  attempts  at  flying,  since  the  mythical  exploits  of  Daedalus 
and  Icarus,  have  been  confined  to  enabling  the  body  to  move  from  one 
place  to  another  by  means  of  ropes  and  appropriate  adjuncts.  Years 
ago,  a  native  of  this  country  exhibited  a  curious  variety  of  progression, 
at  Dover,  England.  He  was  called  the  "flying  phenomenon;"  and  his 
plan,  so  far  as  we  can  recollect,  was  to  have  a  rope  extending  from  the 
heights  to  the  beach  beneath,  along  which  he  descended  by  means  of 
rings  attached  to  different  parts  of  his  person,  which  had  the  rope  pass- 
ing through  them. 

The  sources  of  difficulty,  in  flying,  are; — the  great  weight  of  the 
body,  and  the  insufficient  force  which  the  muscles  are  capable  of  exert- 
ing. It  is  by  no  means  impossible,  however,  that  by  some  contrivance, 
of  which  the  lightest  gases  might  form  a  part,  and  by  an  imponderous 
apparatus,  which  would  enlarge  the  surface  of  the  upper  extremities, 
progression,  in  this  manner,  might  be  effected; — but  to  a  limited  and 
unmanageable  extent  only. 

f.   Other  Varieties  of  Muscular  Action. 

Connected  with  this  subject  we  may  refer  briefly  to  some  varieties 
of  muscular  action,  the  nature  of  which  will  be  easily  intelligible. 


OTHER  VARIETIES  OF  MUSCULAR  MOTION.  453 

In  bearing  a  load,  we  have  simply  a  variety  of  walking  in  the  erect 
attitude,  with  this  addition,  that  the  extensor  muscles  of  the  head, 
neck,  or  back, — according  to  the  part  on  which  the  burden  may  be 
placed, — have  to  contract  forcibly  to  support  it.  The  position  of  the 
individual  has,  also,  to  be  so  regulated,  that  the  centre  of  gravity  shall 
always  be  over  the  base  of  sustentation.  Hence,  if  the  load  be  on  a 
man's  back,  he  leans  forward;  if  borne  before  him,  he  leans  backward; 
and  this  is  the  cause  of  the  portly  and  consequential  appearance  of  the 
corpulent.  If  the  load  be  on  his  head  he  stands  as  upright  as  possible, 
for  a  like  reason. 

In  propelling  a  body  forwards,  either  by  the  hands  or  shoulders,  the 
feet  are  firmly  fixed  on  the  ground ;  the  limbs  are  in  a  state  of  semi- 
flexion,  and  the  centre  of  gravity  is  directed  forward,  so  as  to  aid  the 
force  that  has  to  be  developed  by  the  muscles.  The  limbs  are  then 
suddenly  extended;  the  body  is  thrown  forward,  and  the  whole  power 
exerted  on  the  obstacle  which  has  to  be  moved. 

On  the  other  hand,  when  we  drag  a  weight  after  us,  or  attempt  to 
dislodge  a  stake  from  the  earth,  the  feet  are  equally  fixed  firmly  on 
the  ground,  but  the  body  is  in  a  state  of  extension,  and  is  directed  as 
far  as  practicable  backwards,  in  order  that  the  tendency  to  fall,  owing 
to  the  centre  of  gravity  overhanging  the  base  of  sustentation,  may  aid 
the  force  that  has  to  be  developed  by  the  flexor  muscles  of  the  arms, 
which  are  then  powerfully  contracted,  and  the  whole  force  is  exerted 
upon  the  object.  As,  in  both  these  cases,  there  is  danger  of  falling 
should  the  body  yield  suddenly,  the  feet  are  so  placed  as  to  obviate 
this,  as  far  .as  possible,  by  being  separated  in  the  direction  in  which  the 
force  is  exerted.  • 

Squeezing  consists  in  laying  hold  of  the  object,  either  between  the 
arms  and  body,  or  by  the  fingers ;  and  then  forcibly  contracting  the 
flexor  muscles.  In  all  these,  and  other  varieties  of  strong  muscular 
contraction,  the  respiration  is  interrupted,  in  order  that  the  thorax 
may  be  rendered  fixed,  and  serve  as  an  immovable  point  of  origin  for 
the  muscles  of  the  head,  shoulders,  and  arms.  This  is  effected  by 
taking  in  a  full  inspiration ;  strongly  contracting  the  respiratory  mus- 
cles, and,  at  the  same  time,  closing  the  glottis  to  prevent  the  exit  of 
the  air. 

Lastly :  as  organs  of  prehension,  the  upper  extremities  are  of  admi- 
rable organization,  possessing  great  mobility,  and  at  the  same  time 
solidity.  The  joint  at  the  shoulder  allows  of  extensive  motion ;  and 
the  bones,  to  which  the  arm  is  attached  at  this  joint — scapula  and 
clavicle — are  themselves  movable.  The  forearm  is  likewise  susceptible 
of  various  movements  on  the  arm,  of  which  those  of  pronation  and 
supination  are  not  the  least  important ;  whilst  the  hand  possesses  every 
requisite  for  an  organ  of  prehension.  It  is  composed  of  numerous 
bones,  and  is  capable  of  being  applied  to  the  most  irregular  surfaces. 
The  great  superiority  of  the  human  hand  arises  from  the  size  and 
strength  of  the  thumb,  which  can  be  brought  into  a  state  of  opposition 
to  the  fingers ;  and  is,  therefore,  of  the  highest  use  in  enabling  us  to 
seize  hold  of,  and  grasp  spherical  bodies;  to  take  up  any  object;  to 
lay  firm  hold  of  whatever  we  seize,  and  to  execute  the  various  useful, 


454  MUSCULAR  MOTION. 

and  ornamental  processes  of  the  arts.  These  processes  require  the 
most  accurate,  quick,  and  combined  movements  of  the  muscles.  How 
quick,  for  example,  is  the  motion  of  the  hand  in  writing,  and  in  execut- 
ing the  most  rapid  movements  on  the  piano-forte !  How  accurate  the 
muscular  contraction,  which  stops  the  precise  part  of  the  violin-string 
to  bring  out  the  note  or  semi-tone  in  allegro  movements;  and  what  a 
multitude  of  combinations  must  be  invoked  in  all  these  cases ! 

As  an  organ  of  touch,  the  advantages  of  the  upper  extremity  have 
already  been  depicted ;  and  much  of  what  was  then  said  applies  to  it 
as  an  organ  of  prehension.  "In  this  double  respect,"  observes  M. 
Adelon,1  "man  is  the  best  provided  of  animals.  How  much,  in  fact, 
does  he  stand  in  need  of  an  ingenious  instrument  of  prehension!  As 
we  have  several  times  remarked,  he  has,  in  his  organization,  neither 
the  offensive  nor  defensive  arms,  that  are  bestowed  on  other  animals. 
Naked  from  birth,  and  exposed  to  the  inclemencies  of  the  atmosphere, 
without  means  of  attack  or  defence  against  animals,  he  must  inces- 
santly labour  to  procure  what  he  requires.  It  was  not,  consequently, 
enough  that  he  should  possess  an  intellect,  capable  of  making  him  ac- 
quainted with,  and  of  appropriating  to  himself,  the  universe.  He  must 
have  an  instrument  adapted  for  the  execution  of  all  that  his  intellect 
conceives.  Such  instrument  is  his  upper  extremity.  In  short,  whilst 
other  animals  find  every  thing  in  nature — necessary  for  their  different 
wants — more  or  less  prepared ;  man,  alone,  is  obliged  to  labour  to  pro- 
cure what  he  requires.  He  must  make  himself  clothes,  construct  his 
habitations,  and  prepare  his  food.  He  is  the  labouring  and  producing 
animal  par  excellence;  and  hence  needs  not  only  an  intellect  to  con- 
ceive, but  an  instrument  to  execute."  • 

FUNCTION  OF  EXPRESSION  OR  LANGUAGE. 

Under  this  head  will  be  included  those  varieties  of  muscular  con- 
traction, by  which  man  and  animals  exhibit  the  feelings  that  impress 
them,  and  communicate  the  knowledge  of  such  feelings  to  each  other. 
It  comprises  two  different  sets  of  actions: — those  addressed  to  the  ear — 
or  phenomena  of  voice:  and  those  appreciated  by  the  senses  of  sight  and 
touch — or  gestures.  Of  these  we  shall  treat  consecutively. 

a.   Of  the  Voice. 

By  the  term  voice — or  phonation,  a  term  proposed  by  Chaussier — 
is  meant  the  sound  produced  in  the  larynx,  whilst  the  air  is  passing 
through  it,  either  to  enter,  or  issue  from,  the  trachea. 

1.    ANATOMY   OF   THE    VOCAL   APPARATUS. 

The  apparatus,  concerned  in  the  production  of  voice,  is  composed,  in 
man,  of  the  muscles  concerned  in  respiration  ;  the  larynx ;  the  mouth 
and  nasal  fossae.  The  first  are  merely  agents  for  propelling  the  air 
through  the  instrument  of  voice.  They  will  fall  under  consideration 
under  Respiration  ;  whilst  the^anatomy  of  the  mouth  and  nasal  fossae 
has  been,  or  will  have  to  be,  described  in  other  places.  The  larynx, 

1  Physiologie  de  1'Homme,  ii.  201,  2de  edit,,  Paris,  1839. 


VOICE  —  ANATOMY  OF  THE  VOCAL  APPARATUS.         455 

and  its  primary  dependencies,  which  are  immediately  concerned  in  the 
production  of  voice,  will  alone  engage  us  at  present. 

The  larynx  is  situate  at  the  anterior  part  of  the  neck,  and  forms  the 
projection  so  perceptible  in  that  of  the  adult  male,  called  pomumAdami. 
An  attentive  examination  of  the  various  parts  which  compose  it,  so  far 
as  they  concern  its  physiological  relations,  will 
be  necessary.  This  will  exhibit  the  imperfect  Fi§-  194- 

knowledge  of  several  writers  on  the  voice,  and 
the  false  and  insufficient  views  that  have  been 
entertained  on  the  subject. 

If  we  look  along  the  larynx  from  the  trachea 
of  which  it  is  a  continuation,  we  find  that  the  tube 
becomes  gradually  narrower  from  side  to  side  ; 
and,  at  length,  presents  an  oblong  cleft,  called 
glottis,  the  sides  of  which  are  the  essential  organ 
of  voice. 

The  larynx  is  composed  of  four  cartilages  — 
the  cricoid,  thyroid,  and  two  arytenoid.  The 
cricoid  is  the  lowest  of  these,  and  is  the  inferior 
part  of  the  organ  ;  —  that  by  which  it  joins  the 
trachea.  It  is  shaped  like  a  ring,  whence  its 
name,  but  is  much  deeper  behind  than  before. 
The  thyroid  is  situate  above  the  cricoid,  with  ^terai  View  of  the  Larynx. 
which  it  is  articulated  in  a  movable  manner  by  ^£*$^  "3  . 


. 
means  of  its  inferior  cornua.     In  this  way,  the  majus  of  thyroid  cartilage.  4. 

„  .  _.          .  .,         fi.vsT  Its  angle  and  side.    5.  Cornu 

lower  front  margin  or  the  thyroid,  which  is  com-  minus.  6.  Lateral  portion  of 
monly  separated  by  a  short  space  from  the  upper  $&£?***'•    7' 
margin  of  the  cricoid,  may  be  made  to  approach 

to  or  recede  from  it  ;  as  may  be  ascertained  by  placing  the  finger 
against  the  small  depression  felt  externally,  and  observing  its  change 
of  size  when  various  tones  are  sounded.  It  will  be  observed,  that  the 
higher  the  tone  the  more  the  cartilages  approximate,  and  that  they 
separate  in  proportion  to  the  depth  of  the  tone.  A  ligament  unites 
these  cartilages  —  the  crico  -thyroid,  which  can  be  traced,  although  in 
a  very  thinned  condition,  over  the  whole  of  the  periphery  of  the  ventri- 
cle of  the  larynx,  even  as  far  as  the  pedicle  of  the  epiglottis.  This 
membrane  is  composed  of  the  yellow  elastic  tissue  —  tissu  jaune,  —  and, 
according  to  Dr.  Leidy,1  it  presents,  under  the  microscope,  a  good 
example  of  that  substance,  which  enabled  him  to  detect  its  presence  in 
the  ventricles  of  the  larynx. 

The  thyroid  is  the  large  cartilage  that  occupies  the  anterior,  promi- 
nent, and  lateral  part  of  the  larynx.  The  arytenoid  cartilages  are  two 
in  number.  They  are  much  smaller  than  the  others,  and  are  articu- 
lated with  the  posterior  part  of  the  cricoid  in  a  movable  manner. 
Around  this  articulation  is  a  synovial  capsule.  Before  it  is  the  thyro- 
arytenoid  ligament;  and,  behind,  a  strong,  ligamentous  fascia,  called,  by 
M.  Magendie,2  from  its  attachments  —  crico-arytenoid.  Three  fibro-car- 

1   Amer.  Journ.of  the  Medical  Sciences,  July,  1846,  p.  142. 
*  Precis  Elementaire,  i.  235. 


456 


MUSCULAR  MOTION. 


tilages,  likewise,  enter  into  the  constitution  of  the  larynx.  These  are, — 
the  epiglottis  ;  and  two  small  bodies,  that  tip  the  arytenoid  cartilages, 
and  are  met  with  only  in  man — capitula  Santorini,  supra-arytenoid 
cartilages  or  capitula  cartilaginum  arytenoldarum. 


Fig.  195. 


Fig.  196. 


View  of  the  interior  of  the  left  half  of  the 
Larynx,  to  show  the  Ventricle  and  Laryngeal 
Pouch.  (After  Hilton.) 

a.  Left  arytenoid  cartilage,  e,  e.  Sections  of  the 
cricoid  cartilage,  t.  Thyroid  cartilage,  e.  Epiglot- 
tis, v.  Left  ventricle  of  the  larynx,  r.  Left  inferior 
or  true  vocal  cord.  s.  Laryngeal  pouch,  b.  Ary- 
teno-epiglottidean  muscle,  or  compressor  sacculi 
laryngis.  /.  Inside  of  trachea,  which  has  been 
added  to  this  figure. 


Larynx  from  above.     (Willis.) 

G  E  H.  Thyroid  cartilage,  embracing  the 
ring  of  the  cricoid  r  u  x  w,  and  turning  upon 
the  axis  x  z.  N  F,  N  F.  The  arytenoid  carti- 
lages, connected  by  the  arytenoideus  transver- 
sus.  TV,  TV.  The  vocal  ligaments.  NX.  The 
right  crico-arytenoideus  lateralis  (the  left 
being  removed),  vkf.  The  right  thyro-aryte- 
noideus  (the  left  being  removed).  N  1.  N  I.  The 
crico-arytenoidei  postici.  B^B.  The  crico-ary- 
tenoid  ligaments. 


On  examining  the  interior  of  the  larynx,  two  clefts  are  seen — one 
above  the  other ;  the  uppermost  being  usually  oblong-shaped  ;  ten  or 
eleven  lines  long,  and  two  or  three  broad ;  having  the  shape  of  a  tri- 
angle, the  apex  forwards.  It  is  circumscribed,  anteriorly,  by  the  thy- 
roid cartilage  and  epiglottis  ;  posteriorly,  by  the  arytenoid  cartilages ; 
and,  laterally,  by  two  folds  of  mucous  membrane,  which  pass  from  the 
epiglottis  to  each  arytenoid  cartilage,  and  are  called  superior  ligaments 
of  the  glottis  and  superior  vocal  cords.  A  few  lines  below  this  is  a 
second  cleft,  also  oblong  from  before  to  behind  and  of  a  triangular 
shape,  the  base  of  which  is  behind.  It  is  bounded  anteriorly  by  the 
thyroid  cartilage ;  posteriorly,  by  a  muscle  extending  from  one  aryte- 
noid cartilage  to  the  other — the  arytenoideus;  and,  laterally,  by  two 
folds,  formed  of  the  thyro-arytenoid  ligament,  passing  from  the  ante- 
rior part  of  the  arytenoid  cartilage  to  the  posterior  part  of  the  thy- 


VOICE — ANATOMY  OF  THE  VOCAL  APPARATUS. 


457 


Fig.  197. 


roid,  and  of  a  muscle  of  the  same  name.  These  folds  are  called  infe- 
rior ligaments  or  lips  of  the  glottis  or  inferior  vocal  cords.  They  are 
represented  by  T  V,  in  Fig.  196,  and  B  B,  Fig.  197.  Between  these 
two  clefts  are  the  sinuses  or  ventricles  of  the  larynx,  V  V,  Fig.  197. 
The  inferior,  exterior,  and  superior  sides  of  these  are  formed  ^by  the 
thyro-arytenoid  muscles.  By  means  of  these  ligaments — superior  and 
inferior — the  lips  of  the  superior  and  inferior  aperture  are  perfectly 
free,  and  unencumbered  in  their  action.1 

Anatomical  descriptions  will  be  found  to  give  different  significations 
to  the  word  glottis.  Some  have  applied  it  to 
the  upper  cleft ;  others  to  the  lower ;  some  to 
the  ventricles  of  the  larynx;  and  others  to  the 
whole  space  comprised  between  the  inferior  liga- 
ments and  top  of  the  larynx.  It  is  now,  gene- 
rally perhaps,  restricted  to  the  part  of  the  larynx 
engaged  in  the  production  of  voice,  or  usually 
considered  to  be  so  engaged, — that  is,  the  space 
between  the  inferior  ligaments  plus  the  liga- 
ments themselves; — and  in  this  signification  it 
will  be  employed  here. 

The  mucous  membrane,  which  lines  the  larynx, 
is  continuous  above  with  that  of  the  mouth; 
below,  with  that  of  the  trachea.  It  contains 
several  mucous  follicles,  some  of  which  are  ag- 
glomerated near  the  superior  ligaments  of  the 
glottis  and  the  environs  of  the  ventricles  of  the 
larynx,  seeming  to  constitute  distinct  organs, 
which  have  been  called  arytenoid  glands.  A 
similar  group  exists  between  the  epiglottis  be- 
hind, and  the  os  hyoides  and  thyroid  cartilage  before,  which  has  been 
termed  the  epiglottic  gland.  The  uses  of  this  body  are  not  clear.  M. 
Magendie2  conceives,  that  it  favours  the  frequent  slidings  of  the  thyroid 
cartilage  over  the  posterior  surface  of  the  os  hyoides;  keeps  the  epi- 
glottis separated  above  from  this  bone;  and,  at  the  same  time,  furnishes 
it  a  very  elastic  support,  which  may  aid  it  in  the  functions  it  has  to 
execute,  connected  with  voice  and  deglutition. 

The  larynx  is  capable  of  being  moved  as  a  whole,  as  well  as  in  its 
component  cartilages.  It  may  be  raised,  depressed,  or  carried  forwards 
or  backwards.  The  movements,  however,  which  are  most  concerned  in 
the  production  of  voice,  are  those  effected  by  the  action  of  the  intrinsic 
muscles,  as  they  have  been  termed.  These  are,  1st.  The  crico-thyroid, 
a  thin,  quadrilateral  muscle,  which  arises  from  the  anterior  surface  of 
the  cricoid  cartilage,  and  is  inserted  into  the  lower  and  inner  border  of 
the  thyroid.  M.  Magendie3  affirms,  that  its  use  is  not,  as  generally  ima- 
gined, to  depress  the  thyroid  on  the  cricoid,  but  to  elevate  the  cricoid, 
approximate  it  to  the  thyroid,  and  even  make  it  pass  slightly  under  its  in- 
ferior margin.  The  effects  of  its  contraction  must  be  to  render  the  vocal 

1  Hilton,  Guy's  Hospital  Reports,  No.  v.  October,   1837,  p.  519,  and  Leidy,  American 
Journal  of  the  Medical  Sciences,  p.  142,  July,  1846. 

2  Precis,  &c.,  i.  237.  3  Ibid.,  i.  236, 


Scheme  of  the  Lar  ynx. 


458 


MUSCULAR  MOTION. 


198. 


ligaments  tense.  2dly.  Thecrico-arytenoideipostici,  and  crico-arytenoidei 
later  ales;  the  former  of  which  pass  from  the  posterior  surface  of  the  cri- 
coid  to  the  outer  angle  of  the  base  of  the  arytenoid;  and  the  latter  from 
the  upper  border  of  the  side  of  the  cricoid  to  the  outer  angle  of  the  base  of 

the  arytenoid.  The  use  of  the  crico-arytenoidei 
postici  is  to  carry  the  arytenoid  cartilages 
backwards,  separating  them  at  the  same  time 
from  each  other,  and  thus  opening  the  glottis; 
the  action  of  the  crico-arytenoidei  laterales  is 
like  that  of  the  arytenoidei  to  bring  together 
the  inner  edges  of  the  arytenoid  cartilages,  and 
close  the  glottis.  3dly.  The  arytenoid  muscle 
— of  which  there  is  only  one.  It  extends  across 
from  one  arytenoid  cartilage  to  the  other;  and, 
by  its  contraction,  brings  them  towards  each 
other.  4thly.  The  thy ro- arytenoid  muscle, 
which,  according  to  M.  Magendie,1  is  the  most 
important  to  be  known  of  all  the  muscles  of 
the  larynx,  as  its  vibrations  produce  the  vocal 
sound.  It  forms  the  lips  of  the  glottis,  and 
Magendie  describes  it  as  constituting,  also, 
"the  inferior,  superior,  and  lateral  parietes  of 
the  ventricles  of  the  larynx."  Generally,  it 
is  considered  to  arise  from  the  posterior  surface 
of  the  thyroid  cartilage,  and  the  ligament 
connecting  itwith  the  cricoid,  and  to  beinserted 
into  the  anterior  edge  of  the  base  of  the  ary- 
tenoid. By  drawing  the  point  of  the  thyroid 
back,  it  must  relax  the  vocal  ligaments. 
Lastly. — The  muscles  of  the  epiglottis — the 
thyro-epiglottideus,  aryteno-epiglottideus  supe- 
rior, aryteno-epiglottideus  inferior  (Hilton's 
muscle),2  and  some  fibres  that  may  be  looked 
upon  as  vestiges  of  the  glotto-epiglotticus, 
which  exists  in  many  animals.  These  mus- 
cles,— the  position  of  which  is  indicated  by 
the  name, — modify  by  their  contraction,  the 
situation  of  the  epiglottis. 

The  principal  governors  of  the  pitch  of  the 
voice,  which   is   almost  wholly  regulated  by 

Origin  and  Distribution  of  the      the  degree  °f  tensi°n  °f  the  VOCal   ligaments, 

Eighth  Pair  of  Nerves.         are    the    crico-thyroid   and   thyro-arytenoid. 

1,  3,  4.  Medulla  oblongata.  1.  Corpus  pyramidale  of  one  side.  3.  Corpus  olivare.  4.  Corpus  resti- 
forme.  2.  Pons  Varolii.  5.  Facial  nerve.  6.  Origin  of  glosso-pharyngeal  nerve.  7.  Ganglion  of 
Andersch.  8.  Trunk  of  the  nerve.  9.  Spinal  accessory  nerve.  10.  Ganglion  of  pneumogastric  nerve. 
11.  Its  plexiform  ganglion.  12.  Its  trunk.  13.  Its  pharyngeal  branch  forming  the  pharyngeal  plexus 
(14),  assisted  by  a  branch  from  theglosso-pharyngeal  (8),  and  one  from  the  superior  laryngeal  nerve  (15) . 
16.  Cardiac  branches.  17.  Recurrent  laryngeal  branch.  18.  Anterior  pulmonary  branches.  19.  Pos- 
terior pulmonary  branches.  20.  CEsophageal  plexus.  21.  Gastric  branches.  22.  Origin  of  spinal 
accessory  nerve.  23.  Its  branches  distributed  to  sterno-mastoid  muscle.  24.  Its  branches  to  the 
trapezius  muscle. 


1  Precis,  &c.,  236,  and  his  Memoire  sur  1'Epiglotte. 

3  Wilson's  Anatomist's  Vade  Mecum,  Amer.  edit.,  p.  483,  Philad.,  1843. 


VOICE  —  ANATOMY  OF  THE  VOCAL  APPARATUS.         459 

The   respective  action  of  the  different  muscles  has  been  given  in  a 
tabular  form.1 

Govern  the  Pitch  of  the  Notes. 

w'    fp  .       ,        ...  (  Depress  the  front  of  the  thyroid  cartilage  on  thecricoid  and  stretch 

2      the  vocal   ligaments;  assisted  by  the  arytenoideus  and  crico- 
§  j  (      arytenoidei  postici. 

j  Thyro-arytenoidei     (  Elevate  the  front  of  the  thyroid,  and  draw  it  towards  the  arytenoid, 
Thyro-hyoidei  (      relaxing  the  vocal  ligaments. 


i  L 


Govern  the  Aperture  of  the  Glottis. 
Crico-arytenoidei  postici       .         .         .         Open  the  Glottis. 

11 

Crico-arytenoidei  laterales  (  Press  together   the  inner  edges  of  the  ary- 

«<   I  Arytenoideus £      tenoid  cartilage,  and  close  the  glottis. 

The  intrinsic  muscles  of  the  larynx  receive  their  nervous  influence 
from  the  eighth  pair  (Fig.  198).  Shortly  after  this  nerve  has  issued 
from  the  cranium  it  gives  off  a  branch,  called  superior  laryngeal,  which 
is  distributed  to  the  arytenoid  and  crico-thyroid  muscles;  and,  after  its 
entrance  into  the  thorax,  it  furnishes  a  second,  which  ascends  towards 
the  larynx,  and  is,  on  that  account,  called  recurrent  or  inferior  laryn- 
geal. It  is  distributed  to  the  crico-arytenoidei  postici,  crico-arytenoidei 
laterales,  and  thyro-arytenoid  muscles.  No  ramification  of  this  nerve, 
according  to  M.  Magendie,  goes  to  the  arytenoid,  or  crico-thyroid  mus- 
cles. In  these  views,  he  is  supported  by  M.  J.  Cloquet2  and  by  many 
others.  Other  distinguished  anatomists,  however,  maintain  that  the  ary- 
tenoideus muscle  receives  a  branch  from  each  of  the  inferior  laryngeals. 
Dr.  Reid  asserts,  that  he  has  repeatedly  satisfied  himself  of  the  existence 
of  this  arytenoid  branch  of  the  inferior  laryngeal,  and  the  dissection 
is  one,  he  says,  which  can  leave  no  kind  of  doubt  on  the  matter.3 

In  each  animal  species,  the  glottis  has  a  construction  corresponding 
to  the  kind  of  voice;  and,  when  it  is  examined  in  the  living  animal — 
the  dog  for  example — it  enlarges  and  contracts  alternately, — the  ary- 
tenoid cartilages  separating  when  the  air  enters  the  lungs,  and  approxi- 
mating during  expiration. 

To  the  trachea  the  larynx  is  attached  by  a  fibrous  membrane,  which 
unites  the  cricoid  with  the  first  ring  of  the  trachea ;  and,  above,  it  is 
connected  with  the  os  hyoides  by  a  similar  membrane — the  hyo-thyroid, 
No.  2,  Fig.  194, — as  well  as  by  the  thyro-hyoid  muscle.4 

2.    PHYSIOLOGY   OF   VOICE. 

The  production  of  voice  requires,  that  air  shall  be  sent  from  the  lungs, 
which,  in  passing  through  the  glottis,  throws  certain  parts  into  vibra- 
tion, and  afterwards  makes  its  exit  by  the  vocal  tube, — that  is,  by  the 
mouth  and  nasal  fossae.  Simple  expiration  does  not,  however,  produce 

1  Carpenter's  Human  Physiology,  4th  Amer.  edit.,  §  604,  Philad.,  1850. 
8  Traite  d'Anatomie  Descriptive,  ii.  622,  Paris,  1816. 

3  Art.  Par  Vagum,  by  Dr.  J.  Reid,  in  Todd's  Cyclopaedia  of  Anat.  and  Physiol.,  Parts  xxvii. 
and  xxviii.  p.  893,  London,  1846-7.     For  an  excellent  description  of  the  anatomy  of  the 
vocal  apparatus,  see  J.  Bishop,  art  Larynx,  Cyclop,  of  Anat.  and  Physiol.,  Lond.,  Sept.,  1840. 

4  Willis,  in  Cambridge  Philosoph.  Transact,  for  1832,  iv.  323. 


460  MUSCULAR  MOTION. 

m 

it,  otherwise  we  should  have  the  vocal  sound  accompanying  each  con- 
traction of  the  chest.  Volition  is  necessary  to  excite  the  requisite  action 
of  the  muscles  of  the  larynx,  as  well  as  those  of  respiration  ;  and  by  it 
the  tone  and  intensity  of  voice  are  variously  modified. 

That  voice  is  produced  in  the  larynx,  we  have  both  direct  and  indirect 
testimony.  An  aperture  made  in  the  trachea,  beneath  the  larynx, 
deprives  both  man  and  animals  of  it.  This  occurs  also,  if  the  aperture 
be  made  in  the  larynx  beneath  the  inferior  ligaments ;  but  if  above  the 
glottis,  so  as  to  implicate  the  epiglottis  and  its  muscles,  the  superior 
ligaments  of  the  glottis,  and  even  the  upper  portions  of  the  arytenoid 
cartilages,  voice  continues.  MM.  Magendie1  and  J.  Cloquet  refer  to  the 
cases  of  two  men,  who  had  fistulas  in  the  trachea ;  and  who  were  unable 
to  speak  unless  the  openings  were  accurately  stopped  by  mechanical 
means.  If,  again,  we  take  the  trachea  and  larynx  of  an  animal  or 
man,  and  blow  air  forcibly  into  the  tracheal  extremity  towards  the 
larynx,  no  sound  is  produced,  except  what  results  from  the  friction  of 
the  air  against  the  sides.  But  if  we  approximate  the  arytenoid  carti- 
lages, so  that  they  touch  at  their  inner  surfaces,  a  sound  is  elicited, 
bearing  some  resemblance  to  the  voice  of  the  animal  to  which  the 
larynx  belongs;2 — the  sound  being  acute  or  grave  according  as  the  car- 
tilages are  pressed  against  each  other  with  more  or  less  force;  and 
varying  in  intensity,  according  to  the  degree  of  force  with  which  the 
air  is  sent  through  the  tube.  In  this  experiment,  the  inferior  ligaments 
are  seen  to  vibrate. 

Paralysis  of  the  intrinsic  muscles  of  the  larynx  likewise  produces 
dumbness;  and  this  can  be  effected  artificially.  Much  discussion  at  one 
time  prevailed  regarding  the  effect  of  tying  or  cutting  the  nerves 
distributed  to  these  muscles.  The  experiments  of  Haighton3  induced 
him  to  think,  that  the  recurrent  branches  of  the  par  vagum  supply  parts, 
which  are  essentially  necessary  to  the  formation  of  the  voice;  whilst 
the  laryngeal  seemed  to  him  to  affect  only  its  modulation  or  tone. 
Subsequent  experiments  have  sufficiently  shown,  that  if  both  the  recur- 
rent nerves  and  the  superior  laryngeal  are  divided,  complete  aphonia 
results.  M.  Magendie4  found,  indeed,  that  when  both  recurrents, — which, 
he  says,  are  distributed  to  the  thyro-arytenoid  muscles, — are  cut,  the 
voice  is  usually  lost;  whilst  if  one  only  be  divided,  the  voice  is  but  half 
destroyed.  He  noticed,  however,  that  several  animals,  in  which  the 
recurrents  had  been  cut,  were  still  capable  of  eliciting  acute  sounds, 
when  labouring  under  violent  pain,; — sounds,  which  were  analogous  to 
those  that  could  be  produced  mechanically  on  the  larynx  of  the  dead 
animal,  by  blowing  into  the  trachea  and  approximating  the  arytenoid 
cartilages;  and  this  he  attempts  to  explain  by  the  distribution  of  the 
nerves  to  the  larynx.  The  recurrents  being  divided,  the  thyro-arytenoid 
muscles  are  no  longer  capable  of  contracting,  and  aphonia  results;  but 
the  arytenoid  muscle,  which  receives  its  nerves  from  the  superior  laryn- 
geal, still  contracts;  and,  during  a  strong  expiration,  brings  the  ary- 

'  Precis,  &c.,  i.  241,  and  his  Journal  de  Physiologic,  ix.  119. 

5  Biot,  Traite  Elementaire  de  Physique,  i.  462. 

3  Memoirs  of  the  Medical  Society  of  London,  iii.  435.  4  Precis,  &c.,  i.  243. 


VOICE — PHYSIOLOGY.  461 

tenoid  cartilages  together,  so  that  the  chink  or  cleft  of  the  glottis  is 
sufficiently  narrow  for  the  air  to  cause  vibration  in  the  thyro-arytenoid 
muscles,  although  they  may  not  be  in  a  state  of  contraction.  From 
these,  and  other  experiments,  Bellingeri1  infers,  that  the  superior  laryn- 
geal  nerve  is  the  antagonist  of  the  inferior  laryngeal  or  recurrent, — 
the  former  producing  constriction;  the  latter  dilatation  of  the  glottis. 
They,  however,  who  affirm,  that  the  distribution  of  the  laryngeal  nerves 
is  not  the  same  as  that  described  by  M.  Magendie,  assign  different  func- 
tions to  the  particular  nerves.  Thus,  Mr.  Hilton2  infers  from  his 
observations — first,  that  the  superior  laryngeal  is  a  nerve  of  sensation; 
because,  independently  of  the  crico-thyroideal  nerve,  it  is  distributed 
exclusively  to  the  mucous  membrane,  areolar  tissue,  and  glands ;  and 
secondly,  that  the  inferior  or  recurrent  must  be  the  proper  motive  nerve 
to  the  larynx,  as  it  alone  supplies  all  the  muscles,  which  act  immediately 
upon  the  column  of  air  passing  to  and  from  the  lungs.  Dr.  Reid3  too, 
concludes  from  his  various  experiments ; — first,  that  the  superior  laryn- 
geal furnishes  one  muscle  only  with  motor  filaments, — the  crico-thyroid. 
Secondly,  that  the  superior  laryngeal  furnishes  all,  or  nearly  all,  the 
sensitive  filaments  of  the  larynx,  and  some  of  those  distributed  upon 
the  mucous  surface  of  the  pharynx.  Thirdly,  that  the  inferior  laryn- 
geal or  recurrent  furnishes  the  sensitive  filaments  to  the  upper  part  of 
the  trachea,  a  few  to  the  mucous  surface  of  the  pharynx,  and  still  fewer 
to  the  mucous  surface  of  the  larynx;  and  fourthly,  that  when  any 
irritant  is  applied  to  the  mucous  membrane  of  the  larynx  in  a  healthy 
state,  this  does  not  excite  the  contraction  of  the  muscles,  which  move 
the  arytenoid  cartilages,  by  acting  directly  upon  them  through  the 
mucous  membrane,  but  the  contraction  takes  place  by  a  reflex  action, 
in  the  performance  of  which  the  superior  laryngeal  is  the  sensitive,  and 
the  inferior  laryngeal  the  motor  nerve. 

It  is  obvious  from  this  discrepancy  amongst  observers,  that  we  have 
yet  much  to  learn  before  we  can  pronounce  with  certainty  on  the  pre- 
cise function  of  those  nerves. 

Every  part  of  the  larynx,  with  the  exception  of  the  inferior  liga- 
ments, may  be  destroyed,  and  the  voice  continue.  Bichat  split  the 
upper  edge  of  the  superior  ligaments  of  the  glottis,  without  its  being 
destroyed ;  and  the  excision  of  the  tops  of  the  arytenoid  cartilages  had 
no  more  effect.  Magendie  divided  with  impunity  the  epiglottis  and  its 
muscles :  voice  was  accomplished,  until  he  cut  the  middle  of  the  arytenoid 
cartilages  or  split  the  thyroid  cartilages  longitudinally,  when  he,  of 
course,  destroyed  the  glottis.  Lastly,  when  the  larynx  is  exposed  in  a 
living  animal,  so  that  the  different  parts  can  be  seen  at  the  time  when 
voice  is  accomplished, — the  superior  ligaments,  according  to  Bichat  and 
Magendie,  who  have  performed  the  experiment,  are  manifestly  uncon- 
cerned in  the  function,  whilst  the  inferior  vibrate  distinctly.  These 

1  Ragionamenti,  Sperienze,  &c.,  comprovanti  1'Antagonismo  Nervoso,  &c.,  Torino,  1833; 
noticed  in  Edinb.  Med.  and  Surg.  Journal,  p.  172,  Jan.,  1835. 

2  Op.  cit,  p.  518,  and  Mr.  Cock,  on  the  Crico-Thyroideal  Nerve,  a  branch  of  the  superior 
laryngeal,  ibid.,  p  313. 

3  Op.  cit.,  p.  145. 


462  MUSCULAR  MOTION. 

ligaments  must,  therefore,  be  regarded  as  the  essential  organs  of 
voice.1 

The  interesting,  but  difficult  problem  now  presents  itself;  to  deter- 
mine the  precise  mechanism  of  the  vibration  of  those  ligaments ;  and 
what  kind  of  instrument  the  vocal  organ  resembles.  The  latter  ques- 
tion, on  which,  it  might  be  conceived,  so  much  physical  evidence  must 
exist,  has  been  a  topic  of  dissension,  and  is  not  settled  at  this  day. 
Aristotle,2  Galen,3  and  the  older  writers  in  general,  looked  upon  the 
larynx  as  a  wind  instrument  of  the  flute4  kind,  in  which  the  interior 
column  of  air  is  the  sonorous  body;  the  trachea,  the  body  of  the  flute; 
and  the  glottis  the  beak.  The  air,  they  conceived,  when  forced  from  the 
lungs,  in  passing  through  the  glottis,  is  broken  by  the  inferior  ligaments 
of  the  larynx;  vibrations  are,  consequently,  produced,  and  these  give 
rise  to  the  sound.  Fabricius,  of  Acquapendente,5  was  one  of  the  first 
to  object  to  this  view  of  the  subject.  He  properly  remarked,  that  the 
trachea  cannot  be  regarded  as  the  body  of  the  flute,  but  as  a  porte-vent 
to  convey  air  to  the  glottis.  He  was  of  opinion,  that  the  glottis  corre- 
sponds to  the  beak  of  the  flute,  and  that  the  vocal  tube,  or  the  part  above 
it,  resembles  the  body  of  the  instrument.  Similar  opinions,  with  more 
or  less  modification,  have  been  adopted  by  Blumenbach,6  Sbmmering,7 
Savart,8  &c.  About  the  commencement  of  the  last  century,  Dodart9 
laid  before  the  Academic  des  Sciences  of  Paris  three  memoirs  on  the 
theory  of  voice,  in  which  he  considered  the  larynx  to  be  a  wind  instru- 
ment of  the  horn,  not  of  the  flute,  kind;  the  inferior  ligaments  of  the 
glottis  being  to  the  larynx  what  the  lips  are  to  the  performer  on  the 
horn.  In  1741,  Ferrein,10  in  a  communication  also  made  to  the  Aca- 
demie  des  Sciences,  maintained,  that  the  larynx  is  a  stringed  instru- 
ment;— the  sound  resulting  from  the  oscillation,  caused  in  what  he 
called  the  chordse  vocales  or  inferior  ligaments  of  the  larynx,  by  the 
air  in  expiration;  and  a  modification  of  this  view  was  professed  by  Dr. 
Young.11 

At  the  present  day,  the  majority  of  ^physiologists  and  natural  philo- 
sophers regard  the  larynx  as  a  wind  instrument,  of  the  reed  kind — as 
the  clarionet,  hautboy,  &c.,  and  they  differ  chiefly  in  explaining  the 
various  modifications  of  the  tone  and  quality  of  voice;  for  almost  all 
are  agreed,  that  it  is  produced  by  the  vibrations  of  the  inferior  liga- 
ments of  the  glottis.12  MM.  Piorry  and  Jadelot,  however,  consider  the 
glottis  an  instrument  sui  generis,  eminently  vital,  which,  of  itself,  exe- 
cutes the  movements  necessary  for  the  production  of  vocal  sounds. 
All  we  know  of  the  physiology  of  the  production  of  voice  is, — that  the 

I  Precis,  &c.,  i.  242.  a  Opera,  lib.  ii.  Problemat.,  §  xi. 
a  Opera :  de  Larynge,  lib.  vii. 

*  The  flute,  here  alluded  to,  is  the  common  flute  or  flute  a  bee,  in  which  the  embouchure  is 
at  one  extremity. 

s  De  Locutione,  &c.,  in  Oper.,  Lugd.  Bat.,  1737. 

6  Institutiones  Physiologicae,  §  154,  Golting.,  1798. 

7  Icones  Organorum  Gustus  et  Vocis,  Francof.,  1808;  and  Corp.  Human.  Fabric.,  vi.  93. 
s  Journal  de  Physiologic,  v.  367. 

9  Memoir,  de  1'Acad.  Royale  des  Sciences,  1700,  p.  244,  and  1707,  p.  409. 
'0  Ibid,  pour  1741,  p.  409,  and  Haller,  Elem.  Phys.,  ix.  3. 

II  Lectures  on  Natural  Philosoph.,  i.  400,  and  Philos.  Trans.,  for  1800,  p.  141. 
12  Willis,  in  Cambridge  Philosophical  Transactions,  vol.  iv. 


INTENSITY  OF  THE  VOICE.  463 

expired  air  is  sent  into  the  larynx  by  the  muscles  of  expiration, — that 
the  intrinsic  muscles  of  the  larynx  give  to  the  inferior  ligaments  suffi- 
cient tension  to  divide  the  air,  and  that  the  air  receives  the  vibrations, 
whence  sound  results.  The  process  is  very  complex.  Before  a  single 
word  can  be  uttered,  a  series  of  actions  must  be  executed:  these,  as 
stated  by  Sir  C.  Bell,1  consist  in  compression  of  the  chest;  adjustment 
of  the  glottis;  elevation  and  depression  of  the  larynx,  and  contraction 
of  the  pharynx, — actions  which  will  be  readily  understood  after  what 
has  been  already  said  on  the  mechanism  of  phonation. 

1.  Intensity  or  Strength  of  Voice. 

The  strength  of  a  sound  depends  upon  the  extent  of  the  vibrations 
of  the  body  producing  it.  In  the  case  of  voice,  it  is  dependent,  in 
part,  on  the  force  with  which  the  air  is  sent  from  the  lungs,  and  in  part 
on  the  size  of  the  larynx.  A  strong,  active  person,  with  a  capacious 
chest  and  prominent  pomum  Adami,  that  is,  with  a  large  larynx, — is  of 
an  organization  the  most  favourable  for  a  strong  voice.  But  if  the 
same  individual,  thus  favourably  organized,  be  reduced  in  strength,  his 
voice  is  enfeebled ;  because,  although  the  formation  of  the  larynx  may 
be  favourable,  he  is  incapable  of  sending  the  air  through  it  with  suffi- 
cient force  to  excite  extensive  vibrations  of  the  vocal  ligaments. 

The  voice  of  the  male  is  much  stronger  than  that  of  the  female,  of 
the  eunuch,  or  child.  This  is  greatly  owing  to  his  larynx  being  more 
developed.  The  change  in  the  voice  of  the  male  at  puberty  is  owing  to 
the  same  cause, — the  prominence  of  the  pomum  Adami,  which  is  first 
observed  at  this  age,  indicating  the  elongation  that  has  supervened  in 
the  lips  of  the  glottis.  As  voice  is  commonly  produced,  both  ligaments 
of  the  glottis  participate;  but  if  one  should  lose  its  power  of  vibrating, 
from  any  cause,  as  from  paralysis  of  one-half  the  body,  the  voice  loses, 
cseteris  paribus,  one-half  its  intensity.  M.  Magendie2  affirms,  that  this 
is  manifested  by  cutting  one  of  the  recurrents  on  the  dog. 

2.   Tone  of  Voice. 

Nothing  can  exceed  the  human  organ  of  voice  in  variety  of  tones, 
and  execution.  Dr.  Barclay  has  endeavoured  to  calculate  the  different 
changes  of  which  it  is  susceptible,  proceeding  on  the  principle,  that 
where  a  number  of  movable  parts  constitutes  an  organ  destined  for 
some  particular  function,  and  this  function  is  varied  and  modified  by 
every  change  in  the  relative  situation  of  the  movable  parts,  the  number 
of  changes,  producible  in  the  organ,  must  at  least  equal  the  number  of 
muscles  employed,  together  with  all  the  combinations  of  which  they  are 
capable.  The  muscles,  proper  to  the  five  cartilages  of  the  larynx,  are 
at  least  seven  pairs;  and  fourteen  muscles,  that  can  act  separately  or 
in  pairs,  in  combination  with  the  whole  or  with  any  two  or  more  of  the 
rest,  are  estimated  to  be  capable  of  producing  upwards  of  sixteen 
thousand  different  movements — not  reckoning  as  changes  the  various 
degrees  of  force  and  velocity,  with  which  they  are  brought  into  action. 

1  Philos.  Transact,  for  1832,  p.  299;  and  Nervous  System,  3d  edit.,  Lond.,  1837. 
3  Precis,  &c.,  i.  245. 


464  MUSCULAR  MOTION. 

These  muscles,  too,  are  only  the  proper  muscles  of  the  larynx,  or  those 
restricted  in  their  attachments  to  its  five  cartilages.  They  are  but  a 
few  of  the  muscles  of  voice.  In  speaking,  we  use  a  great  many  more. 
Fifteen  pairs  of  different  muscles,  attached  to  the  cartilages  or  os 
hyoides,  and  acting  as  agents,  antagonists,  or  directors,  are  constantly 
employed  in  keeping  the  cartilages  steady,  regulating  their  situation, 
and  moving  them  as  occasion  requires, — upwards  and  downwards,  back- 
wards and  forwards,  and  in  every  intermediate  direction,  according  to 
the  course  of  the  fibres,  or  in  the  diagonal  between  different  fibres. 
These  muscles, 'independently  of  the  former,  are  susceptible,  it  is  cal- 
culated, of  upwards  of  1,073,841,800  different  combinations;  and,  when 
they  co-operate  with  the  seven  pairs  of  the  larynx,  of  17592186,044,415 ; 
exclusive  of  the  changes  that  must  arise  from  the  different  degrees  of 
force,  velocity,  &c.,  with  which  they  may  be  brought  into  action.  But 
these  muscles  are  not  the  whole  that  co-operate  with  the  larynx  in 
the  production  of  voice.  The  diaphragm,  abdominal  muscles,  inter- 
costals,  and  all,  that  directly  or  indirectly  act  on  the  air,  or  on  the 
parts  to  which  the  muscles  of  the  glottis  or  os  hyoides  are  attached, 
contribute  their  share.  The  numerical  estimate  would,  consequently, 
require  to  be  largely  augmented.  Mr.  Bishop  computes  the  number  of 
muscles  brought  into  action  at  the  same  time  in  the  ordinary  modula- 
tions of  the  voice  to  be  one  hundred.1  Such  calculations  are,  of 
course,  only  approximate;  but  they  show  the  inconceivable  variety  of 
movement  of  which  the  vocal  apparatus  is  directly  or  indirectly  sus- 
ceptible. 

The  tone  of  the  voice  has  been  a  great  stumbling-block  to  the  physi- 
ologist and  physicist.  The  mode,  in  which  it  is  produced,  and  the 
parts  more  immediately  concerned  in  the  function,  have  been  the 
object  of  various  theories  or  hypotheses,  regarding  the  voice. 

Galen,  under  his  theory,  that  the  larynx  is  a  wind  instrument  of  the 
flute  kind,  of  which  the  glottis  is  the  beak  and  the  trachea  the  body 
of  the  flute,  ascribed  the  variety  of  tones  to  two  causes — to  variation 
in  the  length  of  the  musical  instrument,  and  in  the  embouchure.  In 
the  theory  of  Dodart,  in  which  the  human  vocal  instrument  was  likened 
to  a  horn,  the  inferior  ligaments  of  the  glottis  being  compared  to  the 
lips  of  the  performer,  no  importance  was  attached  to  variation  in  the 
length  of  the  instrument.  He  attributed  variety  of  tones  to  simple 
alteration  in  the  embouchure  or  mouth-piece, — in  other  words,  to 
changes  in  the  size  of  the  glottis,  by  the  action  of  its  appropriate  mus- 
cles; and  the  rising  and  falling  of  the  larynx,  he  regarded  as  serving 
no  other  purpose  than  that  of  influencing  mechanically  the  size  of  the 
aperture  of  the  glottis;  whilst  Ferrein,  who  regarded  the  larynx  as  a 
stringed  instrument,  accounted  for  the  variety  of  tones  by  different 
degrees  of  tension  and  length  of  the  inferior  ligaments  of  the  glottis  or 
vocal  cords.  In  the  production  of  acute  tones,  these  cords  were 
stretched  and  shortened.  For  grave  tones,  they  were  relaxed,  and 
lengthened.  He  was  of  opinion,  that  the  length  of  the  vocal  tube  had 
no  influence  on  the  tone. 

1  The  London  and  Edinburgh  Philosoph.  Magazine,  &c.,  for  Sept.,  1836,  p.  209. 


TONE  OF  THE  VOICE.  465 

In  later  years,  several  new  views  have  been  propounded  on  this 
subject,  and  chiefly  by  MM.  Cuvier,  Dutrochet,  Magendie,  Biot,  Savart, 
&c., — men  of  the  highest  eminence  in  various  departments  of  physical 
science. 

M.  Cuvier1  attributes  variety  of  tones,  in  the  first  place,  to  varied 
length  of  the  vocal  tube,  and  to  differences  in  size  of  the  aperture  of  the 
glottis;  and,  secondly,  to  the  shape  and  condition  of  the  external  aper- 
ture of  the  tube, — that  is,  of  the  lips  and  nose.  The  larynx  he  regards 
as  a  wind  instrument,  in  which  the  inferior  ligaments  act,  not  as  cords, 
but  like  the  reed  of  a  clarionet,  or  the  lame  of  an  organ  pipe.  The 
lungs  and  their  external  muscular  apparatus  constitute  the  reservoir  of 
air  and  bellows ;  the  trachea  conducts  the  air,  and  the  glottis  is  the 
embouchure  with  its  reed;  the  mouth,  and  the  whole  of  the  space  com- 
prised between  the  glottis  and  the  opening  of  the  lips,  being  the  body 
of  the  instrument ;  whilst  the  openings  of  the  nostrils  are  lateral  holes, 
that  permit  the  size  of  the  instrument  to  be  varied.  The  tones  are 
changed  by  three  causes  of  a  similar  character  to  those  that  modify 
them  in  musical  instruments ; — the  length  of  the  body  of  the  instru- 
ment, and  the  variableness  of  the  embouchure,  and  of  the  aperture  at 
the  lower  extremity  of  the  instrument.  The  condition  of  the  external 
aperture  of  the  vocal  tube  has,  doubtless,  much  to  do  with  the  charac- 
ter of  the  tone  produced  by  the  glottis ;  but  its  influence  appears  to  be 
greatly  limited  to  giving  it  rotundity,  volume,  or  the  contrary, — as 
will  be  seen  hereafter ;  although  analogy  would  seem  to  show,  that  the 
tone  may  be  varied  by  more  or  less  closure  of  the  aperture.  Many 
different  notes  can  be  produced  in  the  first  joint  of  a  flute,  if  we  modify 
the  size  of  the  opening  at  its  extremity  by  passing  the  thumb  more  or 
less  within  it.  It  is  doubtful,  however,  whether  in  man  the  altered 
size  of  the  external  aperture,  or  the  elongation  or  decurtation  of  the 
tube  exerts  as  much  influence  in  the  production  of  acute  or  grave  sounds 
as  Cuvier  imagined. 

M.  Dutrochet2  again,  believes,  that  the  vocal  tube  has  no  influence  in 
the  production  of  tones,  and  that  the  larynx  is  a  simple  vibrating  in- 
strument, uncomplicated  with  a  tube,  the  vocal  sound  being  caused  by 
the  vibrations  into  which  the  vocal  cords  are  thrown  by  the  impulse  of 
the  expired  air.  In  his  experiments,  he  saw  the  inferior  ligaments 
vibrate ;  and  he  concludes,  that  the  tone  of  the  voice  depends  upon  the 
number  of-  vibrations  of  those  ligaments  in  a  given  time,  and  that  their 
number  will  necessarily  vary  greatly,  as  the  dimensions  of  the  liga- 
ments,— that  is,  their  length  and  thickness, — and  their  elasticity,  are 
susceptible  of  incessant  changes,  by  the  contraction  of  the  thyro-aryte- 
noid  muscle,  of  which  they  are  essentially  composed, — the  ligament, 
covering  the  muscle,  serving  only  "  to  prevent  the  collisions  of  the  mus- 
cles at  the  time  of  vibration," — as  well  as  by  that  of  the  other  intrinsic 
muscles  of  the  larynx. 

MM.  Biot  and  Magendie3  dissent  from  M.  Dutrochet  in  some  important 

1  Le9ons  d' Anatomic  Compares,  torn.  iv.  445. 

a  Mem.  pour  servir  a  1'Histoire  Anat.  et  Physiol.  des  Vegetaux  et  des  Anirnaux,  t.  ii., 
Paris,  1837  ;  and  Adelon,  Physiologic  de  1'Homme,  edit,  cit.,  ii.  239. 
a  Precis  Elementaire,  &c.,  i.  248. 

VOL.  i.— 30 


466  MUSCULAR  MOTION. 

points.  Like  him,  they  do  not  consider  the  human  larynx  to  consti- 
tute a  stringed  instrument.  They  regard  it  as  a  variety  of  reed  instru- 
ment, but  consider  the  vocal  tube  to  be  of  moment  in  the  production 
of  the  voice.  The  objections  they  urge  against  the  view  of  its  resem- 
bling a  stringed  instrument,  are, — the  kind  of  articulation  between  the 
arytenoid  and  cricoid  cartilages,  which  admits  of  motion  inwards  and 
outwards  only;  and  they  ask  how  the  vocal  cords  can  retain  the  length 
requisite  for  the  production  of  grave  tones;  and  how  they  can  elicit 
sounds  of  a  volume  so  considerable  as  those  of  the  human  voice?  They 
esteem  it,  consequently,  a  reed  instrument  of  such  nature  as  to  be 
capable  of  affording  very  grave  tones  with  a  pipe  of  little  length ;  and, 
with  slight  variation  of  its  length,  susceptible,  not  only  of  furnishing  a 
certain  series  of  sounds  in  harmonic  progression,  but  all  the  imaginable 
sounds  and  shades  of  sounds,  in  the  compass  of  the  musical  scale  which 
each  voice  embraces. 

The  theory  of  the  reed  instrument  they  apply  to  the  vocal  appara- 
tus. The  lips  of  the  glottis  are  the  reed,  and  the  thyro-arytenoid  mus- 
cles render  them  fit  for  vibrating.  In  his  experiments,  made  on  living 
dogs,  M.  Magendie  saw,  that  when  grave  sounds  were  produced,  the 
ligaments  of  the  glottis  vibrated  in  their  whole  extent,  and  the  expired 
air  issued  through  the  whole  of  the  glottis.  In  acute  sounds,  on  the 
other  hand,  they  vibrated  only  at  their  posterior  part,  and  the  air 
passed  out  through  the  part  only  that  vibrated,  the  aperture  being, 
consequently,  diminished ;  and,  when  the  sounds  became  very  acute, 
they  vibrated  only  at  their  arytenoid  extremity,  and  scarcely  any  air 
issued ;  so  that  tones  beyond  a  certain  degree  of  acuteness,  cannot  be 
produced  in  consequence  of  the  complete  closure  of  the  glottis.  The 
arytenoid  muscle,  whose  chief  use  is  to  close  the  glottis  at  its  posterior 
extremity,  he  conceives  to  be  the  principal  agent  in  the  production  of 
acute  sounds,  and  this  idea  was  confirmed  by  the  section  of  the  two 
laryngeal  nerves  that  give  motion  to  this  muscle,  which  was  followed 
by  loss  of  the  power  of  producing  almost  all  the  acute  tones;  the 
voice,  at  the  same  time,  acquiring  a  degree  of  habitual  graveness,  which 
it  did  not  previously  possess.  The  influence  of  contraction  of  the 
thyro-arytenoid  muscles  on  the  tones  is  exerted  in  increasing  or  dimi- 
nishing the  elasticity  of  the  ligaments,  and  thus,  in  modifying  the 
rapidity  of  the  vibrations,  so  as  to  favor  the  production  of  acute  or 
grave  tones.  He  thinks,  too,  that  the  contraction  of  these  muscles 
concurs  greatly  in  closing,  in  part,  the  glottis,  particularly  its  anterior 
half;  although  the  course  of  its  fibres,  it  would  appear,  ought  rather 
to  widen  the  aperture.  The  trachea  or  porte-vent  has  usually  been 
thought  to  exert  no  influence  on  the  nature  of  the  sound  produced.  It 
has  been  conceived,  however,  by  M.  Grenie  and  others,  that  its  elonga- 
tion or  decurtation  may  occasion  some  modification. 

Thus  much  for  the  part  that  resembles  the  reed — MM.  Biot  and  Ma- 
gendie include  in  their  theory  of  the  voice  the  action  of  the  vocal  tube 
likewise.  This  tube  being,  in  man,  capable  of  elongation  and  decurta- 
tion, of  dilatation  and  contraction,  and  of  assuming  an  infinite  number  of 
shapes,  they  think  it  well  adapted,  if  placed  in  harmonic  relation  with 
the  larynx,  for  fulfilling  the  functions  of  the  body  of  a  reed  instru- 


TONE  OF  THE  VOICE.  467 

ment, — and  thus  of  favouring  the  production  of  the  numerous  tones  of 
•which  the  voice  is  capable ;  of  augmenting  the  intensity  of  the  vocal  sound 
by  assuming  a  conical  shape  with  a  wide  external  aperture;  of  giving 
rotundity  and  sweetness  by  the  proper  arrangement  of  its  external 
outlet,  or  of  entirely  arresting  it  by  the  closure  of  the  outlet.  The 
larynx  rises  in  the  production  of  acute,  and  sinks  in  that  of  grave 
sounds.  The  vocal  tube  is,  consequently,  shortened  in  the  former  case ; 
elongated  in  the  latter.  It  experiences,  also,  a  simultaneous  change 
in  its  width.  When  the  larynx  descends, — in  other  words,  when  the 
vocal  tube  is  elongated,  the  thyroid  cartilage  is  depressed,  and  separated 
ftxxm  the  os  hyoides  by  the  whole  height  of  the  thyro-hyoid  membrane. 
By  this  separation,  the  epiglottic  gland  is  carried  forwards,  and  lodged 
in  the  concavity  at  the  posterior  surface  of  the  os  hyoides.  The  gland 
drags  after  it  the  epiglottis;  and  a  considerable  enlargement  in  width 
occurs  at  the  inferior  part  of  the  vocal  tube.  The  opposite  effect  re- 
sults when  the  larynx  rises.  The  use  of  the  ventricles  of  the  larynx,  M. 
Magendie1  considers  to  be,  to  isolate  the  inferior  ligaments,  so  that  they 
may  vibrate  freely  in  the  air.  Lastly;  in  this  theory  the  epiglottis  has 
a  use  assigned  to  it  which  is  novel.  In  certain  experiments,  instituted 
by  M.  Grenie'2  for  the  improvement  of  reed  instruments — being  desirous 
of  increasing  the  intensity  of  sound  without  changing  the  reed  in  any 
respect — he  found  that,  to  succeed,  he  was  compelled  to  augment  gradu- 
ally the  strength  of  the  current  of  air ;  but  this  augmentation,  by  ren- 
dering the  sounds  stronger  caused  them  to  rise.  To  remedy  this  incon- 
venience, M.  Grenie  found  nothing  answer  except  placing  obliquely  in  the 
tube  immediately  below  the  reed  a  supple,  elastic  tongue,  nearly  as  the 
epiglottis  is  placed  above  the  glottis.  From  this,  M.  Magendie3  infers, 
that  the  epiglottis  may  assist  in  giving  to  man  the  faculty  of  increasing 
or  inflating  the  vocal  sound,  without  causing  it  to  mount ;  but,  as  Mr. 
Bishop4  properly  remarks,  neither  the  elevation  nor  depression  of  the 
epiglottis  can  affect  or  regulate  the  vibrations  of  the  glottis. 

Such  are  the  main  propositions  of  the  theory  of  the  voice  by  MM. 
!Biot  and  Magendie.  The  larynx  represents  a  reed  with  a  double 
tongue;  the  tones  of  which  are  acute  in  proportion  to  the  decurtation 
of  the  laminae;  and  grave  in  proportion  to  their  length.  They  admit, 
however,  that,  although  the  analogy  between  the  organ  of  voice  and 
the  reed  is  just,  the  identity  is  not  complete.  The  ordinary  reeds  are 
composed  of  rectangular  laminae;  fixed  at  one  side,  but  loose  on  the 
three  others;  whilst,  in  the  larynx,  the  vibrating  laminse,  which  are  also 
nearly  rectangular,  are  fixed  by  three  sides,  and  free  by  one  only. 
Moreover,  the  tones  of  the  ordinary  reed  can  be  made  to  rise  or  descend 
by  varying  its  length ;  whilst  in  the  laminae  of  the  larynx  the  width 
varies.  Lastly — say  they — in  musical  instruments,  reeds  are  never 
employed,  whose  movable  laminse  can  vary  in  thickness  and  elasticity 
every  moment,  as  is  the  case  with  the  ligaments  of  the  glottis ;  so  that, 

1  Precis,  &c.,  i.  252  ;  see,  also,  Sir  C.  Bell,Philos.  Transact,  for  1832;  and  Nervous  System, 
3d  edit.,  p.  484,  Lotid.,  1837. 

a  Biot,  Precis  Elementaire  de  Physique,  p.  399. 

3  Precis,  &c.,  i.  252. 

4  London  and  Edinburgh  Philosophical  Magazine,  p.  205,  for  Sept.  1836. 


468  MUSCULAR  MOTION. 

although  we  may  conceive,  that  the  larynx  can  produce  voice  and  vary 
its  tones,  in  the  manner  of  a  reed  instrument,  we  are  unable  to  demon- 
strate the  particulars  of  its  mode  of  action. 

All  the  more  modern  theories  —  detailed  above,  at  more  or  less  length 
—  agree,  then,  in  considering  the  larynx  to  be  a  wind  instrument  of  the 
reed  kind:  they  differ,  chiefly,  in  the  role  which  they  assign  to  the 
vocal  tube  in  causing  the  variation  of  tones. 

M.  Savart1  has  propounded  a  theory  of  voice,  in  which  he  differs  from 
MM.  Cuvier,  Dutrochet,  and  Magendie.  He  denies,  that  the  mechanism 
of  the  voice  resembles  that  of  the  reed  instrument,  and  returns  to  the 
old  idea,  which  referred  the  vocal  organ  to  an  instrument  of  the  flute 
kind.  The  sounds  of  the  human  voice  have,  —  he  remarks,  —  a  peculiar 
character,  which  no  musical  instrument  can  imitate;  and  this  must 
necessarily  be  the  case,  as  they  are  produced  by  a  mechanism  founded 
on  principles  which  do  not  serve  as  a  basis  in  the  construction  of  any  of 
our  instruments.  He  conceives  that  the  production  of  the  voice  is 
analogous  to  that  of  the  sound  in  the  tube  of  a  flute;  and  that  the 
small  column  of  air,  contained  in  the  larynx  and  mouth,  by  the  nature 
of  the  elastic  parietes  which  bound  them,  as  well  as  by  the  mode  in 
which  it  is  thrown  into  vibrations,  is  susceptible  of  rendering  sounds  of 
a  particular  nature,  and,  at  the  same  time,  much  more  grave  than  the 
dimensions  would  seem  to  permit. 

In  the  tube  of  a  flute,  the  column  of  air  within  is  the  sonorous  body. 
A  sound  is  first  produced  at  the  embouchure  of  the  .instrument,  by  the 
division  which  the  air  experiences  when  blown  in;  and  this  excites  similar 
sonorous  undulations  in  the  column  of  air  that  fills  the  tube.  The 
sound,  resulting  in  this  way,  is  grave  in  proportion  to  the  length  of  the 
tube;  and  in  order  to  vary  its  tones,  the  instrument  has  apertures  -in 
its  sides,  by  means  of  which  its  length  may  be  modified. 

In  assimilating  the  human  vocal  apparatus  to  a  flute,  the  great  diffi- 
culty has  been  to  explain  how,  with  so  short  a  tube  as  the  vocal  tube 
in  man,  and  one  so  little  variable  in  length,  tones  so  different,  and 
especially  so  grave,  can  be  produced.  To  account  for  this,  M.  Savart 
establishes  a  number  of  physical  facts,  previously  unknown  or  unno- 
ticed. In  organ-pipes  of  great  length,  the  velocity  of  the  current  of 
air,  which  acts  as  a  motor,  has  but  little  influence  on  the  number  of 
oscillations.  When  the  length  of  the  pipe,  for  instance,  is  twelve  or  fif- 
teen times  greater  than  its  diameter,  it  is  difficult  to  vary  the  sound  a 
semitone.  When  air  is  forcibly  driven  in,  it  rises  an  octave;  and, 
when  its  velocity  is  diminished,  the  sound  becomes  more  feeble;  but  is 
depressed  an  almost  imperceptible  quantity.  In  short  pipes,  on  the 
contrary,  the  influence  of  the  velocity  of  the  current  of  air  is  much 
greater,  and  several  tones  can  be  elicited.  The  bird- 
call used  by  sportsmen  is  illustrative  of  this  principle. 
It  is  a  small  instrument,  employed  for  imitating  the 
notes  of  certain  birds,  and  consists  of  a  cylindrical  tube, 
about  three-fourths  of  an  inch  in  diameter,  and  a  third 

of  an  inch  hiSn;  closed  at  each  end  bJ  a  thin>  flat  Plate> 


1  Journal  de  Physiologic,  v.  367,  Paris,  1825;  and  Annales  de  Physique  et  de  Chimie, 
xxx.  64,  and  xxxii. 


TONE  OF  THE  VOICE.  .  469 

which  is  pierced,  at  its  centre,  "by  a  hole  about  the  sixth  of  an  inch 
in  diameter.  Sometimes,  it  has  the  shape  represented  in  the  next 
marginal  figure.  By  placing  this  instrument  between  the  teeth  and 
lips,  and  forcing  air,  with  more  or  less  strength, 
through  the  two  apertures,  different  sounds  can  be  Fis-  20°- 

produced.     This  is  more  certainly  effected,  by  attach- 
ing a  porte-vent  to  the  whistle,  as  A  A,  Fig.  200, 
when  it  is  capable  of  producing  all  the  sounds  com- 
prised in  an  extent  of  from  an  octave  and  a  half  to 
two    octaves.     M.   Savart  found,  that,   other   things 
being  equal,  the  diameter  of  the  apertures  has  an  ap-     A. 
preciable  influence  on  the  acuteness  or  graveness  of 
the  sounds,  which  are  graver  the  larger  the  orifices. 
The  nature  of  the  parietes  of  the  instrument  appeared, 
also,  to  exert  some  effect  on  the  number  of  oscillations,   Scheme  of  a  Bird. 
and  the  quality  of  the  sounds ;  and  if,  in  the  hemispher-  •  •          call. 
ical  whistle,  Fig.  200,  the  plain  plate  was  replaced 
by  a  thin  leaf  of  some  extensible  substance,  as  parchment,  the  sounds 
issued  more  rapidly,  and  were  usually  more  grave,  full,  and  agreeable, 
than  when  it  was  formed  of  a  more  solid  substance. 

It  is  an  opinion  generally  admitted,  that  the  material,  which  com- 
poses an  organ-pipe,  has  no  influence  on  the  number  of  vibrations, 
which  the  column  of  air,  contained  in  it,  is  capable  of  executing.  This 
is  true  as  regards  long  pipes ;  but,  according  to  M.  Savart,  it  is  not  so 
with  short ;  and  the  nature  of  the  biseau1  he  conceives,  may  have  a 
glfeat  influence,  even  on  the  sound  of  long  pipes.  For  instance,  if  we 
.substitute,  for  the  stiff  lamina,  which  forms  the  biseau  of  an  organ 
,})ipe  two  feet  long  and  two  inches  on  the  side,  a  lamina,  formed  of 
some  elastic  substance,  as  skin  or  parchment,  so  arranged  as  to  admit 
of  being  stretched  at  pleasure — by  gradually  increasing  the  tension 
of  the  membrane,  at  the  same  time  that  we  increase  the  velocity  of 
the  current  of  air,  the  tone  may  be  made  to  vary^a  fourth,  and  even 
a  fifth.  In  shorter  tubes,  the  much  greater  influence  of  the  velocity  of 
the  current  of  air  being  united  to  that  of  the  tension  of  the  biseau,  the 
result  is  still  more  evident.  Thus,  the  sound  of  a  cubical  tube  may  be 
easily  lowered  an  octave,  when  the  parietes  of  the  biseau  are  suscepti- 
ble of  different  degrees  of  tension;  but  when  all  the  parietes  of  a  short 
pipe  are  of  a  nature  to  enter  into  vibration  along  with  the  air  they 
contain,  and  when  their  degree  of  tension  can  be,  moreover,  varied, 
they  have  such  an  influence  on  the  number  of  vibrations,  that  the 
sound  may  be  greatly  modified.  Short  tubes,  open  at  both  extremities, 
and  formed  of  elastic  parietes,  are  also  susceptible  of  producing  a  great 
variety  of  sounds,  even  when  they  are  only  partly  membranous;  and  the 
quality  of  the  sound  of  membranous  tubes  is  said  to  be  somewhat  pecu- 
liar,— partaking  of  that  of  the  flute,  and  of  the  free  reed.  Again,  in 
order  that  a  mass  of  air  shall  enter  into  vibration,  a  sound  must  be 
produced  in  some  part  of  it.  In  an  organ  pipe,  for  example,  a  sound 

1  The  biseau  or  languette  is  the  diaphragm  placed  between  the  tody  of  an  organ  pipe  and 
its  foot. 


470  MUSCULAR  MOTION. 

is  first  excited  at  the  embouchure,  which  throws  the  column  of  air, 
within  the  instrument,  into  vibration.  Every  sound,  indeed,  produced 
at  the  orifice  of  a  column  of  air,  throws  it  into  vibration,  provided  its 
dimensions  be  adapted  to  the  length  of  the  waves  produced  directly: — 
hence  the  utility  of  a  musical  pipe  having  parietes  susceptible  of  vary- 
ing in  size  and  tension,  whatever  may  be  the  character  of  its  embou- 
chure. Lastly. — The  fundamental  note  of  a  tube  closed  at  one  end, 
whose  diameter  is  every  where  the  same,  is  an  octave  lower  than  the 
sound  of  the  same  tube,  when  open  at  both  extremities.  But  this  is 
not  the  case  with  tubes  that  are  of  unequal  diameter,  conical  and  pyra- 
midal, &c.,  when  made  to  vibrate  at  their  narrowest  part.  The  tone 
produced  in  such  case  increases  in  graveness,  according  to  the  difference 
between  its  narrow  and  expanded  portions. 

These  different  physical  conditions  M.  Savart  invokes  to  account  for 
the  different  tones  of  the  human  voice, — under  the  theory,  that  the  vocal 
organ — composed  of  the  larynx,  pharynx,  and  mouth — forms  a  conical 
tube,  in  which  the  air  is  set  in  vibration  by  a  movement  similar  to  that 
which  prevails  in  organ  pipes.  The  trachea  is  terminated  above  by  a 
cleft — the  glottis — which  is  the  inferior  aperture  of  the  vocal  instru- 
ment. This  cleft,  which  is  capable  of  being  rendered  more  or  less  nar- 
row, plays  the  same  part  as  the  lumiere  des  twjaux  d  bouche  or  narrow 
space  in  the  organ  pipe,  at  the  edge  of  the  biseau  or  languette,  along 
which  the  air  passes.  The  air  clears  it,  traverses  the  ventricles  of  the 
larynx  or  cavity  of  the  instrument,  and  strikes  the  superior  ligaments. 
These  surround  the  upper  aperture  of  the  instrument,  and  fulfil  the 
same  function  as  the  biseau  of  the  organ  pipe.  The  air,  contained  in 
the  interior  of  the  larynx,  now  vibrates,  and  sound  is  produced.  This 
sound  acquires  intensity,  from  the  waves  that  constitute  it  extending 
into  the  vocal  tube  above  the  larynx,  and  exciting  in  the  column  of 
air  filling  it,  a  movement  similar  to  that  occasioned  in  the  tube  of  a 
flute;  except,  that  the  tone  is  susceptible  of  much  variation,  because 
the  larynx,  being  a  short  tube,  can  give  rise  to  various  tones  by  simple 
modification  in  the  velocity  of  the  air  sent  through  it :  moreover,  the 
vocal  tube  has  the  same  power,  its  parietes  being  membranous,  of  a 
vibratory  nature,  and  capable  of  different  degrees  of  tension.  The 
inferior  or  outer  part  of  the  vocal  tube  is  equally  constituted  of  elastic 
parietes,  susceptible  of  varied  tension;  and  the  mouth,  by  modifying  the 
dimensions  of  the  column  of  air  within  the  tube,  exerts  an  influence  on 
the  number  of  vibrations,  which  the  column  is  capable  of  experiencing; 
whilst  the  lips  can  convert  the  channel  at  pleasure  into  an  open  or  closed 
conical  tube.  Certain  sounds,  M.  Savart  affirms,  are  produced  alto- 
gether in  the  ventricles  of  the  larynx,  as  those  of  pain,  and  the  falsetto 
voice,  for  example.  They  can  be  elicited  when  the  vocal  tube  has  been 
removed;  and  there  are  animals,  in  which  the  vocal  organ  is  reduced  to 
the  ventricles  of  the  larynx, — frogs  for  example.  Savart,  consequently, 
considers,  that  the  human  vocal  organ  bears  in  its  essential  parts,  C  C, 
B  B,  Fig.  197,  a  striking  analogy  to  the  action  of  the  bird-call;  and, 
in  this  way,  he  explains  the  use  of  the  superior  ligaments  C  C,  which 
are  entirely  overlooked  in  the  different  theories  of  the  voice  previously 
propounded. 


VOICE — TIMBRE.  471 

We  have  given  M.  Savart's  view  at  some  length,  in  consequence  of  its 
ingenuity,  and  of  its  seeming  to  explain  as  well  as  any  other  theory 
the  varied  tones  of  which  the  human  voice  is  susceptible.  It  cannot, 
however,  be  esteemed  established,  inasmuch  as  it  is  diametrically  op- 
posed, in  many  of  its  points,  to  the  observations  and  vivisections  of 
distinguished  physiologists;  who,  it  has  been  seen,  affirm,  that  voice  is 
produced  solely  by  the  inferior  ligaments;  that  all  the  parts  above 
these  may  be  destroyed,  and  yet  voice  continue ;  and  that  a  wound  in 
the  ventricles,  which  permits  the  exit  of  air  through  the  parietes  of  the 
larynx,  does  not  destroy  the  function.  Our  notions  on  this  point  must 
not,  therefore,  be  considered  definite.  Farther  experiments  are  neces- 
sary; and,  in  all  deductions  from  them,  great  importance  will  have  to 
be  attached  to  the  vital  action  of  the  organs,  especially  of  the  intrinsic 
muscles,  which  are  capable  of  modifying  the  situation  of  parts,  and  the 
character  of  the  function  in  myriads  of  inappreciable  ways.  It  may 
be  added,  that,  more  recently,  Mr.  J.  Bishop,1  from  his  numerous 
investigations,  has  arrived  at  the  conclusion,  that  the  human  voice 
results  from  the  vibration  of  membranous  ligaments,  in  obedience, 
first,  to  the  laws  of  musical  strings ;  secondly,  to  those  of  reed  instru- 
ments; and  thirdly  to  those  of  membranous  pipes;  and  that  the  vocal 
organs  combine  in  reality  the  actions  of  each  of  these  instruments,  and 
exhibit  in  conjunction  the  perfect  type  of  every  one  of  them. 

3.   Timbre  or  Quality  of  Voice. 

In  the  preliminary  essay  on  sound,  attached  to  the  physiology  of 
audition,  it  was  remarked,  that  the  cause  of  the  different  timbres  of 
sound,  in  the  various  musical  instruments,  has  hitherto  remained  un- 
explained. The  same  remark  is  applicable  to  the  timbre  of  the  voice. 
Each  individual  has  his  own,  by  which  he  is  distinguished  from  those 
around  him;  and  it  is  the  same  with  each  sex  and  period  of  life.  In 
this  the  larynx  is,  doubtless,  concerned;  but  in  what  manner  is  not 
clear.  The  feminine  timbre  or  stamp,  that  characterizes  the  voice  of 
the  child  and  the  eunuch,  would  appear  to  be  generally  connected  with 
the  cartilaginous  condition  of  the  larynx;  whilst  the  masculine  voice, 
which  is  sometimes  met  with  in  the  female,  is  connected  with  the  osseous 
condition  of  the  parts,  and  especially  of  the  thyroid  cartilage.  An 
infinity  of  modifications  may  also  be  produced  by  changes  in  the  thick- 
ness, elasticity,  and  size  of  the  lips  of  the  glottis.  The  vocal  tube 
probably  exerts  great  influence  in  this  respect  by  its  shape,  as  well  as 
by  the  nature  of  the  material  composing  it.  Such  conditions,  at  least, 
appear  to  modify  the  timbre  of  our  wind  instruments.  The  timbre  of 
a  flute,  made  of  glass  or  brass,  is  very  different  from  that  of  one  formed 
of  wood,  although  the  instruments  may  resemble  each  other  in  every 
other  respect.  The  form  of  the  body  of  the  instrument  has,  also,  con- 
siderable effect.  If  it  be  conical,  and  wider  towards  its  outlet,  as  in 
the  clarionet,  or  hautboy,  the  quality  of  the  sound  is  shrill.  If  it  be 
entirely  cylindrical,  as  in  the  flute,  we  have  the  soft  quality,  which  cha- 

1  Proceedings  of  the  Royal  Society,  No.  65,  Lond.,  1847. 


472  MUSCULAR  MOTION. 

racterizes  that  instrument ;  and  on  the  other  hand,  if  the  tube  be  ex- 
panded at  its  middle  portion,  the  quality  of  the  sound  is  raucous  and 
dull.  It  is  probable,  therefore,  that  we  must  reckon,  amongst  the  ele- 
ments of  the  varying  character  of  the  timbre  or  stamp  of  the  voice,  the 
different  conditions  of  the  vocal  tube,  as  to  length,  width,  and  form; 
and  that  we  must  likewise  include  the  position  and  shape  of  the  tongue, 
of  the  velum  palati,  mouth  and  nose,  the  presence  or  want  of  teeth,  &c., 
all  which  modify  the  voice  considerably.  The  first  modification  takes 
place,  probably,  in  the  ventricles  of  the  larynx,  in  which  the  voice 
acquires  more  rotundity  and  expansion.  It  was  remarked  by  Dr.  Isaac 
Parrish,1  that  a  peculiar  change  was  induced  in  two  cases  by  the  excision 
of  the  tonsils.  The  voice  was  rendered  shrill  and  whistling. 

By  the  generality  of  physiologists,  it  is  conceived,  that  the  voice 
enters  the  diiferent  nasal  fossae,  and,  by  resounding  in  them,  a  timbre 
or  character  is  given  to  it,  which  it  would  not  otherwise  possess.  Ac- 
cording to  this  view,  when  it  is  prevented  from  passing  through  the 
nose,  from  any  cause,  it  acquires  the  nasal  twang ;  or,  by  a  singular  in- 
accuracy of  language,  we  are  said  "to  talk  through  the  nose."  M.  Ma- 
gendie,2  however,  considers,  that  whenever  the  voice  passes  through  the 
nasal  fossae,  it  becomes  disagreeable  and  nasal.  The  sample  experiment 
of  holding  the  nose  exhibits,  that,  in  the  enunciation  of  the  true  vocal 
sounds,  unmodified  by  the  action  of  the  organs  of  articulation,  the 
timbre  or  quality  is  materially  altered;  and  we  shall  see,  hereafter,  that 
there  are  certain  letters,  that  do  not  admit  of  enunciation,  unless  the 
nasal  fossae  be  pervious — the  m,  the  n,  and  ng,  for  example.  It  would 
seem  that,  under  ordinary  circumstances,  the  sound,  after  it  is  produced 
in  the  larynx,  flows  out  by  both  channels ;  and  that,  if  we  either  shut 
off  the  passage  through  the  nose  altogether,  or  attempt  to  pass  it  more 
than  usually  through  the  nasal  fossae,  the  voice  becomes  nasal.  The 
fine,  sharp  voice  prior  to  puberty  is  especially  owing  to  the  narrowness 
of  the  glottis,  the  shortness  of  the  ligaments,  and,  according  to  M.  Mal- 
gaigne,3  the  want  of  developement  of  the  nasal  cavities.  At  puberty, 
the  size  of  the  opening  of  the  larynx  is  doubled;  the  ligaments  enlarge, 
and  the  size  of  the  passages  of  the  nose  is  augmented.  The  timbre  now 
becomes  raucous,  dull,  and  coarse;  and  for  a  time  the  harmony  of  the 
voice  is  lost.  M.  Bennati,4  himself  an  excellent  theoretical  and  prac- 
tical musician,  whose  voice  marks  three  octaves,  advises,  that  the  voice 
should  not  be  much  exerted  during  this  revolution.  He  has  known 
perseverance  in  singing  at  this  time  in  several  instances  completely 
destroy  the  voice. 

Not  only  does  the  voice,  when  produced  in  the  larynx,  pass  out  by 
the  vocal  tube,  but  it  resounds  along  the  tracheal  and  bronchial  tubes, 
giving  rise  to  the  resonance  or  thrill,  audible  in  certain  parts  of  the 
chest,  more  especially,  when  the  ear  or  the  stethoscope  is  placed  over 
them ;  and,  when  cavities  exist  in  the  lungs,  in  the  consumptive,  if  the 

1  Quarterly  Summary  of  the  Transactions  of  the  College  of  Physicians  of  Philadelphia, 
Nov.  and  Dec.,  1841,  and  Jan.,  1842.  2  Precis  Elementaire,  i.  254. 

3  Archives  Generates  de  Medecine,  pp.  201  and  214,  Fevrier,  1831. 

4  Recherches  sur  le  Mecanisme  de  la  Voix  Humaine,  Paris,  1832. 


VOICE — TIMBRE.  473 

ear  be  placed  upon  the  chest,  immediately  over  one  of  them,  the  voice 
will  appear  to  come  directly  up  to  the  ear.  The  same  thing  happens, 
if  the  stethoscope  be  used.  In  this  case,  when  the  extremity  of  the 
instrument  is  applied  over  the  vomica,  the  voice  appears  to  pass 
directly  through  the  tube  to  the  ear,  so  as  to  give  rise  to  what  has  been 
termed  pectoriloquy.  M.  Adelon1  conceives,  that  this  distribution  of 
the  sound  along  the  trachea  orporte-vent  and  the  lungs  may  suggest  that 
the  condition  of  these  organs  has  some  effect  on  the  quality  of  the  voice. 

In  speaking  of  the  timbre  of  the  voice  in  different  individuals,  we 
have  had  in  view  the  natural  quality, — not  that  which  is  the  result  of 
imitative  action,  and  which  can  be  maintained  for  a  time  only.  Many 
of  the  conditions,  which  have  been  described  as  regulating  the  timbre, 
are  voluntary,  especially  that  of  the  shape  of  the  vocal  tube.  In  this 
way  we  can  modify  the  timbre  and  imitate  voices  different  from  our 
own.  The  table  d'hdte  of  many  of  the  hotels  of  continental  Europe  is 
enlivened  by  the  presence  of  individuals,  capable  of  not  only  imitating 
various  kinds  of  birds,  but  the  timbres  of  different  musical  instruments; 
and  the  success  which  attended  the  personation  of  the  voices  of  public 
speakers,  by  Matthews,  Yates,  and  others,  is  sufficient  evidence  of 
the  fidelity  of  their  representations.  We  see  the  difference  between 
the  natural  and  imitative  voice  strongly  exemplified  in  one  of  the 
feathered  songsters  of  our  forests,  turdus  polyglottis  or  mocking-bird, 
which  is  capable  of  imitating,  not  only  the  voices  of  different  birds,  but 
sounds  of  other  character,  which  cannot  be  regarded  in  the  light  of 
accomplishments. 

There  is  a  singular  variety  of  the  imitative  voice,  now  employed  only 
for  purposes  of  amusement — but,  of  old,  perhaps,  used  in  the  Pagan 
temples,  by  the  priests,  to  infuse  confidence  in  the  oracular  dicta  of  the 
gods — which  requires  notice  :  this  is  engastrimism  or  ventriloquism. 
Both  these  terms,  by  their  derivation,  indicate  the  views  at  one  time 
entertained  of  its  physiology,  namely,  that  the  voice  of  the  ventriloquist 
is  made  to  resound  in  the  abdomen,  in  some  inexplicable  manner,  so  as 
to  give  rise  to  the  peculiarity  it  exhibits.  This  singular  view  seems  to 
have  been  once  embraced  by  M.  Richerand.2  "  At  first,"  says  he,  "  I 
had  conjectured,  that  a  great  part  of  the  air  expelled  by  expiration  did 
not  pass  out  by  the  mouth  and  nostrils,  but  was  swallowed  and  carried 
into  the  stomach;  and,  being  reflected  in  some  part  of  the  digestive 
canal,  gave  rise  to  a  real  echo  ;  but,  having  afterwards  more  attentively 
observed  this  curious  phenomenon  on  Mr.  Fitzjames,  who  exhibits  it  in 
its  greatest  perfection,  I  was  soon  convinced  that  the  name  of  ventrilo- 
quism is  by  no  means  applicable."  M.  Richerand  was  probably  the  last 
remnant  of  the  supporters  of  the  ancient  vague  hypothesis ;  and  his 
views  soon  underwent  conversion. 

Another,  equally  unfounded  notion,  at  one  time  entertained,  was, 
that  the  ventriloquist  possesses  a  double  or  triple  larynx.  It  is  now 
admitted,  that  the  voice  is  produced  at  the  ordinary  place,  and  is  modi- 

1  Physiologie  de  1'Homme,  edit.  cit..  ii.  204. 

a  Siemens  de  Physiologie,  edit.  ISeme,  par  M.  Berard  aine,  edit.  Beige,  cxciv.  p.  300, 
Bruxelles,  1837. 


474  MUSCULAR  MOTION. 

fied  in  intensity  and  quality  by  actions  of  the  larynx  and  vocal  tube,  so 
as  to  give  rise  to  the  deceptions  we  experience.  It  is  known,  that  our 
appreciation  of  the  distance  and  nature  of  a  sonorous  body  is  formed 
from  the  intensity  and  quality  of  the  sound  proceeding  from  it.  We 
instinctively  believe,  that  a  loud  sound  proceeds  from  a  near  object, 
and  a  feeble  sound  from  one  more  remote  ;  accordingly,  if  the  intensity 
and  quality  of  the  sound  from  a  known  body  be  such  as  to  impress  us 
with  the  idea  that  it  is  more  remote  than  it  really  is,  we  incur  an  acous- 
tic illusion.  The  ventriloquist  takes  advantage  of  this  source  of  illu- 
sion ;  and,  by  skilfully  regulating  the  force  and  timbre  of  his  voice, 
leads  us  irresistibly  into  error.  Mr.  Dugald  Stewart1  gives  some  exam- 
ples of  this  kind  of  illusion.  He  mentions  having  seen  a  person,  who, 
by  counterfeiting  the  actions  of  a  performer  on  the  violin,  whilst  he  imi- 
tated the  music  by  his  voice,  riveted  the  eyes  of  the  audience  on  the 
instrument,  although  every  sound  they  heard  proceeded  from  his  own 
mouth.  Mr.  Savile  Carey,  who  imitated  the  whistling  of  the  wind 
through  a  narrow  chink,  told  Mr.  Stewart,  that  he  had  frequently 
practised  the  deception  in  the  corner  of  a  coffee-house,  and  that  he  sel- 
dom failed  to  see  some  of  the  company  rise  to  examine  the  tightness  of 
the  windows ;  whilst  others,  more  intent  on  the  newspapers,  contented 
themselves  with  putting  on  their  hats,  and  buttoning  their  coats.2  It 
is  to  account  for  the  mode  in  which  this  is  effected,  that  different  hypo- 
theses have  been  from  time  to  time  entertained.  Haller,  Nollet,  Mayer,3 
and  others,  believed,  that  the  voice  is  formed  during  inspiration ;  but 
this  does  not  seem  to  be  the  case.  Voice  can  certainly  be  effected 
during  inspiration  ;  but  it  is  raucous,  unequal,  and  of  trifling  extent 
only.  MM.  Dumas  and  Lauth4  considered  ventriloquism  to  be  a  kind  of 
rumination  of  sounds  ;  the  voice,  formed  in  the  larynx,  being  sent  into 
the  interior  of  the  chest,  attaining  there  a  peculiar  timbre,  and  issuing  of 
a  dull  character.  M.  Richerand  is  of  opinion,  that  the  whole  mechanism 
consists  in  a  slow,  gradual  expiration,  which  is  always  preceded  by  a 
deep  inspiration.  By  means  of  this,  the  ventriloquist  introduces  into 
his  lungs  a  considerable  quantity  of  air,  the  exit  of  which  he  carefully 
regulates ;  and  a  similar  view  is  embraced  by  Prof.  J.  Miiller,5  who 
asserts  that  the  sounds  uttered  by  the  ventriloquist  can  be  perfectly 
elicited  by  a  method,  which,  he  is  convinced,  must  be  adopted  by  ven- 
triloquists. This  method  consists  in  inspiring  deeply  so  as  to  protrude 
the  abdominal  viscera  by  the  descent  of  the  diaphragm,  and  then  speak- 
ing, whilst  expiration  is  performed  very  slowly  through  a  narrow  glottis 
by  means  of  the  lateral  parietes  of  the  thorax  alone,  the  diaphragm 
maintaining  its  depressed  position ;  and  M.  Colombat  confirms  the 
general  accuracy  of  Professor  Miiller's  view,  remarking  that  by  con- 
tinually practising  in  a  manner  somewhat  similar  to  that  pointed  out  by 
him  he  was  enabled  to  attain  considerable  skill  in  the  production  of 

1  Elements  of  the  Philosophy  of  the  Human  Mind,  3d  edit.,  Lond.,  1808;  Amer.  edit., 
Brattleborough  (Vermont),  1813. 

3  Brewster,  Natural  Magic,  Amer.  edit.,  p.  158,  New  York,  1832. 

*  Lepelletier,  Physiologic  Medicale,  &c.,  iv.  213,  Paris,  1833. 

4  Memoir,  de  la  Societe  des  Sciences  Agricol.  de  Strasbourg,  i.  427. 

*  Elements  of  Physiology,  by  Baly,p.  1054,  Lond.,  1838. 


VOICE — TIMBRE.  475 

this  variety  of  voice.1  Mr.  Gough2  attempts  to  explain  the  phenomenon 
upon  the  principle  of  echoes  : — the  ventriloquist,  he  conceives,  selects  a 
room,  well  disposed  for  echoes  in  various  parts  of  it,  and  produces  false 
voices,  by  directing  his  natural  voice  in  a  straight  line  towards  such 
echoing  parts,  instead  of  in  a  straight  line  towards  the  audience,  who 
are  supposed,  by  Mr.  Gough,  to  be  placed  designedly  by  the  ventrilo- 
quist on  one  or  both  sides  of  him.  A  sufficient  answer  to  this  is,  that 
the  practised  ventriloquist  is  careless  about  the  room  chosen  for  his 
exhibitions  ;  and  habitually  performs  where  this  system  of  echoes  would 
be  totally  impracticable. 

But  it  is  well  to  inquire  what  the  ventriloquists  themselves  say  of  the 
mechanism  of  their  art.  We  pass  over  the  explanation  of  Baron  von 
Mengen,  an  Austrian  colonel,  who  forms  a  kind  of  vocal  organ  between 
his  tongue  and  his  left  cheek,  if  we  understand  his  description  correctly, 
and  keeps  a  reservoir  of  air  in  his  throat  to  throw  the  organ  into  vibra- 
tion. His  object  must  evidently  have  been  to  mislead. 

In  1811,  M.  L'Espagnol,  a  young  physician,  maintained  a  thesis  on 
this  subject  before  the  Faculte  de  Medecine  of  Paris,  which  may  be 
regarded  as  at  least  an  honest  exposition  of  his  belief  regarding  the 
mode  in  which  the  phenomenon  was  effected  in  his  own  person.  Ac- 
cording to  him,  the  whole  is  dependent  upon  the  action  of  the  velum 
pendulum  palati.  In  ordinary  voice,  he  remarks,  a  part  of  the  sound 
passes  directly  through  the  mouth,  whilst  another  part  resounds  in  the 
nasal  fossae.  If  we  are  near  the  person  who  is  speaking,  these  two 
sounds  strike  equally  and  almost  synchronously  upon  the  ear;  but  if  at 
a  distance,  we  hear  only  the  first  of  the  two  sounds;  when  the  voice 
appears  more  feeble,  and,  especially,  has  another  timbre,  which  experi- 
ence makes  us  judge  to  be  that  of  the  voice  at  a  distance.  The  differ- 
ence, says  M.  L'Espagnol,  between  the  voice  that  proceeds  from  a  near, 
and  that  from  a  more  distant  object  is,  that  in  the  former  we  hear  the 
mixture  of  the  two  sounds;  whilst  in  the  latter  we  hear  that  sound 
only,  which  issues  directly  from  the  mouth.  Now,  the  secret  of  the 
ventriloquist  is,  to  permit  this  direct  sound  only  to  pass  to  the  ear,  and 
prevent  the  nasal  sound  from  being  produced,  or  at  least  from  being 
heard ;  and  this  is  done  by  the  elevation  of  the  velum  pendulum  palati : 
the  vocal  sound  does  not  then  resound  in  the  nasal  fossae ;  the  direct 
sound  is  alone  produced ;  the  voice  has  the  feebleness  and  timbre  that 
belong  to  the  distant  voice,  and  is  judged  to  proceed  from  a  distance; 
and  if,  during  the  performance,  it  seems  to  come  from  any  determinate 
place,  it  is  owing  to  the  ventriloquist  attracting  attention  to  it:  the 
voice  itself  need  only  appear  to  proceed  from  a  distance;  and  this  it 
does  more  or  less,  according  as  the  pendulous  veil  has  more  or  less  com- 
pletely prevented  the  sound  from  issuing  by  the  nasal  fossae.  The 
ventriloquist  thus,  according  to  M.  L'Espagnol,  makes  the  voice  appear 
nearer  or  more  remote  at  pleasure,  by  raising  or  depressing  the  velum 
palati.  He  denies,  that  he  speaks  with  his  mouth  closed ;  and  affirms, 
that  he  articulates,  but  to  a  trifling  extent  only. 

1  Baly  and  Kirkes,  Recent  Advances  in  the  Physiology  of  Motion,  the  Senses,  Generation, 
and  Developement,  p.  11,  Lond.,  1848. 

2  Manchester  MemoirSj  2d  edit.,  v.  622,  Lond.,  1789. 


476  MUSCULAR  MOTION. 

M.  Comte,  another  ventriloquist,  and  of  some  celebrity,  who  has 
endeavoured  to  explain  the  physiology  of  his  art,  affirms,  that  voice 
takes  place  as  usual  in  the  larynx ;  but  is  modified  by  the  action  of 
other  parts  of  the  apparatus;  that  inspiration  directs  it  into  the  thorax, 
where  it  resounds;  and  that  both  strength  and  flexibility  are  required 
in  the  organ  to  produce  this  effect.  This,  however,  is  no  explanation. 
It  is  now  universally  admitted,  that  the  voice  of  the  ventriloquist  is 
produced  in  the  larynx;  and  that  its  character  and  intensity  are  modi- 
fied by  the  action  of  other  parts  of  the  apparatus,  but  the  particular 
agency  that  produces  it  is  not  elucidated  by  any  of  these  attempted 
explanations  of  the  ventriloquist. 

About  forty  years  ago  (1810),  Dr.  John  Mason  Good,1  in  some  lec- 
tures delivered  before  the  Surrey  Institution  of  London,  suggested  that 
the  larynx  alone,  by  long  and  dexterous  practice,  and,  perhaps,  by  a 
peculiar  modification  in  some  of  its  muscles  or  cartilages,  may  be  capa- 
ble of  answering  the  purpose,  and  of  supplying  the  place  of  the  asso- 
ciate organs  of  the  mouth.  In  confirmation  of  this  view,  he  remarks, 
that,  in  singing,  the  glottis  is  the  only  organ  made  use  of,  except  where 
the  notes  are  articulated ;  and  it  is  apparently  the  sole  organ  employed 
in  the  mock  articulations  of  the  parrot  and  other  imitative  birds ;  some 
of  which  have  exhibited  unusual  powers.  A  parrot  belonging  to  a  Colo- 
nel O'Kelly,  could,  it  is  said,  repeat  twenty  of  the  most  popular  English 
songs,  and  sing  them  to  their  proper  tunes.  The.  larynx,  too,  is  the 
sole  organ  of  all  the  natural  cries;  and  hence,  it  has»been  imagined  by 
Lord  Monboddo2  to  have  been  the  chief  organ  of  articulate  language, 
in  its  rudest  and  most  barbarous  state.  "As  all  natural  cries,"  he 
observes,  "  even  though  modulated  by  music,  are  from  the  throat  and 
larynx,  or  knot  of  the  throat,  with  little  or  no  operation  of  the  organs 
of  the  mouth,  it  is  natural  to  suppose,  that  the  first  languages  were,  for 
the  greater  part,  spoken  from  the  throat;  and  that  what  consonants 
were  used  to  vary  the  cries,  were  mostly  guttural ;  and  that  the  organs 
of  the  mouth  would  at  first  be  but  very  little  employed."  Certain  it  is, 
that  privation  of  the  tongue  does  not  necessarily  induce  incapacity  of 
articulation;  whether  the  defect  be  congenital,  or  caused  after  speech 
has  been  acquired.  Professor  John  Thomson  of  Edinburgh  found  the 
speech  but  little  impaired  after  bullets  had  carried  away  more  or  less  of 
the  tongue.3  Under  the  Sense  of  Taste,  several  authentic  cases  were 
stated  of  individuals,  who  were  deprived  of  this  organ,  and  yet  possess- 
ed the  faculty  of  speech.  To  these  we  may  add  one  other,  which  ex- 
cited unusual  interest  at  the  time,  and  was  examined  under  circumstances 
that  could  admit  of  no  deception.  The  case  forms  the  subject  of  various 
papers,  by  Dr.  Parsons,  in  the  Philosophical  Transactions  of  London.4  A 
young  woman,  of  the  name  of  Margaret  Cutting,  of  Wickham  Market, 
near  Ipswich,  in  Suffolk,  when  only  four  years  old,  lost  the  whole  of  her 

1  Book  of  Nature,  ii.  p.  238,  Lond.,  1834;  see  also  his  Study  of  Medicine,  Physiological 
Proem  to  Class  ii.,  Amer.  edit,  i.  206,  Philad.,  1824. 

2  Origin  and  Progress  of  Language,  i.  322,  Edinb.,  1773. 

a  Report  of  Observations  made  in  the  British  Hospital,  in  Belgium,  after  the  Battle  of 
Waterloo,  Edinb.,  1816. 

4  Philosoph.  Transact,  for  1742  and  1747. 


VOICE — VENTRILOQUISM.  477 

tongue,  together  with  the  uvula,  from  a  cancerous  affection ;  she  still, 
however,  retained  the  power  of  speech,  taste,  and  deglutition  without 
any  imperfection ;  articulating  as  fluently  and  correctly  as  other  persons ; 
and  even  those  syllables  that  commonly  require  the  aid  of  the  tip  of  the 
tongue  for  accurate  enunciation.  She  also  sang  admirably;  articulat- 
ing her  words  whilst  singing;  and  could  form  no  conception  of  the  use 
of  a  tongue  in  other  people.  Her  teeth  were  few;  and  rose  scarcely 
higher  than  the  surface  of  the  gums,  owing  to  the  injury  to  the  sockets 
from  the  disease  that  had  destroyed  the  tongue.  The  case,  when  first 
laid  before  the  Royal  Society,  was  attested  by  the  minister  of  the  parish, 
by  a  medical  practitioner  of  repute,  and  by  another  respectable  indivi- 
dual. The  Society,  however,  were  not  satisfied,  and  appointed  commis- 
sioners to  inquire  into  the  case,  whose  report  coincided  minutely  with 
the  first;  and,  to  set  the  matter  completely 'at  rest,  the  young  woman 
was  shortly  afterwards  conveyed  to  London,  and  examined,  in  person, 
before  the  Royal  Society.1 

These  cases  are  not  so  extraordinary  as  they  appear  at  first  sight; 
when  we  consider,  that  the  tongue  is  not  the  sole  organ  of  articulation, 
but  that  it  shares  the  function  with  the  various  parts  that  compose  the 
vocal  tube.  In  reality,  of  the  twenty-four  articulate  sounds,  which  our 
common  alphabet  comprises,  there  are  few  in  which  the  tongue  takes  a 
distinct  lead,  as  I,  d,  £,  r,  &c.,  though  it  is  auxiliary  to  several  others; 
but  the  guttural  or  palatine,  </,  A,  k,  q;  the  nasal,  m,  and  n;  the 
labial,  5,  p,  /,  v;  and  most  of  the  dental,  together  with  all  the  vowels, 
are  little  indebted  to  its  assistance. 

Prom  these,  and  other  concurrent  facts,  Dr.  Good2  concludes,  that 
ventriloquism  appears  to  be  an  imitative  art,  founded  on  a  close  atten- 
tion to  the  almost  infinite  variety  of  tones,  articulations,  and  inflexions, 
which  the  glottis  is  capable  of  producing  in  its  own  region  alone,  when 
long  and  dexterously  practised  upon ;  and  in  a  skilful  modification  of 
these  vocal  sounds,  thus  limited  to  the  glottis,  into  mimic  speech,  passed 
for  the  most  part,  and  whenever  necessary,  through  the  cavity  of  the 
nostrils,  instead  of  through  the  mouth.  It  is  possible,  he  adds,  though 
no  opportunity  has  hitherto  occurred  of  proving  the  fact  by  dissection, 
that  they  who  learn  this  art  with  facility,  and  carry  it  to  perfection, 
possess  some  peculiarity  in  the  structure  of  the  glottis,  and  particularly 
in  respect  to  its  muscles  or  cartilages.  MM.  Magendie3  and  Rullier,4 
however,  affirm,  that  the  quiescence  of  the  lips,  observed  in  the  practised 
ventriloquist  when  enunciating,  is  more  apparent  than  real;  and  that  if 
he  be  capable  of  pronouncing  without  moving  his  lips,  it  is  because  he  is 
careful  to  make  use  of  words  in  which  there  are  no  labial  consonants, 
or  which  do  not  absolutely  require  the  movement  of  the  lips  in  their  for- 
mation. M.  Rullier,  indeed,  denies  positively,  that  the  ventriloquist  can 
speak  without  opening  his  mouth  and  moving  his  lips;  but  he  affirms, 
that  he  uses  his  jaws,  mouth,  and  lips,  as  little  as  possible  in  articula- 
tion; and  he  ascribes  the  common  belief  in  their  perfect  quiescence  to 

1  Elliotson's  Human  Physiology,  p.  507,  Lond.,  1840.    See  a  curious  chapter  on  the  Use  of 
Tongues  in  Southey,  The  Doctor,  vii.  i.,  Lond.,  1847. 

2  Op.  citat.  3  Precis,  &c.,  i.  265. 
4  Art.  Engastrimysme,  in  Diet,  de  Medecine,  torn,  viii.,  Paris,  182 3. 


478  MUSCULAR  MOTION. 

the  habit,  acquired  by  him,  of  restraining  their  movements,  united  to 
the  care  he  takes  in  concealing  them;  and  of  giving  to  his  face  an  im- 
passive expression,  or  one  foreign  to  the  verbal  expression  to  which  he 
is  giving  utterance. 

On  the  whole,  the  explanation  of  Dr.  Good  appears  the  most  satisfac- 
tory:— the  larynx  or  glottis  affords  some  individuals  a  facility  in  acquir- 
ing the  art,  which  others  do  not  possess,  in  the  same  manner  as  it  makes 
some  capable  of  singing,  whilst  others  are  forever  incapacitated.  It  is 
probable,  however,  that  there  may  be  a  greater  degree  of  obscure  action 
about  the  parts  composing  the  vocal  tube  than  Dr.  Good  is  disposed  to 
admit ;  and  that  this  may  be  materially  concerned  in  giving  the  voice 
its  peculiar  quality  and  intensity;  and  eliciting  some  of  the  sounds 
which  might  not  be  so  easily  produced  by  the  action  of  the  glottis 
alone.  Sir  David  Brewster1  observes,  that  when  the  ventriloquist  utters 
sounds  from  the  larynx  without  moving  the  muscles  of  his  face,  he  gives 
them  strength  by  a  powerful  action  of  the  abdominal  muscles;  and 
Bennati  affirms,  that  the  ventriloquist  uses  chiefly  the  pharyngeal  voice, 
of  which  mention  will  be  made  under  the  head  of  Singing. 

Such  is  the  history  of  the  simple  voice,  as  effected  in  the  larynx. 
Articulate  sounds  may,  however,  be  produced  in  the  vocal  tube  alone. 
Whistling,  for  example,  is  caused  by  the  expired  air  being  broken  or 
divided  by  the  lips,  which  act  the  part  of  the  lips  of  the  larynx  in  the 
production  of  voice. 

Whispering  consists  in  articulating  the  air  of  expiration.  It  is  wholly 
accomplished  in  the  vocal  tube;  and,  hence,  the  impracticability  of  sing- 
ing in  a  whisper ;  singing  being  produced  in  the  glottis. 

The  sound  of  sighing  is  produced  by  the  rushing  of  air  along  the  air 
passages,  and  especially  along  the  vocal  tube.  In  laughing,  crying,  and 
yawning,  voice  is  concerned;  but  the  physiology  of  these  functions  of 
expression  will  fall  more  appropriately  under  Respiration. 

Having  described  the  different  views,  that  have  been  entertained, 
with  regard  to  the  production  of  voice,  we  shall  now  inquire  into  the 
function  in  connexion  with  expression.  In  this  respect,  it  admits  of 
division  into  the  natural  or  inarticulate  voice,  and  the  artificial  or 
articulate. 

3.    NATURAL  OR  INARTICULATE  LANGUAGE. 

This,  which  is  sometimes  termed  the  cry  or  native  voice,  is  an  inap- 
preciable sound,  entirely  produced  in  the  larynx,  and  requiring  few  or 
none  of  the  organs  of  articulation  to  aid  in  its  formation.  As,  how- 
ever, it  is  caused  by  different  degrees  of  contraction  of  the  intrinsic 
muscles  of  the  larynx,  it  is  susceptible  of  a  thousand  different  tones. 
It  is  elicited  independently  of  all  experience  or  education;  seems  to  be 
inseparably  allied  to  organization;  and,  consequently,  occurs  in  the 
new-born  infant,  the  idiot,  the  deaf  from  birth,  and  the  wild  man,  if 
any  such  there  be,  as  well  as  in  the  civilized  individual.  The  natural 
voice  differs  as  much  as  the  sentiments  it  is  employed  to  express.  Each 

1  Letters  on  Natural  Magic,  p.  169,  Amer.  edit.,  New  York,  1832. 


VOICE — INAETICULATE  LANGUAGE.  479 

moral  affection  has  its  appropriate  cry; — the  cry  of  joy  is  very  distinct 
from  that  of  grief; — of  surprise  from  that  of  fear,  &c.;  and  the  patho- 
logist finds,  in  the  diseases  of  children  more  especially,  that  he  can 
occasionally  judge  of  the  seat  of  a  disease  by  the  character  of  the  cry, 
to  which  the  little  sufferer  gives  utterance ;  that  there  is,  in  the  language 
of  M.  Broussais,  a  cry  peculiar  to  the  suffering  organ. 

By  the  cry,  our  vivid  sensations  are  expressed,  whether  they  be  of 
the  external  or  internal  kind;  agreeable  or  painful;  and  by  it  we  exhibit 
all  our  natural  passions,  and  most  simple  instinctive  desires.  Generally, 
the  most  intense  sounds,  to  which  the  organ  of  voice  can  give  utter- 
ance, are  embraced  in  the  natural  cry;  and,  in  its  character,  there  is 
frequently  something,  that  annoys  the  ear  and  produces  more  or  less 
effect  on  those  within  hearing.  It  is,  by  its  agency,  that  sympathetic 
relations  are  established  between  man  and  his  fellows;  and  between 
animals  of  the  same  kind.  The  language,  possessed  by  the  greater 
part  of  animals,  is  this  natural  voice  differing  according  to  varying 
organization,  and,  therefore,  instinctive;  hence  the  various  notes  of 
birds;  and  the  ranges,  which  we  find  the  voice  to  possess  in  different 
species.  Yet  each  species  has  one,  by  which  it  is  distinguished  and 
which  it  possesses,  even  when  brought  up  in  the  same  cage  with  one  of 
another  species ;  or  when  hatched,  and  attended  to,  by  a  foster  mother 
endowed  with  very  different  vocal  powers.  In  the  case  of  a  goldfinch 
and  chaffinch,  this  has  been  put  directly  to-  the  proof;  and  it  is  well 
known,  that  the  cuckoo,  which  is  never  hatched  or  nurtured  by  its  own 
parent,  still  retains  the  note,  that  has  acquired  it  its  name  in  almost 
every  language  of  the  globe.  It  is,  probably,  by  this  natural  cry,  and 
not  by  any  signs  addressed  to  the  eye,  that  the  process  of  pairing  is 
effected,  and  that  the  female  is  induced  to  select  her  mate.  The  voca- 
bulary of  the  common  cock  and  hen  is  quoted  as  perhaps  the  most 
extensive  of  that  of  any  tribe  of  birds  with  which  we  are  acquainted;  or 
rather,  as  Dr.  Good  remarks,1  we  are  better  acquainted  with  the  extent 
of  its  range  than  with  that  of  any  other.  The  cock  has  his  watchword 
for  announcing  the  morning;  his  love-speech  and  terms  of  defiance. 
The  voice  of  the  hen,  when  leaving  her  nest,  after  laying,  is  different 
from  that  which  she  assumes  when  the  brood  is  hatched,  and  both  are 
very  different  from  her  cries,  when  her  young  are  placed  in  jeopardy. 
Even  the  chick  exhibits  a  variety  in  its  voice,  according  to  the  precise 
emotion  it  experiences.  All  these  sounds  are  such  as  the  larynx  of  the 
animal  alone  admits  of;  and  hence  we  can  understand  why,  so  far,  they 
should  be  mere  modifications  of  the  natural  voice;  but  it  is  more  than 
probable,  that  the  chick  learns  the  adoption  of  a  particular  sound  by 
the  parent  to  express  a  particular  emotion,  as  an  affair  of  education. 
It  can  scarcely  be  conceived,  that  the  clucking  of  the  hen,  when  she 
meets  with  food  proper  for  her  offspring,  can  be  understood  at  first  by 
the  chick.  But  as  soon  as  it  traces  the  connexion  between  the  sound 
produced  and  the  object  of  such  sound,  it  comprehends  the  signification 
ever  afterwards. 

There  are  sounds,  which,  from  their  discordant  and  harsh  characters, 

1  Book  of  Nature,  ii.  277,  Lond.,  1826. 


480'  MUSCULAR  MOTION. 

affect  most  animals  perhaps  independently  of  all  experience.  The  cry 
of  terror  or  pain  appears  to  occasion  sympathetically  disagreeable  effects 
on  all  that  are  within  its  sphere. 

4.    ARTIFICIAL  OR  ARTICULATE  LANGUAGE. 

Speech,  likewise,  is  a  vocal  sound ;  but  it  is  articulated,  in  its  passage 
through  the  vocal  tube ;  and  is  always  employed  to  convey  ideas,  that 
have  been  attached  to  it  by  the  mind.  It  is  a  succession  of  articulate 
sounds,  duly  regulated  by  volition,  and  having  determinate  significations 
connected  with  them. 

The  faculty  of  speech  has  been  assigned  by  some  philosophers  chiefly 
to  the  organ  of  hearing.  It  is  manifest,  however,  that  this,  like  the 
musical  ear,  is  referable  to  a  higher  organ.  The  brain  must  attach  an 
idea  to  the  impression  made  upon  it  by  the  sounds  that  impinge  upon 
the  organ  of  hearing;  the  sound  thus  becomes  the  sign  of  such  idea, 
and  is  reproduced  in  the  larynx  at  the  will  of  the  individual.  Of  the 
intellectual  character  of  the  process,  we  have  decisive  evidence.  The 
infant  of  tender  age  has  the  ear  and  voice  well  developed,  yet  it  is  long 
before  it  is  capable  of  speech;  this  does  not  happen  until  it  discovers 
the  meaning  of  the  sounds  addressed  to  it,  and  finds  its  own  larynx 
capable  of  producing  similar  sounds,  which  can  be  made  subservient  to 
its  wishes.  It  is  thus,  by  imitation,  that  it  acquires  the  faculty  of  speech. 
Again,  the  idiot,  notwithstanding  his  hearing  may  be  acute,  and  voice 
strong .  is  incapable  of  speech ;  and,  in  the  maniacal  and  delirious,  the 
language  participates  in  the  derangement  and  irregularity  of  ideas. 
The  brain  must,  therefore,  be  regarded  as  the  organ  of  the  faculty  of 
language;  and  the  ear,  larynx,  and  vocal  tube  as  its  instruments.  Man, 
who  is  endowed  with  the  most  commanding  intellect,  has  the  vocal  appa- 
ratus happily  organized  for  expressing  its  various  combinations;  and, 
according  to  Gall,  if  the  ourang-outang  and  other  animals  are  incapable 
of  speech,  it  is  because  they  have  not  the  intellectual  faculty  of  lan- 
guage. In  proof,  that  it  is  not  to  the  vocal  organ  that  this  deficiency 
must  be  ascribed,  he  remarks,  that  animals  may  be  made  to  enunciate 
several  of  the  words  of  human  speech,  and  to  repeat  them  with  music. 
The  case  of  the  far-famed  parrot  of  Colonel  O'Kelly  has  already  been 
referred  to.  Mr.  Herbert1  saw  this  parrot,  about  the  year  1799 :  it  then 
sang  perfectly  about  fifty  different  tunes,  solemn  psalms,  and  humorous 
or  low  ballads;  articulating  every  word  as  distinctly  as  man,  without  a 
single  mistake ;  beating  time  with  its  foot ;  turning  round  upon  its  perch, 
and  marking  the  time  as  it  turned.  If  a  person  sang  part  of  a  song  it 
would  take  it  up  where  he  left  off;  and  when  moulting  and  unwilling  to 
sing,  turned  its  back  and  said,  "Poll's  sick."  Gall,  amongst  other 
cases,  cites  that  of  a  dog  mentioned  by  Leibnitz,  which  could  articulate 
some  German  and  French  words.  This  dog,  of  which  Leibnitz  was  an 
"eye-witness,"  was  at  Zeitz,  in  Misnia.  A  young  child  had  heard  it 
utter  some  sounds,  which  it  thought  resembled  German,  and  this  led  him 
to  teach  it  to  speak.  At  the  end  of  about  eight  years,  it  had  learned 
thirty  words,  some  of  which  were,  tea,  coffee,  chocolate,  and  assembly. 

1  In  a  note  to  the  Rev.  Gilbert  White's  Natural  History  of  Selborne,  p.  227. 


VOICE — ARTICULATE  LANGUAGE.  481 

It  spoke  only  after  its  master  had  pronounced  the  word,  and  appeared 
to  do  so  only  on  compulsion,  although  it  was  not  ill  used.1  In  the 
"Dumfries  Journal,"  Scotland,  for  January,  1829,  mention  is  made  of 
a  dog,  then  living  in  that  city,  which  could  utter  distinctly  the  word 
"William,"  the  name  of  the  young  man  to  whom  it  was  much  attached.2 
There  is  no  doubt,  however,  that  in  numerous  animals  speech  would  be 
impracticable,  owing  to  defective  organization,  even  were  they  gifted 
with  adequate  intellect. 

It  is  difficult — perhaps  impossible — to  say,  how  man  came  to  select 
certain  sounds  as  the  types  of  certain  intellectual  acts ;  nor  is  it  a  mat- 
ter which  strictly  concerns  the  physiologist.  It  may  be  remarked, 
however,  that  whilst  some  contend,  that  speech  is  a  science  which  was 
determined  upon,  and  inculcated,  at  an  early  period  of  the  world,  by 
one  or  more  superior  persons  acting  in  concert,  and  inducing  those 
around  them  to  adopt  their  articulate  and  arbitrary  sounds ;  others 
affirm,  that  it  has  grown  progressively  out  of  the  natural  language, 
as  the  increasing  knowledge  and  wants  of  mankind  demanded  a  more 
extensive  vocabulary.3  The  first  view  is  that  of  Pythagoras  and  Plato; 
but  it  was  opposed  by  Lucretius  and  the  Epicureans,  on  the  ground, 
that  it  must  have  been  impossible  for  any  one  person  or  synod  of  per- 
sons to  invent  the  most  difficult  and  abstruse  of  all  human  sciences 
with  the  paucity  of  ideas,  and  of  means  of  communicating  them,  which 
they  must  have  possessed ;  and  that  even  allowing  they  could  have 
invented  such  a  science,  it  must  still  have  been  utterly  impossible  for 
them  to  teach  it  to  the  barbarians  around  them. 

The  opinions  of  those  philosophers  who  confine  themselves  to  the 
phenomena  of  nature,  and  hold  themselves  uncontrolled  by  other  au- 
thority, accord  with  those  of  the  Epicureans. 

In  the  origin  of  language,  it  is  probable,  that  words  were  suggested  to 
mankind  by  sounds  heard  around; — by  the  cries  of  quadrupeds; — notes 
of  the  birds  of  the  forest ; — noises  emitted  by  the  insect  tribe ; — audjble 
indications  from  the  elements,  &c.  These,  being  various,  probably 
first  of  all  suggested  discriminative  names,  deduced  from  the  sounds 
heard.  It  is  this  imitation  of  the  noise  made  by  objects,  that  consti- 
tutes the  figure  of  speech  called  onomatopoeia, — the  "vox  repercussa 
nature"  or  "echo  of  nature,"  as  Wachter4  has  defined  it.  Daily  ex- 
perience shows  us,  that  this  source  of  words  is  strictly  physiological. 
Children  designate  a  sonorous  object  by  an  imitation  of  the  sounds 
rendered  by  it ;  and  the  greater  number  of  sonorous  bodies  have  had 
names,  radically  similar,  given  to  them  in  languages  differing  most 
from  each  other.  We  say  the  serpents  "Am;"  the  bees  "  hum ;"  the 
storm  "blusters;"  the  wind  "whistles;"  the  hogs  "grunt;"  the  hen 
"  cackles;"  the  man  "snores,"  &c.,  words  used,  originally,  not  perhaps 
in  these  very  shapes,  but  varying  according  to  the  varying  idiom  of 
language,  to  imitate  the  sounds  elicited  by  those  objects.  Such  words 

1  Letter  to  the  Abbe  Saint  Pierre,  Oper.  ii.  180. 

3  Sharon  Turner's  Sacred  History  of  the  World,  p.  280,  Amer.  edit.,  New  York,  1832. 

3  Harris's  Hermes,  3d  edit.,  Book  iii.  p.  314,  London,  1771 ;  Beattie's  Theory  of  Language, 
p.' 246,  London,  1803,  and  Good's  Book  o'f  Nature,  ii.  254,  London,  1834. 

4  Glossarium  Germanicum,  Lips.,  1737. 

VOL.  I. — 31 


482  MUSCULAR  MOTION. 

are  numerous  in  all  languages,  and  have  been  adopted  to  depict  both 
the  sound  emitted,  and  the  sonorous  body  itself;  but,  in  some  cases, 
the  word  imitating  the  sound  has  survived  its  transmission  from  lan- 
guage to  language  to  the  most  modern  times,  whilst  the  name  of  the 
object  whence  it  proceeded  has  experienced  considerable  mutation. 
The  Sanskrit,  the  antiquity  of  which  will  not  be  contested,  has  a  num- 
ber of  such  words — as  wilala,  cat — kukada,  hen — and  waihu,  wind; 
in  the  last  of  which  the  sound  of  the  w  (00),  imitates  that  of  the  pas- 
sage of  the  air,  and  is  found  in  the  word  corresponding  to  wind,  (ooind,) 
in  many  languages.  The  Hebrew  and  the  Greek  have  numerous  pho- 
netic words ;  but  no  language  is  richer,  in  this  respect,  than  the  Teu- 
tonic in  all  its  ramifications,  including  the  English.  The  animal 
kingdom  affords  us  many  examples,  of  which  the  following  is  one : — 

Cuckoo. — This  word  is  nearly  the  same  in  almost  all  languages.  Greek,  xoxxi/£ ;  Latin, 
cucullus  •  Irish,  cuach ;  Bask,  cucua ;  Sclavonic,  kukulka,  kukuscka,  &c.;  Hungarian,  kukuk  ; 
Hebrew,  cacatha  ;  Syriac,  coco  •  Arabic,  cuchem ;  Persian,  kuku;  Koriak,  kaikuk  ;  Kamtscha- 
dale,  koakutschith  ;  Kurile,  kakkok ;  Tartar,  kauk ;  German,  kuckucks  or  guckguck ;  Dutch, 
koekoek  •  whence  our  words  cuckoo  and  cuckold,  and  the  Scottish  gouckoo,  gowk,  or  golk ;  French, 
cocu;  &c. 

In  the  greater  part  of  languages,  words,  expressive  of  the  cries  of 
animals,  are  accurate  imitations.  Of  this,  the  following  are  a  few 
examples. 

Bleating.of  sheep. — Greek,  B\v%ao/Lt,a,t ;  Latin,  balare ;  Italian,  belare /  Spanish,  balar ;  French 
beler  •  German,  bloken  ;  Dutch,  bleeten ;  Saxon,  blcetan,  &c. 

Holding  of  wolves. — Greek,  cXoXy^a;;  Latin,  ululare ;  German,  heulen ;  Dutch,  huilen ; 
Spanish,  aullar  •  French,  hurler,  &c.  v  Hence  the  word  owl. 

Neighing  of  the  horse. — Latin,  hvnnire;  French,  hennir  •  German,  wiehern;  Saxon,  hnxgan, 
&c. 

Clocking  or  clucking  of  hens. — Latin,  glocire  ;  French,  glousser ;  Greek,  x«xx«£«jv;  German, 
glucken  /  Dutch,  klokken  ;  Saxon,  clocran,  &c. 

To  crow,  like  a  cock. — Greek,  xf>a£a>;  German,  krahen,  Dutch,  kraayen;  Saxon,  craw,  &c., 
whence  the  word  crow,  the  bird. 

The  Latin  words  tinnimentum,  tinnitus,  tintinndbulum,  &c.,  from 
tinnio,  "  I  ring,"  are  all  from  the  radical  tin,  and  imitate  the  sound  ren- 
dered on  striking  a  metallic  vessel.  The  gurgling  of  water;  the  clang- 
ing of  arms ;  the  crash  of  falling  ruins  ;  are  of  the  same  character  ; 
and  the  game  trictrac,  formerly  tictac,  seems  to  have  been  so  called  from 
the  noise  made  in  putting  down  the  men  or  dice. 

In  whatever  manner  language  was  first  formed,  ft  is  manifest  that 
the  different  sounds  could  make  but  transient  impression,  until  they  were 
reduced  to  legible  characters,  which  could  recal  them  to  mind.  On  our 
continent,  the  fact  has  often  been  noticed  of  a  tribe  of  Indians  separat- 
ing themselves  into  two  parties,  and  remaining  distinct  for  years.  In 
such  case,  the  language  has  become  so  modified, 'that  after  the  lapse  of 
a  considerable  period  they  have  scarcely  been  able  to  comprehend  each 
other.  Hence,  the  importance  of  the  art  of  writing, — certainly  the 
most  valuable  of  human  inventions.  Of  this,  there  have  been  two  kinds, 
— imitative  or  alphabetical, — and  symbolical,  allegorical,  or  emblemati- 
cal, the  latter  consisting  of  hieroglyphics,  designs  representing  external 
objects,  or  symbolical  allegories.  The  former,  or  the  written  represen- 
tation of  spoken  sounds,  alone  concerns  us.  To  attain  this,  every  com- 


VOICE — ARTICULATE  LANGUAGE.  483 

pound  sound  has  been  reduced  to  certain  elementary  sounds,  which  are 
represented  by  signs,  called  letters.  These  elementary  sounds,  by  com- 
bination, form  syllables  ;  and  the  syllables,  by  combination,  words.  The 
number  of  elementary  sounds,  admitted  in  each  language,  constitutes 
its  alphabet,  which  differs  more  or  less  in  certain  languages  ;  but  as  it  is 
entirely  a  matter  of  human  invention,  and  as  the  elementary  sounds,  of 
which  the  human  voice  is  capable,  are  alike  in  the  different  races  of 
mankind,  we  see  readily,  that  the  alphabets  of  the  different  languages 
must  correspond,  although  the  combinations  of  letters  constituting  syl- 
lables and  words  may  vary  essentially. 

Into  the  origin  of  written  legible  language,  it  is  not  necessary  to 
inquire.  We  may  remark,  that  the  invention  has  been  considered 
so  signally  wonderful  as  to  transcend  human  powers  ;  and  hence,  St. 
Cyril,  Clement  of  Alexandria,  Eusebius,  Isidore,  and,  in  more  modern 
times,  Messrs.  Bryant,  Costard,  &c.,  have  been  of  opinion,  that  the 
knowledge  of  letters  was  first  communicated  to  Moses  by  the  Almighty 
himself,  and  that  the  decalogue  was  the  earliest  specimen  of  alphabetic 
writing.  Many  passages  in  the  writings  of  Moses,  show  unequivocally, 
however,  that  written  records  must  have  existed  prior  to  his  time.  In 
the  passage  in  which  writing  is  first  mentioned  in  the  sacred  volume, 
the  art  is  alluded  to  as  orre  of  standing : — "  And  the  Lord  said  un-to 
Moses,  4  Write  this  for  a  memorial  in  a  book  or  table  ;'  "  and  in  a  sub- 
sequent chapter — "And  thou  shalt  make  a  plate  of  pure  gold,  and  grave 
upon,  like  the  engravings  of  a  signet,  Holiness  to  the  Lord."1 

The  English  alphabet  is  considered  to  consist  of  twenty-six  letters. 
It  may,  however,  by  ultimate  analysis,  be  reduced  to  twenty-five  sim- 
ple sounds— A,  B,  D,  E,  F,  G,  H,  I,  J,  K,  L,  M,  N,  0,  P,  R,  S,  T, 
U,  V,  Z,  Ch,  Sh,  Th,  and  Ng.  To  these  letters  arbitrary  names  have 
been  assigned,  as  Bee  (B,)  See  (C,)  Dee  (D,)  &c.,  which  express  very 
different  sounds  from  those  that  belong  to  the  letter  when  it  forms  part 
of  a  word  or  syllable.  The  word  bad  is  not  pronounced  bee-a-dee,  as 
the  child,  just  escaped  from  learning  his  alphabet,  must  imagine  ;  hence, 
he  has  to  unlearn  all  that  he  has  acquired  ;  or  to  imagine,  that  different 
letters  have  very  different  sounds,  according  to  the  situation  in  which 
they  are  placed.  To  obviate  this  inconvenience,  some  persons  are  in  the 
habit  of  teaching  their  children  syllabicall^  from  the  very  first,  by 
which  they  acquire  the  true  sound  attached  to  each  letter  of  the  alpha- 
bet. In  the  preceding  enumeration  of  the  simple  sounds,  that  consti- 
tute the  alphabet,  C,  Q,  W,  X,  and  Y,  have  been  excluded,  for  the  fol- 
lowing reasons.  C  has  always  the  sound  of  either  S  or  K,  as  in  cistern 
or  consonant.  Q  has  the  sound  of  koo,  as  in  quart,  (kooart;)  W  of  oo, 
as  in  word  (oourd;)  X.  of  ks,  or  Z,  as  in  vex,  (vecks,)  or  Xerxes,  (zerk- 
ses;)  whilst  Y  has  the  sound  of  I  or  E,  as  in  wry  or  yard,  (wri  or  eeard.) 
Ch,  Sh,  and  Th,  have  been  added,  as  being  true  alphabetic  or  simple 
sounds. 

Letters  have  been  usually  divided  into  two  classes,  vowels  and  conso- 
nants. The  vowels  or  vocal  sounds  are  so  called,  because  they  appear 
to  be  simple  modifications  of  the  voice  formed  in  the  larynx,  uninter- 

1  Good,  op.  citat.,  ii.  273. 


484  MUSCULAR  MOTION. 

rupted  by  the  tongue  and  lips,  and  passing  entirely  through  the  mouth. 
Such  at  least  is  the  case  with  those  that  are  reckoned  pure  vowels. 
These,  in  the  English  alphabet,  are  five  in  number, — A,  E,  I,  0,  and  U. 
W  and  Y  are,  likewise,  vowel  sounds  in  all  situations.  In  enunciating 
A,  as  in  fate,  the  tongue  is  drawn  backwards  and  slightly  upwards,  so 
as  to  contract  the  passage  immediately  above  the  larynx.  In  sounding 
E,  the  tongue  and  lips  are  in  their  most  natural  position  without  exer- 
tion. I  is  formed  by  bringing  the  tongue  nearly  into  contact  with  the 
bony  palate ;  0,  by  the  contraction  of  the  mouth  being  greatest  imme- 
diately under  the  uvula,  the  lips  being  also  somewhat  contracted.  In 
the  production  of  U,  the  contraction  is  prolonged  beneath  the  whole  of 
the  soft  palate.  From  these  principal  vowels,  all  the  other  vowel 
sounds  of  the  language  may  be  formed,  by  considering  them  as  partak- 
ing more  or  less  of  the  nature  of  each.  They  are,  in  our  language, 
fourteen  in  number :  besides  compound  sounds,  as  in  oil  and  pound.  Of 
these  fourteen,  four  belong  to  A ;  two  to  E  ;  two  to  I;  three  to  0;  and 
three  to  U. 


A,  asm- 


E,  as  in  - 


fFate. 
Far. 


Fall. 
Me. 
Met. 


Pine. 
I,  asm 


(No. 

0,  as  in  •         •         -       <  Not. 
(  Move. 
CTune. 


U,  as  in  -         -        -       <  Tub. 
/Bull. 


The  vowels  are  more  easy  of  pronunciation  than  the  consonants. 
They  merely  require  the  mouth  to  be  opened  ;  and  howsoever  it  may 
be  arranged  in  the  enunciation  of  the  different  vowels,  the  vocal  tube 
is  simply  modified,  to  vary  the  impression,  which  has  to  be  made  on 
the  organ  of  hearing.  The  shape  of  the  cavity  is  altered  ;  but  the 
passage  of  the  air  continues  free,  and  the  voice,  consequently,  issues  in 
an  unrestrained  manner.  Hence,  perhaps,  the  physiological  origin  of 
the  Danish  word  Aa,  "  a  river" — a  generic  term,  which  became  after- 
wards applied  to  three  rivers  in  the  Low  Countries,  three  in  Switzer- 
land, and  five  in  Westphalia, — the  sound  of  the  two  broad  A's  flowing 
without  obstacle,  like  a  river.  Time  passes  away  in  a  similar  manner; 
hence,  for  a  like  reason,  the  Greek  twi  which  signifies  "always,  per- 
petually ;"  and  the  German  je,  which  has  the  same  signification. 

The  consonants  are  more  difficult  of  enunciation  than  the  vowels;  as 
they  require  different,  and  sometimes  complex,  and  delicate  movements 
of  the  vocal  tube;  and,  on  this  account,  they  are  not  acquired  so  early 
by  children.  The  term  consonant  is  derived  from  one  of  its  uses, — that  of 
binding  together  vowels,  and  being  sounded  with  them.  By  most,  and 
according  to  Mr.  Walker,1  by  the  best  grammarians,  w  and  y  are  con- 
sonants when  they  begin  a  word;  and  vowels  when  they  end  one.  Dr. 
Lowth,2  however,  a  man  of  learning  and  judgment,  who  certainly  would 
not  suffer  in  a  comparison  with  any  of  his  opponents,  regards  them,  as 
the  author  does,  to  be  always  vowels.  Physiologically,  it  is  not  easy  to 
look  upon  them  in  any  other  light.  Yet  Mr.  Walker  exclaims: — "How 

1  Preface  to  his  Dictionary.  a  Introduction  to  English  Grammar,  p.  3. 


VOICE — ARTICULATE  LANGUAGE.  485 

so  accurate  a  grammarian  as  Dr.  Lowth  could  pronounce  so  definitely 
on  the  nature  of  y,  and  insist  on  its  being  always  a  vowel,  can  only  be 
accounted  for  by  considering  the  small  attention  which  is  generally  paid 
to  this  part  of  grammar."  No  stronger  argument,  however,  could  be 
used  against  the  useless  expenditure  of  time  on  this  subject,  than  the 
conclusion  to  which  Mr.  Walker  himself  has  arrived;  and  for  which  he 
can  find  no  stronger  reasons,  than  that  "if  w  and  y  have  every  pro- 
perty of  a  vowel,  and  not  one  of  a  consonant;  why,  when  they  begin 
a  word,  do  they  not  admit  of  the  euphonic  article  an  before  them?"! 

The  consonants  are  usually  divided  into  mutes,  semi-vowels,  and 
liquids.  Mutes  are  such  as  emit  no  sound  without  a  vowel, — 6,  p,  t,  d, 
k,  and  c  and  g  hard.  Semi-vowels  are  such  as  emit  a  sound,  without 
the  concurrence  of  a  vowel,  as/,  v,  *,  2,  x,  g  soft  or  j.  Liquids  are  such 
as  flow  into,  or  unite  easily  with,  mutes,  as  Z,  m,  n,  r.  These  letters 
issue  without  much  obstacle;  hence  perhaps  their  name. 

In  tracing  the  modes  in  which  the  different  consonants  are  articulated, 
we  find,  that  certain  of  them  are  produced  by  an  analogous  action  of 
the  vocal  tube ;  so  that  the  physiology  of  one  will  suffice  for  the  other. 
For  instance,  the  following  nearly  correspond: — 

p  f  t  s  k  ch 
£&&&&& 
b  v  d  z  g  j 

B  and  P  are  produced  when  the  lips,  previously  closed,  are  suddenly 
opened.  B  differs  from  P  in  the  absence,  in  the  latter,  of  an  accom- 
panying vocal  sound.  F  and  V  are  formed  by  pressing  the  upper 
incisor  teeth  upon  the  lower  lip.  They  are,  consequently,  not  well 
enunciated  by  the  aged,  who  have  lost  their  teeth.  F  differs  from  V 
only  in  the  absence  of  an  accompanying  vocal  sound.  T  and  D  are 
formed  by  pressing  the  tip  of  the  tongue  against  the  gums  behind  the 
upper  incisor  teeth.  D  is  accompanied  by  a  vocal  sound;  T  not.  S 
and  Z  are  produced  by  bringing  the  point  of  the  tongue  nearly  in  con- 
tact with  the  upper  teeth,  and  forcing  the  air  against  the  edges  of  the 
teeth  with  violence.  S  differs  from  Z  in  the  absence  of  the  vocal  sound. 
K  and  G  are  formed  by  pressing  the  middle  of  the  tongue  against  the 
roof  of  the  mouth,  near  the  throat ;  separating  the  parts  a  little  more 
rapidly  to  form  the  former,  and  more  gently  to  form  the  latter  of  those 
letters.  In  K,  the  accompanying  vocal  sound  is  absent.  Ch  and  J 
are  formed  by  pressing  t  to  sh;  and  d  to  zh.  In  Ch,  there  is  no  ac- 
companying vocal  sound.  SH  and  ZH  are  formed  in  the  same  part  of 
the  tube  as  s  and  z.  TH  is  formed  by  protruding  the  tongue  between 
the  incisor  teeth,  and  pressing  it  against  the  upper  incisors  to  produce 
its  sound  in  think.  Its  sound  in  that  is  effected  by  pressing  the  tongue 
behind  the  upper  incisor  teeth.  In  the  former  case,  it  is  unaccompanied 
by  a  vocal  sound.  In  M,  the  lips  are  closed,  as  in  B  and  P;  and  the 
voice  issues  by  the  nose.  N  is  formed  by  resting  the  tongue  against 
the  gums,  as  in  the  enunciation  of  t  and  d;  breathing  through  the  nose 
with  the  mouth  open.  In  L,  the  tip  of  the  tongue  is  pressed  against 
the  palate,  the  sound  escaping  laterally.  In  forming  the  letter  K,  the 
middle  and  point  of  the  tongue  strike  the  palate  with  a  vibratory  mo- 
tion; the  tip  being  drawn  back.  Lastly,  in  the  formation  of  H,  the 


486  MUSCULAR  MOTION. 

breath  is  forced  through  the  mouth,  which  is  every  where  a  little  con- 
tracted. It  need  hardly  be  said,  that  the  enunciation  of  these  letters 
requires,  that  the  vocal  tube,  or  the  parts  concerned  in  the  function, 
shall  be  in  a  sound  condition.1 

A  few  years  ago,  (1846,)  an  ingenious  German,  named  Faber,  ex- 
hibited publicly  in  Philadelphia  a  speaking  automaton,  in  the  construc- 
tion of  which  he  found  that  the  alphabet  can  be  simplified  still  further. 
The  precise  mechanism  he  did  not  unfold ;  but  affirmed  that  the  parts 
were  made  of  elastic  materials  to  resemble  as  nearly  as  possible  the 
human  vocal  organs.  These  parts  were  susceptible  of  varied  move- 
ments by  means  of  keys.  The  author  was  much  struck  by  the  distinct- 
ness with  which  the  automaton  could  enunciate  various  letters  and  words. 
The  combination  three  was  well  pronounced;  the  th  less  perfectly;  but 
astonishingly  well.  It  also  enunciated  diphthongs  and  numerous  diffi- 
cult combinations  of  sounds.  Sixteen  keys  were  sufficient  to  produce 
all  the  sounds.  It  sang  "  God  save  the  Queen"  and  "Hail  Columbia" — 
the  words  and  air  combined. 

The  following  is  the  alphabet  of  the  automaton.  1.  Five  simple 
vowels:  for  example — a  as  in  father;  o  as  in  home;  u  as  in  ruin;  i  as  e 
and  e  as  a.  2.  Nine  consonants,  I,  r,  w  (the  German  w — the  English 
w  is  oo),  /,  8,  sh  in  shall,  and  b,  d,  g  hard,  as  in  give.  3.  A  nasal 
sound  and  an  aspirate;  making  in  all  sixteen  simple  sounds.  From 
these  the  compound  sounds  are  formed,  as  in  the  following  examples : 
b  and  the  nasal  form  m;  d  and  the  nasal,  n:  if  the  nasal  sound  be  pre- 
vented, me  becomes  be;  not  becomes  dot ;  g  and  the  nasal  form  ng ;  b 
and  the  aspirate  formp;  d  and  the  aspirate,  t;  g  and  the  aspirate,  Jc; 
sh  and  the  nasal,  th;  wf  or  uf  form  v;  d  and  sh,j  and  g  soft;  t  and  sh, 
ch  in  chin.  The  diphthongs  admitted  by  Mr.  Faber  are  ai  i,  eu  u;  and 
au  sounded  as  in  how. 

Wolfgang  von  Kempelen,2  in  a  work  on  the  mechanism  of  human 
speech,  which  is  considered  classical  in  Germany, — and  in  which  he 
treats  of  a  speaking  automaton  (Sprachmaschine)  of  his  inven- 
tion,— divides  the  consonants  into  four  classes.  1.  Mutes,  (ganz 
s  t  u  m  m  e ,)  as  K,  P,  T.  2.  Explosives,  ( W  indmitlauter,)  as  F, 
H,  Ch,  S,  and  Sh.  3.  Vocal  consonants,  (S  t  i  m  m  i  1 1  a  u  t  e  r ,)  as  B, 
D,  G,  L,  M,  and  N;  and  4.  Vocal  Explosives,  (W ind  und  Stimm- 
lauter  zugleich,)  as  R,  I,  W,  V,  Z.  Dr.  Thomas  Young  has, 
likewise,  divided  the  English  consonants  into  classes;  of  which  he  enu- 
merates five.  1.  Pure  semi-vowels,  as  L,  R,  V,  Z,  and  J.  2.  Nasal 
semi-vowels,  as  M  and  N.  3.  Explosive  letters,  as  B,  D,  and  G.  4. 
Susurrant  letters,  as  H,  F,  X,  and  S ;  and  5.  Mutes,  as  P,  T,  K ;  but 
the  most  satisfactory  classification,  in  a  physiological,  as  well  as  philo- 
logical point  of  view,  is  according  to  the  parts  of  the  vocal  tube  more 
immediately  concerned  in  their  articulation. 

1  See  Mayo,  Outlines  of  Human  Physiology,  3d  edit.,  p.  357,  Lond.,  1833,-  also,  Haller, 
Element.  Physiol.,  lib.  ix.  §  4,  Lausan.  1766. 

a  Mechanismus  der  Menschlichen  Sprache,  s.  228,  Wien,  1791;  and  Rudolphi,  Grundriss 
der  Physiologic,  2ter  Band,  Iste  Abtheil.  s.  398,  Berlin,  1823. 


VOICE — ARTICULATE  LANGUAGE. 


487 


Labial. 

Dento-labial. 

Linguo-dental  . 

Linguo-palatal. 

Guttural. 

B 

F 

Th 

D  J  L  N 

G 

M 

V 

R  S  T  Z 

K 

P 

Ch  Sh  Ng 

That  this  physiological  arrangement  has  had  much  to  do  with  the 
formation  of  congenerous  tongues  more  especially  is  exhibited  by 
facts  connected  with  the  permutation  or  change  of  letters; — when  a 
word  passes,  for  example,  from  one  of  the  Teutonic  or  Romanic  lan- 
guages to  another.  uThe  changes  of  vowels,"  says  Mr.  Lhuyd,1 
"whether  by  chance  or  affectation,  are  so  very  easy  and  so  common  in 
all  languages,  that  in  etymological  observations,  they  need  not,  indeed, 
be  much  regarded;  the  consonants  being  the  sinews  of  words,  and  their 
alterations  therefore  the  most  perceptible.  The  changes  of  consonants 
also  into  others  of  the  same  class,  (especially  labials,  palatals,  and  lin- 
guals,}  are  such  obvious  mistakes,  that  there  is  no  nation  where  the 
common  people  in  one  part  or  other  of  their  country  do  not  fall  into 
some  of  them."  A  few  examples  will  show  to  what  extent  this  permu- 
tation occurs  between  letters  of  the  same  class  in  different  languages. 
In  this  view,  we  may  regard  the  labials  and  dento-labials  as  belonging 
to  the  same. 

P  into  B. — Greek,  $\f 4,5  Latin,  phlebs.  .  Latin,  (and  Greek,)  episcopus  •  English,  bishop  ; 
Anglo  Saxon,  biscop  •  German,  b  i  s  c  h  o  f . 

P  into  F  and  V. — Latin, pater  ;  German,  vater;  Dutch,  vader ;  English,/a//ier. 

T  into  S. — German,  b  e  s  s  e  r  ;  English,  belter.     German,  w  a  s  s  e  r ;  English,  water. 

D  into  Th. — German,  das;  Dutch,  dat;  English,  that. 

T  into  Z. — German,  z  u  n  g;  Dutch,  tong  •  English,  tongue.  German,  z  w  e  i  g;  English, 
twig. 

L  into  R. — Spanish,  Gil  Bias ;  Portuguese,  Gil  Bras.     Latin,  arbor  ;  Spanish,  albero. 

C  or  K  into  G. — Latin,  hemicranium ;  French,  migraine.  Latin,  cibarium  ;  French,  gibier. 
Latin,  acer  ;  Italian,  agro.  Latin,  alacer  •  Italian,  allegro.  Greek,  xuxvc? ;  Latin,  cygnus. 

The  most  harmonious  languages  are  such  as  have  but  few  consonants 
in  their  words,  compared  with  the  number  of  vowels;  hence  the  musical 
superiority  of  the  Greek  and  Italian,  over  the  English,  German,  &c. 
"Among  certain  northern  nations,"  says  M.  Richerand,2  "all  articu- 
lated sounds  appear  to  issue  from  the  nose  or  the  throat,  and  make  a 
disagreeable  pronunciation,  doubtless  because  it  requires  greater  effort ; 
and  he  who  listens,  sympathizes  in  the  difficulty,  which  seems  to  be 
felt  by  him  that  speaks;" — and  he  adds: — "would  it  not  seem  that  the 
inhabitants  of  cold  countries  have  been  led  to  use  consonants  rather 
than  vowels,  because  as  the  pronunciation  does  not  require  the  same 
opening  of  the  mouth,  it  does  not  afford  the  same  space  for  the  continual 
admission  of  cold  air  into  the  lungs?"!  The  whole  of  Richerand's  re- 
marks on  this  topic  are  singularly  fantastic  and  feeble,  and  unworthy 
of  serious  discussion. 

In  regard  to  consonants,  it  has  been  presumed,  that  some  common 
imitative  principle  must  have  existed  with  all  nations,  so  as  to  cause 
them  to  conform  in  adopting  such  as  produce  a  certain  sound  to  convey 


1  Archseologia  Britannica,  Oxford,  1707. 
a  Elernens  de  Physiologie,  edit,  cit.,  p.  298. 


488  MUSCULAR  MOTION. 

the  same  effect  to  the  ear.  Dr.  John  Wallis1  turned  his  attention  to 
this  matter,  chiefly  as  regards  the  English  language,  and  he  has  col- 
lected a  multitude  of  examples  to  show,  that  a  certain  collocation  of 
consonants  at  the  commencement  of  a  word  generally  designates  the 
class  of  ideas  intended  to  be  conveyed  by  it.  For  instance,  he  re- 
marks that: — 

Str,  always  carries  with  it  the  idea  of  great  force  and  effort : — as  strong,  strike,  stripe,  strife, 
struggle,  stretch,  strain,  &c. 

St,  the  idea  of  strength,  but  in  less  degree — the  vis  inertia,  as  it  were  : — as  stand,  stay,  stop, 
stick,  stutter,  stammer,  stumble,  stalk,  steady,  still,  stone,  &c. 

Thr,  the  idea  of  violent  motion  : — as  throw,  thrust,  throb,  threat,  throng,  &c. 

Wr,  the  idea  of  obliquity  or  distortion : — as  wry,  wreathe,  wrest,  wring,  wrestle,  wrench,  wrig- 
gle,  urrangle,  &c. 

Br,  the  idea  of  violent — chiefly  sonorous — fracture  or  rupture  : — as  break,  brittle,  brust,  or 
burst,  brunt,  bruise,  broil,  &c. 

Cr,  the  idea  of  straining  or  dislocation,  chiefly  sonorous  : — as  crack,  creak,  crackle,  cry,  crow, 
crisp,  crash.  Other  words,  beginning  with  these  consonants,  communicate  the  idea  of  curva- 
ture, as  if  from  curvus : — as  crook,  cringe,  crouch,  creep,  crawl,  cripple,  crumple,  crotchet,  &c. 
Others,  again,  denote  decussation,  as  if  from  crux: — as  cross,  cruise,  crutch,  crosier. 

Shr,  the  idea  of  forcible  contraction  : — as  shrink,  shrivel,  shrug,  shrill,  &c. 

Gr,  the  idea  of  the  rough,  hard,  onerous  and  disagreeable,  (either  owing  to  the  letter  of 
loughness  r,  or  from  gravis,) — as  grate,  grind,  gripe,  grapple,  grieve,  grunt,  grave,  &c. 

Sw,  the  idea  of  silent  agitation  or  of  gentle  lateral  motion  : — as  sway,  swag,  swerve,  sweat, 
swim,  swing,  swift,  &c. 

Sm,  a  very  similar  idea  to  the  last : — as  smooth,  small,  smile,  smirk,  &c. 

Cl,  the  idea  of  some  adhesion  or  tenacity: — as  cleave,  clay,  cling,  climb,  cloy,  cluster,  close,  &c. 

Sp,  the  idea  of  some  dispersion  or  expansion,  generally  quick,  (especially  with  the  addi- 
tion of  the  letter  r,) — as  spread,  spring,  sprig,  sprinkle,  split,  splinter,  spill,  &c. 

SI,  the  idea  of  a  gently  gliding  or  slightly  perceptible  motion  : — as  slide,  slip,  slippery,  slime, 
sly,  slow,  sling,  &c. 

Lastly :  Sq,  Sk,  Scr,  denote  violent  compression : — as  squeeze,  squirt,  squeak,  squeal,  skreek, 
screw,  &c. 

Other  interesting  observations  on  the  collocation  of  consonants,  at 
the  termination,  and  in  the  body,  of  words,  are  contained  in  the  gram- 
mar of  Wallis.  His  remarks,  however,  are  chiefly  confined  to  his  own 
tongue.  The  President  de  Brosses2  has  taken  a  wider  range,  with  a 
similar  object,  and  endeavoured  to  discover  why  certain  consonants,  or 
a  certain  arrangement  of  consonants  in  a  word,  should  designate  certain 
properties,  in  all  languages.  Why,  for  instance,  the  st  should  enter 
into  most  words  signifying  firmness  and  stability: — as,  in  the  Sanskrit, 
stabatu,  to  stand,  stania,  a  town,  &c. ;  in  the  Greek,  ot^,  a  column, 
tfffpsoj,  solid,  immovable,  crr-fipa,  sterile,  remaining  constantly  without 
fruit,  (j^pifw,  "  I  fix  firmly,"  &c. ;  in  the  Latin,  stare,  to  stand;  stirps, 
a  stem;  stupere,  to  be  astonished;  stagnum,  stagnant  water,  &c.;  and 
he  might  have  added,  in  the  German,  still-stehend,  stagnant; 
stadt,  a  town;  stand,  condition;  sterben,  to  die;  still-stand, 
cessation,  &c.,  besides  the  English  words,  commencing  with  st,  already 
quoted  from  Wallis.  He  farther  inquires,  why  words,  commencing  with 
so,  denote  hollowness,  as  axcvttu,  I  dig;  axa,^,  skiff  or  boat,  in  the 
Greek;  scutum,  a  shield;  scyphm,  a  large  jug;  sculpere,  to  engrave; 
scrobs,  a  ditch,  in  the  Latin; — ecuelle,  formerly  escuelle,  a  dish;  scarifier, 
to  scarify;  scabreux,  scabrous;  sculpture,  &c.,  in  the  French;  and  simi- 

1  Grammatica  Linguae  Anglicanae,  &c.,  edit.  6,  Lond.,  1765. 

a  Traite  de  la  Formation  Mechanique  des  Langues  et  des  Principes  Physiques  de  1'Ety- 
mologie,  i.  199,  Paris,  1765. 


VOICE — ARTICULATE  LANGUAGE.  489 

lar  words  might  be  added  from  our  own  language.  Ecrire,  formerly 
escrire,  the  French  for  "  to  write,"  is  from  the  Latin  scribere;  and, 
anciently,  a  kind  of  style  was  used  for  tracing  the  letters  in  wax;  which 
instrument,  by  a  like  analogy,  was  called,  by  the  Greeks,  <jxapi$oj.  M. 
de  Brosses1  accounts  for  these,  by  supposing,  that  the  teeth,  being  the 
most  immovable  of  the  organic  apparatus  of  the  voice,  the  firmest  of, 
what  he  calls  the  dental  letters,  T,  has  been  mechanically  employed  to 
denote  stability;  and  to  denote  hollowness,  the  K  or  C  has  been 
adopted, — which  are  produced  in  the  throat,  the  most  hollow  of  the 
vocal  organs.  The  letter  S  serves,  he  conceives,  merely  as  an  augmen- 
tative; as  the  sound  can,  by  its  addition,  be  made  continuous.  It  is 
itself,  however,  a  letter  expressive  of  softness,  when  combined,  as  we 
have  seen,  with  certain  other  consonants;  or  when  employed  alone  at 
the  commencement  of  a  word. 

In  the  same  manner,  the  letters  fl  are  used  tp  designate  the  motion 
of  fluids  more  especially, — as  in  the  Greek,  $>ju>t,  a  flame ;  $te^,  a  vein ; 
^teytQuv,  a  burning  river  in  the  infernal  regions: — in  the  Latin,  flamma, 
flame;  fluo,  I  flow;  flatus,  wind;  fluctus,  wave,  &c. : — in  the  German, 
floss  en,  to  float;  f  lot  en,  to  play  on  the  flute;  flu  as,  a  river; 
f  lug,  flight,  &c.;  and  in  the  French  and  English  words  of  the  same 
meaning.  Lastly,  the  idea  of  roughness  and  asperity  is  conveyed  by  the 
letter  r,  as  in  the  words  rough,  rude,  rock,  romp,  &c.  How  different, 
for  example,  in  smoothness  are  the  two  following  lines,  in  which  the  S 
predominates,  from  those  that  succeed  them,  where  the  R  frequently, 
and  perhaps  designedly,  occurs: 

"  Softly  sweet  in  Lydian  measures, 
Soon  he  soothed  his  soul  to  pleasures ;" 

And: — 

"  Now  strike  the  golden  lyre  again, 
A  louder  yet,  and  yet  a  louder  strain ; 
Break  his  bands  of  sleep  asunder ; 
And  rouse  him  like  a  rattling  peal  of  thunder." 

DRTDEN'S  "  Mexander^s  Feast" 

The  foregoing  remarks,  suggested  by  those  of  Wallis  and  M.  de  Bros- 
ses, must  not,  however,  be  received  too  absolutely.  In  the  condition  in 
which  we  find  languages  at  the  present  day,  it  would  be  impossible  that 
they  should  hold  good  universally ;  but  they  will  tend  to  show,  that  the 
physiology  of  the  voice  is  intimately  connected  with  this  part  of  philo- 
logy; and  that  the  sounds  emitted  by  the  agency  of  particular  parts  of 
the  vocal  tube,  may  have  led  to  the  first  employment  of  those  sounds, 
according  to  the  precise  idea  it  may  have  been  desired  to  convey; — 
gutturals,  for  example,  for  sounds  conveying  the  notion  of  hollowness: 
— resisting  dentals,  that  of  obstacles,  &c.  The  words  mamma  and  papa 
are  composed  of  a  vowel  and  consonant,  which  are  the  easiest  of  enun- 
ciation ;  and  which  the  child,  consequently,  pronounces  and  unites 
earlier  than  any  other.  Hence  they  have  become  the  infantile  appella- 
tions for  mother  and  father  with  many  nations.  President  de  Brosses2 
affirms — and  he  has  brought  forward  numerous  examples  to  prove  his 
position — that  in  all  ages,  and  in  every  country,  a  labial,  or,  in  default 

*0p.  cit.,i.261.  9  Op.  cit.,  i.  244. 


490  MUSCULAR  MOTION. 

of  it,  a  dental,  or  both  together,  are  used  to  express  the  first  infantile 
words  "papa"  and  "mamma;"  but  it  is  scarcely  necessary  to  say,  that 
the  child,  when  it  first  pronounces  the  combinations,  attaches  no  such 
meaning  to  them  as  the  parent  fondly  imagines. 

There  is  a  rhetorical  variety  of  onomatopoeia,  frequently  considered 
under  the  head  of  alliteration,  but  by  no  means  deriving  its  chief  beau- 
ties from  that  source.  It  happens  when  a  repetition  of  the  same  letter 
concurs  with  the  sonorous  imitations  already  described ;  as  in  the  fol- 
lowing line  in  one  of  the  books  of  the  ^Eneid  of  Virgil; — 

"  Luctentes  ventos  tempesZatesque  sonoras," 

in  which  the  frequent  occurrence  of  the  letter  of  firmness  and  stability, 
T,  communicates  the  idea  of  the  striking  of  the  wind  on  objects. 
In  the  "Andromaque"  of  Racine,  a  line  of  this  character  occurs: 

"  Pour  qui  sont  ces  serpens  qui  sifflent  sur  vos  tetes,"1 

in  which  the  sound  impressed  on  the  ear  has  some  similarity  to  the 
hissing  of  serpents:  and  in  the  "  Poeme  des  Jar  dins"  of  the  Abb£  De- 
lille,  there  is  the  following  example: — 

"  Soil  que  sur  /e  /imon  une  riviere  /ente, 
Derou/e  en  paix  les  pZis  de  son  onde  indoJente ; 
Soil  qu'a  travers  les  rocs  un  torrent  en  courroux 
Se  brise  avec  fracas."2 

In  the  first  two  lines,  the  liquid  L  denotes  the  tranquil  flow  of  the 
river ;  whilst  in  the  two  last,  the  letter  of  roughness  and  asperity,  R, 
resembles  the  rushing  of  the  stream  like  a  torrent.  The  remarks 
already  made  will  have  exhibited  the  radical  difference  in  the  ideas 
communicated  by  the  sound  of  those  letters,  by  the  common  consent 
of  languages.  In  the  German  this  variety  of  expression  is  often  had 
recourse  to;  and  by  none  more  frequently  than  by  the  poet  Burger.3 
The  English  language  affords  a  few  specimens,  but  not  as  many  as 
might  be  imagined.  Of  simple  alliteration  there  are  many ;  some  that 
give  delight;  others  that  do  violence  to  the  suggestive  principle ;  but 
there  are  comparatively  few  where  the  words  are  selected,  which  by 
their  sound  convey  to  the  mind  the  idea  to  be  communicated.  The 
galloping  of  horses  may  be  assimilated  by  a  frequent  succession  of 
short  syllables;  slow,  laborious  progression  by  the  choice  of  long;  but 
in  the  onomatopoeia  in  question,  the  words  themselves  must  consist  of 
such  a  collocation  of  one  consonant,  or  of  particular  consonants,  as 
adds  force  to  the  idea  communicated  by  the  words  collectively.  Of 
this,  we  have  a  good  example  in  the  lines  before  cited,  in  which  the 

1  "  For  whom  are  those  serpents  that  hiss  o'er  your  heads  ?" 

2  Which  may  be  translated  as  follows  : — 

"  If  o'er  deep  slime  a  river  laves 
In  peace  the  folds  of  its  sluggish  waves; 
Or  o'er  the  rocks  a  torrent  breaks 
In  wrath  obstrep'rous." 

3  Art.  Alliteration,  and  Onomatopoeia,  in  Encyclopedie,  par  Diderot,  D'Alembert,  &c.,  and 
in  Allgemeine  Deutsche  Real-Encyclopadie  fur  die  gebildeten  Stiinde,  (Conversations  Lexi- 
kon})  Aufl.  8,  Leipz.,  1837. 


VOICE — SINGING.  491 

repetition  of  the  letter  R,  in  the  phonetic  words,  adds  considerable 
force  to  the  idea  intended  to  be  conveyed  by  the  passage — 

"Break his  bands  of  sleep  asunder; 
And  rouse  him  like  a  rattling  peal  of  thunder," 

and  in  Byron's  "Darkness," 

"Forests  were  set  on  fire — but  hour  by  hour 
They  fell  and  faded — and  the  crackling  trunks 
Extinguish 'd  with  a  crash — and  all  was  black." 

5.  SINGING. 

The  singing  voice  differs  from  other  vocal  sounds  in  consisting  of 
appreciable  tones,  the  intervals  of  which  can  be  distinguished  by  the 
ear,  and  admit  of  unison.  Under  the  sense  of  hearing  we  endeavoured 
to  show,  that  the  musical  ear  is  an  intellectual  faculty;  and  that  the 
ear  is  only  the  instrument  for  attaining  a  knowledge  of  sounds,  which 
are  subsequently  reproduced  by  the  larynx,  under  the  guidance  of  the 
intellect.  In  this  respect,  therefore,  there  is  a  striking  resemblance 
between  music  and  spoken  language. 

Like  the  latter,  singing  admits  of  considerable  difference,  as  regards 
intensity,  timbre,  &c.  Voices  are  sometimes  divided  into  the  grave 
and  acute  ;  the  difference  between  them  amounting  to  about  an  octave. 
The  former  is  the  voice  of  the  adult  male ;  but  he  is  capable  of  acute 
sounds,  by  assuming  the  falsetto,  which  M.  Savart1  conceives  to  be  pro- 
duced in  the  ventricles  of  the  larynx;  M.  Bennati  in  the  pharynx;  and 
more  recently,  Mr.  J.  Bishop2  has  suggested,  that  it  may  arise  either 
from  the  partial  closing  of  the  glottis,  or  from  a  nodal  division  of  the 
vocal  chords,  "the  pitch  of  the  sound  in  the  production  of  this  peculiar 
modification  of  the  voice  being  such,  that  the  column  of  air  in  the  vocal 
tube  is  of  the  precise  length  requisite  to  vibrate  in  unison  with  the 
larynx."  The  mode,  however,  in  which  the  falsetto  voice  is  produced  is 
by  no  means  determined.  It  has  given  rise  to  great  diversity  of  views.3 
The  acute  voice  is  that  of  the  grown  female,  children,  and  eunuchs. 
According  to  M.  Pouillet,4  the  gravest  sound  of  the  male  voice  makes 
190  vibrations  per  second ;  the  most  acute  678  per  second ;  whilst  the 
female  voice  makes  572  vibrations  for  the  gravest,  and  1606  for  the 
most  acute.  By  adding  all  the  tones  of  an  acute  to  those  of  a  grave 
voice,  they  are  found  to  embrace  nearly  three  octaves ;  but,  according 
to  M.  Magendie,  it  does  not  appear,  that  such  a  compass  of  voice,  in  pure 
and  agreeable  tones,  has  ever  existed  in  one  individual.5  On  the 
other  hand,  M.  Biot  calculated  three  octaves  and  a  half  to  be  the  ex- 
treme range ;  this,  Mr.  Bishop6  says,  he  knows  from  experience  is  too 
low  an  estimate.  Independently  of  the  falsetto,  the  compass  of  the 
natural  voice  would  seem  to  rarely  exceed  two  octaves ;  but  in  some 
cases,  as  in  those  of  Catalani  and  Malibran,  it  has  extended  beyond 

1  Magendie's  Journal  de  Physiologic,  torn,  v.,  Paris,  1825. 

2  Proceedings  of  the  Royal  Society,  No.  65,  London,  1847. 

3  Miiller,  Physiology,  P.  iv.,  p.  1032,  Lond.,  1838. 

4  Elemens  de  Physiologic  Experimental,  torn.  iii.  130,  Paris,  1832. 
6  Precis  Elementaire,  i.  262. 

«  The  Lond.  and  Edinburgh  Philosophical  Magazine,  for  October,  1836,  p.  272. 


492  MUSCULAR  MOTION. 

three.  Some  singers  can  descend  sixteen  tones  below,  others  can  rise 
sixteen  above,  the  medium.  The  former  are  called  tenor  bass;  the 
latter  soprano;  but  hitherto  no  example  has-  occurred  of  a  person,  who 
could  run  through  the  thirty  notes. 

The  musician  establishes  certain  distinctions  in  the  voice;  such  as 
counter,  tenor,  treble,  bass,  &c.  We  find  it,  also,  differing  considerably 
in  strength,  sweetness,  flexibility,  &C.1 

The  singing  voice,  according  to  M.  Bennati,2  is  not  limited  to  the 
larynx, — the  pharynx  being  likewise  concerned.  The  voice,  produced 
in  those  two  different  parts,  has  long  been  termed  voce  di  petto,  and 
voce  di  testa.  M.  Bennati  calls  the  former  laryngeal  notes  or  notes  of  the 
first  register ;  the  latter  supra-laryngeal  or  notes  of  the  second  register  ; 
and  M.  Lepelletier  designates  them  laryngeal  and  pharyngeal  respect- 
ively;— comprising,  in  the  dependencies  of  the  pharynx,  the  tongue, 
tonsils,  and  velum  palati,  by  means  of  which  the  latter  class  of  sounds 
is  elicited.  The  laryngeal  voice,  which  is  always  more  elevated  by  an 
octave  in  the  female  than  the  male,  is  most  commonly  met  with.  It 
furnishes  the  types  called,  1.  Alt  or  soprano  ;  2.  Counteralt;  3.  Tenor; 
4.  Tenor  Bass.  The  pharyngeal  voice  presents  only  modifications  of 
these  types.  It  is  met  with  in  but  few  persons  in  its  finest  develope- 
ment.  It  has  usually  been  supposed  to  be  formed  by  the  superior 
ligaments  of  the  larynx,  or  in  the  ventricles;  but  these  gentlemen 
esteem  it  demonstrated,  that  it  is  formed  at  the  guttural  aperture,  cir- 
cumscribed by  the  base  of  the  tongue,  velum  palati,  its  pillars,  and  the 
tonsils.  By  it  is  produced  the  laritenor,  the  contraltino  tenor,  and  the 
soprano  sfogato.  Bennati  concludes  his  memoir  on  the  human  voice 
by  remarking, — that  not  only  are  the  muscles  of  the  larynx  inservient 
to  the  modulation  of  the  notes  of  song,  but  those  of  the  os  hyoides, 
tongue,  and  the  superior,  anterior,  and  posterior  part  of  the  vocal  tube 
are  called  into  action,  without  the  simultaneous  and  properly  associated 
operation  of  which  the  degree  of  modulation  requisite  for  song  could 
not  take  place. 

When  the  voice  is  raised  in  the  scale  from  grave  to  acute,  a  corre- 
sponding elevation  takes  place  in  the  larynx  towards  the  base  of  the 
cranium.  By  placing  the  finger  on  the  pomum  Adami,  this  motion  can 
be  easily  felt;  at  the  same  time,  the  thyroid  cartilage  is  drawn  up 
within  the  os  hyoides,  and  presses  on  the  epiglottis ;  the  small  space 
between  the  thyroid  and  cricoid  closes ;  the  pharynx  is  contracted ;  the 
velum  pendulum  depressed  and  carried  forwards;  the  tonsils  approach 
each  other ;  and  the  uvula  is  folded  on  itself.  The  reverse  of  these 
phenomena  takes  place  during  the  descent  of  the  voice.3 

It  has  been  already  remarked,  that  the  natural  voice  or  cry  is  con- 
nected with  the  organization  of  the  larynx.  So  far  as  it  can  be  modified 
into  tones  independently  of  the  participation  of  the  intellect,  a  natural 
singing  voice  may  be  said  to  exist.  To  repeat,  however,  any  song, 
requires  both  ear  and  intelligence ;  and,  therefore,  singing  may  be  said 

1    Magendie's  Jour,  de  Physiologic,  x.  179. 

•  Recherches  sur  le  Mecanisme  de  la  Voix  Humaine,  Paris,  1832. 

8  Bishop  and  Bennati,  in  op.  cit. 


GESTURES.  493 

to  have  originated  in  social  life.     It  can  be  employed,  as  it  is  in  many 
of  our  operas,  to  depict  the  different  intellectual  and  moral  conditions, 

"And  bid  alternate  passions  fall  and  rise." 

When  the  air  is  accompanied  by  the  words,  or  is  articulated,  we  are 
capable  of  expressing,  by  singing,  any  of  the  thoughts  or  feelings,  that 
can  be  communicated  by  ordinary  artificial  language. 

Declamation  is  a  kind  of  singing,  except  that  the  intervals  between 
the  tones  are  not  entirely  harmonic,  and  the  tones  themselves  not 
wholly  appreciable.  With  the  ancients — it  has  been  imagined — it  dif- 
fered much  less  from  singing  than  with  the  moderns,  and  probably  re- 
sembled the  recitative  of  the  operas.  The  ingenious  work  of  Dr.  James 
Rush  of  Philadelphia,1  may  be  consulted  on  all  this  subject,  with  great 
advantage. 

b.  Creatures. 

Under  this  appellation,  and  that  of  muteosis,  are  included  those 
functions  of  expression,  that  are  addressed  to  the  sight  and  touch.  It 
comprises  not  only  the  partial  movements  of  the  face,  but  also  those  of 
the  upper  extremities ;  besides  the  innumerable  outward  signs  that  cha- 
racterize the  various  emotions.  In  many  tribes  of  animals,  the  con- 
ventional language  appears  to  be  almost,  if  not  entirely,  confined  to 
the  gestures;  and  even  in  man — favoured  beyond  all  animals  in  the 
facility  of  communicating  his  sentiments  by  the  voice — the  language  of 
gestures  is  rich  and  comprehensive.  It  is  in  the  gestures  of  the  face 
chiefly,  that  he  far  exceeds  other  animals.  This  is,  indeed,  in  him,  the 
great  group  of  organs  of  expression.  In  animals,  the  function  is  dis- 
tributed over  different  parts  of  the  body,  the  face  assuming  but  little 
expression,  whilst  the  animal  is  labouring  under  any  emotion,  if  we 
make  exception  of  the  brute  passion  of  anger  and  of  one  or  two  others. 
Hence  it  is,  that,  by  some  naturalists,  man  has  been  defined,  by  way  of 
distinction,  "a  laughing  and  crying  animal."  In  animals,  almost  all 
the  facial  expression  of  internal  feeling  is  confined  to  the  eye  and  mouth, 
but,  in  addition,  the  attitude  of  the  body  is  variously  modified,  and  the 
hair  is  raised  by  the  panniculus  carnosus,  as  we  see  on  the  back  of  the 
dog  when  enraged. 

In  the  human  countenance,  alone,  in  the  state  of  society,  can  the 
passions  be  read, — the  rest  of  the  body  being  covered  by  clothing;  and 
even  were  it  not,  the  absence  of  a  coat  of  hair,  and  of  a  panniculus 
carnosus,  would  enable  it  to  minister  but  little  to  expression.  The  skin 
of  the  face  is  very  fine,  and  on  certain  parts,  as  the  lips  and  cheeks,  is 
habitually  more  or  less  florid,  and  admits  of  considerable  and  expressive 
variations  in  its  degree  of  colour.  The  union  of  the  different  parts 
composing  the  face  gives  occasion  to  numerous  reliefs,  which  are  called 
traits  or  features;  and  beneath  the  skin  are  muscles,  capable,  by  their 
contraction,  of  modifying  the  features  in  a  thousand  ways. 

To  comprehend  fully  the  physiology  of  the  facial  expression  of  the 

1  Philosophy  of  the  Human  Voice,  3d  edit.,  Philad.,  1845. 


494 


MUSCULAR  MOTION. 


Muscles  of  the  Head  and  Face. 


>• 20L  passions,  a   few   observations    on   the 

muscles  of  the  human  face  will  be  ne- 
cessary.    (Fig.  201.) 

The  eyebrow  is  greatly  concerned  in 
expression;  and  certain  muscles  are 
attached  to  it  for  the  purpose  of  moving 
it.  The  fasciculus  of  fibres  which  de- 
scends from  the  frontal  muscle,  and  is 
attached  to  the  side  of  the  nose,  has 
been  esteemed,  by  some,  a  separate  mus- 
cle, and  to  have  a  distinct  operation. 
It  draws  the  inner  extremity  of  the 
eyebrow  downwards.  When  the  orbicu- 
laris  palpebrarum,  and  the  last  muscle 
act,  there  is  a  heavy  lowering  expres- 
sion. If  they  yield  to  the  action  of  the 
frontal  muscle,  the  eyebrow  is  arched, 
and  there  is  a  cheerful,  inquiring  ex- 

i.  Frontal  portion  of  occipito-frontaiis.  pression.     If  the  corruQator  supercilii 
2.  Occipital  portion.  3.  Aponeurosis.  4.   acts  there  is  more  or  less  of  mental  an- 

Orbiculans    palpebrarum,   which    conceals  .   \  j»  '-.•'«•  i  •  i»     i 

corrugator    superpilii  and  tensor  tarsi.    5.    gUlSll,  Or  01  pamiui  CXerClSC  01  thought. 

If  it  combines  with  the  frontalis,  the 

Pomon.  y.  i^vator  mDusupenonsproprius;  forehead  is  furrowed,  and  there  is  an 
the  lower  part  of  the  levator  anguii  oris  is  upward  inflection  of  the  inner  extremity 

seen  between  muscles  10  and  11.     10.  Zygo-  J.     ,                 ,                    ,  .    ,      .      ,. 

maticus  minor.    11.  Zygomaticus  major.    12.  01    the    CyebrOW,  Which    indicates    more 

Depressor   labii    inferioris.      13.    Depressor  f  miprnlrma   anrl  wAnlr  an viot AT          "TV>o> 

anguii  oris.    14.  Levator  labii  inferioris.    15.  01  qUClUiOUS  and  W6aJ£  anxiety. 

Superficial  portion  of  masseter.   16  itsdeep  arched  and    polished  forehead,"   says 

portion.    17.  Attrahens  aurem.    18.  Buccina-  "  J° 

tor.   19.  Attoiiens  aurem.    20.  Temporal   feir  Charles  Joell — or  whose  elegant  and 

fascia  which  covers  temporal  muscle.    21.  -w-j              ,    ,-,                -,              .->-, 

Retrahens  aurem.    22.  Anterior  belly  of  di-  accurate  JiiSSayS     the   author  Will    OCCa- 

gastricus  muscle;  the  tendon   seen  passing  ei'rmillv  avail   him<?plf  nn   thi<a  Krnnnh  nf 

through  its  aponeurotic  pulley.    23.  Stylo-  OnailV  avail 

hyoid  muscle  pierced  by  posterior  belly  of    theSublCCt "  terminated  by  the  distinct 

digastricus.    24.  Mylo-hyoideus muscle.    25.  ...             .»  .               ..               .               v                       . 

Upper  part  of  stemo-mastoid.  26.  Upper  line  ot  the  eyebrow,  is  a  table,  on  which 
and^is^tEpTeniu^^wn^onO6^         ^  we  may  see  written,  in  perishable  cha- 
racters, but  distinct  while  they  continue, 

the  prevailing  cast  of  thought ;  and  by  the  indications  here,  often  the  mere 
animal  activity,  displayed  in  the  motions  of  the  lower  part  of  the  face,  has 
a  meaning  and  a  force  given  to  it.  Independent  of  the  actions  of  the 
muscles,  their  mere  fleshiness  gives  character  to  this  part  of  the  face. 
The  brow  of  Hercules  wants  the  elevation  and  form  of  intelligence ; 
but  there  may  be  observed  a  fleshy  fulness  on  the  forehead,  and  around 
the  eyes,  which  conveys  an  idea  of  dull  brutal  strength,  with  a  lower- 
ing and  gloomy  expression,  which  accords  with  the  description  in  the 
Iliad" 

Sir  Charles  separates  the  orbicular  is  palpebrarum  into  two  muscles; — 
the  outer,  fleshy,  circular  band,  which  runs  round  the  margin  of  the 
orbit;  and  the  lesser  band  of  pale  fibres,  which  lies  upon  the  eyelids. 
The  latter  is  employed  in  the  act  of  closing  the  eyelids,  but  the  former 
is  only  drawn  into  action  in  combination  with  the  other  muscles  of  the 

1  Essays  on  the  Anatomy  and  Philosophy  of  Expression,  3d  edit.,  Lond.,  1844. 


GESTURES — MUSCLES  OF  THE  FACE.  495 

face  in  expressing  passion,  or  in  some  convulsive  excitement  of  the 
organ.  In  laughing  and  crying,  the  outer  and  more  powerful  muscle 
is  in  action,  gathering  up  the  skin  about  the  eye,  and  forcing  back  the 
eyeball  itself.  In  drunkenness,  the  power  of  volition  over  this  muscle 
is  diminished;  and  there  is  an  attempt  to  raise  the  upper  eyelid  by  a 
forcible  elevation  of  the  eyebrow. 

The  muscles  of  the  nostrils  are;  1st,  levator  labii  superioris  alseque 
nasi,  which,  as  its  name  imports,  raises  the  upper  lip  and  nostril;  2dly, 
compressor  nasi,  a  set  of  fibres  which  compress  the  nostril;  and  3dly, 
depressor  alse  nasi,  which  lies  under  orbicularis  oris,  and  whose  function 
is  indicated  by  its  name.  The  three  muscles  serve  to  expand  and  con- 
tract the  opening  or  canal  of  the  nostril,  moving  in  consent  with  the 
muscles  of  respiration,  and  thus  the  inflation  of  the  nostrils  indicates 
general  excitement,  and  animal  activity. 

The  muscles  of  the  lips  are;  1st,  levator  labii  proprius,  which  raises 
the  upper  lip ;  2dly,  levator  anguli  oris,  which  raises  the  angle  of  the 
mouth;  and  3dly,  the  zygomatic  muscle,  which  is  inserted  into  the  angle 
of  the  mouth.  Sometimes  an  additional  muscle  of  the  name  exists: — 
zygomaticus  minor.  These  last  muscles  raise  the  upper  lip  and  angle 
of  the  mouth,  so  as  to  expose  the  canine  teeth.  If  they  be  in  action 
contrary  to  the  orbicularis  oris,  there  is  a  painful  and  bitter  expression ; 
but  if  they  be  influenced  along  with  the  orbicularis  oris,  and  orbicularis 
palpebrarum, — if  the  former  of  these  muscles  be  relaxed,  and  the  latter 
contracted, — there  is  a  fulness  of  the  upper  part  of  the  face,  and  a 
cheerful,  smiling  expression  of  countenance.  The  orbicularis  oris  closes 
the  mouth;  and,  when  allowed  to  act  fully,  purses  the  lips.  The  nasalis 
labii  superioris  draws  down  the  septum  of  the  nose.  The  triangularis 
oris  or  depressor  labiorum  indicates,  by  its  name,  its  function.  The 
quadratus  menti  is  a  depressor  of  the  lower  lip.  The  levatores  menti, 
by  their  action,  draw  up  the  chin,  and  project  the  lower  lip;  and  the 
buccinator  is  chiefly  for  turning  the  alimentary  bolus  in  the  mouth;  and, 
in  broad  laughter,  retracts  the  lips.  The  orbicularis  muscle  is  affected 
in  the  various  emotions  of  the  mind;  trembling  and  relaxing  in  both 
grief  and  joy:  it  relaxes  pleasantly  in  smiling. 

The  union  of  these  various  muscles  at  the  angle  of  the  mouth  pro- 
duces the  fleshy  prominence  noticed  in  those  who  have  thin  faces ;  and 
who  are,  at  the  same  time,  muscular.  When  the  cheeks  are  fat  and 
ful!5  the  action  of  these  muscles  produces  the  dimpled  cheek.  The 
angle  of  the  mouth  is  full  of  expression,  according  as  the  orbicularis, 
or  the  superior  or  inferior  muscles  inserted  into  it  have  the  preponder- 
ance. 

Lastly;  the  temporal  is  a  strong  muscle,  which  raises  the  lower  jaw. 
It  is  assisted  by  the  masseter,  a  deep-seated  muscle,  which  lies  on  the 
outside  of  the  lower  jaw;  arises  from  the  jugum,  and  is  inserted  into 
the  angle  of  the  jaw. 

Two  different  nerves  are  distributed  to  these  muscles, — the  fifth  pair, 
and  portio  dura  or  facial  of  the  seventh;  the  latter  of  which,  according 
to  the  experiments  of  Sir  Charles  Bell,  is  concerned  in  the  instinctive 
movements  of  expression;  and  comparative  anatomy  exhibits,  that  the 
number  and  intricacy  of  these  nerves  vary  in  proportion  to  the  animal's 


496 


MUSCULAR  MOTION. 


- 202-  power   of  expression.       The 

nerves  of  the  face  and  neck 
of  the  monkey  are  numerous, 
and  have  frequent  connexions ; 
but  on  cutting  the  seventh 
pair,  or  respiratory  nerve  of 
the  face  of  Sir  Charles  Bell's 
system,  the  features  are  found 
to  be  no  longer  influenced  by 
the  passions.  Yet  the  skin 
continues  sensible,  and  the 
muscles  of  the  jaws  and  tongue 
are  capable  of  the  actions  of 
chewing  and  swallowing.  If 
the  respiratory  nerve  of  one 
side  be  cut,  the  expression  of 
that  side  is  destroyed;  whilst 
the  chattering,  grinning,  and 
other  movements  of  expres- 
sion continue  on  the  other. 
In  a  dog,  too,  if  the  respira- 

1.  Facial  nerve,  escaping  from  stylo-mastoid  foramen,  ^YJ  nerVC  of  the  face  be  CUt, 
and  crossing  ramus  of  lower  jaw ;  the  parotid  gland  has  V>p  wni  fln-V«t  88  bittprlv  hilt 
been  removed  in  order  to  see  the  nerve  more  distinctly.  .  "g^u  ii^ciy ,  wu 

2.  Posterior  auricular  branch;    the   digastric  and  stylo-   With  nO  retraction  of   hlS  llDS, 
mastoid  filaments  are  seen  near  origin  of  this  branch.     3.  -i-i.  p  ,1 

Temporal  branches,  communicating  with  (4)  branches  of  Sparkling  01  the  eye,  Or 

frontal  nerve.     5.   Facial  branches  communicating  with    •  V^^lr    r»f   fVio    OQT-O 

°1    tfcC    ears. 


COtttinUC    their     office. 


Distribution  of  Facial  Nerve. 


(6)  infra-orbital  nerve.    7.  Facial  branches,  communicat-   ln&     ' 

ing  with  (8)  mental  nerve.      9.   Ceryico-facial  branches  face  Jg  inanimate,  although  the 

communicating  with   (10)    superficiahs  colh  nerve,  and  '  e. 

forming  a  plexus  (11)  over  submaxillary  gland.    Distribu-    mUSClCS  01    the  laCC  and  laWS, 

tion  of  branches  of  the  facial  in  a  radiated  direction  over  f  ,1  r    »\. 

side  of  face  constitutes  the  pes  anserinus.    12.  Auricularis  SO     lar    aS     they  are    HaDlC    tO 

magnus   nerve,    one    of  ascending   branches  of   cervical   K0 

plexus.     13.  Occipitalis  minor,  ascending  along  posterior 

border   of   sterno-mastoid  muscle.      14.    Superficial   and 

deep  descending  branches  of  cervical  plexus.     15.   Spinal   pp. 

accessory  nerve,  giving  off  a  branch  to  external  surface  of   JLhe    game-COCK,    111    the    pOSl- 

trapezius  muscle.     16    Occipitalis  major  nerve,  posterior    ,•  r>  r>    i,«  i  cc 

branch  of  second  cervical  nerve.  tlOn  Of  lighting,  Spreads  a  rutt 

of  feathers  around  his  head. 

The  position  of  his  head  and  the  raised  feathers  are  the  expressions  of 
hostile  excitement;  but  on  the  division  of  the  respiratory  nerve,  the 
feathers  are  no  longer  raised,  although  the  pugnacious  disposition  con- 
tinues. It  has  been  found,  moreover,  that  if  the  galvanic  influence  be 
passed  from  one  divided  extremity  of  the  respiratory  nerve  to  the  other, 
the  facial  expression  returns;  and,  in  certain  cases  of  incomplete  hemi- 
plegia,  in  which  the  movements  of  expression  of  the  face  were  alone 
rendered  impracticable,  the  disease  was  found  to  have  implicated  only 
the  respiratory  or  facial  nerve.  The  views  of  Sir  Charles  Bell  regard- 
ing the  connexion  alleged  by  him  to  subsist  between  the  seventh  pair 
and  the  associated  movements  of  respiration  have,  however,  been  con- 
tradicted by  the  experiments  of  Mr.  Mayo,1  and  his  inferences  regard- 
ing the  fifth  pair  as  being  jointly  a  nerve  of  sensation  and  of  voluntary 
motion  have  been  considered  to  require  qualification.  By  dividing  the 


Outlines  of  Human  Physiology,  4th  edit.,  p.  254,  London,  1837. 


GESTURES — NERVES  OF  THE  FACE. 


497 


portio  dura  of  the  seventh  pair  in  the  ass,  and  on  both  sides  instead  of 
one,  as  done  by  Sir  Charles  Bell,  Mr.  Mayo  found,  that  the  nerve  pre- 
sides over  simple  voluntary  motion  only ;  and  by  a  similar  division  of 
the  second  and  third  branches  of  the  fifth,  at  their  points  of  con- 
vergence, he  showed,  that  the  lips  were  deprived  of  sensation,  not 
of  motion.  "No  doubt,  I  believe,"  says  Mr.  Mayo,  "is  now  enter- 
tained, that  the  inference  which  I  drew  from  these  experiments  is 
correct ; — namely,  that  the  portio  dura  of  the  seventh  pair  is  a  simple 
voluntary  nerve,  and  that  the  facial  branches  of  the  fifth  are  exclusively 
sentient  nerves."  In  the  prosecution  of  his  inquiries,  Mr.  Mayo  ob- 

Fig.  203. 


Plan  of  the  Branches  of  the  Fifth  Nerve,  modified  from  a  sketch  by  Sir  C.  Bell. 

tt.  Submaxillary  gland,  with  the  submaxillary  ganglion  above  it.  1.  Small  root  of  the  fifth  nerve, 
Which  joins  the  lower  maxillary  division.  2.  Larger  root,  with  the  Gasserian  ganglion.  3.  Oph- 
thalmic nerve.  4.  Upper  maxillary  nerve,  5.  Lower  maxillary  nerve.  6.  Chorda  tympani.  7.  Facial 
nerve. 

served,  that  the  masseter  muscle,  temporal,  pterygoids,  and  circumflexus 
palati  receive  no  branches  from  any  nerve  except  the  fifth,  and  yet  that 
they  receive  no  twigs  from  the  ganglionic  portion  of  the  nerve;  and 
thence  he  concludes,  that  almost  all  the  branches  of  the  large  or  gan- 
glionic portion  of  the  fifth  pair  are  nerves  of  sensation,  whilst  those  of 
the  small  fasciculus  or  ganglionless  portion  are  nerves  of  motion.  This 
smaller  portion  of  the  fifth  pair  issues  from  the  peduncles  of  the  brain ; 
constitutes  a  gangliform  plexus  with  the  inferior  maxillary  only;  pre- 
sents the  common  aspect  of  most  nerves  of  the  body,  and  is  distributed 
to  the  chief  muscles  concerned  in  the  process  of  mastication.  Hence 
VOL.  i.— 32 


498 


MUSCULAR  MOTION. 


Fig.  204. 


it  was  termed  by  Bellinger!1  nervus  masticatorius  ;  and  by  Sir  Charles 
Bell,  long  afterwards,  motor  or  manducatory  portion  of  the  fifth  nerve. 
To  this  smaller  fasciculus  of  the  fifth,  twigs  from  the  ganglionic  portion 
of  the  nerve  are  distributed.  The  ganglionless  portion,  and  portio  dura 
of  the  seventh,  Mr.  Mayo  conceives  to  be  voluntary  nerves  to  parts, 
which  receive  sentient  nerves  from  the  larger  or  ganglionic  portion  of 
the  fifth.  The  facial  nerve,  however,  after  it  has  passed  through  the 
parotid  gland,  becomes  sensory  also,  owing  to  its  having  received  a 
twig  from  the  fifth  pair. 

Pathology  affords  numerous  examples  of  injury  done  to  the  facial 
nerve.  In  some  of  these,  the  nerve  itself  may  be  in  a  morbid  condi- 
tion in  a  portion  of  its 
course ;  in  others,  the  part 
of  the  encephalon,  whence 
the  nerve  originates,  may 
be  the  seat  of  the  lesion. 
The  prognosis  will,  of 
course,  vary  according  to 
the  seat;  but,  as  a  general 
rule,  paralysis  of  the  facial 
nerve  is  not  of  great  mo- 
ment. The  author  has  seen 
several  cases  of  partial 
paralysis  of  this  kind; 
some  of  which  have  wholly 
disappeared;  but  in  others 
the  loss  of  power  appears 
to  be  permanent.  In  a 
case,  which  presented  itself 
to  him  in  the  Baltimore 
Infirmary,  the  mischief  was 
probably  seated  near  the 
origin  of  the  nerve,  as  it 
resulted  from  serious  injury 
to  the  head.  A  carriage- 
horse,  belonging  to  a  friend, 
by  exerting  considerable 
power,  forced  its  head  through  an  aperture  in  the  partition  of  the 
stall,  and  was  unable  to  withdraw  it,  in  consequence  of  the  under 
jaw  catching  the  sides  of  the  aperture.  During  the  efforts  to  extract 
it,  so  much  pressure  was  made  upon  the  portio  dura  of  one  side, 
that  the  animal  lost  all  power  of  expression  in  the  corresponding 
side  of  the  head;  the  soft  parts  about  the  mouth  dropped,  and  the  ear 
no  longer  associated  with  that  of  the  opposite  side  in  expression;  yet 
the  movements  of  mastication  and  deglutition  were  scarcely  affected. 
This  state  of  paralysis  continued  for  a  few  days,  and  gradually  disap- 
peared. Fig.  204  represents  a  case  of  paralysis  of  this  nerve,  produced 


Paralysis  of  the  Facial  Nerve.     (Marshall  Hall.) 


1  Dissert.  Inaugur,  Turin.,  1823;  cited  in  Edinb.  Med.  and  Surg.  Journ.,  July,  1S34. 


GESTURES — NERVES  OF  THE  FACE.  499 

by  the  pressure  of  a  tumour  beneath  the  ear:  the  orbicularis  palpebrarum 
was  paralysed  so  that  the  patient  was  unable  to  close  his  eyelids. 

Independently  of  the  various  muscular  actions  which  modify  the 
expression  of  the  human  countenance,  there  are  certain  others  that 
mark  the  different  mental  emotions.  The  skin  varies  in  colour,  be- 
coming pale  or  suffused,  and  frequently  alternating  rapidly  between 
these  two  conditions.  The  changes  are  more  especially  witnessed  on 
the  forehead,  cheeks,  and  lips ;  and  arise  from  an  augmented  or  dimi- 
nished flow  of  blood  into  the  capillaries  of  the  part,  under  the  influence 
of  the  existing  emotion.  Under  such  circumstances,  the  eye  may  par- 
ticipate in  the  suffusion.  The  skin  may,  also,  vary  in  its  degree  of 
moisture  or  heat;  it  may  be  dry,  or  bathed  in  perspiration;  and  the 
perspiration  may  be  warm  or  cold ; — the  two  conditions  occasionally 
alternating.  Particular  parts  of  the  face,  again,  are  more  susceptible 
of  this  "sweat  of  expression,"  as  it  has  been  termed, — the  forehead  and 
temples  for  example.  The  heat  of  the  head  is  also  occasionally  modi- 
fied; a  sudden  glow  is  felt  in  the  countenance;  and  the  expression 
is  sometimes  evident  to  a  second  person. 

The  expression  of  the  human  eye,  connected  with  the  action  of  the 
oblique  muscles,  has  been  referred  to  under  Vision.  It  was  there 
asserted,  that  in  insensibility,  the  organ,  it  has  been  presumed,  is  given 
up  to  the  action  of  the  oblique  muscles,  and  is  drawn  up  under  the 
upper  eyelid.  The  eye  itself  is,  however,  capable  of  various  expres- 
sions, depending  upon  varied  positions  of  its  tutamina;  and  especially 
of  the  secretion  from  its  mucous  covering — the  conjunctiva, — and  from 
the  lachrymal  gland;  so  that  it  may  be  swimming,  or  the  tears  may 
flow  over  the  cheeks  and  constitute  weeping. 

In  addition  to  these,  which  may  be  esteemed  sources  of  expression 
in  the  human  countenance,  may  be  added  the  action  of  osculation  or 
kissing ;  which,  wherever  practiced,  is  employed  as  an  expression  of 
love  and  friendship ; — confined  with  us  to  those  of  the  female  sex,  or 
of  opposite  sexes ;  but,  in  some  countries,  employed  as  an  expression  of 
regard  between  males  also. 

It  is  impracticable  to  describe  all  the  facial  expressions — JProso- 
posis,  as  they  have  been  collectively  termed — of  which  the  human 
countenance  is  susceptible.  They  are  commonly  classed  under  two 
heads;  the  exhilarating,  in  which  the  face  is  flushed,  and  the  counte- 
nance expanded; — the  muscles  being  contracted  from  within  to  without; 
and  the  depressing,  in  which,  on  the  contrary,  the  face  is  pale,  and  the 
features  are  drawn  inwards  and  sunken. 

Let  us  inquire  into  the  physiology  of  a  few  of  these  expressions; 
beginning  with  the  play  of  the  features  in  broad  laughter,  (Fig.  205,) 
as  being,  perhaps,  the  most  easy  of  explanation.  In  laughing,  it  is 
in  vain  that  we  endeavour  to  confine  the  lips;  a  complete  relaxation  of 
the  orbicularis  oris  gives  uncontrolled  power  to  the  opponent  muscles 
inserted  into  the  angles  of  the  mouth  and  upper  lip.  Hence,  the  late- 
ral retraction  of  the  angles  of  the  mouth;  the  elevation  of  the  upper 
lip  disclosing  the  teeth;  the  peculiar  elevation  of  the  nostrils  without 
their  being  expanded,  and  the  dimple  of  the  cheek,  where  the  acting 
muscles  congregate:  hence,  also,  the  fulness  of  the  cheeks,  rising  so  as 


500 


MUSCULAR  MOTION. 


Broad  Laughter.     (Sir  Charles  Bell.) 


to  conceal  the  eye,  and  throw 
wrinkles  about  the  lower  eye- 
lids and  temples.  In  this 
expression,  the  whole  of  the 
movable  features  are  raised 
upwards.  The  orbicularis 
palpebrarumdoes  not  partake 
of  the  relaxation  of  the  or- 
bicularis oris.  It  is  excited, 
so  as  to  contract  the  eyelids, 
and  sink  the  eye,  whilst  the 
struggle  of  a  voluntary  effort 
of  the  muscles  to  open  the 
eyelids,  and  raise  the  eye- 
brow, gives  a  twinkle  to  the 
eye,  and  a  peculiar  obliquity 
to  the  eyebrow,  the  outer 
part  of  which  is  most  ele- 
vated. At  the  same  time, 
the  individual  holds  his  sides 
to  control  the  contractions  of  the  muscles  of  the  ribs.  The  diaphragm 
is  violently  agitated.  The  same  influence  spreads  to  the  throat,  and 
the  sound  of  laughter  is  as  distinct  as  the  signs  in  the  face. 

In  this  movement 

Fig.  206.  of  expression  we  have 

an  instance  of  the 
associated  action  of 
different  parts,  which 
are  considered  to  be 
under  the  influence 
of  the  respiratory 
system  of  nerves  of 
Sir  Charles  Bell.  The 
facial  expression  is 
under  the  direction  of 
the  portio  dura  or 
respiratory  nerve  of 
the  face. 

In  the  face  of  a 
faun,  (Fig.  206,) 
sketched  by  Sir 
Charles  Bell,  we  have 
the  expression  of 
weeping  from  pain. 
In  the  violence  of 
weeping,  accompa- 
nied with  lamenta- 
tion and  outcry,  the 
face  is  flushed  or  suf- 
fused from  stagna- 


Faun  Weeping.    (Sir  Charles  Bell.) 


GESTURES — CRYING.  501 

tion  of  blood  in  the  vessels.  The  muscles  of  respiration  are  affected 
from  the  commencement,  and  the  return  of  blood  from  the  head  is 
s6mewhat  impeded.  The  muscles  of  the  cheeks  are  in  movement. 
Those  that  depress  the  angles  of  the  mouth  are  powerfully  con- 
tracted, and  the  orbicularis  oris  is  not  relaxed,  but  drawn  open 
by  the  predominant  action  of  its  opponents.  A  convulsive  move- 
ment in  the  muscles  about  the  eyes  attends  ;  the  eyebrow  is  drawn 
down  ;  the  eyes  are  compressed  by  the  eyelids ;  the  cheek  is  raised ; 
the  nostril  drawn  out,  and  the  mouth  stretched  laterally.  In  weep- 
ing, also,  unless  the  convulsive  movement  of  the  muscles  is  very 
strong,  the  expression  of  grief  affects  that  part  of  the  eyebrows  next 
the  nose.  It  is  turned  up  with  a  peevish  expression,  which  corresponds 
with  the  depression  of  the  corners  of  the  mouth.  This  depression  gives 
an  air  of  despondency  and  languor  to  the  countenance,  when  accompa- 
nied by  general  relaxation  of  the  muscles.  When  the  corrugator  co- 
operates, there  is  mingled  in  the  expression  something  of  mental  energy, 
moroseness,  or  pain.  If  the  frontal  muscle  unites  its  action,  an  acute 
turn  upwards  is  given  to  the  inner  part  of  the  eyebrow,  very  different 
from  the  effect  of  the  general  action  of  the  frontal  muscle,  and  charac- 
teristic of  anguish,  debilitating  pain,  or  discontent,  according  to  the 
prevailing  cast  of  the  rest  of  the  countenance.  The  depression,  how- 
ever, of  the  angle  of  the  mouth,  that  indicates  languor  and  despondency, 
must  be  slight ;  as  the  depressor  anguli  oris  cannot  act  forcibly,  with- 
out the  action  of  the  superbus  participating — a  muscle,  which  quickly 
produces  a  revolution  in  the  expression,  and  makes  the  under  lip  pout 
contemptuously. 

The  expression  at  the  angles  of  the  mouth  demands  the  careful  study 
of  the  painter ;  the  most  opposite  characters  being  communicated  to 
the  countenance  by  their  elevation  or  depression.  When  Peter  of  Cor- 
tona  was  engaged  on  a  picture  of  the  iron  age  for  the  royal  palace  of 
Pitti,  Ferdinand  II.,  who  often  visited  him,  and  witnessed  the  progress 
of  the  piece,  was  particularly  struck  with  the  exact  representation  of  a 
child  in  the  act  of  crying.  "  Has  your  majesty,"  said  the  painter,  "a 
mind  to  see  how  easy  it  is  to  make  this  very  child  laugh  ?"  The  king 
assented :  and  the  artist,  by  merely  elevating  the  corner  of  the  lips  and 
inner  extremity  of  the  eyebrows,  made  the  child,  which  at  first  seemed 
breaking  its  heart  with  weeping,  seem  equally  in  danger  of  bursting  its 
sides  with  immoderate  laughter,  after  which,  with  the  same  ease,  he 
restored  to  the  figure  its  proper  expression  of  sorrow.1 

It  is  at  the  angle  of  the  mouth  and  the  inner  extremity  of  the  eye- 
brow, that  the  expression  which  is  peculiarly  human  is  situate.  These 
are  the  most  movable  parts  of  the  face.  On  them  the  muscles  are  con- 
centrated, and  it  is  upon  their  changes  that  expression  is  acknowledged 
chiefly  to  depend.  All  the  parts,  however,  of  an  impassioned  counte- 
nance are  in  accordance  with  each  other.  When  the  angles  of  the 
mouth  are  depressed  in  grief,  the  eyebrows  are  not  elevated  at  the  outer 
angles  as  in  laughter.  When  a  smile  plays  around  the  mouth,  or  when 
the  cheek  is  elevated  in  laughter,  the  eyebrows  are  not  ruffled  as  in 

1  Good's  Book  of  Nature,  iii.  291,  Lond.,  1834. 


502  MUSCULAR  MOTION. 

grief.  In  real  emotion,  these  opposite  actions  cannot  be  combined ; 
and,  when  united  by  the  mimic,  the  expression  is  farcical  and  ridicu- 
lous. 

Dr.  Wollaston1  has  shown,  that  the  same  pair  of  eyes  may  appear  to 
direct  themselves  either  to  or  from  the  spectator,  by  the  addition  of 
other  features  in  which  the  position  of  the  face  is  changed.  The  nose 
principally  produces  the  change  of  direction,  as  it  is  more  subject  to 
change  of  perspective  than  any  other  feature ;  and  Dr.  Wollaston  has 
shown,  that  even  a  small  portion  of  the  nose  will  carry  the  eyes  along 
with  it.  He  obtained  four  exact  copies  of  the  same  pair  of  eyes  look- 
ing at  the  spectator,  by  transferring  them  upon  copper  from  a  steel 
plate,  and  having  added  to  each  of  two  pairs  of  them  a  nose — in  one 
case  directed  to  the  right,  and  in  the  other  to  the  left,  and  to  each  of 
the  other  two  pairs  a  very  small  portion  of  the  upper  part  of  the  nose — 
all  the  four  pairs  of  eyes  lost  their  front  direction,  and  looked  to  the 
right  or  to  the  left,  according  to  the  direction  of  the  nose,  or  of  the 
portion  of  it  that  was  added.  But  the  effect  thus  produced  is  not 
limited  to  the  mere  change  in  the  direction  of  the  eyes  ;  for  a  total  dif- 
ference of  character  may  be  given  to  the  same  eyes  by  a  due  represent- 
ation of  the  other  features.  A  lost  look  of  devout  abstraction  in  an 
uplifted  countenance  may  be  exchanged  for  an  appearance  of  inquisi- 
tive archness  in  the  leer  of  a  younger  face  turned  downwards  and 
obliquely  towards  the  opposite  side.  This,  however,  as  Sir  David 
Brewster  has  remarked,  is  not  perhaps  an  exact  expression  of  the  fact. 
The  new  character,  which  is  said  to  be  given  to  the  eyes,  is  given  only 
to  them  in  combination  with  the  new  features ;  or  what  is  probably 
more  correct,  the  inquisitive  archness  is  in  the  other  features,  and  the 
eye  does  not  belie  it.  Sir  David  adds,  that  Dr.  Wollaston  has  not 
noticed  the  converse  of  these  illusions,  in  which  a  change  of  direction 
is  given  to  fixed  features  by  a  change  in  the  direction  of  the  eyes. 
This  effect  is  seen  in  some  magic  lantern  sliders,  where  a  pair  of  eyes 
is  made  to  move  in  the  head  of  a  figure,  which  invariably  follows  the 
motion  of  the  eyeballs. 

In  bodily  pain,  the  jaws  are  pressed  together,  and  there  is  grinding 
of  the  teeth  ;  the  lips  are  drawn  laterally,  so  as  to  expose  the  teeth  and 
gums ;  the  nostrils  are  distended  to  the  utmost,  and  at  the  same  time 
drawn  up  ;  the  eyes  are  largely  uncovered,  and  the  eyebrows  elevated ; 
the  face  is  turgid  with  blood,  and  the  veins  of  the  temple  and  forehead 
are  distended  ;  the  breath  being  suspended,  and  the  descent  of  the 
blood  from  the  head  impeded. 

In  anguish,  conjoined  with  bodily  suffering,  the  jaw  falls,  the  tongue 
is  seen  ;  and,  in  place  of  the  lateral  retraction  of  the  lips,  the  lower  lip 
falls ;  the  eyebrows  are  knit,  whilst  their  inner  extremities  are  ele- 
vated ;  the  pupils  of  the  eyes  are  in  part  concealed  by  the  upper  eye- 
lids, and  the  nostrils  are  agitated.  Agony  of  mind  is  here  added  to 
the  bodily  suffering,  which  is  particularly  indicated  by  the  change  in 
the  eyebrow,  and  forehead. 

i  Philosophical  Tiati'sact.  for  1824,  p.  247;  see,  also,  Letters  on  Natural  Magic,  by  Sir 
D.  Brewster,  Amer.  edit.,  p.  115,  New  York,  1832. 


GESTURES — FACIAL   EXPRESSION.  503 

In  rage,  the  features  are  unsteady ;  the  eyeballs  are  largely  seen, 
roll,  and  are  inflamed.  The  forehead  is  alternately  knit  and  raised  in 
furrows  by  the  motion  of  the  eyebrows  ;  and  the  nostrils  are  inflated  to 
the  utmost ;  the  lips  are  swelled,  and,  being  drawn,  open  the  corners 
of  the  mouth.  The  action  of  the  muscles  is  strongly  marked.  The 
whole  countenance  is  at  times  pale  ;  at  others,  inflated,  dark  and  almost 
livid ;  the  words  are  passed  forcibly  through  the  fixed  teeth,  and  the 
hair  is  on  end. 

Fear  has  different  degrees.  Mere  bodily  fear  resembles  the  mean 
anticipation  of  pain.  The  eyeball  is  largely  uncovered ;  the  eyes  are 
staring,  and  the  eyebrows  elevated  to  the  utmost  stretch.  To  these  are 
added  a  spasmodic  affection  of  the  diaphragm  and  muscles  of  the  chest, 
which  affects  the  breathing,  and  produces  a  gasping  in  the  throat,  with 
an  inflation  of  the  nostrils,  convulsive  opening  of  the  mouth,  and  drop- 
ping of  the  jaw  ; — the  lips  nearly  concealing  the  teeth,  yet  allowing  the 
tongue  to  be  seen,  and  the  space  between  the  nostril  and  lip  being  full. 
There  is  a  hollowness  and  convulsive  motion  of  the  cheeks,  and  a  trem- 
bling of  the  lips  and  muscles  on  the  sides  of  the  neck.  The  lungs  are 
kept  distended;  and  the  breathing  is  short  and  rapid.  The  surface  is 
pale  from  the  recession  of  blood ;  and  the  hair  is  lifted  up  by  the  creep- 
ing of  the  skin.  In  fear,  where  the  apprehended  danger  is  more  remote, 
but  is  approaching,  the  person  trembles  and  looks  pale  ;  a  cold  sweat 
is  on  the  face ;  the  scream  of  fear  is  heard ;  the  eyes  start  forward ; 
the  lips  are  drawn  wide  ;  the  hands  are  clenched,  and  the  expression 
becomes  more  strictly  animal,  and  indicative  of  such  fear  as  is  common 
to  brutes. 

In  terror  or  that  kind  of  fear  in  which  the  mind  participates  more 
there  i?  a  more  varying  depression  in  the  features,  and  an  action  of 
those  muscles,  which  are  peculiar  to  man,  and  seem  to  indicate  his 
superior  intelligence  and  mental  feeling.  The  eye  is  bewildered  ;  the 
inner  extremity  of  the  eyebrows  is  turned  up,  and  strongly  knit  by 
the  action  of  the  corrugator  and  orbicular  muscles  ;  and  distracting 
thoughts,  anxiety  and  alarm  are  strongly  indicated  by  this  expression, 
which  does  not  belong  to  animals.  The  cheek  is  slightly  elevated,  and 
all  the  muscles,  that  concentrate  about  the  mouth,  are  in  action. 

In  admiration,  the  forehead  is  expanded  and  unruffled  ;  the  eyebrow 
gently  raised  ;  the  eyelid  lifted  so  as  to  expose  the  coloured  circle  of 
the  eye,  whilst  the  lower  part  of  the  face  is  relaxed  into  a  gentle  smile. 
The  mouth  is  open ;  the  jaw  is  a  little  fallen  ;  and,  by  the  relaxation 
of  the  lower  lip,  we  just  perceive  the  edge  of  the  lower  teeth  and  the 
tongue. 

In  joy,  the  eyebrow  is  raised  moderately,  but  without  any  angularity; 
the  forehead  is  smooth  ;  the  eye  full,  lively  and  sparkling  ;  the  nostril 
moderately  inflated,  and  a  smile  is  on  the  lips. 

This  subject  is,  however,  interminable.  Enough  has  been  stated  to 
exhibit  the  anatomy  of  the  varying  characters  of  facial  expression.  It 
will  be  found  beautifully  treated  and  illustrated  in  the  work  of  Sir 
Charles  Bell,  to  which  reference  has  been  made. 

From  all  that  has  been  said,  it  is  evident,  that  the  countenance  is  a 
good  general  index  of  the  existing  state  of  the  feelings ;  but  farther 


504  MUSCULAR  MOTION. 

than  this  it  cannot  be  depended  upon.  Yet,  in  all  ages,  it  has  been 
regarded  as  the  index  of  individual  character.  Allusion  has  been  made 
to  the  estimate  of  personal  character  from  the  shape  of  the  head,  as 
described  by  the  older  poets.  Similar  indications  were  conceived  to  be 
deducible  from  the  form  of  the  face,  expression  of  the  eyes,  &c.  Thus 
Shakspeare : — 

Ckopat.  "  Bear'st  thou  her  face  in  mind?  is't  long  or  round  1 
Messeng.    Round,  even  to  faultiness. 
Cleopat.     For  the  most  part,  too, 

They  are  foolish  that  are  so.     Her  hair,  what  colour? 
Messeng.    Brown,  madam,  and  her  forehead 

As  low  as  she  would  wish  it." 

ANTONT  AITD  CLEOPATRA,  iii.  3. 

And  again : — 

"  Which  is  the  villain  ?    Let  me  see  his  eyes, 
That  when  1  note  another  man  like  him, 
I  may  avoid  him." 

MUCH  ADO  ABOUT  NOTHIWG. 

John  Baptist  Porta;  and  Lavater2  have  endeavoured  to  establish  a 
"  science,"  by  which  we  can  be  instructed,  how  to  discover  the  secret 
dispositions  of  the  head  and  heart  from  the  examination  of  particular 
features.  The  latter  enthusiast,  in  particular,  appears  to  have  carried 
his  notions  to  the  most  chimerical  extent.  "No  study,"  he  remarks, 
"  excepting  mathematics,  more  justly  deserves  to  be  termed  a  science 
than  physiognomy.  It  is  a  department  of  physics  including  theology 
and  belles  lettres,  and  in  the  same  manner  with  these  sciences  may  be 
reduced  to  rule.  It  may  acquire  a  fixed  and  appropriate  character.  It 
may  be  communicated  and  taught."  In  another  place,  he  remarks, 
that  no  person  can  make  a  good  physiognomist  unless  he  is  a  well-pro- 
portioned and  handsome  man  ;3  yet  he  himself  was  by  no  means  highly 
favoured  in  these  respects ;  and  it  is  difficult  to  say,  according  to  his 
own  theory,  how  he  obtained  such  progress  in  the  "  science  !" 

There  is  one  case,  and  perhaps,  one  only,  in  which  physiognomy  can 
aid  us  in  the  appreciation  of  character.  It  has  been  remarked,  that 
the  facial  expression  may  accurately  depict  the  existing  emotion.  If, 
therefore,  any  passion  be  frequently  experienced,  or  become  habitual, 
its  character  may  remain  impressed  upon  the  countenance,  and  admit 
of  an  opinion  being  formed  of  the  individual.  No  one,  who  has  seen 
the  melancholy  mad,  can  mistake  the  piteous  expression  produced  by 
brooding  over  the  corroding  idea  that  engrosses  him.  In  the  sketch 
(Fig.  207),  from  Sir  Charles  Bell,4  we  have  the  testy,  peevish  counte- 
nance, bred  of  melancholy;  of  one  who  is  incapable  of  receiving  satis- 
faction from  whatever  source  it  may  be  offered,  and  who  "cannot  endure 
any  man  to  look  steadily  upon  him,  even  to  speak  to  him,  or  laugh,  or 
jest,  or  be  familiar,  or  hem,  or  point,  without  thinking  himself  contemned, 
insulted,  or  neglected."  Such  a  countenance  no  one  can  misapprehend. 

1  La  Physiognomic  Humaine  de  Jean  Baptiste  Porta,  Rouen,  1655. 

2  Woiks,  from  the  French,  by  G.  Grenville,  Esq.,  Lond.;  or  Precis  Analytique  et  Raisonne 
du  Systeme  de  Lavater,  par  N.  J.  Ottin,  Bruxelles,  1834. 

3  Good's  Book  of  Nature,  iii.  309,  Lond.,  1834. 

4  Anat.  of  Expression,  edit.  cit. 


GESTURES. 


505 


In    lesser    degrees,  Fig.  207. 

particular  features 
are  found  bearing, 
or  seeming  to  bear, 
the  impress  of  par- 
ticular emotions; 
and,  accordingly,  we 
are  in  the  daily  habit 
of  forming  opinions 
at  first  sight,  both  of 
the  intellectual  and 
moral  characteris- 
tics of  individuals, 
by  the  expression  of 
the  countenance.  Of 
course,  we  are  fre- 
quently led  into  er- 
ror ;  inasmuch  as 
habitual  feelings 
alone  are  indicated 
by  the  physiognomy, 
whilst  the  natural 
disposition  may  be 
of  an  opposite  cha- 
racter. The  fallar 
ciousness  of  this 
mode  of  judging  of 
mankind  has  been 
proverbial  in  all 
times.  Whenever 
we  attempt  to  decide  upon  a  man's  intellectual  powers  by  the  rules  laid 
down  by  Lavater  we  are  constantly  deceived;  and,  in  this  respect,  he 
has  himself  evidently  fallen  into  gross  errors. 

What  may  be,  not  inappropriately,  styled  "medical  physiognomy," 
or  the  changes  of  features  indicative  of,  and  peculiar  to,  different  dis- 
eases and  stages  of  disease,  is  a  subject  of  moment,  and  has  not  met 
with  sufficient  attention.  In  diseases  of  infancy  in  particular,  the  ap- 
pearance of  the  countenance  often  materially  aids  us  in  discriminating 
their  seat.  There  is  a  marked  difference  between  the  facial  expression 
of  one  labouring  under  violent  pain  in  the  head,  and  of  one  suffering 
from  excruciating  pain  in  the  abdomen,  even  in  the  adult.  Less  degrees 
of  pain  are,  of  course,  disregarded;  and  it  is  only  in  severe  cases,  that 
physiognomy  can  be  inservient  to  diagnosis;  but  in  the  infant,  which 
readily  gives  expression  to  pain  or  uneasiness,  the  countenance  is  an 
excellent  medium  of  discrimination,  and  frequently  indicates,  at  the  first 
glance,  the  seat  of  the  derangement.  The  character,  too,  of  the  coun- 
tenance, in  serious  disease,  as  to  anxiety,  convulsion,  &c.,  is  often  a 
subject  of  watchful  interest  with  the  physician.1  Mute  expression  is 

1  See,  on  special  medical  physiognomy,  M.  Jadelot,  cited  by  M.  de  Salle,  in  Traite  des 
Maladies  des  Enfans  de  Michael  Underwood,  &c.,  p.  36  etseq.;  and  in  the  author's  Com- 
mentaries on  Diseases  of  the  Stomach  and  Bowels,  p.  vii.,  Lond.,  1824. 


Physiognomy  of  Melancholy.     (Sir  Charles  Bell.) 


506  MUSCULAR  MOTION. 

not,  however,  restricted  to  the  face,  although,  as  already  remarked,  in 
civilized  man,  whose  nakedness  is  covered,  we  are  shut  out  from  the 
observation  of  many  acts  of  -this  nature.  During  emotion,  the  skin 
covering  the  body  may  participate  with  that  of  the  face  in  its  changes 
from  pale  to  red;  and  it  may  be  warm  or  cold;  dry  or  bathed  in  perspi- 
ration; or,  during  particular  depressing  passions,  may  creep  and  exhibit 
the  rough  character  of  the  cutis  anserina  or  goose  skin.  Under  special 
emotions,  the  erectile  tissues  of  the  organs  of  generation,  and  of  the 
nipple  in  the  female,  experience  turgescence.  All  these  changes  are 
more  or  less  concealed  from  view.  We  are,  therefore,  more  familiar 
with  the  sight  of  phenomena  of  expression,  that  affect  the  whole  body, 
as  regards  its  different  attitudes  and  modes  of  progression.  How  tre- 
mulous and  vacillating  is  the  attitude  of  one  labouring  under  fear;  and 
how  different  the  port  of  the  meek  and  lowly  from  that  of  the  proud 
and  haughty!  In  walking,  we  observe  a  similar  difference;  and  can 
frequently  surmise  the  passion,  whether  exhilarating  or  depressing, 
under  which  a  person,  at  a  distance,  may  be  labouring,  from  the  cha- 
racter of  his  progression. 

"  You  may  sometimes  trace 
A  feeling  in  each  footstep,  as  disclosed 

By  Sallust,  in  his  Catiline,  who,  chased 
By  all  the  demons  of  all  passions,  showed 
Their  work  even  by  the  way  in  which  he  trode." — BTROJI 's  "Don  Juan" 

Again,  on  the  communication  of  sudden  tidings  of  joy,  we  feel  a 
desire  to  leap  up,  and  give  way  to  the  most  wild  and  irregular  motions ; 
whilst  the  shrinking  within  ourselves,  as  it  were,  and  the  involuntary 
shudder,  sufficiently  mark  the  reception  of  a  tale  of  horror. 

Properly  speaking,  the  subject  of  cranioscopy  belongs  to  the  func- 
tion of  expression,  but  it  has  already  been  considered  under  another 
head. 

Many  of  the  partial  movements  constitute  an  important  part  of  the 
language  of  expression,  especially  with  the  savage,  and  with  those 
unfortunates  who  are  debarred  the  advantages  of  spoken  language. 
In  almost  all  nations,  the  motions  of  the  head  on  the  vertebral  column 
are  used  as  signs  of  affirmation  or  negation; — the  former  being  indi- 
cated by  a  sudden  and  short  forward  flexion  of  the  head  on  the  column; 
the  latter,  by  a  rapid  and  short  rotation  on  the  axis  or  vertebra  den- 
tata.  The  shoulders  are  shrugged  in  testimony  of  impatience,  con- 
tempt, &c.  The  upper  extremities  are  extensively  employed  as  a 
part  of  conventional  language,  and  were  probably  used  for  this  pur- 
pose before  speech  was  invented.  The  open  and  the  closed  hands 
communicate  different  impressions  to  the  observer ;  the  pointed  finger 
directs  attention  to  the  object  we  desire  to  indicate,  &c.  When  per- 
sons are  at  such  a  distance  from  each  other,  that  the  voice  cannot  be 
heard,  this  is  the  only  language  they  can  have  recourse  to ;  and  the 
various  important  inventions,  by  which  we  communicate  our  feelings  to 
a  distance,  such  as  writing  and  telegraphing,  belong  to  this  variety  of 
language.  For  the  deaf  and  dumb,  our  ordinary  spoken  language*  is 
translated  into  gestures,  by  which  a  conversation  can  be  held,  sufficient 
for  all  useful  purposes;  whilst  the  deaf,  dumb,  and  blind  are  mainly 


GESTURES — NATURAL  SIGNS  OF  THE  PASSIONS.  507 

restricted  to  those  gestures  that  are  conveyed  through  their  sense  of 
touch. 

Each  acquired  gesture  is,  like  each  acquired  movement  of  the  glottis, 
an  evidence  of  the  possession  of  intellect.  The  infant  and  the  idiot 
have  them  not,  because  unable  to  appreciate  their  utility.  The  ges- 
tures resemble  the  spoken  language  in  this  and  many  other  respects. 
The  eye  sees  the  gesture,  to  which  the  intellect  attaches  an  idea  as  it 
does  to  the  sound  conveyed  by  the  organ  of  hearing;  and  the  will 
reproduces  the  gesture,  in  the  same  manner  as  it  reproduces  the  sound 
heard.  The  lower  extremities  are,  also,  slightly  concerned  in  the  func- 
tion of  expression.  They  are  agitated  when  impatient,  and  incessantly 
changing  their  position.  The  foot  is  stamped  upon  the  ground  in 
anger;  and,  like  the  upper  extremity,  is  employed  to  convey  to  the 
object  that  has  aroused  the  emotion  the  most  unequivocal  evidences  of 
expression.  Occasionally,  the  lower  extremity  is  used  as  a  part  of 
conventional  language,  as  when  we  tread  upon  the  toes  to  arouse  atten- 
tion, or  to  convey  insult.  Nor  are  the  internal  organs  foreign  to  the 
function  of  expression.  The  respiratory  movements  are  affected, — the 
number  of  respirations  being  accelerated  or  retarded,  or  manifesting 
themselves  under  the  different  modifications  of  sighing,  yawning, 
laughing,  and  sobbing.  The  heart,  too,  throbs  at  times  to  such  an 
extent,  that  its  action  is  perceptible  externally;  or,  it  may  be  retarded 
or  hurried  in  its  pulsations, — from  a  state  of  syncope  or  fainting  to  that 
of  the  most  violent  palpitation. 

Lastly:  the  excretions,  certain  of  them  especially,  are  greatly  impli- 
cated in  many  of  these  moral  changes.  That  of  the  tears  is  a  well- 
known  and  characteristic  expression — of  grief  more  especially,  but 
occasionally  of  joy.  The  mind,  however,  may  be  so  possessed  by  the 
emotion,  that  the  ordinary  power  over  the  sphincter  muscles  may  be 
more  or  less  destroyed,  and  the  contents  of  the  rectum  be  spontane- 
ously evacuated.  The  action  of  the  stomach  is,  at  times,  inverted; 
and,  at  others,  the  peristaltic  action  is  augmented.  Who  has  not  felt, 
whilst  labouring  under  anxiety  or  dread,  the  constant  desire  not  only 
to  evacuate  the  faeces,  but  also  the  urinary  secretion  ! 

It  is  obvious,  from  this  detail,  that  there  is  scarcely  a  function, 
which  does  not  express  some  participation,  when  the  mind  is  engaged 
in  deep  emotion ;  and  that  it  would  be  vain  to  attempt  to  depict  the 
various  forms  under  which  these  manifestations  may  occur.  What  has 
been  said  will  suffice  to  attract  attention  to  the  subject,  which  is  not 
devoid  of  interest  to  the  anthropologist. 

In  conclusion,  we  may  refer  to  the  question  that  has  often  been  agi- 
tated, whether  these  rapid  and  violent  movements,  that  characterize 
the  expression  of  emotions,  be  instinctive  or  natural  signs  of  the  pas- 
sion existing  in  the  mind;  or  whether  they  be  not  voluntary  muscular 
exertions,  called  for  by  the  stress  of  the  case,  and  constituting  the 
means  of  resistance,  or  belonging  simply  to  the  outward  manifestation 
of  the  inward  emotion.  The  supporters  of  the  latter  view  contend, 
that  the  various  changes  of  facial  expression  or  of  gesture,  which 
accompany  the  different  mental  emotions  and  indicate  their  character, 


508  MUSCULAR  MOTION. 

are,  in  all  cases,  the  effect  of  habit,  or  are  suddenly  excited  to  accom- 
plish some  beneficial  purpose.  It  is  difficult,  however,  to  regard  the 
different  concomitants  of  the  passion  as  separate  from  it.  Without 
them,  the  expression  is  incomplete;  and,  moreover,  we  observe  the  dif- 
ferent gestures  similarly  developed  in  all  the  various  races  of  mankind, 
when  affected  with  the  same  mental  contention.  We  must,  conse- 
quently, regard  the  expressions  as  constituting  a  natural  language,  in 
which  each  has  its  appropriate  sign;  and  this  view  is  confirmed  by  the 
fact,  that  there  are  certain  muscles  of  the  face,  which  seem,  in  our 
existing  state  of  knowledge,  to  be  exclusively  destined  for  expression; 
— those  about  the  eyebrows  and  angles  of  the  mouth  for  example.  When 
the  triangularis  muscle  and  levator  menti  combine  action,  an  expres- 
sion is  produced,  which  is  peculiar  to  man ;  the  angle  of  the  mouth  is 
drawn  down,  and  the  lip  arched  and  elevated;  hence  the  most  con- 
temptuous and  proud  expression. 

A  question  of  a  different  character  has,  however,  been  mixed  up  with 
this: — whether  the  infant  be  capable  instinctively  or  naturally  of  com- 
prehending the  difference  between  the  facial  expressions  of  kindness  or 
of  frowns;  some  believing,  that  smiles  are  merely  considered  by  it  to 
be  expressions  of  kindness,  because  accompanied  by  endearments, — 
and  frowns  to  be  proofs  of  displeasure,  because  followed  by  punishment. 
It  is  certain,  however,  that  the  infant  interprets  the  countenance  long 
before  it  can  trace  such  sequences  in  its  mind;  but  this  does  not  remove 
the  difficulty.  The  face  of  one,  whom  it  has  not  been  accustomed  to 
see,  will,  at  a  very  early  period,  impress  it  unfavourably,  although  the 
countenance  may  be  unusually  prepossessing;  and  the  alteration  of  the 
ordinary  expression  of  the  material  countenance  may  be  attended  with 
similar  results.  It  is  difficult,  indeed,  to  comprehend  how  the  child 
should  be  capable  of  discriminating  between  the  smile  and  frown,  when 
first  presented  to  it.  That  organs  may  be  associated  in  the  expression 
of  any  encephalic  act  is  intelligible;  but  that  an  act  of  judgment  can 
be  executed  naturally  or  instinctively  appears  inexplicable.  Sir  Charles 
Bell,1  who  maintains  the  doctrine  of  the  instinctive  character  of  the 
expression  of  human  passions,  rejects  the  notion  of  instinctive  expres- 
sion in  the  face  of  the  quadruped,  contending  that,  even  in  the  passion 
of  rage,  which  is  the  most  strongly  marked  of  all  the  changes  that 
occur  in  the  features,  are  merely  motions  accessory  to  the  great  objects 
of  opposition,  resistance,  and  defence.  "In  carnivorous  animals,"  he 
remarks,  "the  eyeball  is  terrible,  and  the  retraction  of  the  flesh  of  the 
lips  indicates  the  most  savage  fury.  But  the  first  is  merely  the  excited 
attention  of  the  animal,  and  the  other  a  preparatory  exposure  of  the 
canine  teeth."  It  appears  to  be  a  sufficient  answer  to  this  view,  that 
no  such  expression  is  ever  witnessed  in  other  cases  of  excited  attention, 
or  in  the  simple  exposure  of  the  canine  teeth,  when  the  animal  is  de- 
vouring its  food;  unless,  indeed,  the  repast  be  made  during  the  exist- 
ence of  the  passion. 

On  a  former  occasion,  it  was  remarked,  that  the  encephalon  is  ex- 
clusively concerned  in  the  production  of  the  different  passions,  and  that 

1  Anat.  of  Expression,  edit.  cit. 


GESTURES — NATURAL  SIGNS  OF  THE  PASSIONS.  509 

the  parts  to  which  they  are  usually  referred,  attract  our  attention  to 
them  principally,  in  consequence  of  the  sensation  which  accompanies 
them  being  there  chiefly  experienced.  The  same  may  be  said  of  the 
different  gestures  that  accompany  the  various  emotions.  They  are 
dependent  upon  the  influence  exerted  by  the  function  of  sensibility  on 
the  other  functions.  Gall,1  in  his  system,  has  feebly  attempted  to  show, 
that  each  gesture  has  a  reference  to  the  encephalic  situation  of  the 
organ  concerned  in  the  production  of  the  emotion  of  which  it  is  a  con- 
comitant. The  idea  was  suggested  to  him,  he  asserts,  by  the  fact, 
observed  by  him  a  thousand  times,  that  in  fractures  of  the  skull,  the 
hand,  (naturally  we  should  think,)  was  carried  mechanically  to  the  seat 
of  the  fracture.  He  farther  remarks,  that  the  organs  of  the  memory 
of  words  and  of  meditation  are  seated  in  the  forehead ;  and  that  the 
hand  is  carried  thither,  whenever  we  are  engaged  in  deep  study; — that 
the  organ  of  religious  instinct  corresponds  to  the  vertex;  and  hence,  in 
the  act  of  prayer,  all  the  gestures  are  directed  towards  that  part  of  the 
body.  Like  every  professed  systematist,  Gall  is  here  pushing  his  prin- 
ciples ad  absurdum.  They  are,  indeed,  controverted  by  facts.  The 
hand  is  usually  carried,  not  to  the  part  of  the  encephalon  in  which  any 
passion  is  effected,  but  to  the  part  of  the  body  in  which  its  more  pro- 
minent effects  are  perceptible, — as  to  the  region  of  the  stomach  or  heart ; 
and  frequently  the  gesture  is  referable  to  the  determinate  action,  which 
must  be  regarded  as  a  necessary  effect  of  the  passion. 

Finally,  poetry  and  painting  belong  properly  to  the  varieties  of  ex- 
pression; but  they  are  topics  that  do  not  admit  of  elucidation  by  phy- 
siology. 


Here  terminates  the  history  of  the  animal  functions,  which  have  the 
common  character  of  being  periodically  suspended  by  sleep.  By  many 
physiologists,  this  function  has,  therefore,  been  examined  in  this  place; 
but  as  the  nutritive  and  generative  functions  are,  likewise,  greatly  in- 
fluenced by  sleep,  we  shall  follow  the  example  of  M.  Magendie,2  and  defer 
its  study  until  those  functions  have  been  inquired  into. 

CILIARY  MOTION. 

Although  not  an  animal  function,  it  may  be  convenient  to  allude,  in 
this  place,  to  the  phenomena  of  vibratory  or  ciliary  motion,  which,  in 
recent  times,  have  received  the  attention  of  observers.  These  terms 
have  been  employed  to  express  the  appearance  produced  by  cilia, — a 
peculiar  sort  of  moving  bodies  resembling  small  hairs,  which  are  visible 
by  the  aid  of  the  microscope,  on  parts  that  are  covered  with  ciliary  or 
vibratory  epithelium.3 

1  Sur  les  Fonctions  du  Cerveau,  v.  436,  Paris,  1825. 

*  Precis  Elementaire,  i.  306. 

8  See  page  132 ;  and,  also,  Sharpey,  art.  Cilia,  Cyclop,  of  Anat.  and  Phyiiol.,  P.  vi .,  p.  606, 
Lond.,  1836;  and  Henle,  Allgem.  Anat.,  or  Jourdan's  French  Translation,  p.  251,  Paris,  1843  5 
and  the  excellent  article  Flirnmerbewegung,  by  Valentin,  in  Wagner's  Handwdrterbuch  der 
Physiologic,  3te  Lieferung,  s.  484,  Braunschweig,  1842. 


510 


CILIARY  MOTION. 


Fig.  208. 


This  ciliary  motion  has  been 
seen  in  different  animals,  on  the 
external  surface,  in  the  aliment- 
ary canal,  the  respiratory  sys- 
tem, the  female  generative  or- 


gans ; 


and  in  the  cavities  of  the 


Cilia. 


nervous  system.  It  has  not  been 
observed,  however,  in  the  vagina  ; 
but  may  be  traced  from  the  lips 
of  the  os  uteri  through  its  cavity, 
and  through  the  Fallopian  tubes 
to  their  fimbriated  extremities. 
In  the  upper  classes  of  animals, 
it  is  not  witnessed  on  the  external 

1.  Portion  of  a  bar  of  the  gill  of  the  Mytilis  edu-  Q1ir.fq/>p  pvnpnt  in  thp  pmhrvn       Tn 

If*,  showing  cilia  at  rest  and  in  motion.    2.  Ciliated  SUHdCC  CXCCpt  in  tE  DryO.    ^ 

epithelium  particles  from  frog's  mouth.  3.  Ciliated  most  animals,  a  high  magnifying 
epithelium  particle  from  inner  surface  of  human  .  3  .  •*  .  ° 

membrana  tympani.  4.  Ditto,  ditto  :  from  the  human  pOWCr  IS  nCCCSSary  to  perCClVC  it. 
bronchial  mucous  membrane.  5.  Leucophrys  patula,  A  email  r^io^o  r»f  Tniinmia  TYIPTYI 

a  polygastric  infusory  animalcule;  to  show  its  sur-  A    Small    plCCC    01    HlUtOUS     mem- 

face  covered  with  cilia,  and  the  mouth  surrounded  by  brane  on  Which  it  exists,  should 
them.  (Todd  and  Bowman.)  '  . 

be    moistened   with   water,    and 

Fig.  209.  covered  with  a  plate  of  glass,  by 

which  the  membrane  is  spread 
out,  and  its  border  rendered  clear- 
ly visible.  With  the  aid  of  a  pow- 
erful microscope,  an  appearance 
of  undulation  is  perceptible,  and 
small  bodies  floating  in  the  water 

Vibratile  or  Ciliated  Epithelium.  ,  ~«       t,      j  c 

may  be  seen,  near  the  border  or 
mftie*uttinac.ells' ™***  on  their  smaller  ****  the  membrane,  to  be  driven  along 

in  a  determinate  direction.    With 

a  still  higher  magnifying  power,  the  cilia  themselves  may  sometimes 
be  recognized,  although  seldom  very  distinctly,  owing  to  the  great 
rapidity  of  their  motion.  The  influence  of  the  motion  on  the  fluids 
and  small  bodies  in  contact  with  the  membrane  may  be  well  exhibited 
by  strewing  a  fine  powder  on  the  surface ;  as  the  motion  of  the  cilia 
has  a  uniform  direction,  it  gives  rise  to  currents  over  the  surface  of  the 
membrane. 

An  easy  mode  of  observing  the  phenomenon  is  to  scrape  with  a 
knife  a  few  scales  of  epithelium  from  the  back  of  the  throat  of  a  living 
frog.  If  these  be  moistened  with  water  or  serum,*  they  will  continue 
to  exhibit  the  motion  of  the  adherent  cilia  for  a  very  considerable  time, 
if  the  epithelium  be  only  kept  moistened.  On  one  occasion,  Messrs. 
Todd  and  Bowman  observed  a  piece  of  epithelium  prepared  in  this 
manner  exhibit  motion  for  seventeen  hours ;  and  they  thought  it  would 
probably  have  done  so  for  a  longer  time  had  not  the  moisture  around 
it  evaporated.  In  the  turtle,  after  death  by.  decapitation,  MM. 
Purkinje  and  Valentin  found  it  lasted  in  the  mouth  nine  days;  in  the 
trachea  and  lung,  thirteen  days;  and  in  the  oesophagus,  nineteen  days.1 

1  Physiological  Anatomy  and  Physiology  of  Man,  by  Messrs.  Todd  and  Bowman,  p.  62, 
Lond.,  1843. 


CILIARY  MOTION.  511 

According  to  M.  Donne,1  cilia  are  seen  only  on  the  "true  mucous 
membranes"  of  his  division,2  or  those  that  secrete  an  alkaline  mucus. 
They  are  never  met  with  on  the  acid  membranes,  which  are  analogous 
to  the  skin,  and  simple  reflections  of  the  cutaneous  envelope.  Hence, 
they  are  not  found  in  the  mouth  or  vagina,  but  in  the  nasal  and  bron- 
chial mucous  membrane. 

•  The  organs  of  ciliary  motion  are  delicate  transparent  filaments, 
varying  in  length,  according  to  Purkinje  and  Valentin,  from  j^o7?  to 
y^jg  of  an  inch,  and  are  generally  thicker  at  the  base  than  at  the  free 
extremity.  Their  motion  continues  after  death  as  long  as  the  tissues 
retain  their  contractility,  and  often  much  longer.  Miiller3  thus  sums 
up  the  present  state  of  our  knowledge  in  regard  to  the  phenomenon: 
That  the  ciliary  motion  of  the  mucous  membranes  is  due  to  the  action 
of  some  unknown  contractile  tissue,  which  lies  either  in  the  substance 
of  the  cilia  or  at  their  base, — that  this  tissue  resembles  in  contractility 
the  muscular  and  other  contractile  tissues  of  animals; — that  its  pro- 
perties so  far  agree  with  those  of  the  muscular  tissues — at  all  events 
with  those  of  the  involuntary  muscles  of  the  heart,  and  the  vibratory 
laminse  of  the  lower  Crustacea  ; — that  the  motions,  which  it  produces, 
continue  without  ceasing  with  an  equable  rhythm  ; — that  its  properties 
agree  also  with  those  of  the  muscular  tissue  of  the  heart  in  its  motions, 
continuing  long  after  the  separation  of  the  part  from  the  rest  of  the 
animal  body  ; — that  this  tissue  differs  essentially,  however,  from  muscle, 
in  the  circumstance  of  its  motions  not  being  arrested  by  the  local  ap- 
plication of  narcotics;  and  lastly,  that  the  ciliary  motion  presents 
itself  under  conditions  where  it  is  not  probable  that  a  complicated 
organization  exists, — namely,  in  the  undeveloped  embryos  of  polypiferous 
animals. 

M.  Donne*4  regards  the  cilia  as  animalcules;  resembling  in  many 
respects  the  spermatozoids.  They  certainly  resemble  each  other  ;  but 
there  is  no  sufficient  reason  to  believe  either  of  them  animalcular. 

The  production  of  currents  by  the  ciliary  motion  is  not  easy  of  ex- 
planation. Purkinje  and  Valentin  ascribe  them  to  the  return  of  the 
cilia  from  the  bent  to  the  erect  state,  which  gives  an  impulse  to  the 
fluid.  The  direction  in  which  the  cilia  act  is  most  commonly  towards 
the  outlet  of  the  canal  on  which  they  are  placed;  but,  as  Mr.  Paget5 
has  remarked,  their  special  purpose  is  in  many  instances — for  example, 
in  the  ventricles  of  the  brain — as  uncertain  as  the  power  by  which  they 
act. 

We  shall  have  to  refer  to  ciliary  motion  under  other  heads. 


1  Coursde  Microscopie,  p.  170,  Paris,  1844. 

2  See  Secretion  of  Mucus  in  vol.  ii.  of  this  work. 


3  Elements  of  Physiology,  by  Baly,  P.  iv.  p.  866,  Lond.,  1838. 

4  Op.  cit.,  p.  176.  6  Brit,  and  For.  Med.  Review,  July,  1842,  p.  264. 


512  DIGESTION. 


BOOK    II. 

NUTRITIVE  FUNCTIONS. 

THE  human  body,  from  the  moment  of  its  formation  to  the  cessation 
of  existence,  is  undergoing  constant  decay  and  renovation — decomposi- 
tion and  composition : — so  that  at  no  two  periods  can  it  be  said  to  have 
exactly  the  same  constituents.  The  class  of  functions  about  to  engage 
attention,  embraces  those  that  are  concerned  in  effecting  such  changes. 
They  are  seven  in  number ; — digestion,  by  which  the  food,  received 
into  the  stomach,  undergoes  such  conversion  as  fits  it  for  the  separa- 
tion of  its  nutritious  and  excrementitious  portions ;  absorption,  by 
which  this  nutritious  portion,  as  well  as  other  matters,  is  conveyed  into 
the  mass  of  blood ;  respiration,  by  which  the  products  of  absorption 
and  venous  blood  are  converted  into  arterial  blood ;  circulation,  by 
which  the  vital  fluid  is  distributed  to  every  part  of  the  system ;  nutri- 
tion, by  which  the  intimate  changes  of  composition  and  decomposition 
are  accomplished ;  calorification,  by  which  the  system  is  enabled  to 
resist  the  effects  of  greatly  elevated  or  depressed  atmospheric  tempera- 
ture, and  to  exist  in  the  burning  regions  within  the  tropics,  or  amidst 
the  arctic  snows;  and  secretion,  by  which  various  fluids  and  solids  are 
separated  from  the  blood ; — some  to  serve  useful  purposes  in  the  ani- 
mal economy ;  others  to  be  rejected  from  the  body. 

CHAPTER  I. 

OF  DIGESTION. 

THE  food,  necessary  for  animal  nutrition,  is  rarely  found  in  such  a 
condition  as  to  be  adapted  for  absorption.  It  has,  therefore,  to  be 
subjected  to  various  actions  in  the  digestive  organs ;  the  object  of 
which  is  to  enable  the  nutritive  matter  to  be  separated  from  it.  These 
actions  constitute  the  function  of  digestion ;  in  the  investigation  of 
which  we  shall  commence  with  a  brief  description  of  the  organs  con- 
cerned in  it.  These  are  numerous,  and  of  a  somewhat  complicated 
nature. 

1.    ANATOMY   OF    THE    DIGESTIVE    ORGANS. 

The  human  digestive  organs  consist  of  a  long  canal,  varying  con- 
siderably in  its  dimensions  in  different  parts,  and  communicating  ex- 
ternally by  two  outlets, — the  mouth  and  anus.  It  is  usually  divided 
into  four  chief  portions — the  mouth,  pharynx,  oesophagus,  stomach,  and 
intestines.  These  we  shall  describe  in  succession. 


DIGESTIVE  ORGANS. 


513 


1.  The  mouth  is  the  first  cavity 
of  the  digestive  tube,  and  that  into 
which  the  food  is  immediately  re- 
ceived, and  subjected  to  the  action 
of  the  organs  of  mastication  and  in- 
salivation.  Above  and  below,  it  is 
circumscribed  by  the  jaws,  and  la- 
terally by  the  cheeks  ;  —  anteriorly 
by  the  lips  and  their  aperture,  con- 
stituting the  mouth  proper;  and, 
posteriorly,  it  communicates  with 
the  next  portion  of  the  tube,  —  the 
pharynx.  It  is  invested  by  a  mu- 
cous exhalant  membrane,  which  is 
largely  supplied  with  follicles;  and 
into  it  the  ducts  from  the  different 
salivary  glands  pour  their  secre- 
tion. 

In  all  animals  furnished  with 
distinct  digestive  organs,  means 
exist  for  comminuting  the  food,  and 
enabling  the  stomach  to  act  with 
greater  facility  upon  it.  These 
consist,  for  the  most  part,  as  in 
man,  of  the  jaws,  the  teeth  fixed 
into  the  jaws,  and  muscles  by  which 
the  jaws  are  moved. 

The  jaws  chiefly  determine  the 
shape  and  dimensions  of  the 
mouth;  the  upper  forming  an  es- 
sential part  of  the  face,  and  mov- 
ing only  with  the  head  ;  the  lower, 
on  the  contrary,  possessing  great 
mobility.  Each  of  the  jaws  has  a 
prominent  edge,  forming  a  semi- 


Fig. 210. 


Diagram  of  the  Stomach  and  Intestines  to  show 
their  course. 

1.  Stomach'.    2.  (Esophagus.  3.  Left,  and  4.  Right 

circle,  in  which  the  teeth  are  im-  e.nd  °f  stomach.  5,  G.  Duodenum.  7.  convoiu- 

mi  .         1          .  ..     -      .         tions  of  jejunum.    8.  Those  of  ileum.     9.  Csecum. 

ThlS  edge  IS  Called,  the  10.  Vermiform  appendix.  11.  Ascending;  12.  Trans- 
verse; and -13.  Descending  colon.  14.  Commence- 
ment of  sigmoid  flexure.  15.  Rectum. 


planted. 
alveolar  arch. 

The  teeth  are  small  organs,  of  a 
density  superior  to  bone;  and  covered  externally  by  a  hard  substance 
called  enamel.  By  many,  they  have  been  regarded  as  bone;  but  they 
differ  from  it  in  many  essential  respects,  although  they  resemble  it  in 
hardness  and  chemical  composition.  At  another  opportunity  we  shall 
inquire  into  their  origin,  structure,  and  developement.  We  may  merely 
remark,  at  present,  that  by  many  they  are  looked  upon  as  analogous 
to  the  corneous  substances,  which  develope  themselves  in  the  tissue  of 
the  skin.  De  Blainville  assimilates  them  to  the  hair;  and  believes,  that 
they  are  primarily  developed  in  the  substance  of  the  membrane  lining 
the  mouth ;  and  that  their  enclosure  in  the  substance  of  the  alveolar 
arches  of  the  jaws  occurs  subsequently. 
VOL.  I.— 33 


514  DIGESTION. 

A 

The  number  of  the  teeth  is  sixteen  in  each  jaw.  These  are  divided 
into  classes,  according  to  their  shape  and  use.  There  are,  in  each  jaw, 
four  incisores;  two  cuspidati  or  canine  teeth;  four  bicuspidati ;  and  six 
molares  or  grinders.  Each  tooth  has  three  parts: — the  crown,  neck, 
and  fang  or  root; — the  first  being  the  part  above  the  gum ;  the  second 
that  embraced  by  the  gum;  and  the  third,  the  part  contained  in  the 
alveolus  or  socket.  The  crown  varies  in  the  different  classes.  In  the 
incisors,  it  is  wedge-shaped;  in  the  canine,  conical;  and  in  the  molar, 
cubical.  In  all,  it  is  of  extreme  hardness,  but  in  time  wears  away 
by  the  constant  friction  to  which  it  is  exposed.  The  incisor  and 
canine  teeth  have  only  one  root;  the  molares  of  the  lower  jaw,  two; 
and  the  upper,  three.  In  all  cases,  they  are  of  a  conical  shape,  the 
base  of  the  cone  corresponding  to  the  corona,  and  the  apex  to  the  bot- 
tom of  the  alveolus.  The  alveolar  margin  of  the  jaws  is  covered  by  a 
thick,  fibrous,  resisting  substance,  called  gum.  It  surrounds  accurately 
the  inferior  part  of  the  crown  of  the  tooth,  adheres  to  it  strongly,  and 
thus  adds  to  the  solidity  of  the  junction  of  the  teeth  with  the  jaws.  It 
is  capable  of  sustaining  considerable  pressure  without  inconvenience. — 
But  we  shall  have  to  return  to  the  subject  of  the  teeth  hereafter. 

The  articulation  of  the  lower  jaw  is  of  such  a  nature  as  to  admit  of 
depression  and  elevation;  of  horizontal  motion  forwards,  backwards, 
and  laterally;  and  of  a  semi-rotation  upon  one  of  its  condyles.  The 
muscles  that  move  it  may  be  thrown  into  two  classes: — elevators  and 
depressors.  These,  by  a  combination  of  their  contraction,  can  produce 
every  intermediate  movement  between  elevation  and  depression.  The 
raisers  or  levator  muscles  of  the  jaw  extend  from  the  cranium  and  upper 
jaw  to  the  lower,  They  are  four  in  number  on  each  side, — the  temporal, 

and    masseter,    which 

Fig.  2ti  are  entirely  concerned 

in  the  function;  the 
external  pterygoid, 
which,  whilst  it  raises 
the  jaw,  carries  it  at 
the  same  time  forward, 
and  to  one  side;  and 
the  internal  pterygoid, 
which,  according  as  it 
unites  its  action  with 
the  temporal  or  with 
Skull  of  the  Polar  Bear.  the  external  pterygoid, 

is  an   elevator  of  the 

jaw  or  a  lateral  motor.  The  depressors  may  be  divided  into  imme- 
diate and  mediate,  according  as  they  are,  or  are  not,  attached  to  the 
lower  jaw  itself.  There  are  only  three  of  the  former  class:  1,  the 
digastricus,  the  anterior  fasciculus  of  which,  or  that  which  passes  from 
the  os  hyoides  to  the  lower  jaw,  depresses  the  latter;  2,  the  genio- 
Jiyoideus;  and  3,  the  mylo-hyoideus,  all  of  which  concur  in  the  forma- 
tion of  the  floor  of  the  mouth.  The  indirect  or  mediate  depressors 
are  all  those,  that  are  situate  between  the  trunk  and  the  lower  jaw, 
without  being  directly  attached  to  the  latter; — as  the  thyro-hyoideus, 


DIGESTIVE  ORGANS. 


515 


Fig.  212. 


the  sterno-thyroideus,  and  the  omo-hyoideus;  the  names  of  which  indi- 
cate their  origin  and  insertion.  These,  in  the  aggregate,  form  a  mus- 
cular chain,  which,  when  it  makes  the  trunk  its  fixed  point,  depresses 
the  lower  jaw.  The  arrangement  of  the  elevators  and  depressors  is 
such,  that  the  former  predominate  over  the  latter;  and  hence  during 
sleep  the  jaws  continue  applied  to  each  other,  and  the  mouth  is  conse- 
quently closed. 

The  human  organs  of  mastication  hold  an  intermediate  place  between 
those  of  the  carnivorous  and  herbivorous  animal.  In  the  carnivorous 
animal,  which  has  to  seize  hold  of,  and  retain  its  prey  between  its  teeth, 
the  jaws  have  considerable  strength;  and  the  movement  of  elevation  is 
all  that  is  practicable ;  or,  at  least,  that  can  be  effected  to  any  extent. 
This  is  dependent  upon  organization.  The  condyle  is  broader  from  side 
to  side,  which  prevents  motion  in  that  direction:  the  glenoid  cavity  is  very 
deep,  so  that  the  head  of  the  jaw-bone  cannot  pass  out  of  it;  and  it 
is,  moreover,  fixed  in  its  place  by  two  eminences  before  and  behind. 
The  muscular  apparatus  is  also  so  arranged  as  to  admit  of  energetic 
action  on  the  part  of  the  muscles  that  raise  the  jaw;  but  of  scarcely 
any  in  a  horizontal  direction.  The  deep  impressions  in  the  regions  of 
the  temporal  and  masseter  muscles  indicate  the  large  size  of  these  mus- 
cles in  the  purely  carnivorous  animal ;  whilst  the  pterygoid  muscles  are 
extremely  small.  The  teeth,  too,  are  characteristic ;  the  molars  being 
comparatively  small,  at  the  same  time  that  they  are  much  more  pointed. 
On  the  other  hand,  the  cuspidati  are 
remarkably  large,  and  the  incisors,  in 
general,  acuminated. 

The  herbivorous  animal  has  an  ar- 
rangement the  reverse  of  this.  The 
condyle  or  head  of  the  lower  jaw  is 
rounded;  and  can,  therefore,  be  moved 
in  all  directions;  and  as  easily  hori- 
zontally as  up  and  down.  The  glenoid 
cavity  is  shallow,  and  yields  the  same 
facilities.  The  articula-tion,  which  is 
very  close  in  the  carnivorous  animal,  is 
here  quite  loose.  The  levator  muscles 
are  much  more  feeble;  the  temporal 
fossa  is  less  deep;  the  zygomatic  arch 
less  convex;  and  the  zygomatic  fossa 
less  extensive.  On  the  other  hand, 
the  pterygoid  fossa  is  ample  and  the 
muscles  of  the  same  name  are  largely 
developed.  The  molares  are  large  and 
broad;  and  their  magnitude  is  so  great 
as  to  require,  that  the  jaw  should  be 
much  elongated  in  order  to  make  room 
for  them. 

The  joint  of  the  lower  jaw  has,  in  man,  solidity  enough  for  the  jaws 
to  exert  considerable  pressure  with  impunity,  and  laxity  enough  that  the 
lower  jaw  may  execute  horizontal  movements.  The  action  of  the  leva- 


Skull  of  the  Cow. 


516  DIGESTION. 

tor  muscles  is  the  most  extensive;  but  the  lateral  or  grinding  motion 
is  practicable  to  the  necessary  extent;  and  the  muscles  of  both  kinds 
have  a  medium  degree  of  developement.  The  teeth,  likewise,  partake 
of  the  characteristics  of  those  of  the  carnivorous  and  herbivorous 
animals  ; — twelve — the  canine  teeth  and  lesser  molares — corresponding 
to  those  of  the  carnivorous ;  and  twenty — the  incisors  and  larger  mo- 
lares — to  those  of  the  herbivorous. 

The  tongue  must  be  regarded  as  an  organ  of  mastication.  It  rests 
horizontally  on  the  floor  of  the  mouth ;  is  free  above,  anteriorly ;  and, 
to  a  certain  extent,  beneath  and  at  the  sides.  Behind,  it  is  united  to 
the  epiglottis  by  three  folds  of  the  mucous  membrane  of  the  mouth; 
and  is  supported  at  its  base  by  the  os  hyoides,  with  which  it  partici- 
pates in  its  movements.  The  tongue,  as  the  organ  of  taste  and  articu- 
lation, has  been  described  already  (p.  145).  We  have  only,  therefore, 
to  describe  the  os  hyoides  and  its  attachment  to  that  bone.  The 
hyoid  bone  has,  as  its  name  imports,  the  shape  of  the  Greek  letter  v, 
the  convex  part  being  before.  (Fig.  194.)  It  is  situate  between  the 
tongue  and  larynx  :  and  is  divided  into  body  or  central  part ;  and  into 
branches,  one  extremity  of  which  is  united  to  the  body  by  an  inter- 
mediate cartilage,  that  admits  of  slight  motion ;  whilst  the  other  is  free, 
and  is  called  greater  cornu.  Above  the  point,  at  which  the  branch  is 
articulated  with  the  body,  is  an  apophysis  or  process,  called  lesser  cornu. 
The  os  hyoides  is  united  to  the  neighbouring  parts  by  fibrous  organs, 
and  muscles.  The  former  are; — above,  the  stylo-hyoid  ligament,  which 
extends  from  the  lesser  cornu  of  the  bone  to  the  styloid  process  of  the 
temporal  bone ;  below,  a  fibrous  membrane,  called  thyro-hyoid,  passing 
between  the  body  of  the  bone  and  the  thyroid  cartilage;  and  two  liga- 
ments, extending  from  the  greater  cornu  of  the  hyoid  bone  to  the  thyroid 
cartilage,  called  thyro-hyoid.  Of  the  muscles;  some  are  above  the  hyoid 
bone,  and  raise  it; — viz.,  the  genio-  and  mylo-hyoideus,  already  referred 
to ;  the  stylo-hyoid,  and  some  fibres  of  the  middle  constrictor  of  the 
pharynx.  Others  are  below,  and  depress  it.  They  are  the  sterno-thyro- 
hyoideus,  omo-hyoideus  and  sterno-thyroideus.  The  base  of  the  tongue 
is  attached  to  the  body  of  the  bone  by  a  ligamentous  tissue,  and  by  the 
fibres  of  the  hyoglossus  muscle. 

Among  the  collateral  organs  of  mastication  are  those  which  secrete 
the  saliva,  and  the  various  fluids  which  are  poured  out  into  the  mouth, 
— constituting  together  what  has  been  termed  the  apparatus  of  insali- 
vation.  These  fluids  proceed  from  different  sources.  The  mucous 
membrane  of  the  mouth,  like  other  mucous  membranes,  exhales  a 
serous  or  albuminous  fluid,  besides  a  mucous  fluid  secreted  by  the  nu- 
merous follicles  contained  in  its  substance.  Four  glands  likewise  exist 
on  each  side,  destined  to  secrete  the  saliva,  which  is  poured  into  the 
mouth  by  distinct  excretory  ducts.  They  are  the  parotid,  submaxil- 
lary,  sublingual,  and  intra-lingual  or  lingual.  The  first  is  situate  be- 
tween the  ear  and  the  jaw;  and  its  excretory  duct  opens  into  the  mouth 
opposite  the  second  small  molaris  of  the  upper  jaw.  By  pressing 
upon  this  part  of  the  cheek,  the  saliva  can  be  made  to  issue  into  the 
mouth,  in  perceptibly  increased  quantity.  The  submaxillary  gland  is 
situate  beneath  the  base  of  the  jaw;  and  its  excretory  duct  opens  into 


DIGESTIVE  ORGANS — SALIVARY  GLANDS. 


51T 


Salivary  Glands  in  situ. 

1.  Parotid  gland  in  situ,  extending  from  the  zygoma  above,  to  the 
angle  of  the  "jaw  below.  2.  Duct  of  Steno.  3.  Submaxillary  gland. 
4.  Its  duct.  5.  Sublingual  gland. 


the  mouth  at  the  side  Fis-  213- 

of  thefrsenum  linguae. 
The  sublingual  gland 
is  situate  under  the 
tongue,  and  its  excre- 
tory ducts  open  at  the 
sides  of  that  organ, 
and  the  intra-lingual 
or  lingual  is  seated  at 
the  inferior  surface  of 
the  tongue,  where  the 
mucous  membrane 
forms  a  fringed  fold. 
These  glands  are  con- 
stantly pouring  saliva 
into  the  mouth ;  and 
it  has  been  presumed, 
that  the  fluids  se- 
creted by  them  may 
differ  from  each  other 
in  physical  and  che- 
mical characters.  Such,  at  least,  has  been  the  view  of  some  as  re- 
gards the  sublingual,  the  texture  of  which  more  nearly  resembles 
that  of  the  compound  follicles  than  of  glands ;  but  the  circumstance 
has  not  been  proved  by  any  direct  experiment.  The  saliva,  as  met 
with,  is  a  compound  of  every  secretion  poured  into  the  mouth ;  and  it 
is  this  fluid  which  has  been  chiefly  subjected  to  analysis.  The  secretion 
of  the  saliva,  and  its  various  properties,  will  be  considered,  however, 
hereafter. 

The  two  apertures  of  the  mouth  are  the  labial  and  pharyngeal.  The 
former,  as  its  name  imports,  is  formed  by  the  lips,  which  consist  ex- 
ternally of  a  layer  of  skin  ;  are  lined  internally  by  a  mucous  membrane; 
and,  in  their  substance,  contain  numerous  muscles,  already  described 
under  the  head  of  Gestures.  These  muscles  may  be  separated  into 
constrictors  and  dilators;  the  orbicularis  oris  being  the  only  one  of 
the  first  class,  and  the  antagonist  to  the  others,  which  are  eight  in 
number,  on  each  side — levator  labii  superioris  alseque  nasi,  levator  labii 
superioris  proprius,  levator  anguli  oris,  zygomaticus  major,  zygomati- 
cus  minor,  buccinator,  triangularis,  and  quadratus  menti.  (Fig.  201.) 
To  the  last  two  muscles  are  added  some  fibres  of  the  platysma  myoides. 

The  pharyngeal  opening  is  smaller  than  the  labial,  and  of  a  quadri- 
lateral shape.  It  is  bounded  above  by  the  velum  palati  or  pendulous 
veil  of  the  palate;  below,  by  the  base  of  the  tongue ;  and  laterally,  by- 
two  muscles,  which  form  the  pillars  of  the  fauces.  The  pendulous  veil 
is  a  musculo-membranous  extension,  constituting  a  kind  of  valve,  at- 
tached to  the  posterior  margin  of  the  bony  palate,  by  which  all  com- 
munication between  the  mouth  and  pharynx,  or  between  the  pharynx 
and  nose  can  be  prevented.  (Fig.  214.)  To  produce  the  first  of  these 
effects,  it  becomes  vertical;  to  produce  the  latter,  horizontal.  At  its 
inferior  and  free  margin,  it  has  a  nipple-like  shape,  and  bears  the  name 


518 


DIGESTION. 


Fig.  214. 


Cavity  of  the  Mouth,  as  shown  by  dividing  the  An- 
gles and  turning  off  the  Lips. 

1.  Upper  lip,  turned  up.  2.  Its  frsenum.  3.  Lower 
lip,  turned  down.  4.  Its  fraenum.  5,  Internal  sr -face 
of  cheeks.  6:  Opening  of  duct  of  Stenrt.  7.  F  jf  of 
mouth.  8.  Anterior  portion  of  lateral  half  arches.  9. 
Posterior  portion  of  lateral  half  arches.  10.  Velum 
pendulum  palati.  11.  Tonsils.  12.  Tongue. 

Fig.  2 1 5. 


of  uvula.  It  is  composed  of 
two  mucous  membranes,  and  of 
muscles.  One  of  the  mem- 
branes,— that  forming  its  ante- 
rior surface — is  a  prolongation 
of  the  membrane  lining  the 
mouth,  and  contains  numerous 
follicles ;  the  other,  forming  its 
posterior  surface,  is  an  extension 
of  the  mucous  membrane  lining 
the  nose,  and  is  redder,  and  less 
provided  with  follicles  than  the 
other.  The  muscles  that  con- 
stitute the  body  of  the  velum 
palati  are  —  the  circumflexus 
palati  or  spheno-salpingo-sta- 
phylinus  of  Chaussier;  the  leva- 
tor  palati  or  petro-salpingo-sta- 
phylinus  ;  and  the  azygos  uvulae 
or  palato-staphylinus.  The 
velum  is  moved  by  eight  mus- 


Fig.  216. 


Fig.  217. 


Pharynx  seen  from  behind. 

1.  A  section  carried  transversely  through  base  of 
skull.  2,2.  Walls  of  pharynx  drawn  to  each  side. 
3,  3.  Posterior  nares,  separated  by  vomer.  4.  Ex- 
tremity of  Eustachian  tube  of  one  side.  5.  Soft 
palate.  6.  Posterior  pillar  of  soft  pal;ite.  7.  Its 
anterior  pillar ;  the  tonsil  seen  situate  in  the  niche 
between  the  two  pillars.  8.  Root  of  tongue,  partly 
concealed  by  uvula.  9.  Epiglottis,  overhanging 
(10)  opening  of  glottis.  11.  Posterior  part  of  larynx. 
12.  Opening  into  oesophagus.  13.  External  surface 
of  oesophagus.  14.  Trachea. 


Longitudinal  Section  of  CEso-  Section  of  the 
phagus,  near  the  Pharynx,  (Esophagus, 
seen  on  its  inside. 

a,   b.    Inter- 
1,  1.  Superior  part  near  pha-    nal        circular 

rynx.    2,2.  Longitudinal  folds    fibres,     c.  Ex- 

of  its  mucous  membrane.     3,3.     ternal  longitu- 

Prominences  formed  by  its  mu-     dinal  fibres. 

ciparous glands.    4,4.  Capillary 

bloodvessels.      5.     Shows     the 

muscular  coat  after  the  mucous 

coat  has  been  turned  off. 


DIGESTIVE  ORGANS — STOMACH.  519 

cles.  The  two  internal  pterygoids  raise  it;  the  two  external  ptery golds 
stretch  it  transversely ;  the  two  palato-pharyngei  Qvpharyngo-staphylini, 
and  the  two  constrictores  isthmi  faucium  or  glosso-staphylini  carry  it 
downwards.  The  last  four  muscles  form  the  pillars  of  the  fauces; — 
the  first  two  the  posterior  pillars  ;  and  the  last  two  the  anterior ;  be- 
tween which  are  situate  the  tonsil  glands  or  amygdalae,  which  are  not 
really  glandular,  but  composed  of  a  congeries  of  mucous  follicles. 

2.  The  pharynx  and  oesophagus  constitute  a  muscular  canal,  which 
forms  the  medium  of  communication  between  the  mouth  and  stomach, 
and  conveys  the  food  from  the  former  of  these  cavities  to  the  latter. 

The  pharynx  has  the  shape  of  an  irregular  funnel, — the  larger  open- 
ing of  the  funnel  looking  towards  the  mouth  and  nose  ;  the  under  and 
smaller  end  terminating  in  the  oesophagus.  Into  its  upper  part,  the 
nasal  fossae,  Eustachian  tubes,  mouth,  larynx,  and  oesophagus  open. 
It  is  inservient  to  useful  purposes  in  the  production  of  voice,  respira- 
tion, audition,  and  digestion  ;  and  extends  from  the  basilary  process  of 
the  occipital  bone,  to  which  it  is  attached,  as  far  as  the  middle  part  of 
the  neck.  Its  transverse  dimensions  are  determined  by  the  os  hyoides, 
larynx,  and  pterygo-maxillary  apparatus,  to  which  it  is  attached.  It 
is  lined  by  a  mucous  membrane,  less  red  than  that  which  lines  the 
mouth,  but  more  so  than  that  of  the  cesophagus,  and  the  rest  of  the 
digestive  tube ;  and  it  is  remarkable  for  the  developement  of  its  veins, 
which  form  a  very  distinct  network.  Around  this  is  the  muscular  layer, 
the  circular  fibres  of  which  are  often  divided  into  three  muscles — supe- 
rior, middle,  and  inferior  constrictors.  The  longitudinal  fibres  form 
part  of  the  stylo-pharyngei  and  palato-pharyngei  muscles.  The  pharynx 
is  raised  by  the  action  of  the  last  two  muscles,  as  well  as  by  all  those 
that  are  situate  between  the  lower  jaw  and  os  hyoides,  which  cannot 
raise  the  latter  without,  at  the  same  time,  raising  the  larynx  and  pha- 
rynx. These  muscles  are : — mylo-hyoideus,  genio-hyoideus,  and  the 
anterior  belly  of  the  digastricus. 

The  oesophagus  is  a  continuation  of  the  pharynx ;  and  extends  to  the 
stomach,  where  it  terminates.  Its  shape  is  cylindrical,  and  it  is  con- 
nected with  the  surrounding  parts  by  loose  and  extensible  areolar  tissue, 
which  yields  readily  to  its  movements.  On  entering  the  abdomen,  it 
passes  between  the  pillars  of  the  diaphragm,  with  which  it  is  intimately 
united.  The  mucous  membrane  lining  it  is  pale,  thin,  and  smooth ; 
forming  longitudinal  folds,  well  adapted  for  favouring  the  dilatation  of 
the  canal.  Above,  it  is  confounded  with  that  of  the  pharynx ;  but 
below,  it  forms  several  digitations,  terminated  by  a  fringed  extremity, 
which  is  free  in  the  cavity  of  the  stomach.  It  is  well  supplied  with 
mucous  follicles.  The  muscular  coat  is  thick ;  its  texture  is  denser 
than  that  of  the  pharynx, — and  cannot,  like  it,  be  separated  into  dis- 
tinct muscles,  but  consists  of  circular  and  longitudinal  fibres,  the  former 
of  which  are  more  internal,  and  very  numerous,  the  latter  external  and 
less  numerous.  Fig.  217  exhibits  the  situation  and  arrangement  of  the 
two  sets  of  fibres. 

3.  The  stomach  is  situate  in  the  cavity  of  the  abdomen,  and  is  the 
most  dilated  portion  of  the  digestive  tube.     It  occupies  the  epigastric 
region,  and  a  part  of  the  left  hypochondre.     Its  shape  has  been  com- 


520 


DIGESTION. 


pared,  not  inappropriately,  to  that  of  the  bag  of  a  bag-pipe.  It  is 
capable  of  holding,  in  the  adult  male,  when  moderately  distended, 
about  three  pints.  The  left  half  of  the  organ  has  always  much  greater 


Fig.  218. 


Stomach  seen  Externally. 

A,  A.  Anterior  surface.    B.  Enlargement  at  lower  part.    D.  Cardiac  orifice.    E.  Commencement  of 
duodenum.     F  and  C.  Coronary  vessels.     H.  Omentum. 

dimensions  than  the  right.  The  former  has  been  called  the  splenic 
portion,  because  it  rests  upon  the  spleen;  the  latter  the  pyloric  portion, 
because  it  corresponds  to  the  pylorus.  The  inferior  border  of  the 
stomach,  which  is  convex,  is  termed  the  great  curvature  or  arch;  the 
superior  border,  the  lesser  curvature  or  arch.  The  two  orifices  are  the 
cesophageal,  cardiac,  or  upper  orifice,  formed  by  the  termination  of  the 
oesophagus;  and  the  intestinal,  pyloric  or  inferior  orifice,  which  com- 
municates with  the  small  intestine. 

The  three  coats  that  constitute  the  parietes  of  the  stomach,  are  ar- 
ranged in  a  manner  the  most  favourable  for  permitting  variation  in  the 
size  of  the  organ.  The  outermost  or  peritoneal  coat  consists  of  two 
laminae,  which  adhere  but  slightly  to  the  organ,  and  extend  beyond  it, 
where  they  form  the  epiploons  or  omenta,  the  extent  of  which  is  in  an 
inverse  ratio  to  the  degree  of  distension  of  the  stomach.  The  omentum 
majus  or  gastro-colic  epiploon  is  the  part  that  hangs  down  from  the 
stomach  in  Fig.  218. 

The  mucous  or  lining  membrane  is  of  a  whitish,  marbled,  red  appear- 


DIGESTIVE  ORGANS — STOMACH. 


521 


ance,  having  a  number  of  irregular  folds,  situate  especially  along  the 
inferior  and  superior  margins  of  the  organ.  These  folds  are  evident, 
also,  at  the  splenic  extremity;  and  are  more  numerous  and  marked,  the 
more  the  stomach  is  contracted.  They  are  radiated  towards  the  car- 
diac? — longitudinal  towards  the  pyloric,  orifice.  This  membrane,  like 
every  other  of  the  kind,  exhales  an  albuminous  fluid  from  a  multitude 


Fig.  219. 


Fig.  220. 


Vertical  and  Longitudinal  Section  of  Stomach  and 
Duodenum. 

1.  (Esophagus;  upon  its  internal  surface,  the  plicated 
arrangement  of  cuticular  epithelium  shown.  2.  Cardiac 
orifice  of  stomach,  around  which  the  fringed  border  of 
cuticular  epithelium  is  seen.  3.  Great  end  of  stomach. 
4.  Its  lesser  or  pyloric  end.  5.  Lesser  curve.  G.  Greater 
curve.  7.  Dilatation  at  lesser  end  of  stomach  which  re- 
ceived from  Willis  the  name  of  antrum  of  pylorus.  This 
may  be  regarded  as  the  rudiment  of  a  second  stomach. 
3.  Rugae  of  the  stomach  formed  by  mucous  membrane  : 
their  longitudinal  direction  is  shown.  9.  Pylorus.  10. 
Oblique  portion  of  duodenum,  11.  Descending  portion. 
12.  Pancreatic  duct,  and  ductus  cornmunis  choledochus, 
close  to  their  termination.  13.  Papilla  upon  which  ducts 
open.  14.  Transverse  portion  of  duodenum.  15.  Com- 
mencement of  jejunum.  In  interior  of  duodenum  and 
jejunum,  the  valvulse  conniventes  are  seen.  (Wilson.) 


Section  of  a  piece  of  Stomach  not  far 
from  Pylorus. 

1.  Magnified  about  three  diameters.  2. 
A  few  of  the  glands  with  their  racemiform 
ends  distended  with  fluid,  magnified  about 
20  diameters.  (Wagner.) 


of  delicate  villi,  which  are  as  perceptible  in  the  stomach  as  in  any  part 
of  the  digestive  tube.  It  contains,  likewise,  many  follicles,  which  are 
especially  abundant  in  the  pyloric  portion.  (Fig.  220.)  Several,  also, 
exist  in  the  vicinity  of  the  cardiac  orifice,  but  in  the  rest  of  the  mem- 
brane they  are  few  in  number.  When  examined  with  a  magnifying 
glass,  the  internal  or  free  surface  presents  a  peculiar  honeycomb  ap- 
pearance, produced  by  shallow  polygonal  depressions  or  cells  as  repre- 
sented in  the  marginal  figure.  (Fig.  223.)  The  diameter  of  these  cells 
varies  from  2Joth  to  3^ota  °f  an  inch;  but,  near  the  pylorus,  it  is  as 
much  as  TJota  °f  an  inch.  In  the  bottom  of  the  cells,  minute  openings 
are  visible,  which  are  the  orifices  of  perpendicular  glands  embedded, 
side  by  side,  in  bundles  in  the  substance  of  the  mucous  membrane,  and 
composing  nearly  the  whole  structure.1  These  tubular  follicles  vary  in 


1  Dr.  Sprott  Boyd,  Edinb.  Med.  and  Surg.  Journal,  vol.  xlvi. 


522 


DIGESTION. 


Fig.  221.  length  from  one-fourth  of  a  line  to  nearly  a  line.  They 
are  longer  and  more  closely  set  towards  the  pylorus  than 
elsewhere,  their  length  being  equal  to  the  thickness  of 
the  mucous  membrane  of  the  stomach,  which  varies. 

The  office  of  these  tubular  follicles,  it  has  been  thought, 
is  to  secrete  the  gastric  fluid,  during  digestion ;  for  in  the 
intervals  they  are  at  rest.  They  are  formed  by  inflections 
of  basement  membrane,  with  cylindrical  epithelium  rest- 
ing upon  it.  One  of  them  is  represented  in  the  marginal 
figure,  which  exhibits  the  nucleated  cells  at  the  bottom 
of  the  follicle;  becoming  more  and  more  developed  as 
they  approach  the  free  surface.  These  cells  prepare 
the  gastric  fluid,  and  ultimately  burst  and  discharge  it 
to  become  mixed  with  the  aliment  in  the  stomach. 

Besides  these  glands  or  follicles,  small  opaque — white 
sacculi,  resembling  Peyer's  glands,  are  met  with,  which 
Tubular  Follicle  of  are  fiHed  with  minute  cells  and  granules.     They  are 

Pig  s      Stomach.       .  ,  .    a        ,  „    ,  ^        , 

(After  Wasmann.)  situate  chiefly  along  the  lesser  curvature  of  the  stomach 


Fig.  222. 


Fig.  223. 


B 


Vertical  Section  of  a  Stomach  Cell,  with 
its  Tubes. 

A.  In  the  middle  region.  B.  In  the  pyloric 
region,  a,  a.  OrificeB  of  the  cells  on  the 
inner  surface  of  the  stomach.  6,  b.  Different 
depths  at  which  the  columnar  epithelium  is 
exchanged  for  glandular,  c.  Pyloric  tube, 
or  prolonged  stomach  cell.  d.  Pyloric  tubes, 
terminating  variously,  and  lined  to  their  ex- 
tremities with  sub-columnar  epithelium. 

From  the  dog,  after  twelve  hours'  fasting, 
—Magnified  200  diameters. 


Mucous  Membrane  of  the  Stomach. 

A.  Inner  surface  of  the  stomach,  showing 
the  cells  after  the  mucus  has  been  washed 
out. — Magnified  25  diameters. 

B.  Columnar  epithelium  of  the  inner  sur- 
face and  cells  of  the  stomach,     a.  Free  ends 
of  the  epithelial  particles,  seen  on  looking 
down  upon  the  membrane,     b.  Nuclei  visible 
at  a  deeper   level,     c.  The  free   ends   seen 
obliquely,     d.  Deep  or  attached  ends  of  the 
same.     The  oval  nuclei  are  seen  near  the 
deeper  ends. 

From  the  dog.— Magnified  300  diameters. 


DIGESTIVE  ORGANS — STOMACH. 


523 


beneath  the  lining  membrane;  are  probably  concerned  in  the  separa- 
tion of  some  secretion  from  the  blood,  and  when  filled  burst,  like  other 
secreting  cells,  and  discharge  their  contents  into  the  stomach.1 

The  pylorus,  or  the  part  at  which  the  stomach  terminates  in  the 
small  intestine,  isrnarked, 

externally,  by  a  manifest  Fig.  224. 

narrowness,  as  at  9,  Fig. 
219.  Internally,  the  mu- 
cous membrane  forms  a 
circular  fold,  which  has 
been  called  valve  of  the 
pylorus,  between  the  two 
laminae  of  which,  a  dense, 
fibrous  tissue  exists.  This 
has  been  called  by  some 
authors,  pyloric  muscle. 

The  muscular  coat, 
which  is  exterior  to  the 
mucous  coat, — as  in  the 
parts  of  the  digestive 
tube  already  described, — 

Consists  of  Several  laminae    Front  View  of  Stomach,  distended  by  flatus,  with  Peritoneal 

of  fibres,  less  distinct  than  Coat  turned  off- 

fVinco  r»f   fVio    rAarvrvViQ  rrnc  •        1.  Anterior  face  of  ossophagus.    2.  Cul-de-sac,  or  greater  ex  - 

SOpnagUS,  tremity      3.  Lesser  or  pyloric  extremity.    4.  Duodenum.     5,5. 

Or  rather  more  irregularly  -^  portion  of  the  peritoneal  coat  turned  back.     6.  A  portion  of 

-,.        .,  mu  ^e  lonoituc'ina'  fibres  of  the  muscular  coat.     7.  Circular  fibres 

distributed.          Hie      mOSt  of  the  muscular  coat.     8.  Oblique  muscular  fibres,  or  muscle  of 

/•» -krnmrvn     /-vK>ir>ir»r»    ia     -fliaf  Gavard.     9.  A  portion  of  the  muscular  coat  of  the  duodenum, 

Ib,  Uld,L  where  its  peritoneal  coat  has  been  removed. 

there  are  three  laminae: — 

an  external,  longitudinal  series ;  a  middle  transverse  or  circular  stratum ; 
and  an  inner  stratum  with  fibres  running  obliquely.  Both  circular  and 
longitudinal  fibres  are  separated  from  each  other,  especially  in  the 
splenic  portion, — the  separation  augmenting  or  diminishing  with  the 
varying  size  of  the  stomach. 

The  blood-vessels  and  nerves  of  the  stomach  are  more  numerous  than 
those  of  any  other  organ  of  the  body.  The  arteries  are  disposed  along 
the  curvatures.  On  the  lesser  curvatures  are, — coronaria  ventriculi, 
and  the  pyloric  branch  of  the  hepatic  artery;  on  the  great  curvature, 
the  right  gastro-epiploic,  which  is  a  branch  of  the  hepatic;  and  the  left 
gastro-epiploic, — a  branch  of  the  splenic.  The  splenic  artery,  too, 
furnishes  numerous  branches  to  the  left  cul-de-sac  behind.  These  are 
called  vasa  brevia  or  Castro-splenic.  The  nerves  of  the  stomach  are  of 
two  kinds.  Some  proceed  from  the  great  sympathetic,  from  the  cceliac 
plexus,  and  accompany  the  arteries  through  all  their  ramifications. 
Others  are  furnished  by  the  pneumogastric  or  eighth  pair ;  the  two 
nerves  of  which  surround  the  cardiac  orifice  like  a  ring.  The  number 
of  the  nerves,  and  the  variety  of  sources  whence  they  are  derived,  ex- 
plain the  great  sympathetic  influence  exerted  upon  the  stomach  by 
affections  of  other  parts  of  the  system.  It  sympathizes,  indeed,  with 


1  Kirkes  and  Paget,  Manual  of  Physiology,  Amer.  edit.,  p.  167,  Philad.,  1849, 


524 


DIGESTION. 


Fig.  225. 


every  protracted  mor- 
bid change  in  the  in- 
dividual organs ;  and 
hence  was  termed,  by 
Mr.  Hunter,  the  centre 
of  sympathies. 

Like  the  teeth,  the 
human  stomach  holds  a 
medium  space  between 
that  of  the  carnivorous 
and  herbivorous  animal. 
As  the  former  makes 
use  of  aliment,  which  is 
more  readily  assimilated 
to  its  own  nature,  and 
more  nutritious,  it  is  not 
necessary  that  it  should 
take  food  in  such  large 
quantities  as  the  latter, 
or  that  this  should  re- 
main so  long  in  the 
stomach.  On  this  ac- 
count, the  organ  is  ge- 
nerally of  much  smaller 
size.  On  the  other 
hand,  as  the  herbivora 
subsist  solely  upon 


grass, 


which    contains 


Distribution  of  the  Glosso-Pharyngeal,  Pneumogastric  and 
Spinal  Accessory  Nerves,  or  the  Eighth  Pair. 

1.  The  inferior  maxillary  nerve.  2.  The  gustatory  nerve.  3.  The 
chorda  tympani.  4.  The  auricular  nerve.  5.  Its  communication 
with  the  portio  dura.  6.  The  facial  nerve  coming  out  of  the  stylo- 
mastoid  foramen.  7.  The  glosso-pharyngeal  nerve.  8.  Branches  to 
the  stylo-pharyngeus  muscle.  9.  The  pharyngeal  branch  of  the 
pneumogastric  nerve  descending  to  form  the  pharyngeal  plexus. 

10.  Branches  of  the  glosso-pharyngeal  to  the  pharyngeal  plexus. 

11.  The  pneumogastric  nerve.    12.  The  pharyngeal  plexus.    13.  The 
superior  laryngeal  branch.    14.  Branches  to  the  pharyngeal  plexus. 
15, 15.  Communication  of  the  superior  and  inferior  laryngeal  nerves. 
16.  Cardiac  branches.   17.  Cardiac  branches  from  the  right  pneumo- 
gastric nerve.    18.  The  left  cardiac  ganglion  and  plexus.    19.  The 
recurrent  or  inferior  laryngeal  nerve.    20.  Branches  sent  from  the 
curve  of  the  recurrent  nerve  to  the  pulmonary  plexus.    21.  The 
anterior  pulmonary  plexus.    22,  22.  The  cesophageal  plexus. 


but  a  small  quantity  of 
nutritious  matter,  and 
that  not  easy  of  assimi- 

i    ,•  •,     • 

ifttlOn,    It    IS 


that  the  quantity  taken 
in  should  be  ample; 
that  it  should  remain 
for  some  time  in  the 
organ,  subjected  to  the 
action  01  its  secretions ; 
and,  in  the  ruminant 
class,  be  returned  into 
the  mouth,  to  undergo 
fresh  mastication. 
In  this  class,  the  stomach  is  of  prodigious  extent.  In  the  ox,  which 
we  may  take  as  an  example  of  the  general  structure  of  the  organ,  it 
consists  of  four  separate  compartments.  The  first  stomach,  A  A,  Fig. 
226,  ventrieulus  or  paunch,  is  much  the  largest.  Externally,  it  has  two 
sacs  or  appendices;  and,  internally,  is  slightly  divided  into  four  compart- 
ments. The  second  stomach  is  the  reticulum,  bonnet  or  honey -comb  bag,  B, 
which  appears  to  be  a  globular  appendix  to  the  paunch.  It  is  situate  to 
the  right  of  the  resophagus,  Or,  and  has  usually  a  thicker  muscular  coat 
than  the  paunch.  Its  inner  surface  is  arranged  in  irregular  pentagonal 


DIGESTIVE  ORGANS  OF  THE  RUMINANT  ANIMAL. 


525 


Stomach  of  the  Ox. 

A,  A.  Paunch.  B.  Reticulum.  C.  Omasum. 
D.  Abomasum.  E.  Pylorus.  F.  Duodenum. 
G.  CEsophagus. 


cells,  and  is  covered  with  fine  papillae.  Fig.  226. 

The  third  stomach,  C,  is  the  smallest, 
and  is  called  omasum  or  manyplies. 
It  is  of  a  globular  shape,  and  has 
a  thinner  muscular  coat  than  the 
former.  It  consists  of  numerous 
broad  laminae,  sent  off  from  the  inter- 
nal coat,  running  in  a  longitudinal 
direction,  alternately  varying  in 
breadth,  and  covered  with  a  small  gra- 
nular papillae.  The  fourth  stomach, 
D,  is  the  abomasum,  ventriculus  in- 
testinalis  or  caillette.  It  has  a  pyri- 
form  shape,  and  is  next  in  size  to  the 
paunch.  It  has  large  longitudinal  rugae, 
covered  with  villi.  The  muscular  coat 
is  still  thinner  than  that  of  the  former. 
This  stomach  is  the  only  one  that 
resembles  the  human  organ;  and,  in  the  young  of  the  ruminant 
animal,  with  the  milk  curdled  in  it,  forms  the  runnet  or  rennet. 
The  property  of  curdling  milk  is,  however,  possessed  by  all  digestive 
stomachs.  The  inner  surface  of  the  three  first  stomachs  is  covered 
with  cuticle;  whilst  that  of  the  fourth  is  lined  by  a  true  mucous  or 
secreting  membrane.  There  is  in  the  interior  arrangement  of  the 
stomachs  of  the  ruminant  animal  a  singular  provision  by  which  the  food 
can  be  either  received  into  the  first  and  second  stomachs,  or  be  carried 
on  into  the  third,  if  its  character  be  such  as  to  be  fitted  at  first  for  the 
action  of  the  omasum. 

From  the  oesophagus,  in  Fig.  227,  a  gutter  passes  into  the  second 
and  third  stomachs.     The 

third  leads  into  the  fourth  Fi§-  227- 

by  a  narrow  opening,  and 
the  fourth  terminates  in 
the  duodenum,  which  has  a 
pylorus  as  its  origin.  When 
the  animal  eats  solid  food, 
it  is,  after  slight  masti- 
cation, passed  into  the 
paunch,  and  thence,  by 
small  portions,  into  the 
second  stomach.  When  this 
has  become  mixed  with 
fluid,  and  kept  for  some 
time  at  a  moderately  high 
temperature,  a  morsel  is 
thrown  back  with  velocity 
from  the  stomach  into  the 
mouth,  where  it  is  "rumi- 
nated," and  then  swallowed  and  passed  on  into  the  third  stomach, — the 
groove  or  gutter  being  now  so  contracted  as  to  form  a  channel  for  its 


Section  of  the  Stomach  of  the  Ruminant  Animal. 


526 


DIGESTION. 


Fig.  228. 


passage  through  the  first  two.  In  the  third  and  fourth  stomachs,  more 
especially  the  latter,  true  digestion  takes  place.  When  the  food  is  of 
such  a  character  as  not  to  require  rumination,  it  can  be  sent  on  directly 
into  the  third  stomach,  by  the  arrangement  just  described. 

In  the  bird  tribes,  we  see  an  admirable  adaptation  of  structure  to 
the  functions  which  the  digestive  organs  have  to  execute.  Animals 
of  this  class  may  be  divided  into  the  granivorous  and  the  carnivorous. 
It  is  in  the  former,  that  we  are  so  much  impressed  with  the  organiza- 
tion of  this  part 
of  their  economy. 
The  grain  on  which 
they  feed,  although 
more  nutritious 
than  grass,  which 
constitutes  the  ali- 
ment of  the  herbi- 
vorous quadruped, 
requires  equal  diffi- 
culty in  being  assi- 
milated to  the  na- 
ture of  the  being 
it  has  to  nourish. 
Added  to  this,  it 
is  in  such  a  condi- 
tion, that  the  juices 
of  the  digestive  or- 
gans cannot  rea- 
dily act  upon  it. 
The  bird  having  no 
masticatory  appa- 
ratus within  the 
mouth,  the  grain 
must  of  necessity 
be  swallowed  whole. 
But  we  find  that 
lower  down  in  the 
alimentary  tube,  a 
powerful  mastica- 
tory apparatus  ex- 
ists, which  has  fre- 
quently been  con- 
sidered as  a  part 
of  the  digestive  sto- 
mach ;  but  really  seems  destined  for  mastication  only.  The  following 
is  the  arrangement  of  their  gastric  apparatus. 

The  oesophagus  terminates  at  the  bottom  of  the  neck  in  a  large  sac 
— ingluvies,  crop  or  craw — which  is  of  the  same  structure  with  the 
oesophagus,  but  thinner.  On  the  inner  side  of  the  crop  are  numerous 
glands,  with  very  distinct  orifices  in  large  birds,  which  secrete  a  fluid 
to  assist  in  the  solution  of  the  food.  To  the  crop  succeeds  another 


Gastric  Apparatus  of  the  Turkey. 


DIGESTIVE  ORGANS  OF  THE  GALLINACEA. 


527 


Fig.  229. 


cavity,  in  the  shape  of  a  funnel,  called  ventriculus  succenturiatus,  pro- 
ventriculus,  infundibulum  or  second  stomach.  This  is  seated  in  the 
abdomen,  and  is  generally  smaller  than  the  former.  It  is  usually 
thicker  than  the  oesophagus,  partly  owing  to  its  numerous  glands,  which 
are  very  large  and  distinct  in  many  birds.  In  the  ostrich,  they  are  as 
large  as  the  garden-pea,  and  have  very  manifest  orifices.  The  infun- 
dibulum terminates  in  the  ventriculus  callosus,  gizzard  or  third  stomach 
— the  most  curious  of  all  the  parts  of  the  apparatus.  Figs.  228  and 
229  afford  an  external  and  internal  view  of  the  gastric  apparatus  of 
the  turkey ;  a,  representing  the  oesophagus  immediately  below  the 
crop,  covered  with  cu- 
ticle ;  bj  the  openings 
of  the  gastric  glands 
in  the  second  stomach, 
placed  on  a  surface, 
that  has  no  cuticular 
covering ;  £,  horny 
ridges,  between  the 
gastric  glands  and  the 
lining  of  the  gizzard ; 
dj  a  minutely  granu- 
lated surface  between 
the  cavity  of  the  giz- 
zard and  duodenum; 
and  e,  the  inner  sur- 
face of  the  duodenum. 
Fig.  228  accurately 
represents  the  mode  in 
which  the  second  sto- 
mach terminates  in  the 
gizzard,  and  the  latter 
in  the  duodenum;  the 
gizzard  forming  a  kind 
of  pouch  depending 
from  the  alimentary 
canal.  The  gizzard  is 
usually  of  a  globular 
figure,  flattened  at  the 
sides,  and  is  considered 
to  consist  of  four  mus- 
cles, remarkable  for 
their  great  thickness  and  strength; — a  large  hemispherical  pair  at  the 
sides,  and  a  small  pair  situate  at  the  extremities  of  the  stomach.  The 
gizzard  is  covered  externally  by  a  beautiful  tendinous  expansion ;  and 
is  lined  by  a  thick,  strong,  callous  coat,  which  appears  to  be  epider- 
mous  in  its  character.  On  this  are  irregularities,  adapted  to  each 
other  on  the  opposite  surfaces.  The  cavity  of  the  organ  is  remarkably 
small,  when  compared  with  its  outward  magnitude,  and  its  two  orifices, 
represented  in  Fig.  228,  are  very  near  each  other.  In  the  pouch 
formed  by  the  small  muscles  at  the  lower  part  of  the  gizzard,  numerous 
pebbles  are  contained,  which  seem  to  be  indispensable  to  the  digestion 


Interior  of  the  Gastric  Apparatus  of  the  Turkey. 


528  DIGESTION. 

of  certain  tribes,  by  acting  as  substitutes  for  teeth.  In  the  gizzard  of 
the  turkey,  two  hundred  have  been  found ;  in  that  of  the  goose, 
one  thousand.1  The  prodigious  power  with  which  the  digastric  muscle 
— as  it  has  been  termed — acts,  and  the  callous  nature  of  the  cuticle, 
are  strikingly  manifested  by  certain  experiments,  instituted  by  the 
Academia  del  Cimento,2  and  by  Redi,  Keaumur,3  and  Spallanzani.4 
They  compelled  geese  and  other  birds  to  swallow  needles  and  lancets, 
and  in  a  few  hours  afterwards  killed  and  examined  them.  The  needles 
and  lancets  were  uniformly  found  broken  off  and  blunted,  without  the 
slightest  injury  having  been  sustained  by  the  stomach. 

In  the  carnivorous  bird,  the  food  being  readily  assimilated,  in  con- 
sequence of  its  analogy  to  the  substance  of  the  animal,  the  gastric 
apparatus  is  as  simple  as  in  the  carnivorous  mammalia.  The  oesopha- 
gus is  of  great  size  for  receiving  the  large  substances  swallowed  by 
these  animals,  and  for  enabling  the  feathers  and  other  matters,  that 
cannot  easily  be  digested,  to  be  rejected  by  the  mouth.  The  stomach 
is  a  mere  musculo-membranous  sac ;  but  the  secretion  from  it  is  of  a 
potent  character,  so  as  to  enable  the  animal  to  dispense  with  mastica- 
tion, and  yet  to  admit  of  the  stomach  and  intestines  being  disposed 
within  a  small  compass,  so  as  to  give  them  the  necessary  lightness  to 
fit  them  for  flight. 

We  can  thus,  from  organization,  generally  form  an  idea  of  the  kind 
of  food  for  which  an  animal  is  naturally  destined ;  whether,  for  exam- 
ple, it  is  naturally  granivorous  or  carnivorous.  There  are  some  strik- 
ing facts,  however,  that  exhibit  the  signal  changes  exerted,  even  on 
organization,  by  restricting  an  animal  to  diet  of  a  different  character 
from  that  to  which  it  has  been  accustomed;  or  to  one  which  is  foreign 
to  its  nature.  In  birds  of  prey,  the  digastric  muscle  has  the  bellies, 
which  compose  it,  so  weak,  that,  according  to  Sir  Everard  Home,5 
nothing  but  an  accurate  examination  can  determine  its  existence. 
But  if  a  bird  of  this  kind,  from  want  of  animal  food,  be  compelled  to 
live  upon  grain,  the  bellies  of  the  muscle  become  so  large,  that  they 
would  not  be  recognized  as  belonging  to  the  stomach  of  a  bird  of  prey. 
Mr.  Hunter  kept  a  sea-gull  for  a  year  upon  grain,  when  he  found  the 
strength  of  the  muscle  much  augmented.  This  wondrous  adaptation 
of  structure  to  the  kind  of  food  which  the  animal  is  capable  of  obtain- 
ing, is  elucidated  by  the  South  American  and  African  ostriches.  The 
former  is  the  native  of  a  more  productive  soil  than  the  latter ;  and,  ac- 
cordingly, the  gastric  glands  are  less  complex  and  numerous;  and  the 
triturating  organ  is  less  developed.6 

4.  The  intestines  are  the  lowest  portion  of  the  digestive  apparatus; 
constituting  a  musculo-membranous  canal,  which  extends  from  the 
pyloric  orifice  of  the  stomach  to  the  anus.  The  human  intestines  are 
six  or  eight  times  longer  than  the  body;  and  hence  the  number  of  con- 

1  J.  Hunter,  Observations  on  certain  parts  of  the  Animal  Economy,  with  Notes  by  Prof. 
Owen,  Amer.  edit.,  p.  119,  Philad.,  1840  ;  and  Roget,  Animal  and  Vegetable  Physiology,  edit, 
citat.,  ii.  126. 

2  Ex  per.  Fatte  nell'  Acnd.  del  Cimento,  2da  ediz.,  Firenz.,  1691. 

3  Memoir  de  1'Acad.  pour  1752,  p.  266  and  p.  461. 

4  Dissertations  relative  to  the  Natural  History  of  Animals  and  Vegetables,  English  trans- 
lation, i.  16,  Lond,  1789. 

6  Lectures  on  Comparative  Anatomy,  i.  271,  Lond.,  1814.  «  Ibid.,  i.  293. 


DIGESTIVE  ORGANS — INTESTINES. 


529 


Fig.  230. 


volutions  in  the  abdominal  cavity.  They  are  attached  to  the  vertebral 
column  by  folds  of  peritoneum  called  mesentery  ;  and  according  to  the 
length  of  these  folds  or  duplicatures  the  intestine  is  bound  down,  or 
floa,ts  in  the  abdominal  cavity.  Their  structure  is  nearly  alike  through- 
out: a  mucous  membrane  lines  them:  immediately  without  this  is  a 
muscular  coat;  and,  externally,  a  serous  coat,  formed  by  a  prolonga- 
tion of  the  peritoneum.  The  mucous  membrane  is  soft  and  velvety, 
and  is  the  seat  of  a  similar  secretion  to  that  of  other  membranes  of  the 
same  class.  The  muscular  coat  is  composed  of  two  planes  of  fibres,  so 
united  that  they  cannot  be  separated, — the  innermost  consisting  of 
circular,  and  the  outermost  of  longitudinal  fibres,  the  arrangement  of 
which  differs  in  the  small  and  large  intestines.  The  serous  or  peri- 
toneal coat  receives  the  intestine  between  two  of  its  laminse,  which, 
in  their  passage  to  it,  form  the  mesen- 
tery. The  serous  coat  only  comes  in 
direct  contact  with  the  intestine  at  the 
sides  and  forepart.  Behind,  or  on  the 
mesenteric  side,  is  a  vacant  space,  by 
which  the  vessels  and  nerves  reach  the 
intestine.  These  form  their  first  net- 
work between  the  serous  and  muscular 
coats ;  their  second,  between  the  muscu- 
lar and  mucous. 

Between  the  upper  four-fifths  of  the 
intestinal  canal,  and  the  lower  fifth, 
there  is  a  well-marked  distinction;  not 
only  as  regards  structure  and  magnitude, 
but  function.  This  has  given  occasion 
to  a  division  of  the  canal  into  small 

and    Tarne    ivif0<iti>nt>  •    anrl     rriA«P     jjo-ain      denum.  "6.  Opening  of  the  ductus  commu- 

ana  large  intestine,    ana  tnese,  again,   nis  choiedochus  into  the  duodenum. 
have   been   subdivided    in   the    various 

modes  that  will  fall  under  consideration.  As  the  small  intestine  fills 
so  large  a  portion  of  the  intestinal  canal,  its  convolutions  occupy  con- 
siderable space  in  the  abdominal  cavity, 
—  in  the  middle,  umbilical,  and  hypo- 
gastric  regions, — and  terminate — in  the 
right  iliac  region — in  the  large  intestine 
(see  Fig.  210).  Its  calibre  differs  in  dif- 
ferent parts;  but  it  may  be  regarded  on 
the  average  as  about  one  inch.  It  is 
usually  divided,  arbitrarily,  into  three 
parts; — duodenum,  jejunum,  and  ileum. 
The  duodenum  is  so  called,  in  consequence 
of  its  length  having  been  estimated  at 
about  twelve  fingers'  breadth.  It  is  larger 
than  the  rest  of  the  small  intestine; 
and  has  received,  also,  the  name  of 
second  stomach,  and  of  ventriculus  succen- 

turiatUS.       It    is    more    firmlv  fixed    to  the    Longitudinal    Section   of  the   Upper 
,      -,       .,          ,,          ,,          .  .,<  ,     .  Part  of  the  Jejunum  extended  under 

body  thaa  the  other  intestines ;  and  does      water. 
VOL.  I. — 34 


Portion  of  the  Stomach  and  Duodenum 
laid  open  to  show  their  interior. 

1,  1.  Right,  or  pyloric  extremity  of  sto- 
mach. 2,  2.  Folds  and  mucous  follicles  of 
mucous  coat  of  stomach.  3.  Points  into 
the  pylorus.  4.  Thickness  of  the  pylorus. 
5,  5.  Rugae  of  the  internal  coat  of  the  duo- 


Fig.  231. 


530 


DIGESTION. 


not,  like  them,  float  loosely  in  the  abdomen.  In  its  course  to  its  termi- 
nation in  the  jejunum,  it  describes  a  kind  of  Italic  <?,  the  concavity  of 
which  looks  to  the  left.  From  this  shape  it  has  been  separated  into 
three  portions ; — the  first  situate  horizontally  beneath  the  liver:  the 
second  descending  vertically  in  front  of  the  right  kidney;  and  the  third 
in  the  transverse  mesocolon.  Its  mucous  membrane  presents  a  number 
of  circular  folds  or  rugse,  very  near  each  other,  which  have  been  called  val- 

vulse  conniventes.  (Figs.  230  and  231.) 
By  some  anatomists,  however,  this  name 
is  not  given  to  the  irregular  rugse  of 
its  mucous  coat;  but  to  those  of  the 
lining  membrane  of  the  jejunum.  The 
valvulse  are  not  simple  rugse,  passively 
formed  by  the  contraction  of  the  mus- 
cular coat.  They  are  dependent  upon 
the  original  formation  of  the  mucous 
membrane;  and  are  not  effaced,  what- 
ever may  be  the  distension  of  the  in- 
testine. On  and  between  these  dupli- 
catures,  the  different  exhalant  and 
absorbent  vessels  are  situate,  forming, 

in  part,  the  villi  of  the  intestine,  which  are  from  a  quarter  of  a  line  to 
a  line  and  two-thirds  in  length.1  These  villi  give  to  the  membrane  a 
velvety  appearance,  and  are  not  simply  composed  of  exhalants  and 
absorbents,  but  of  nerves;  all  of  which  are  distributed  on  an  areolar 
and  perhaps  erectile  tissue.  In  its  healthy  state,  when  successfully- 
injected,  the  membrane  appears  to  consist  almost  entirely  of  a  cribri- 
form intertexture  of  veins.  It  was  formerly  believed,  that  the  villi 
are  not  supplied  with  bloodvessels.  In  each  villus,  however,  there  is 


Muscular  Coat  of  the  Ileum. 


m  different  parts  of  the  intestine. 


Fig.  233. 


Fig.  234. 


Distribution  of  Capillaries  in  the 
Villi  of  the  Intestine. 


Distribution  of  Capillaries  around 
Follicles  of  Mucous  Membrane. 


a  minute  vascular  plexus,  the  larger  branches  of  which,  when  distended 
with  blood,  may  be  seen  even  by  the  naked  eye.  Marginal  illustra- 
tion, Fig.  235,  exhibits  the  vessels  of  one  of  the  intestinal  villi  of  the 
hare,  from  Wagner,  after  an  extremely  beautiful  dry  preparation  by 
Dollinger,  magnified  about  45  diameters.  The  most  obvious  use  of 
these  villi  is  to  increase  the  surface  from  which  the  secretion  is  pre- 
pared, and  from  which  absorption  is  effected.  Within  the  membrane 

1  J.  Muller,  Elements  of  Physiology,  by  Baly,  2d  edit.,  p.  285,  Lond.,  1£40. 


DIGESTIVE  ORGANS — SMALL  INTESTINE. 


531 


Fig.  235. 


Fig.  236. 


are  numerous  follicles, 
which,  with  the  exhalants, 
secrete  a  mucous  fluid, 
called  by  Haller  succus 
intestinalis.  Their  entire 
number  in  the  whole  ali- 
mentary canal  is  estimated 
by  Dr.  Horner  to  be  46,- 
900,000.1  At  about  four 
or  five  fingers'  breadth 
from  the  pylorus,  the  duo- 
denum is  perforated  by 
the  termination  of  the 
biliary  and  pancreatic 
ducts,  which  pour  bile 
and* pancreatic  fluids  into 
it.  (Fig.  219.)  Generally, 
these  ducts  enter  the  in- 
testine by  one  opening; 
at  times,  they  are  distinct, 
and  lie  alongside  each  ^®'  Longitudinal  Section  of  the 

„,          o  „  Jejunum,     showing     the 

Other.       The    Structure    of   Bloodvessels  of  Villi   of  the       Villi   as    seen  under   the 

the  duodenum  is  the  same  Hare>  Microscope. 

flq     that     of    thp     whole     of       lj  1'  Veins  filled  With  Whlte        *>   *•   Terminal    orifices  of 

mi         Section.     2,  2.  Arteries  filled    the'villi.    2,2.  Internal  coats 

the  intestinal  Canal.       The    ^jJ^Ses  between^he  two6         of  the  intestine.  3.  Peritoneal 

muscular  coat  is,  however, 

thicker,  arid  the  peritoneal  coat  only  covers  its  first  portion,  passes 
before  the  second,  and  is  totally  wanting  in  the  third,  which  we  have 
described  as  included  in  the  transverse  mesocolon. 

The  other  two  portions  of  the  small  intestine  are  of  considerable 
length ;  the  jejunum  commencing  at  the  duodenum, 
and  the  ileum  terminating,  in  the  right  iliac  fossa,  in 
the  first  of  the  great  intestines — the  caecum.  They 
occupy  the  middle  and  almost  the  whole  of  the 
abdomen,  being  surrounded  by  the  great  intestine 
(Fig.  210).  The  jejunum  is  so  called  from  being  ge- 
nerally found  empty;  and  the  ileum  from  its  numerous 
windings.  The  line  of  demarcation,  however,  be- 
tween the  duodenum  and  jejunum,  as  well  as  between 
the  latter  and  the  ileum,  is  not  fixed  :  it  is  an  arbi- 
trary division.  The  jejunum  has,  internally,  the  One  of  the  Gianduiae 
greatest  number  of  valvulse  conniventes  and  villi.  SJLa?g?Ztestfnef 
The  ileum  is  the  lowest  portion.  It  is  of  a  paler  as  seen  from  above, 
colour,  and  has  fewer  valvulse  conniventes.  The  andalso 
jejunum  is  situate  at  the  upper  part  of  the  umbilical  region ;  the  ileum 
at  the  lower  part,  extending  as  far  as  the  hypogastric  and  iliac  regions. 
The  mucous  membrane  of  the  jejunum  and  ileum  resembles,  in  all 
essential  respects,  that  of  the  duodenum;  the  valvulge  conniventes  are, 


Fig.  237. 


1  Special  Anatomy  and  Histology,  7th  edit.,  ii.  55,  Philad.,  1846. 


532 


DIGESTION. 


Fi°  238 


however,  more  numerous  in  the  jejunum  than  in  the  duodenum  ;  and, 
in  the  course  of  the  ileum,  they  gradually  disappear,  and  are  replaced 
by  simple  longitudinal  rugae.  The  villi,  too,  which  are  chiefly  destined 
for  chylous  absorption,  abound  in  the  jejunum,  but  gradually  disappear 
in  the  ilerim.  The  mucous  membrane  of  both  is  largely  supplied  with 
follicles,  called  glands  of  Peyer,  Btfcmer,  and  Lieberkiihn  ;  some,  if 
not  all,  of  which  are  probably  -concerned  in  secreting  the  succus  enteri- 
cuSj  succus  intestinalis, — a  mucous  fluid,  to  which  in  digestion  Haller 
attached  unnecessary  importance.  M.  Lelut1  estimates  the  number  of 
these  glands  in  the  small  intestine  at  40,000.  Dr.  Horner  considers 
the  follicles  to  be  formed,  in  every  instance,  of  meshes  of  veins ;  the 
arteries  entering  inconsiderably  into  their  composition, — in  about  the 
same  proportion  as  they  do  in  other  erectile  tissues.2 

The  glands,  as  they  are  termed,  of  the  small  intestine  have  long  been 
known  under  the  name  of  follicles  of  Lieberkiihn.      These   become 
especially  evident  if  the  mucous  membrane  is1 'in- 
flamed, when  they  are  filled  with  an  opaque  whitish 
secretion,  which  is  absent  in  the  healthy  state.3 

The  true  glands  of  Brunn  or  Brunner  are 
chiefly  in  the  duodenum.  They  are  situate  in  the 
submucous  tissue,  where  they  form  a  continuous 
layer  of  white  bodies  surrounding  the  intestine. 
They  are  not  larger  than  a  hemp-seed ;  each  con- 
Hiied  with  tenacious  sisting  of  numerous  minute  lobules,  the  ducts  of 

ve!-lte  (Boehm1)  "*  Fe~  wn^c^  °Pen  ^nto  a  common  excretory  duct.     They 
are  complex   structures,  differing  from  the  other 
glands  and  follicles  of  the  intestines.     Nothing  is  positively  known  of 
the  nature  of  their  secretion. 

The  glands  of  Peyer  form  large  patches  on  the  mucous  membrane, 
when  they  are  called  glandule  agminatse  and 
Peyer 's  patches.  Examined  in  a  healthy  mucous 
membrane,  they  have  the  appearance  of  circular 
white,  slightly  raised  spots,  about  a  line  in  dia- 
meter, over  which  the  mucous  membrane  is  least 
studded  with  villi,  and  often  wholly  without  them. 
On  rupturing  one  of  the  white  bodies  a  cavity  is 
found,  but  it  has  no  excretory  duct.  It  contains 
100"  a  grayish-white  mucous  matter.  There  are  like- 
wise closed  solitary  glands  in  both  the  small  and 
large  intestines.4  The  precise  use  of  the  glands 
of  Peyer  is  unknown.  Wagner5  has  well  observed,  that  the  intimate 
structure  of  the  whole  of  these  glandular  bodies  requires  farther  study, 
and  is  almost  as  little  known  as  their  individual  functions.  There  is 
reason  to  believe,  however,  that  they  secrete  a  putrescent  matter  from  the 
blood,  which  may  be  concerned  in  giving  to  the  excrement  its  peculiar 
odour;  this  matter,  as  in  other  cases,  being  formed  by  cells,  which 

1  Gazette  Medicale,  Juin,  1832. 

2  Op.  cit.,  h.  54.  3  Boehm,  cited  in  Brit,  and  For.  Med.  Rev.,  i.  521,  Lond.,  1836. 
4  Baly,  Lond.  Med.  Gazette,  Mar.,  1847. 

*  Elements  of  Physiology,  translated  by  R.  Willis,  §  137,  Lond.,  1812. 


Fig.  239. 


times.    (Boehm.) 


DIGESTIVE  ORGANS — LARGE  INTESTINE. 

Fig.  240.  Fig.  241. 


533 


Portion  of  one  of  the  Patches  of  Peyer's  Glands    Section  of  Small  Intestine,  containing  some  of 


from  the  end  of  the  Ileum  :  highly  magnified. 
The  Villi  are  also  shown.     (Boehm.) 


the  Glands  of  Peyer,  as  shown  under  the 
microscope. 

These  glands  appear  to  be  small  lenticular  ex- 
cavations, containing,  according  to  Boehrn,  a 
white,  milky,  and  rather  thick  fluid,  with  nume- 
rous round  corpuscles  of  various  sizes,  but  mostly 
smaller  than  blood  globules.  The  meshes  seen  in 
the  cut  are  the  ordinary  tripe-like  folds  of  the 
mucous  coat. 


Fig.  242. 


burst  on  the  free  surface  of  the  mucous 
membrane,  and  discharge  their  contents 
to  be  mixed  with  the  faeces.  The  marginal 
figure,  after  Bendz,1  illustrates  the  mor- 
phology of  a  Peyer's  gland. 

The  muscular  coat  of  the  small  intestine 
is  composed  of  circular  and  longitudinal 
fibres ;  and  the  outer  coat  is  formed  by 
the  prolongation  of  the  peritoneum,  which, 
after  having  surrounded  the  intestines, 
completes  the  mesentery,  by  which  the 
gut  floats,  as  it  were,  in  the  abdominal 
cavity. 

The  large  intestine  terminates  the  intes- 
tinal canal.     It  is  much  shorter  than  the  side  View  of  Intestinal  Mucous  Mem- 
small,  and    Considerably    more    Capacious,          braneofaCat.     (After  Bendz.) 

being  manifestly  intended,  in  part,  as  a      «•  A  Peyer'sgiand,  imbedded  in  sub- 

*     .  .  J  '.         ."         '  .      mucous  tissue,/,     b.  A  tubular  follicle. 

reservoir.       It    IS    leSS  lOOSe  in  the  abdomi-    c.  Fossa  in  mucous  membrane,    d.  Villi. 

nal  cavity  than  the  portion  of  the  tube   «'  F 

which  we  have  described.     It  commences 

at  the  right  iliac  fossa  (Fig.  210,  9);  ascends  along  the  right  flank,  as 

far  as  the  under  surface  of  the  liver ;  crosses  over  the  abdomen  to  gain 

the  left  flank,  along  which  it  descends  into  the  left  iliac  region,  and 


1  Haandbog  i  den  Almindenige  Anatomic.  Kjobenhavn,  1847,  cited  by  Kirkes  and  Paget, 
Manual  of  Physiology,  Amer.  edit.,  p.  186,  Philad.,  1849. 


534  DIGESTION. 

thence  through  the  pelvis,  along  the  hollow  of  the  sacrum,  to  terminate 
at  the  anus.  Like  the  small  intestine  it  is  divided  into  three  portions ; 
the  caecum,  colon,  and  rectum. 

The  caecum  or  blind  gut  is  the  part  of  the  great  intestine  into  which 
the  ileum  opens.  It  is  about  four  fingers'  breadth  in  length,  and  nearly 
double  the  diameter  of  the  small  intestine.  It  occupies  the  right  iliac 
fossa,  in  which  it  is  bound  down,  so  as  not  to  be  able  to  change  its 
position.  The  extremity  of  the  ileum  joins  the  caecum,  at  an  angle; 
and  if  we  examine  the  interior  of  the  caecum,  at  the  point  of  junction, 
we  find  a  valvular  arrangement,  which  has  been  called  valve  of  Tulpius, 
valve  of  Bauhin,  ileo-csecal  valve,  &c.  Fig.  244  exhibits  the  nature  of 
this  arrangement.  At  the  point  of  union  of  the  two  intestines,  a  soft 
eminence  exists,  flattened  from  above  to  below,  and  elliptical  trans- 
versely, which  is  divided  into  two  lips.  One  of  these  seems  to  belong 
to  the  ileum  and  colon — hence  called  ileo-colic;  the  other  to  the  ileum 
and  caecum,  and  termed  ileo-csecal.  From  the  disposition  of  these  lips 
a  valve  results,  so  constituted,  that  the  lips,  which  form  it,  separate 
when  the  faecal  matters  pass  from  the  small  to  the  large  intestine; 
whilst  they  approximate,  cross,  and  completely  prevent  all  retrogression, 
when  the  faeces  tend  to  pass  from  the  great  intestine  to  the  small.  At 
the  extremities  of  the  valve  are  small  tendons,  which  give  it  strength, 
and  have  been  termed  frsena  or  retinacula  of  the  valve  of  Bauliin. 

Although  this  valvular  arrangement  prevents  the  ready  return  of' 
the  excrementitious  matter  into  the  small  intestine,  we  have  many 
pathological  opportunities  for  discovering  that  it  is  not  effectual  in  all 
cases.  In  stricture  of  the  large  intestine,  stercoraceous  vomiting  is  a 
frequent  phenomenon,  and  there  have  been  cases  of  substances,  thrown 
into  the  rectum,  having  been  evacuated  by  the  mouth. 

At  the  posterior  and  left  side  of  the  caecum,  a  small  process  detaches 
itself,  called,  from  its  resemblance  to  a  worm,  appendix  vermiformis; 
and,  from  its  connexion  with  the  caecum,  appendix  cseei.  It  is  convo- 
luted, variable  in  length,  and  attached,  by  its  sides,  to  the  caecum. 
Its  free  extremity  is  impervious;  the  other  opens  into  the  back  part  of 
the  caecum.  This  appendage  has  all  the  characters  of  an  intestine. 
Various  hypotheses  have  been  indulged  regarding  its  uses.  Some  have 
conceived  it  to  be  a  reservoir  for  the  faeces ;  but  its  diminutive  size,  in 
the  human  subject,  precludes  this  idea:  others  have  thought,  that  it 
secretes  a  ferment,  necessary  for  faecal  formation;  and  others,  again,  a 
mucus  for  preventing  the  induration,  that  might  result  from  the  deten- 
tion of  the  faeces  in  the  caecum.  The  opinion — that  it  is  a  mere  vestige 
of  the  useful  and  double  caeca,  which  exist  in  certain  animals — is  as 
philosophical  as  any.  M.  de  Blainville,1  indeed,  regards  it  as  the  true 
caecum;  and  what  is  named  the  caecum  as  the  commencement  of  the 
colon.  It  is  manifestly  of  little  importance,  as  it  has  been  found 
wanting  or  obliterated  in  many  subjects,  and  has  been  extirpated 
repeatedly  with  impunity.  The  caecum  is  said  to  be  wanting  in  all  ani- 
mals that  hybernate.  It  is  small  in  the  Carnivora;  very  large  and 
long  in  the  Solidungula,  Ruminantia  and  Rodentia;  in  which, — as  will 

1  De  1'Organisation  des  Animaux,  &c.,  Paris,  1825. 


DIGESTIVE  ORGANS — LARGE  INTESTINE. 


535 


be  seen  hereafter, — there  is  reason  to  believe,  that  digestion  of  the  ali- 
ment, which  has  escaped  change  higher  up,  occurs. 

The   colon  is   by  much  the  longest   of  the   large  intestines,  (Fig. 
210.)     It   is   a   continuation    of  the    caecum,  from  which   it   cannot 
be  distinguished;  but  is  con- 
sidered to  commence  at  the  Fi£-  243- 
termination     of     the     ileum. 
From  the  right  iliac  fossa  it 
ascends  along  the  right  lum- 
bar region,  over  the  kidney, 
to  which  it  is  connected.     It 
is,  in  this  part,   called  colon 
dextrum,  ascending  or   right 
lumbar  colon.     From  the  kid- 

nev    it    DaSSeS    forwards    and    Muscular  Coat  of  the  Colon,  as  seen  after  the  removal 
J  ,   ,  of  the  Peritoneum. 

crosses  the   abdomen  in   the 

.   .  ,          ,    .  1,1.  One  of  its  three  bands  of  longitudinal  muscular 

epigastric    and   hypochondriac    fibres.    2,  2.  Circular  fibres  of  the  muscular  coat. 

regions,   being    connected   to 

the  duodenum.  This  portion  is  called  great  arch  of  the  colon,  colon 
transversum.  The  right  portion  of  the  great  arch  is  situate  under  the 
liver  and  gall-bladder ;  and  hence  is  found  tinged  yellow  after  death, 
owing  to  the  transudation  of  bile.  The  left  portion  of  the  arch  is  situate 
under  the  stomach ;  and,  immediately  below  it,  are  the  convolutions  of 
the  jejunum.  In  the  left  hypochondre,  the  colon  turns  backward  under 
the  spleen,  and  descends  along  the  left  lumbar  region,  anterior  to  the 
kidney,  to  which  it  is  closely  connected.  This  portion  is  termed  colon 
sinistrum,  descending  or  left  lumbar 
colon.  In  the  left  iliac  region,  it  forms 
two  convolutions,  which  have  been  com- 
pared to  the  Greek  $,  or  to  the  Roman 
s;  and  hence  this  part  of  the  intestine 
has  been  designated  sigmoid  flexure, 
Roman  s,  or  iliac  turn  of  the  colon. 
This  flexure  varies  greatly  in  length 
in  different  persons,  extending  fre- 
quently into  the  hypogastric  region, 
and,  in  some  instances,  as  far  as  the 
caecum.  The  colon,  through  its  whole 
extent,  is  fixed  to  the  body  by  the 
mesocolon. 

The  coats  of  the  great  intestine  are 
the  same  in  number  and  structure  as 
those  of  the  small;  but  are  thinner, 
and  not  as  easily  separable  by  dissec-  Longitudinal  Section  of  the  End  of  the 

mi  J         "          .          J    .      ,  lleum,  and  of  the  Beginning  of  the  .Large 

tion.  Ihe  mucous  membrane  is  less 
villous  and  velvety.  The  most  cha- 
racteristic difference,  however,  in  their  ,  muscuiar  cuai,  COVB1CU  uy  ^ „„„.  „, 

general   appearance,   is   the   pouched  5-  Areoiar  and  mucous  coats,   e,  6  Folds  of 

r  4_  mucous  coat  at  this  end  of  the  colon.     /,  7. 

Or      Cellular      aspect      Of      the      former.    Prolongations  of  areolarcoaHnto  these  folds. 

These  pouches  are  reservoirs  for  excre- 


Intestine. 

1,1.  Portion  of  the  ascending  colon.    2,  2. 


Union  of  the 


536  DIGESTION. 

ment,  and  in  them  it  becomes  more  indurated,  by  the  absorption  of  the 
fluid  portions.  In  torpor  of  this  part  of  the  intestinal  canal,  the  faeces 
are  retained,  at  times,  so  long,  that  they  form  hard  balls  or  scybala; 
and  not  unfrequently  occasion  the  inflammation  of  the  lining  membrane 
of  the  large  intestine,  which  constitutes  dysentery.  The  longitudinal 
muscular  fibres  are  concentrated  into  three  ligamentous  bands  or  fasci- 
culi, which  run  the  whole  length  of  the  intestine.  These  being  shorter 
than  the  intestine,  pucker  it,  and  are  the  occasion  of  the  pouched  or 
saccated  arrangement.  The  inner  or  circular  muscular  fibres  are,  like 
those  of  the  small  intestine,  uniformly  spread  over  the  surface,  but  are 
stronger.  Lastly,  on  the  great  intestine,  especially  the  colon,  are 
numerous  processes  of  the  peritoneum  containing  fat,  and  hence  called 
appendiculse  epiplo'icse  and  appendiculse  pinguedinosse.  These  are  seen 
in  greatest  abundance  on  the  right  and  left  lumbar  portions  ot  the 
colon. 

The  rectum  terminates  the  intestinal  canal,  and  extends  from  the  end 
of  the  colon  to  the  anus.  It  commences  about  the  fifth  lumbar  vertebra, 
and  descends  vertically  into  the  pelvis,  following  the  concavities  of  the 
sacrum  and  coccyx;  and,  consequently,  is  not  straight,  as  its  name 
would  import.  At  its  upper  part,  there  are  a  few  appendiculse  epiploicae ; 
and  a  small  duplicature  of  the  mesentery,  called  mesorectum,  attaches 
it  to  the  sacrum.  It  differs  from  the  other  intestines  in  becoming  wider 
in  its  progress  downwards,  and  in  its  parietes  being  thicker.  The  lower 
part  of  the  mucous  membrane  exhibits  several  longitudinal  folds  or 
rugae,  called  "columns,"  which  have  been  considered  as  the  effect  of  the 
contraction  of  the  circular  fibres  of  the  muscular  coat.  At  the  lower 
ends  of  the  wrinkles  between  the  columns  are  small  pouches,  from  two 
to  four  lines  in  depth,  the  orifices  of  which  point  upwards.  They  are 
occasionally  the  seat  of  disease,  and,  when  enlarged,  give  rise  to  painful 
itching.  The  nature  of  this  affection  was  first  pointed  out  by  Dr. 
Bhysick,  and  the  remedy  consists  in  slitting  them  open.  The  longi- 
tudinal fibres  of  the  muscular  coat  have  a  different  arrangement  from 
that  which  exists  in  the  other  portions  of  the  large  intestine.  They 
are  distributed  over  the  whole  surface,  as  in  the  small  intestine, — or 
rather,  as  in  the  oesophagus.  At  the  anus,  an  arrangement  of  the 
muscular  coat  prevails,  which  has  been  pointed  out  by  Professor  Homer.1 
The  longitudinal  fibres,  having  reached  the  lower  margin  of  the  internal 
sphincter,  turn  under  this  margin  between  it  and  the  external  sphincter, 
and  then  ascend  upwards  for  an  inch  or  two  in  contact  with  the  mucous 
coat,  into  which  they  are  finally  inserted  by  fasciculi,  which  form  the 
base  of  the  columns  of  the  rectum :  many  of  the  fibres,  however,  termi- 
nate also  between  the  fasciculi  of  the  circular  fibres.  The  circular  fibres 
are  more  and  more  marked,  as  they  approach  the  outlet,  and,  by  cir- 
cumscribing the  margin  of  the  anus,  they  form  the  sphincter  ani  muscle. 
Immediately  within  the  anus  is  the  widest  portion  of  the  rectum ;  and, 
in  this,  accumulations  of  indurated  faeces  sometimes  take  place  in  old 
people  to  a  surprising  extent,  owing  to  torpor  of  the  muscular  powers 
concerned  in  the  expulsion  of  the  faeces.  The  mucous  coat  of  the  rectum 
is  thick  and  red,  and  abounds  in  follicles. 

1  General  Anatomy  and  Histology,  7th  edit.,  ii.  50,  Philada.,  1846. 


DIGESTIVE  ORGANS. 


537 


Fig.  245. 


Lastly;  there  are  a  few  muscles,  which  are  concerned  in  the  act  of 
expelling  the  faeces.  These  require  a  short  notice.  1.  The  sphincter 
ani,  coccygeo-anal  muscle,  which  keeps  the  anus  constantly  closed,  ex- 
cept during  defecation.  2.  The  levator  ani,  subpubio-coccygeus,  which, 
with  the  next  muscle,  constitutes  the  floor  of  the  pelvic  and  abdominal 
cavities.  It  restores  the  anus  to  its  place,  when  pushed  outwards  during 
defecation.  3.  The  coccygeus,  ischio-coccygeus,  which  assists  the  leva- 
tor  ani  in  supporting  or  raising  the  lower  extremity  of  the  rectum;  and 
4.  The  transversus  perinei,  ischio-perineal  muscle,  some  fibres  of  which 
unite  both  with  the  bulbo-cavernosi  and  with  the  sphincter  ani  muscles; 
and,  consequently,  it  is  associated  slightly  with  the  action  of  both  one 
and  the  other. 

In  regard  to  the  intestinal  canal,  we  find,  that  man  holds  a  medium 
place  between  the  carnivorous  and  herbivorous  animal,  although  approxi- 
mating more  to  the  latter.  In 
the  carnivorous-  —  for  reasons 
more  than  once  mentioned  —  it 
is  unnecessary  that  the  food 
should  remain  long;  accord- 
ingly, the  canal  is  very  short. 
In  the  herbivora,  on  the  other 
hand,  and  for  opposite  reasons, 
the  canal  is  long,  and  there  is 
generally  a  large  caecum  and  a 
pouched  colon.  Cuvier1  has 
given  tables  of  the  length  of 
the  digestive  tube,  compared 
with  that  of  the  body;  but 
where  the  comparison  has  been 
applied  to  man,  the  length  of 
the  body  has  included  that  of 
the  legs.  Instead,  therefore, 
of  the  canal,  in  him,  being  con- 
sidered to  bear  the  proportion 
of  six  to  one,  it  ought  to  be 
doubled,  or  be  regarded  as 
twelve  to  one;  a  proportion 
somewhat  greater  than  prevails 
in  the  simise  or  ape  tribe.  It  is 
not,  however,  always  in  length, 

that  the  Canal  of  the  herbivor-    View  of  External  Parietes  of  Abdomen,  with  the  po- 
OUS    exceeds  that  of  the   Omni-      sition  of  the  Lines  drawn  to  mark  off  its  Regions. 

VOrOUS  animal  ;  but  aS  a  general        *»  l-  Line  dfawn  from  the  highest  point  of  one  ilium 

-•  ,          «?  ii         •         to  the  same  point  of  the  opposite  one.    2,2.  Line  drawn 

rule,  It  may  DC  amrmed,  that  itS    from  the  anterior  superior  spinous  process  to  the  carti- 

capacity  is  much  more  consi- 


5.     Ihe     abdomen*    in    Which    chondriac  regions. 
,1  i      v          ..  region 

the  principal    digestive    Organs 

are  situate,  and  whose  parietes 

1  Leyons  d'Anatomie  Comparee,  Paris,  1799. 


touching  the  most  prominent  part  of  the  costal  cartilages, 
thus  forming  nine  regions.    5,  5.  Right  and  left  hypo- 
c  regions.    6.  Epigastric  region.     7.  Umbilical 
8,  8.  Right  and  left  lumbar  regions.    9.  Hypo- 
astric  region.     10,  10.  Right  and  left  iliac  regions.     11. 

part  °f  the  hypogastric'  sc 


538  DIGESTION. 

exert  considerable  influence  on  the  digestive  function,  requires  a  brief 
description.  It  is  the  division  of  the  body,  which  is  betwixt  the  thorax 
and  pelvis;  is  bounded,  above,  by  the  arch  of  the  diaphragm;  behind, 
by  the  vertebral  column ;  laterally,  and  anteriorly,  by  the  abdominal 
muscles;  and,  below,  by  the  ossa  ilii,  os  pubis,  and  the  cavity  of  the 
pelvis. 

To  connect  the  knowledge  of  the  internal  parts  of  the  abdomen  with 
the  external,  it  is  customary  to  mark  certain  arbitrary  divisions  on  the  sur- 
face, called  regions.  (Fig.  245.)  The  epigastric  region  is  at  the  upper 
portion  of  the  abdomen,  under  the  point  of  the  sternum,  and  in  the  angle 
formed  by  the  cartilages  of  the  ribs.  The  hypochondriac  regions  are 
covered  by  the  cartilages  of  the  ribs.  These  three  regions — the  epigas- 
tric, and  right  and  left  hypochondre — constitute  the  upper  division  of  the 
abdomen,  in  which  are  seated  the  stomach,  liver,  spleen,  pancreas,  duo- 
denum, and  part  of  the  arch  of  the  colon.  The  space  surrounding  the 
umbilicus,  between  the  epigastric  region  and  a  line  drawn  from  the  crest 
of  one  os  ilii  to  the  other,  is  the  umbilical  region.  Here  the  small  intes- 
tines are  chiefly  situate.  This  region  is  bounded  by  lines,  raised  per- 
pendicularly to  the  spine  of  the  ilium;  and  the  lateral  portions  on  the 
outside  of  these  lines,  form  the  iliac  regions,  behind  which,  again,  are 
the  lumbar  regions  or  loins.  In  these,  the  colon  and  kidneys  are  chiefly 
situate.  The  hypogastric  is,  likewise,  divided  into  three  regions, — the 
pubic  in  the  middle,  in  which  is  the  bladder;  and  an  inguinal  on  each 
side. 

The  muscles  that  constitute  the  abdominal  parietes,  are, — first  of  all, 
above,  the  diaphragm,  which  is  the  boundary  between  the  thorax  and 
abdomen,  convex  towards  the  chest,  and  considerably  concave  towards 
the  abdominal  cavity.  Below,  if  we  add  the  pelvic  cavity, — which,  as 
it  contains  the  rectum,  and  muscles  concerned  in  the  evacuation  of  the 
faeces,  it  may  be  proper  to  do, — the  cavity  is  bounded  by  the  perineum, 
formed  chiefly  of  the  levatores  ani  and  coccygei  muscles.  Behind,  la- 
terally, and  anteriorly,  from  the  lumbar  vertebrae  round  to  the  umbilicus, 
the  parietes  consist  of  planes  of  muscles,  and  aponeuroses  in  super- 
position, united  at  the  median  line,  by  a  solid,  aponeurotic  band,  extend- 
ing from  the  cartilago-ensiformis  of  the  sternum  to  the  pubes,  called 
tinea  alba.  The  abdominal  muscles,  properly  so  called,  are, — reckoning 
the  planes  from  within  to  without, — the  greater  oblique  muscle,  lesser 
oblique,  and  transversalis,  which  are  situate  chiefly  at  the  sides  of  the 
abdomen; — and  the  rectus  and  pyramidalis,  which  occupy  the  anterior 
part.  The  greater  oblique,  obliquus  externus,  costo-abdominalis  ;  lesser 
oblique,  obliquus  internus,  ilio-abdominalis,  and  transversalis,  transver- 
sus  abdominis,  lumbo-abdominalis,  support  and  compress  the  abdominal 
viscera ;  assist  in  the  evacuation  of  the  faeces  and  urine,  and  in  the 
expulsion  of  the  foetus;  besides  other  uses,  connected  with  respiration 
and  the  attitudes.  The  rectus,  pubio-sternalis  or  sterno-pubialis ;  and 
the  pyramidalis  or  pubio-subumbilicalis,  are  more  limited  in  their  action, 
and  compress  the  forepart  of  the  abdomen;  besides  having  other 
functions. 

Lastly,  a  serous  membrane — the  peritoneum — lines  the  abdomen,  and 
gives  a  coat  to  most  of  the  viscera.  The  mode,  in  which  its  various 


DIGESTIVE  ORGANS — PERITONEUM. 


539 


reflections  are  made,  is  singular,  but  easily  intelligible  from  the  accom- 
panying figure  (Fig.  246).    It  has  neither  beginning  nor  end,  constitut- 

Fig.  246. 


1.  Section  of  the  spinal  column  and  canal. 
2.  Section  of  the  sacrum.  3.  Section  of  the 
sternum,  &c.  4.  Umbilicus.  5.  A  section 
of  the  linea  alba  and  abdominal  muscles. 
6.  Mons  veneris.  7.  Section  of  the  pubis. 

8.  Penis  divided  at  the  corpora  cavernosa. 

9.  Section  of   the  scrotum.     10.    Superior 
right  half  of  the  diaphragm.     11.  Section 
of  the   liver.     12.  Section  of  the   stomach, 
showing   its  cavity.      13.    Section    of    the 
transverse  colon.     14.  Section  of  the  pan- 
creas.    15.  Section  of  the  bladder,  deprived 
of  the  peritoneum.     16.  Rectum  cut  off,  tied 
and  turned  back  on  the  promontory  of  the 
sacrum.     17.    Peritoneum  covering   the  an- 
terior parietes  of  the  abdomen.     18.  Peri- 
toneum  on  the*  inferior  under   side  of  the 
diaphragm.     19.  Peritoneum  on  the  convex 
side  of   the  diaphragm.     20.  Reflection   of 
peritoneum  from  diaphragm   to  liver.    21. 
Peritoneum    on    front   of  liver.      22.    The' 
same,   on   its  under   surface.    23.   Hepato- 
gastric   omentum.    24.  A   large  pin  passed 
through   the  foramen  of  Winslow  into  the 
cavity  behind  the  omentum.    25.  Anterior 
face  of  the  hepato-gastric  omentum,  pass- 
ing in  front  of  the  stomach.    26.  The  same 
membrane  leaving  the  stomach  to  make  the 
anterior  of   the  four  layers   of    the    great 
omentum.      27,  28.  Junction    of    the    peri- 
toneum from  the  front  and  back  part  of  the 
stomach,  as  they  turn  to  go  up  to  the  colon. 
29.  Gastro-colic,  or  greater  omentum.    30. 
Separation  of  its  layers,  so  as  to  cover  the 
colon.    31.  Posterior  layer  passing  over  the 
jejunum.    32.  Peritoneum  in  front   of    the 
right  kidney.    33.  Jejunum  cut  off  and  tied. 
34,  34.   Mesentery  cut  off   from  the   small 
intestines.    35.   Peritoneum  reflected  from 
the  posterior  paries   of  the  bladder   to  the 
anterior  of  the  rectum.    36.  Cul-de-sac  be- 
tween the  bladder  and  the  rectum. 


Reflections  of  the  Peritoneum,  as  shown  in  a  Verti 
cal  Section  of  the  Body. 


ing,  like  all  serous  membranes,  a  shut  sac ;  and,  in  reality,  having  no 
viscus  within  it.  If  we  assume  the  diaphragm  as  the  part  at  which  it 
commences,  we  find  it  continued  from  the  surface  of  that  muscle  over 
the  abdominal  muscles,  5 ;  then  reflected,  as  exhibited  by  the  curved 
line,  over  the  bladder,  15 ;  and,  in  the  female,  over  the  uterus  ;  thence 
over  the  rectum,  16 ;  the  kidney,  enveloping  the  intestine,  13,  and 
constituting,  by  its  two  laminae,  the  mesentery,  34 ;  giving  a  coat  to 
the  liver,  11  ;  and  receiving  the  stomach,  12,  between  its  duplicatures. 
The  use  of  this  membrane  is  to  fix  and  support  the  different  viscera ;  to 
constitute,  for  each,  a  pedicle,  along  which  the  vessels  and  nerves  may 
reach  the  intestine  ;  and  to  secrete  a  fluid,  which  enables  them  to  move 
readily  upon  each  other.  When  we  speak  of  the  cavity  of  the  perito- 
neum, we  mean  the  inside  of  the  sac  ;  and  when  it  is  distended  with 
fluid,  as  in  ascites,  the  fluid  is  contained  between  the  peritoneum  lining 
the  abdominal  muscles,  and  that  which  forms  the  outer  coat  of  the  intes- 
tines. The  omenta  or  epiploa  are  fatty  membranes,  which  hang  over 
the  face  of  the  bowels ;  and  are  reflections,  formed  by  the  peritoneum 
after  it  has  covered  the  stomach  and  intestines.  Their  names  sufficiently 
indicate  their  position  : — the  lesser  epiploon  or  omentum, — the  omentum 


540  DIGESTION. 

hepato-gastricum;  the  greater  or  g astro-colic;  and  the  appendices  or 
appendiculse  epiploicse;  which  last  have  already  been  referred  to,  and 
may  be  regarded  as  so  many  small  epiploons. 

The  abdomen  is  entirely  filled  by  the  contained  viscera.  There  are 
several  apertures  in  it ;  three,  above,  in  the  diaphragm,  for  the  passage 
of  the  oesophagus,  vena  cava  inferior,  and  aorta ;  one  anteriorly  in  the 
course  of  the  linea  alba,  which  is  closed  after  birth, — the  umbilicus; 
and  two  anteriorly  and  inferiorly  ;  the  one — the  abdominal,  inguinal; 
or  supra-pubian  ring — which  gives  passage  to  the  vessels,  nerves,  &c., 
of  the  testicle ;  and  the  other — the  crural  arch — through  which  the 
vessels  and  nerves  pass  to  the  lower  extremity.  Lastly,  two  others 
exist  in  the  inferior  paries,  for  the  passage  of  the  obturator  vessels  and 
nerves,  and  sciatic  vessels  and  nerves,  respectively. 

Such  is  a  brief  view  of  the  various  organs  concerned  in  digestion. 
To  this  might  have  been  added  the  general  anatomy  of  the  liver  and 
pancreas, — each  of  which  furnishes  a  fluid,  that  is  a  material  agent  in 
the  digestive  process, — and  of  the  spleen,  which  has  been  looked  upon 
by  many  as  inservient,  in  some  manner,  to  the  same  function.  As,  how- 
ever, the  physiology  of  these  organs  will  be  considered  in  another  place, 
we  defer  their  anatomy  for  the  present. 

2.  FOOD  OF  MAN. 

The  articles,  inservient  to  the  nourishment  of  man,  have  usually  been 
considered  to  belong  entirely  to  the  animal  and  vegetable  kingdoms ; 
but  there  seems  to  be  no  sufficient  reason  for  excluding  those  articles  of 
the  mineral  kingdom  that  are  necessary  for  the  due  constitution  of  the 
different  parts  of  the  body.  Generally,  the  term  food  or  aliment  is 
applied  to  substances,  which,  when  received  into  the  digestive  organs, 
are  capable  of  being  converted  into  chyle ;  but,  from  this  class  again, 
the  products  of  the  mineral  kingdom — chloride  of  sodium,  phosphorus, 
sulphur,  and  lime,  either  in  combination  or  separately — cannot,  with 
entire  propriety ,  be  excluded.  There  are  numerous  tribes  who  feed  at 
particular  seasons  more  especially  on  mineral  substances.  Kessler 
affirms,  that  the  quarriers  on  the  Kyffhauser,  in  northern  Thuringia, 
spread  a  Steinbutter — "rock  butter,"  on  bread,  which  they  eat  with 
appetite;  and  Humboldt  relates,  among  many  other  instances,  that  of 
the  Ottomacs,  who,  during  the  periodical  rise  of  the  Orinoco  and  Meta, 
when  the  taking  of  fish  ceases — a  period  of  two  or  three  months'  dura- 
tion— swallow  great  quantities  of  earth.  They  found  piles  of  clayballs 
in  pyramidal  heaps  in  the  huts,  and  Humboldt  was  informed,  that  an 
Ottomac  would  eat  from  three-quarters  of  a  pound  to  a  pound  and  a 
quarter  in  a  day.  Some  of  this  earth  was  analyzed  by  M.  Vauquelin, 
and  found  to  contain  no  organic  matter.  It  would  appear,  that 
the  practice  of  eating  earth  exists  in  many  parts  of  the  torrid  zone, 
among  indolent  nations,  who  inhabit  the  finest  and  most  fertile  regions 
of  the  globe.  But  it  is  not  confined  to  them;  for  the  same  writer 
affirms,  that  in  the  north,  by  information  communicated  by  Berzelius 
and  Retzius,  hundreds  of  cartloads  of  earth  containing  infusoria  are 
annually  consumed  by  the  country  people  in  the  most  remote  parts  of 


FOOD  OF  MAN.  541 

Sweden  as  bread  meal,  and  even  more  as  a  luxury — like  tobacco — than 
as  a  necessary.  In  Finland,  the  earth  is  occasionally  mixed  with  the 
bread.  It  consists  of  empty  shells  of  animalcules,  so  small  and  soft  as 
not  to  cranch  perceptibly  between  the  teeth,  filling  the  stomach,  but 
affording  no  real  nutriment.  Many  similar  cases  are  recorded  by  Hum- 
boldt.1 

Animals  are  often  characterized  by  the  kind  of  food  on  which  they 
subsist.  The  carnivorous  feed  on  flesh ;  the  piscivorous  on  fish ;  the 
insectivorous  on  insects  ;  the phytivorous  on  vegetables ;  the  granivorous 
on  seeds  ;  ihefrugivorous  on  fruits  ;  the  graminivorous  and  herbivorous 
on  grasses  ;  and  the  omnivorous  on  the  products  of  both  the  animal  and 
vegetable  kingdoms.  In  antiquity,  we  find  whole  tribes  designated 
according  to  the  aliment  they  chiefly  used.  Thus,  there  were  the  Ethio- 
pian and  Asiatic  ichthyophagi  or  fish-eaters ;  the  hylophagi,  who  fed  on 
the  young  shoots  of  trees ;  the  elephantophagi,  and  struthiophagi,  ele- 
phant and  ostrich-eaters,  &c.  &c. 

We  have  already  shown,  that  the  digestive  apparatus  of  man  is  inter- 
mediate between  that  of  the  carnivorous  and  the  herbivorous  animal; 
that  it  partakes  of  both,  and  that  man  may,  consequently,  be  regarded 
omnivorous  ;  that  is,  capable  of  subsisting  on  both  the  products  of  the 
animal  and  the  vegetable  kingdom ; — an  important  capability,  seeing,  that 
he  is  destined  to  live  in  arctic  regions,  in  which  vegetable  food  is  not  to 
be  met  with,  as  well  as  in  the  torrid  zone,  which  is  more  favorable  for 
vegetable  than  animal  life. 

The  nature  of  the  country  must,  to  a  great  extent,  regulate  the  food 
of  its  inhabitants  ;  for  although  commerce  can  furnish  articles  of  luxury, 
and  many,  which  are  looked  upon  as  necessaries,  no  nation  is  entirely 
indebted  to  it  for  its  supplies.  Besides,  numerous  extensive  tribes  of 
the  human  family  are  denied  the  advantages  of  commerce,  and  com- 
pelled to  subsist  on  their  own  resources.  This  is  the  main  cause  why 
the  Esquimaux,  Samoiedes,  &c.,  live  wholly  on  animal  food ;  and  why 
the  cocoa-nut,  plantain,  banana,  sago,  yam,  cassava,  maize  and  millet, 
form  chief  articles  of  diet  with  the  natives  of  torrid  regions. 

In  certain  countries,  the  scanty  supply  of  the  useful  and  edible  ani- 
mals has  given  occasion  to  certain  prohibitory  dietetic  rules  and  regula- 
tions, which  have  been  made  to  form  part  of  the  religious  creed,  and,  of 
course,  are  most  scrupulously  observed.  Thus,  in  Hindoostan,  animal 
food  is  not  permitted  to  be  eaten;  but  the  milk  of  the  cow  is  excepted. 
Accordingly,  to  insure  the  necessary  supply  of  this  fluid,  the  cow  is 
made  sacred ;  and  its  destruction  a  crime  against  religion.  Amongst 
the  laws  of  the  Egyptians  are  similar  edicts,  but  they  seem  to  have 
been  chiefly  enacted  for  political  purposes,  and  not  in  consequence  of 
the  unwholesome  character  of  the  interdicted  articles.  The  same 
remark  applies  to  many  of  the  dietetic  rules  of  Moses,  for  the  regula- 
tion of  the  tables  of  the  Hebrews.  Blood  was  forbidden,  in  consequence, 
probably,  of  the  fear  entertained,  that  it  might  render  the  people  too 
familiar  with  that  fluid,  and  diminish  the  horror  inculcated  against 

1  Ansichten  der  Natnr;  translated  under  the  title  of  Aspects  of  Nature,  by  Mrs.  Sabine, 
Amer.  edit.,  p.  159,  Philad.,  1849. 


542  DIGESTION. 

shedding  it :  the  parts  of  generation  were  excluded  from  the  table, 
because  the  taste,  if  indulged,  might  interfere  with  the  reproduction  of 
the  species,  &c.  &c. 

We  have  said,  that,  in  his  arrangement  of  the  digestive  organs,  man  is 
intermediate  between  the  carnivorous  and  the  herbivorous  animal.  Not 
the  slightest  ground  is  afforded  by  anatomy  for  the  opinion  of  Rousseau, 
that  man  was  originally  herbivorous;  or  for  that  of  Helvetius,1  that  he 
was  exclusively  carnivorous.  Broussonet  affirms,  that  he  is  more  herb- 
ivorous than  carnivorous,  since,  of  his  thirty-two  teeth,  twenty  resem- 
ble those  of  the  herbivorous,  whilst  twelve  only  resemble  those  of  the 
carnivorous  animal.  Accordingly,  he  infers,  that,  in  the  origin  of 
society,  the  diet  of  man  must  have  been  exclusively  vegetable.  Mr. 
Lawrence,2  too,  concludes,  that,  whether  we  consider  the  teeth  and 
jaws,  or  the  immediate  instruments  of  digestion,  the  human  structure 
closely  resembles  that  of  the  simige — the  great  archetypes,  according  to 
Lord  Monboddo3  and  Rousseau,  of  the  human  race, — all  of  which  are, 
in  their  natural  state,  herbivorous. 

Again: — a  wide  discrepancy  between  man  and  animals  is  observed  in 
the  variety  of  their  aliments.  Whilst  the  latter  are  generally  restricted 
to  either  the  animal  or  vegetable  kingdom,  and  to  but  a  small  part  of 
either,  man  embraces  an  extensive  range,  and  by  means  of  his  culinary 
inventions  can  convert  a  variety  of  articles  from  both  kingdoms  into 
materials  of  sustenance.  But  it  has  been  argued  by  those,  who  are 
sticklers  for  the  natural,  that  man  probably  confined  himself,  primi- 
tively, like  animals,  to  one  kind  of  food;  that  he  adhered  to  this  whilst 
he  remained  in  his  natural  state,  and  that  his  omnivorous  practices  are 
a  proof  of  his  degeneracy.  Independently,  however,  of  all  arguments 
deduced  from  organization,  experience  sufficiently  shows  the  inaccuracy 
of  such  assertions.  If  we  trace  back  nations  to  their  state  of  infancy, 
we  find,  that  then,  as  in  their  more  advanced  condition,  their  diet  was 
animal,  or  vegetable,  or  both,  according  to  circumstances.  Of  this  fact 
we  have  some  signal  examples  in  a  part  of  the  globe  where  the  lights 
of  civilization  have  penetrated  to  a  less  extent  than  in  most  others ; 
and  where  the  influence  of  circumstances  that  prevailed  in  ancient 
periods  has  continued,  almost  unmodified,  until  the  present  time.  Aga- 
tharchides4  describes  the  rude  tribes,  who  lived  on  the  coast  of  the  Red 
Sea,  and  subsisted  on  fish,  under  the  name  ichthyophagi.  Along  both 
banks  of  the  Astaboras,  which  flows  on  one  side  of  Meroe,  dwelt 
another  nation,  who  lived  on  roots  of  reeds  growing  in  the  neighbour- 
ing swamps.  These  roots  they  cut  to  pieces  with  stones,  formed  them 
into  a  tenacious  mass,  and  dried  them  in  the  sun.  Close  to  them  were  the 
hylophagi,  who  lived  on  the  fruits  of  trees,  vegetables  growing  in  the 
valleys,  &c.  To  the  west  of  these  were  hunting  nations,  who  fed  on 
wild  animals,  which  they  killed  with  the  arrow.  There  were,  also,  other 
tribes,  who  lived  on  the  flesh  of  the  elephant  and  ostrich, — elephanto- 

1  De  1'Homme,  ii.  23,  Londres,  1775. 

a  Lectures  on  Physiology,  Zoology,  &c.,  p.  221,Lond.,  1819. 

3  On  the  Origin  and  Progress  of  Language,  Pt.  i.  Book  2,  Chap.  2,  Edinb.,  1773. 

4  De  RubroMare,  in  Hudson's  Geograph.  Minor.,  i.  37. 


FOOD  OF  MAN.  543 

phagi  and  struthiophagi.  Besides  these,  lie  mentions  another  and  less 
populous  tribe,  who  fed  on  locusts,  which  came  in  swarms  from  'the 
southern  and  unknown  districts.  The  mode  of  life,  with  the  tribes 
described  by  Agatharchides,  does  not  seem  to  have  varied  for  the  last 
two  thousand  years.  Although  cultivated  nations  are  situated  around 
them,  they  have  made  no  progress  themselves.  Hylophagi  are  still  to 
be  met  with.  The  Dobenahs,  the  most  powerful  tribe  amongst  the 
Shangallas,  still  live  on  the  elephant;  and,  farther  to  the  west,  dwells  a 
tribe,  which  subsists  in  the  summer  on  the  locust ;  and,  at  other  seasons, 
on  the  crocodile,  hippopotamus,  and  fish.1 

In  the  infancy  of  society,  as  in  his  own  infancy,  man  was  perhaps 
almost  wholly  carnivorous;  as  the  tribes  least  advanced  in  civilization 
are  at  the  present  day.  For  a  time,  he  may,  in  most  situations,  have 
confined  himself  to  the  vegetable  banquet  prepared  for  him  by  his  boun- 
teous Maker ;  but,  as  population  increased,  the  means  of  subsistence 
would  become  too  scattered  for  him,  and  it  would  be  necessary  to  crowd 
together  a  number  of  nutritious  vegetables  into  a  small  space,  and  to 
cultivate  the  earth,  so  as  to  multiply  its  produce ;  but  this  would  imply 
the  existence  of  settled  habits  and  institutions  which  could  only  arise 
after  society  had  made  progress.  Probably,  much  before  this  ^period, 
it  would  have  been  discovered,  that  certain  of  the  beasts  of  the  forest, 
and  of  the  birds  of  the  air,  and  some  of  the  insect  tribes,  could  minister 
to  his  wants,  and  form  agreeable  and  nutritious  articles  of  diet;  and 
thus  would  arise  their  adoption  as  food.  On  the  coasts  of  the  ocean, 
animal  food  was  perhaps  employed  from  the  period  of  their  first  settle- 
ment; as  well  as  on  the  banks  of  the  large  streams  which  are  so  com- 
mon in  Asia, — the  cradle  of  mankind.  The  fish,  left  upon  the  land 
after  the  periodical  inundations  of  the  rivers,  or  thrown  on  the  sea- 
coast,  would  minister  to  their  necessities,  without  the  slightest  effort  on 
their  part;  and,  hence,  they  would  have  but  little  incentive  to  mental 
or  corporeal  exertion.  This  is  the  cause  of  the  abject  condition  of  the 
ichthyophagous  tribes  of  old;  and  of  their  comparatively  low  state  of 
civilization  at  the  present  day.2  Again: — savages,  in  various  parts  of 
the  globe,  live  by  the  chase  or  the  fishery;  and  must,  consequently,  be 
regarded  as  essentially  carnivorous.  It  would  not,  however,  be  justifi- 
able, to  regard  barbarism  as  the  natural  state  of  man ;  nor  is  it  clear 
what  the  different  writers  on  this  point  of  anthropology  have  meant  by 
the  term.  The  Author  of  nature  has  invested  him  with  certain  prero- 
gatives, one  of  which  is  the  capability  of  rendering  the  organized  king- 
dom subservient  to  his  wishes  and  necessities;  and,  by  the  invention  of 
the  culinary  art,  of  converting  various  organized  bodies  into  wholesome 
and  agreeable  articles  of  diet,  which  thus  become  as  natural  to  him  as 
the  restriction  to  one  species  of  aliment  is  to  the  animal. 

It  has  been  remarked,  that  the  exclusive  or  predominant  use  of  ani- 
mal or  of  vegetable  food  has  a  manifest  effect  upon  the  physical  and 
moral  powers.  Buffon  affirms,  that  if  man  were  obliged  to  abstain 
from  flesh  in  our  climates,  he  could  not  exist,  nor  propagate  his  kind. 

1  Bruce,  Travels,  3d  edit.,  v.  83. 

a  The  Author,  in  Amer.  Med.  Intelligencer,  i.  99,  Philad.,  1838. 


544  DIGESTION. 

Others,  again,  have  depicted  a  state  of  ideal  innocence,  in  the  infancy 
of  society,  when  he  lived,  as  they  conceive,  entirely  on  vegetables ; 

"  His  food  the  fruits ;  his  drink  the  crystal  well ;" 

unsolicitous  for  the  future  in  consequence  of  the  abundant  subsistence 
spread  before  him ;  independent ;  and  always  at  peace  with  his  fellows, 
and  with  animals ;  but  he  gradually  sacrificed  his  liberty  to  the  bonds 
of  society;  and  cruelty,  with  an  insatiable  appetite  for  flesh  and  blood, 
were  the  first  fruits  of  a  depraved  nature.  Either  immediately  or 
remotely,  all  the  physical  and  moral  evil,  by  which  mankind  are 
afflicted,  arose  from  these  carnivorous  practices.  "The  principal 
patrons  of  this  twaddle,  in  modern  times" — says  Dr.  Fletcher — "to 
say  nothing  of  Pythagoras  and  the  ancients — have  been  Gassendi, 
Rousseau,  Wallis,  Lamb,  and  Newton;  the  last  of  whom,  in  the 
plenitude  of  his  infatuation,  asserts  that  real  men  have  never  yet  been 
seen,  nor  ever  will  be,  till  they  shall  be  content  to  subsist  entirely  on 
herbs  and  fruits  and  distilled  water."1  In  point  of  fact,  we  find,  that 
the  inhabitants  of  countries,  in  which  mankind  are  accustomed  to  be 
omnivorous,  or  to  unite  animal  with  vegetable  diet,  are  those  most  dis- 
tinguished for  both  mental  and  corporeal  endowments.  The  tribes, 
which  feed  altogether  on  animal  food, — as  the  Laplanders,  Samoiedes, 
Esquimaux,  &c., — are  far  inferior,  in  both  these  respects,  to  the 
European,  or  Europeo- American ;  and  the  same  may  be  said,  although 
not  to  the  like  extent,  of  the  various  tribes  in  whose  diet  animal  food 
predominates, — as  the  Indian  inhabitants  of  our  own  continent.  A 
similar  remark  is  applicable  to  those,  who  live  almost  exclusively  on 
vegetables,  as  the  Hindoos,  millions  of  whom  are  kept  in  subjection  by 
a  few  Europeans.2 

Attempts  have  frequently  been  made  to  refer  the  nutrient  properties 
of  all  articles  of  diet  to  a  particular  principle  of  a  constant  character, 
which,  alone,  of  all  the  elements,  is  entirely  capable  of  assimilation. 
Haller3  conceived  this  to  be  jelly; — Dr.  Cullen4  thought  it  to  be  oily, 
or  saccharine,  or  what  seemed  to  be  a  combination  of  the  two; — Becker, 
Stahl,  Fordyce,5  &c.,  to  be  mucilage;  M.  Dumas,6  mucus ;  and  M. 
Halle,  a  hydro-carbonous  oxide  very  analogous  to  gummi-saccharine 
matter  !7  It  is  probable,  that  there  is  no  such  special  principle  as  the 
one  contended  for ;  and  that,  in  all  cases,  in  the  formation  of  the  chyle 
or  reparative  fluid,  which  is  separated  from  it,  the  food  is  resolved  into 
its  elements.  To  this  conclusion  we  are  necessarily  impelled,  when  we 
reflect,  that  chyle  can  be  formed  from  both  animal  and  vegetable  sub- 
stances. In  an  early  part  of  this  work,  occasion  was  taken  to  mention, 
that  all  organized  tissues,  animal  and  vegetable  are  reducible  into 
nearly  the  same  ultimate  elements, — oxygen,  hydrogen,  carbon,  and 

1  Rudiments  of  Physiology,  Part  ii.,  a.  p.  121,  Edinb.,  1836. 
a  Lawrence's  Lectures,  edit,  cit.,  p.  216. 

3  Elementa  Physiologise,  Lib.  xix.,  Sect.  3,  Bernse,  1764. 

4  Institutions  of  Medicine,  Part  i.,  Physiology,  §  211,  Edinb.,  1785. 
6  Treatise  on  the  Digestion  of  Food,  p.  84,  2d  edit.,  Lond.,  1791. 

6  Principes  de  Physiologic,  i.  187,  Paris,  1806. 

'  Tiedemann,  Physiologic  des  Menschen,  in.  95,  Darmstadt,  1836. 


FOOD  OF  MAN.  545 

nitrogen.  Great  light  has  been  thrown  on  this  subject,  in  recent  pe- 
riods, by  the  labours  of  the  organic  chemist.  These  have  shown,  that 
the  chief  proximate  principles  of  animal  tissues,  and  those  that  have 
been  regarded  as  highly  nutritious  amongst  vegetables,  have  almost 
identically  the  same  composition;  and  are  modifications  of  protein.1 
The  following  tables  from  Liebig2  exhibit  the  striking  similarity  in  con- 
stitution, and  in  the  proportion  of  constituents,  of  different  animal  and 
vegetable  compounds  of  organization. 

jUnimal  proximate  principks,  according  to  Mulder. 

Albumen.  Fibrin.  Casein. 

Carbon,  .  54-84  54-56  54-96 


Hydrogen, 
Nitrogen, 
Oxygen,  . 
Sulphur,  . 
Phosphorus, 


6-90 

15-72 

22-13 

0-33 

0-36 


7-15 
15-80 
21-73 

0-36 


100-00  100-00  100-00 


Vegetable  proximate  principles,  according  to  Scherer  and  Jones. 

Albumen,  from  wheat.  Fibrin.  Casein  or  Legumin. 

Carbon,   ....         55-01         .  .       54-603  .         .       54-138 

Hydrogen,        .         ...  7-23         .  .         7-302  .         .         7-156 

Nitrogen,          ...         15'92         .  .       15-809  .         .       15-672 
Oxygen,         ~) 

Sulphur,         ^         .         .         21-84         .  .       22-286  .         .       23-034 
Phosphorus,  j 


100-00  100-000  100-000 

As  the  different  parts  of  organized  bodies  contain  a  considerable 
portion  of  nitrogen,  a  question  has  arisen  regarding  its  source ;  some 
believing,  that  it  is  obtained  from  the  food,  others  by  respiration. 

M.  Magendie3  instituted  experiments  with  the  view  of  determining 
the  nutritive  qualities  of  non-nitrogenized  substances.  They  consisted 
in  feeding  animals,  for  the  necessary  time,  on  a  diet  whose  chemical 
composition  was  rigidly  determined.  He  fed  a  dog,  three  years  old 
and  in  good  condition,  on  pure  white  sugar  and  distilled  water.  For 
seven  or  eight  days,  the  animal  appeared  to  thrive  well,  was  lively,  and 
ate  and  drank  with  avidity.  In  the  second  week,  it  began  to  fall  off, 
although  its  appetite  continued  good,  and  it  ate  six  or  eight  ounces  of 
sugar  in  the  twenty-four  hours.  In  the  third  week,  it  became  ema- 
ciated, its  strength  diminished,  its  gaiety  was  gone,  and  its  appetite 
impaired.  An  ulcer  formed  on  each  eye,  at  the  centre  of  the  cornea, 
which  subsequently  perforated  it,  and  allowed  the  humours  to  escape. 
The  emaciation,  as  well  as  loss  of  strength,  went  on  progressively  in- 
creasing; and,  although  the  animal  ate  daily  three  or  four  ounces  of 
sugar,  the  debility  became  so  great,  that  it  could  neither  chew,  swallow, 
nor  execute  the  slightest  movement.  It  died  on  the  thirty-second  day 
of  the  experiment.  On  dissection,  the  fat  was  found  to  have  entirely 

1  See  page  47. 

*  Animal  Chemistry,  Gregory's  and  Webster's  edit.,  pp.  100,  283,  and  301,  Cambridge, 
Mass.,  1842. 

s  Precis  Elementaire,  2de  edit.  ii.  488,  Paris,  1825. 

VOL.  i. — 35 


546  DIGESTION. 

disappeared;  the  muscles  were  reduced  to  less  than  five-sixths  of  their 
ordinary  size;  the  stomach  and  intestines  were  much  diminished,  and 
powerfully  contracted;  and  the  gall  and  urinary  bladders  filled  with 
fluids  not  proper  to  them.  These  were  examined  by  M.  Chevreul,  who 
found  them  to  possess  almost  all  the  characters  of  the  bile  and  urine  of 
herbivorous  animals.  The  urine,  in  place  of  being  acid,  as  it  is  in  the 
carnivora,  was  sensibly  alkaline,  and  presented  no  trace  of  uric  acid  or 
phosphates.  The  bile  contained  a  considerable  proportion  of  picromel, 
like  that  of  the  ox  and  herbivora  in  general.  The  excrements  con- 
tained very  little  nitrogen,  which  they  usually  do  in  abundance. 

A  second  dog  was  subjected  to  the  like  regimen,  and  with  similar 
results.  He  died  on  the  thirty-fourth  day  of  the  experiment.  A  third 
experiment,  having  eventuated  in  the  same  manner,  M.  Magendie  con- 
cluded that  sugar  alone  is  incapable  of  nourishing  the  dog.  In  all 
these  cases,  ulceration  of  the  cornea  occurred,  but  not  exactly  at  the 
same  period  of  the  experiment.  He  next  endeavoured  to  discover, 
whether  these  effects  might  not  be  peculiar  to  sugar;  or  whether  non- 
nitrogenized  substances,  generally  considered  nutritious,  might  not  act 
in  the  same  manner.  He  took  two  young  and  vigorous  dogs,  and  fed 
them  on  olive  oil  and  distilled  water.  For  fifteen  days  they  were  ap- 
parently well ;  but,  after  this,  the  same  train  of  phenomena  supervened 
as  in  the  other  cases,  except  that  there  was  no  ulceration  of  the  cornea. 
They  died  about  the  thirty-sixth  day  of  the  experiment.  Similar  ex- 
periments were  made  with  gum  Arabic,  and  with  butter — one  of  the 
animal  substances  that  do  not  contain  nitrogen.  The  ^results  were 
identical. 

Although  the  character  of  the  excrements  passed  by  the  different 
animals  indicated  that  the  substances  were  well  digested,  M.  Magendie 
was  desirous  of  establishing  this  in  a  positive  manner.  Accordingly, 
after  having  fed  animals  for  several  days  on  oil,  gum,  or  sugar,  he 
opened  them,  and  found  that  each  of  these  substances  was  reduced  to 
a  particular  kind  of  chyme  in  the  stomach ;  and  that  all  afforded  an 
abundant  supply  of  chyle  ; — that  from  oil  being  of  a  manifest  milky 
appearance,  and  that  from  gum  or  sugar  transparent,  opaline,  and 
more  aqueous  than  the  chyle  from  oil ;  facts  which  prove,  that  if  the 
various  substances  did  not  nourish  the  animals,  the  circumstance  could 
not  be  attributed  to  their  not  having  been  digested.  These  results,  M. 
Magendie  thought,  render  it  likely,  that  the  nitrogen,  found  in  different 
parts  of  the  animal  economy,  is  originally  obtained  from  the  food.  This, 
however,  is  doubtful.  We  have  no  proof,  that  the  animals  died  simply 
from  privation  of  nitrogen.  It  is,  indeed,  probable,  that  it  had  little 
or  no  agency  in  the  matter,  for  there  seems  to  be  no  sufficient  reason 
why  it  should  not  have  been  procured  from  the  air  in  respiration,  as 
well  as  from  that  contained  between  the  particles  of  the  sugar,  where 
this  substance  was  administered.  It  must  be  recollected,  moreover, 
that  the  subjects  of  these  experiments  were  dogs; — animals  which,  in 
their  natural  state,  are  carnivorous,  and,  in  a  domestic  state,  omni- 
vorous ;  and  that  they  were  restricted  to  a  diet  foreign  to  their  nature, 
and  one  to  which  they  had  not  been  accustomed.  Ought  we,  under  such 
circumstances,  to  be  surprised,  that  they  should  sicken,  and  fall  off? 


FOOD  OF  MAN.  547 

In  the  period  that  elapsed  between  the  publication  of  the  first  and 
second  editions  of  his  Precis  Element  air  e  de  Physiologic,  M.  Magendie 
found  that  his  deductions  were  not,  perhaps,  as  absolute  or  demonstra- 
tive as  he  had  at  first  imagined;  and  additional  experiments  induced 
him  to  conclude, — as  Dr.  Bostock1  afterwards  did,  without  being  aware, 
apparently,  of  his  observation, — "that  variety  and  multiplicity  of 
articles  of  food  constitute  an  important  hygienic  rule."  "  This,"  M. 
Magendie2  adds,  "is  indicated  to  us  by  our  instinct,  as  well  as  by  the 
changes  that  wait  upon  the  seasons,  as  regards  the  nature  and  kind  of 
alimentary  substances."  The  additional  facts,  detailed  by  M.  Magendie, 
are  the  following :— A  dog,  fed  at  discretion  on  pure  wheaten  bread, 
and  drinking  common  water,  does  not  live  beyond  fifty  days;  whilst 
another,  fed  exclusively  on  military  bread — pain  de  munition — seems 
to  suffer  hi  no  respect.  Rabbits  or  Guinea-pigs,  fed  on  a  single  sub- 
stance, as  wheat,  oats,  barley,  cabbage,  carrots,  &c.,  commonly  die, 
with  every  mark  of  inanition,  in  a  fortnight;  and,  at  times,  much 
earlier.  When  the  same  substances  are  given  together,  or  in  succes- 
sion, at  short  intervals,  the  animals  continue  in  good  keeping.  An 
ass,  fed  on  rice,  lived  only  fifteen  days,  refusing  his  food  for  the  last 
few  days ;  whilst  a  cock  was  fed  upon  boiled  rice  for  several  months 
without  his  health  suffering.  Dogs,  fed  exclusively  on  cheese,  and 
others  on  hard  eggs,  lived  for  a  long  time ;  but  they  were  feeble  and 
lean,  losing  their  hair,  and  their  whole  appearance  indicated  imperfect 
nutrition.  The  substance,  which,  when  given  alone,  appeared  to  sup- 
port the  rodentia3  for  the  greatest  length  of  time,  was  muscular  flesh. 

Lastly,  M.  Magendie  found,  that  if  an  animal  had  subsisted  for  a  cer- 
tain time  on  a  substance,  which,  taken  alone,  is  incapable  of  nourishing 
it, — on  white  bread,  for  instance,  for  forty  days, — it  is  useless,  at  the 
end  of  that  time,  to  vary  his  nourishment,  and  restore  him  to  his  ac- 
customed regimen.  He  will  feed  greedily  on  the  new  food  presented 
to  him;  but  continues  to  fall  off;  and  dies  at  the  same  period  as  he 
would  probably  have  done,  if  maintained  on  his  exclusive  regimen. 
That  these  effects  are  not  owing  to  privation  of  nitrogen,  the  same  ob- 
server4 has  since  been  amply  satisfied.  As  chairman  of  a  committee 
appointed  to  inquire  into  the  nutritive  properties  of  gelatin,  he  reported 
that  gelatin,  albumen,  and  fibrin — all  of  which  are  highly  nitrogenized 
— when  taken  separately,  nourish  animals  for  a  limited  period  only, 
and  imperfectly.  They  generally  soon  excite  so  insurmountable  a  dis- 
gust that  the  animals  would  rather  die  than  partake  of  them.  These 
experiments  led  to  the  too  hasty  conclusion,  that  the  gelatinous  tissues 
are  incapable  of  conversion  into  blood.  "The  gelatinous  substance," 
says  Liebig,5  "is  not  a  compound  of  protein;  it  has  no  sulphur,  no 

1  Physiology,  3d  edit.,  p.  561,  Lond.,  1836.  2  Qp.  chat.,  ii.  494. 

3  The  rodentia  are   gnawing  animals,  having  large   incisors  in   each   jaw,  with   which 
they  divide  hard    substances.      They  are   the  rongeurs   of   the    French  naturalists.      The 
squirrel,  mouse,  rat,  Guinea-pig,  hare,  rabbit,  beaver,  kangaroo,  porcupine,  &c.,  belong  to 
this  division. 

4  Comptes  Rendus,  Aout,  1841.     Similar  results  were  obtained  by  the  Amsterdam  Com- 
mission, in  Het  Instituut,  No.  ii.  1843,  pp.  97-114,  cited  by  Mr.  Paget,  Brit,  and  For.  Med. 
Rev.,  April,  1845,  p.  563. 

5  Animal  Chemistry,  Amer.  edit.,  by  Webster,  p.  124,  Cambridge,  Mass.,  1842. 


548  DIGESTION. 

phosphorus,  and  contains  more  nitrogen  or  less  carbon  than  protein* 
The  compounds  of  protein,  under  the  influence  of  the  vital  energy  of 
the  organs  that  form  the  blood,  assume  a  new  form,  but  are  not  altered 
in  composition ;  whilst  these  organs,  as  far  as  our  experience  reaches^ 
do  riot  possess  the  power  of  producing  compounds  of  protein,  by  virtue 
of  any  influence,  from  substances  that  contain  no  protein.  Animals, 
which  were  fed  exclusively  on  gelatin,  the  most  highly  nitrogenized  ele- 
ment of  the  food  of  carnivora,  died  with  symptoms  of  starvation."  "In 
short,"  he  adds,  "gelatinous  tissues  are  incapable  of  conversion  into 
blood."  Such  too,  seems  to  be  the  opinion  of  Professor  Be'rard.1  Yet 
it  has  been  shown  above,  that  fibrin  and  albumen — both  compounds  of 
protein — when  exhibited  singly  to  animals,  nourished  them  as  imper- 
fectly as  gelatin;  and  there  is  some  reason  to  believe,  that  it  is  mainly 
on  chemical  considerations  that  the  value  of  gelatin  as  a  nutriment 
has  been  much  underrated.  "  Such  persons  only/'  says  Professor 
Mulder,2  "as  are  under  the  influence  of  prejudice  (making  their  experi- 
ments with  dogs — animals  which,  according  to  the  account  of  the  gela- 
tin committee,  prefer  to  starve  in  the  midst  of  gelatin,  rather  than 
touch  it),  such  persons  only  as  deny  the  results  of  innumerable  ob- 
servations, will  refuse  to  gelatin  its  place  among  useful  nutritive  sub- 
stances." And  he  adds:  "I  have  thought  it  necessary,  before  closing 
this  short  account  of  gelatin,  to  express  my  opinion  of  the  experiments 
by  which  pure  gelatin  is  rejected  as  food: — namely,  that  these  experi- 
ments have  taught  me  nothing  but  how  experiments  ought  not  to  be 
made."  It  is  somewhat  singular,  too,  that  most  of  those  who  deny 
much  nutrient  property  to  gelatin  are  of  opinion,  that  the  nutritious 
properties  of  different  articles  of  vegetable  food  may  be  generally  esti- 
mated by  the  proportion  of  nitrogen  they  contain,  and  on  this  principle 
tables  have  been  formed  by  several  experienced  chemists, — by  Boussin- 
gault,  Schlossberger,  Kemp,3  and  Professor  Horsford,4  of  Cambridge, 
Massachusetts.  The  latter  gentleman,  especially,  has  furnished  us 
with  the  results  of  elaborate  investigations  into  the  nature  of  different 
kinds  of  vegetable  food,  based  upon  the  amount  of  nitrogen.  The 
tables  of  Boussingault  and  Horsford  are  considered  by  Professor  Fre- 
richs,5  of  value;  whilst  those  of  Schlossberger  and  Kemp  are  declared 
to  be  practically  useless,  because  no  regard  was  paid  to  the  quantity 
of  water  in  the  fresh  condition;  and  for  the  strange  reason,  "that  the 
nitrogen  found  in  most  of  the  substances  analyzed  that  contain  gelatin 
is  no  measure  of  the  quantity  of  the  hsematogenetics  or  blood-forming 
constituents!" 

Independently  of  showing  the  necessity  of  variety  of  food  for  animal 
sustenance,  the  experiments  of  M.  Magendie  exhibit  some  singular 
anomalies ;  and  sufficiently  demonstrate,  that  we  have  yet  much  to  learn 

1  Archives  Generates  de  Medecine,  Fevrier,  1850,  p.  247. 

2  The  Chemistry  of  Vegetable  and  Animal   Physiology,  by  G.  J.  Mulder,  &c.,  p.  328, 
Edinb.  and  Lond.,  1849. 

3  Annal.  der  Chemie  und  Pharmacie,  B.  Ivi.  s.  78-94  ;  see  also,  Philosophical  Magazine 
for  Nov.,  1845. 

4  Philosophical  Magazine,  for  Nov.,  1846,  p.  365. 

5  Art.  Verdauung,  in  Wagner's  Handworterbuch  der  Physiologic,  19te  Lieferung,  s.  732, 
Braunschweig,  1848. 


I 


FOOD  OF  MAN.  549 

on  the  subject.  A  great  deal,  doubtless,  depends  on  the  habits  of  the 
particular  animal  or  individual;  and  on  the  morbid  effects  excited  by 
completely  changing  the  function  of  assimilation.  It  has  been  long 
known,  that  if  a  man,  previously  habituated  to  both  animal  and  vege- 
table diet,  be  restricted  exclusively  to  one  or  the  other,  he  will  fall  off, 
and  become  scorbutic;  and  yet,  that  he  is  capable  of  subsisting  on 
either  one  or  the  other  exclusively,  provided  the  restriction  has  been 
enforced  from  early  infancy,  has  been  sufficiently  shown  by  the  refer- 
ence made  to  carnivorous  and  herbivorous  tribes  existing  in  different 
regions  of  our  globe.  The  importance  of  variety  of  diet  is  illustrated 
by  the  experiments  made  by  Dr.  Stark,1  upon  his  own  digestive  powers, 
and  to  which  he  ultimately  became  a  martyr.  His  object  was  to  dis- 
cover the  relative  effect  of  various  simple  substances,  when  used  exclu- 
sively for  a  long  space  of  time  as  articles  of  food.  The  system,  he 
found,  was  in  all  cases  reduced  to  a  state  of  extreme  debility,  and  there 
was  not  a  single  aliment,  that  was  capable,  of  itself,  of  sustaining  the 
vigour  of  the  body  for  any  considerable  period.  By  this  kind  of  regi- 
men Dr.  Stark  is  said  to  have  so  completely  ruined  his  own  health,  as 
to  bring  on  premature  death. 

In  accordance  with  his  views,  that  nitrogenized  food  is  alone  capable 
of  forming  organized  tissue;  and  that  the  non-nitrogenized  food  is  in- 
servient  to  respiration  only,  Liebig  thus  classifies  aliments: — 

Nitrogenized  Food  or  Plastic  Elements  of  Non-nitrogenized  Food  or  Elements  of  Respi~ 

Nutrition.  ration. 

Vegetable  Fibrin,  Fat,  Pectin, 

"          Albumen,  Starch,  Bassorin, 

"          Casein,  Gum,  Wine, 

Flesh,  Cane  Sugar,  Beer, 

Blood.  Grape  Sugar,  Spirits* 

Sugar  of  Milk, 

These  views,  however,  demand  further  proof.  They  are  not  confirmed 
by  what  is  observed  in  chylification.  In  the  small  chyliferous  vessels, 
more  fat,  which  is  a  non-nitrogenized  substance,  is  found  than  can  be 
accounted  for  by  the  adipose  matter  in  the  food;  and  of  the  conver- 
sion of  the  amylaceous  and  saccharine  matters  in  the  food  to  oil  during 
the  digestive  function  a  striking  example  has  been  published  by  M. 
Koss.2  A  workman  was  killed  on  a  railroad  after  having  eaten  a 
full  meal  of  bread  and  grapes  only.  On  examining  his  body,  the  pro- 
cess of  chymification  was  found  to  have  been  in  full  activity;  and  in 
those  portions  of  the  small  intestine,  which  the  chyme  had  reached, 
the  mucous  membrane  was  dotted  with  white  points,  which,  on  closer 
examination,  were  found  to  be  owing  to  drops  of  oil  in  the  epithelial 
cells  surrounding  the  extremities  of  the  villi.  As  the  chyle  proceeds 
along  the  lacteals,  the  proportion  of  fat  becomes  less  and  less,  whilst 
that  of  the  nitrogenized  matters  increases;  hence  nitrogen  must 
have  been  obtained,  and  a  conversion  have  taken  place  of  non-nitro- 
genized into  nitrogenized  matters.  (See  PHYSIOLOGY  OF  CHYLOSIS.)  On 
the  other  hand  it  has  been  shown,  that  the  followers  of  Liebig  maintain, 

1  The  Works  of  the  late  Wm.  Stark,  M.  D.,  &c.,  by  Dr.  J.  C.  Smyth.,  Lond.,  1787. 
*  Cited  in  Londqn  Med.  Gazette,  Oct.,  1846. 


550  DIGESTION. 

that  gelatin  is  not  convertible  into  a  proteinaceous  substance;  and  hence 
it  is  not  classed  by  them  amongst  the  elements  of  nutrition;  yet  it  con- 
tains an  unusual  amount  of  nitrogen.  It  has  been  affirmed,  that  all 
nitrogenized  food,  according  to  the  above  classification  of  Liebig,  is 
reduced  in  the  stomach  to  the  form  of  albumen;  which  is  said  to  resemble 
the  gum  of  plants  in  being  the  raw  material,  as  it  were,  out  of  which 
the  various  fabrics  of  the  body  are  constructed.  Yet  this  is  not  demon- 
strated; and  it  is  probable  that  the  conversion  into  albumen  takes  place 
mo^e  especially  in  the  chyliferous  vessels. 

The  alimentary  substances,  employed  by  man,  have  generally  been 
classed  either  according  to  the  ultimate  chemical  elements  entering  into 
their  composition;  or  to  the  chief  proximate  principle  or  compound  of 
organization..  In  the  former  case,  they  have  been  grouped  into : — 1? 
those  that  contain  nitrogen,  carbon,  hydrogen,  and  oxygen; — 2,  those 
that  contain  carbon,  hydrogen,  and  oxygen;  and  3,  those  that  contain 
neither  nitrogen  nor  carbon.  The  first  class  will  comprise  most  animal 
and  many  vegetable  substances;  the  second,  vegetable  substances  chiefly; 
whilst  water  is  perhaps  the  only  alimentary  matter  that  belongs  to  the 
third. 

The  division  proposed  by  M.  Magendie,1  and  adopted  by  Dr.  Paris,2 
is  according  to  the  proximate  principles,  which  predominate  in  the  ali- 
ment. 

1.  Jlmylareous  aliments;  wheat,  barley,  oats,  rice,  rye,  Indian  corn,  potato,  sago,  salep,  peas, 
haricots,  lentils,  &c. 

2.  Mucilaginous  aliments;  carrot,  salsify,  beet,  turnip,  asparagus, cabbage,  lettuce,  artichoke, 
melon,  &c. 

3.  Saccharine  aliments  ;  the  different  kinds  of  sugar,  figs,  dates,  raisins,  &c. 

4.  Acidulous  aliments  ;  the  orange,  currant,  cherry,  peach,  raspberry,  strawberry,  mulberry. 


grapes,  prunes,  pears,  apples,  tornatos,  &c. 
5.  Oily  and  fatty  •  cocoa,  olives,  sweet  a 


sweet  almonds,  hazelnuts,  walnuts,  animal  fats,  oils,  but- 
ter, &c. 

6.  Caseous  aliments;  the  different  species  of  milk,  cheese, &c. 

7.  Gelatinous  aliments  ;•  the  tendons,  aponeuroses,  skin,  areolar  tissue,  the  flesh'  of  very 
young  animals,  &c. 

8.  Albuminous  aliments  ;  the  brain,  nerves,  eggs,  &c. 

9.  Fibrinous  aliments  ;  comprehending  the  flesh  and  blood  of  different  animals. 

To  these  proximate  principles  gluten  may  be  added,  which  has  been 
termed  the  most  animalized  of  vegetable  principles.  According  to  Dr. 
Prout,3  it  is  separable  into  two  portions,  analogous  to  gelatin  and  albu- 
men. It  is  very  generally  met  with,  although  only  in  small  proportion, 
in  the  vegetable  kingdom  ; — in  all  the  farinaceous  seeds,  in  the  leaves 
of  cabbage,  cress,  &c.  ;  in  certain  fruits,  flowers,  and  roots,  and  in  the 
green  fecula  of  vegetables  in  general ;  but  it  is  especially  abundant  in 
wheat,  and  imparts  to  wheaten  flour  the  property  of  fermenting  and 
making  bread.  Of  the  nutritious  properties  of  gluten,  distinct  from 
other  principles,  we  know  nothing  precise  :  the  superior  nutritious 
powers  of  wheaten  flour  over  those  of  all  other  farinaceous  substances 

1  Precis,  &c.,  ii.  34. 

2  A  Treatise  on  Diet,  3d  edit.,  p.  182,  Lond.,  1837;  and  art.  Dietetics,  in  Cyclopaedia  of 
Practical  Medicine,  Amer.  edit.,  Philad.,  1845. 

3  Chemistry,  Meteorology,  and  the  Function  of  Digestion,  (Bridgewater  Treatise,)  Amer. 
edit.,  p.  558,  Philad.,  1834. 


FOOD  OF  MAN.  551 

sufficiently  attest,  that,  in  combination  with  starch,  it  is  highly  nutri- 
tive. 

Dr.  Prout1  arranges  alimentary  principles  in  four  great  divisions — 
the  aqueous,  saccharine,  oleaginous,  and  albuminous.  This  has  been 
taken  as  the  basis  for  a  classification  by  Dr.  Pereira,2  who  admits 
twelve  divisions  : — the  aqueous,  mucilaginous  or  gummy,  saccharine, 
amylaceous,  ligneous,  pectinaceous,  acidulous,  alcoholic,  oily  or  fatty, 
proteinaceous,  gelatinous,  and  saline.  By  the  combination  of  these 
alimentary  principles  and  simple  aliments,  our  ordinary  articles  of  food 
or  compound  aliments  are  formed.  In  this  classification,  the  protein- 
aceous and  gelatinous  aliments  are  separated.  The  following  simple 
arrangement  is,  perhaps,  as  little  liable  to  objection  as  any  : — 

f  Fibrinous  (Glutinous  ?) 

I.  Nitrogenized  aliments,  J  Albuminous. 

(Albuminous  of  Prout.)  j  Caseinous. 

^Gelatinous. 
C  Amylaceous. 

II.  Non-nitrogenized  aliments.  <  Saccharine. 

(  Oleaginous. 

The  second  division  might  be  still  farthir  simplified;  for  amyla- 
ceous aliments  are  convertible  into  sugar  during  the  digestive  process ; 
and  of  both — as  has  been  seen, — oleaginous  matter  may  be  formed. 

Water  forms  the  basis  of  all  drinks ;  but  it  frequently  contains  in 
addition  other  substances.  These  have  been  classed  as  follows : — 1. 
Water,  of  different  kinds.  2.  Vegetable  and  animal  juices  and  infu- 
sions, as  lemon-juice,  orange-juice,  whey,  tea,  coffee,  &c.  3.  Fermented 
liquors,  as  wines,  beer,  cider,  perry,  &c.  ;  and  4.  Alcoholic  liquors,  as 
brandy,  alcohol,  kirsch-wasser,  rum,  gin,  whisky,  arrack,  &c.  &c.  Dr. 
Pereira3  has  proposed  the  following  more  complete  classification  :— 1. 
Mucilaginous,  farinaceous  or  saccharine  drinks.  2.  Aromatic  or  astrin- 
gent drinks.  3.  Acidulous  drinks.  4.  Animal  broths,  or  drinks  con- 
taining gelatin  and  osmazome.  5.  Emulsive  or  milky  drinks ;  and  6. 
Alcoholic  and  other  intoxicating  drinks.  Water — as  has  been  seen — 
is  considered  by  him  amongst  the  alimentary  principles. 

An  inquiry  into  the  different  properties  of  these  various  liquids  does 
not  belong  to  the  physiologist.  It  may  be  remarked,  however,  that  the 
arguments  regarding  the  natural  have  been  extended  to  this  variety  of 
aliments ;  and  it  has  been  contended,  that  water  is  "  the  most  natural 
drink  ;"  and  that  all  others,  which  are  the  products  of  art,  ought  to  be 
avoided.  The  remarks,  already  made  on  this  subject,  are  sufficient. 
Water  was,  doubtless,  at  one  period,  the  only  beverage  of  man,  as 
nakedness,  the  use  of  raw  aliment,  and  the  most  profound  ignorance 
of  the  universe,  were  his  original  condition ;  but  no  one  will  be  presump- 
tuous enough  to  declare,  that  he  ought  to  continue  naked,  abjure  cook- 
ery, and  be  plunged  into  his  primitive  darkness,  on  the  plea  that  all  these 

1  On  the  Nature  and  Treatment  of  Stomach  and  Renal  Diseases,  Amer.  edit.,  from  the 
4th  revised  London  edit.,  ii.  354,  Philad.,  1843. 

2  A  Treatise  on  Food  and  Diet,  Amer.  edit,  by  Dr.  C.  A.  Lee,  p.  38,  New  York,  1843. 
s  Op.cit.,  p.  189. 


552  DIGESTION. 

changes  are  so  many  artificial  sophistications.1  Water  is,  unquestiona- 
bly, sufficient  for  all  his  wants ;  but  the  moderate  use  of  fermented 
liquors,  even  if  habitual,  except  in  particular  constitutions,  is  devoid, 
we  think,  of  every  noxious  result.  They  are  grateful ;  and  many  of 
them  are  even  directly  nutritious  from  the  undecomposed  sugar  and 
mucilage  which  they  contain.  For  this  reason  beer  has  been  termed, 
not  inaptly,  "  liquid  bread."2  With  regard  to  distilled  spirits,  no  evil 
would  result  from  their  total  rejection  from  the  table.  Although  they 
may,  by  their  action  on  the  digestive  organs,  be  indirect  means  of  nutri- 
tion, they  contain  no  alimentary  principle.  They  are  received  into  the 
vessels  of  the  stomach  by  imbibition  ;  and  always  produce  undue  stimu- 
lation, when  taken  to  any  amount.  This  maybe  productive  of  little  or 
no  mischief,  provided  they  be  only  used  occasionally;  but,  if  taken 
habitually,  serious  visceral  disorder  may  sooner  or  later  ensue. 

Lastly. — There  are  certain  substances  called  condiments  employed 
in  diet,  not  simply  because  they  are  nutritive, — for  many  of  them  pos- 
sess no  such  properties, — but  because,  when  taken  with  food  capable  of 
nourishing,  they  promote  its  digestion,  correct  some  injurious  property, 
or  add  to  its  sapidity.  Dr.  Paris  has  divided  these  into  saline,  spicy  or 
aromatic,  and  oily.  It  may  be  remarked,  however,  that  certain  articles 
are  called,  at  times,  aliments;  at  others,  condiments,  according  as  they 
constitute  the  basis  or  the  accessory  to  any  dish  ; — such  are  cream,  but- 
ter, mushrooms,  olives,  &c.  The  advantage  of  condiments  in  animal 
digestion  is  exemplified  by  many  cases.  The  bitter  principle,  which 
exists  in  grasses  and  other  plants,  appears  to  be  essential  to  the  diges- 
tion of  the  herbivora, — acting  as  a  natural  stimulant ;  and  it  has  been 
found  that  cattle  do  not  thrive  upon  grasses  which  are  destitute  of  it. 
Of  the  value  of  salt  to  the  digestive  function  of  his  cattle,  the  agricul- 
turist has  ample  experience  ;  and  the  salt  licks  of  our  country  show  how 
grateful  this  natural  stimulant  is  to  the  beasts  of  the  forests.  Charcoal, 
administered  with  fat, — as  is  done,  in  rural  economy  for  fattening  poul- 
try, in  many  parts  of  England, — exhibits  the  advantage  of  administer- 
ing a  condiment ;  the  charcoal  of  itself  contains  no  nourishment,  but  it 
puts  the  digestive  function  in  a  condition  for  separating  more  nutritious 
matter  from  the  food  taken  in,  than  it  could  otherwise  do.  A  similar 
effect  is  produced  by  the  plan, — adopted  for  the  same  purpose  in  cer- 
tain parts  of  Great  Britain, — of  cramming  the  animal  with  walnuts, 
coarsely  bruised,  with  the  shell.  This  is  asserted,  by  many  rural  econo- 
mists, to  be  the  most  effectual  plan  for  fattening  poultry  speedily;  the 
coarse  shell,  in  passing  along  the  mucous  membrane  of  the  intestines; 
seems  to  stimulate  it  to  augmented  action,  and  a  more  bountiful  separa- 
tion of  nutritious  matter  is  the  consequence.  The  aromatic  condiments 
act  in  a  similar  manner. 

In  regard  to  the  quantity  of  food  required  for  human  sustenance, 
nothing  definite  can  be  laid  down.  It  must  differ  according  to  habit, 
constitution,  way  of  life,  age,  sex,  &c.  The  diet  scale  of  the  British 
navy  affords  a  good  average  for  the  adult  male  in  busy  life,  who  requires 

1  See  an  article  by  the  author  in  the  American  Quarterly  Review,  ii.  422,  PhilacL  1827; 
and  Fletcher,  op.  citat.,  p.  121. 

2  Kitchener,  Invalid's  Oracle,  Amer.  edit.,  p.  136,  New  York,  1831. 


PHYSIOLOGY  OF  DIGESTION.  553 

more  aliment  than  those  in  less  active  employment.  It  consists  of  from 
31  to  35  J  ounces  of  dry  nutritious  matter  daily;  of  which  26  ounces 
are  vegetable  and  the  rest  animal, — 9J-  ounces  of  salt  meat,  or  4^  ounces 
of  fresh,  being  the  proportion  of  the  latter.  This  is  found  to  be  an 
ample  allowance.  In  prisons  a  reduction  must  be  made.  In  a  convict 
ship,  which  took  out  433  prisoners  to  New  Holland,  in  1802,  the  mor- 
tality was  trifling,  and  the  general  health  good,  although  the  prisoners 
were  allowed  only  16  ounces  of  vegetable  food,  and  7J  ounces  of  animal 
food  per  day.  Whenever  the  allowance  is  more  restricted,  or  a  due  ad- 
mixture of  animal  and  vegetable  food  is  not  permitted,  the  health  suffers, 
and  signs  of  scorbutus  appear; — a  result  occasionally  witnessed  in  our 
public  eleemosynary  institutions,  when  under  the  care  of  ignorant  and 
too  economical  superintendents.  It  would  seem,  from  the  experiments 
of  M.  Chossat,1  that  under  such  circumstances  an  incapability  is  induced 
of  digesting  even  the  inadequate  amount  supplied. 

The  smallest  quantity  of  food  upon  which  life  is  known  to  have  been 
actively  supported  was  in  the  case  of  Cornaro,  who  affirms  that  he  took 
no  more  than  12  ounces  a  day,  and  that  chiefly  vegetable,  for  a  period 
of  sixty-eight  years.  Of  the  amount  that  can  be  eaten  by  the  glutton, 
we  have  surprising  instances  on  record, — the  stomach  acquiring,  at 
times,  an  enormous  capacity.  Captain  Parry  relates  the  case  of  a  young 
Esquimaux,  who  was  permitted  to  devour  as  much  as  he  chose.  It 
amounted,  in  the  twenty-four  hours,  to  thirty-five  pounds  of  various 
kinds  of  aliment,  including  tallow  candles;  and  a  case  has  been  pub- 
lished of  a  Hindoo,  who  could  eat  a  whole  sheep  at  a  time. 

These  few  remarks  on  the  food  of  man  will  serve  as  an  introduction 
to  the  mode  in  which  the  various  digestive  processes  are  accomplished. 
The  more  intimate  consideration  of  alimentary  substances,  with  their 
comparative  digestibility,  &c.,  will  be  found  in  another  work  of  the 
author,  to  which  the  reader  is  referred.2 

3.    PHYSIOLOGY   OP    DIGESTION. 

The  detail  entered  into  regarding  the  various  organs  concerned  in 
digestion  will  have  led  to  the  anticipation,  that  the  history  of  the  func- 
tion must  be  multiple  and  complex.  The  food  is  not,  in  the  case  of  the 
animal — as  it  is  in  that  of  the  vegetable — placed  in  immediate  contact 
with  the  being  to  be  nourished;  an  act  of  volition  is,  consequently,  neces- 
sary to  procure  and  to  convey  it  to  the  upper  orifice  of  the  digestive 
tube.  This  act  of  volition  is  excited  by  an  internal  sensation — that  of 
hunger — which  indicates  the  necessity  for  taking  fresh  nourishment  into 
the  system.  The  appetite  and  hunger,  with  the  prehension  or  reception 
of  food,  must  therefore  be  regarded  part  of  the  digestive  operations. 
These  may  be  enumerated  and  investigated  in  the  following  order: — 
1st.  Hunger,  or  the  sensation  that  excites  us  to  take  food.  2dly.  Pre- 
hension 'of  food,  the  voluntary  muscular  action,  that  introduces  it  into 
the  mouth.  3dly.  Oral  or  buccal  digestion,  comprising  the  changes 

1  Referred  to.  at  page  558. 

2  Human  Health,  p.  179,  Philad.,  1844.    For  different  dietaries,  &c.,  see  Pereira,  Treatise 
on  Food  and  Diet,  Amer.  edit.,  by  Dr.  C.  A.  Lee,  p.  222,  New  York,  1843;  and  Art.  Diet 
Scale,  in  the  author's  Med.  Dictionary,  7th  edit.,  Philad.,  1848. 


554  DIGESTION. 

•wrought  on  the  food  in  the  mouth.  4thly.  Deglutition,  or  the  part 
taken  by  the  pharynx  and  resophagus  in  digestion.  5thly.  Chymifica- 
tion,  or  the  action  of  the  stomach  on  the  food.  6thly.  The  action  of 
the  small  intestine.  Tthly.  The  action  of  the  large  intestine.  And, 
Sthly.  Defecation  or  the  expulsion  of  the  fseces.  All  these  processes  are 
not  equally  concerned  in  the  formation  of  chyle.  It  is  separated  in  the 
small  intestine:  the  first  six,  therefore,  belong  to  it; — the  remainder 
relate  only  to  the  excrementitious  part  of  the  food.  The  digestion  of 
solid  food  requires  all  the  eight  processes:  that  of  liquids  is  more  simple; 
comprising  only  thirst,  prehension,  deglutition,  the  action  of  the  stomach, 
and  that  of  the  small  intestine.  Fluid  rarely  reaches  the  large  intestine. 
In  inquiring  into  this  important  and  interesting  function,  we  shall  first 
attend  to  the  digestion  of  solids,  and  afterwards  to  that  of  liquids. 

4.    DIGESTION   OF    SOLID   FOOD. 

a.  Hunger. 

Hunger  is  an  internal  sensation,  the  seat  of  which  is  invariably  refer- 
red to  the  stomach.  Like  every  internal  sensation,  it  proceeds  from 
changes  in  the  very  texture  of  the  organ.  It  is  not  produced  by  any 
external  cause;  and  to  it  are  applicable  all  those  observations,  that  were 
made  on  internal  sensations  in  general.  In  its  slightest  condition,  it  is 
merely  an  appetite,  (opst^;  Germ.  E  s  s  1  u  s  t;)  but  if  this  be  not  heeded, 
the  painful  sensation  of  hunger  (Fames,  TU^OJ),  supervenes,  which 
becomes  more  and  more  acute  and  lacerating  unless  food  is  taken.  If 
this  be  the  case,  however,  the  uneasiness  gradually  abates ;  and  if  suffi- 
cient be  eaten,  a  feeling  of  satiety  is  produced.  The  sensation  usually 
occurs,  in  the  healthy  state,  after  the  stomach  has  been  for  some  time 
empty,  having  finished  the  digestion  of  substances  taken  in  at  the  previous 
meal.  Habit  has  a  great  effect  in  regulating  this  recurrence  ;  the  appe- 
tite always  appearing  about  the  time  at  which  the  stomach  has  been 
accustomed  to  receive  food.  This  artificial  desire  may  be  checked  by 
various  causes; — by  the  exciting  or  depressing  passions,  the  sight  of  a 
disgusting  object,  or  anything  that  occasions  intense  mental  emotion; 
or  it  may  be  appeased  by  filling  the  stomach  with  substances  that  con- 
tain no  nutritious  properties.  As,  however,  the  feeling  of  true  hunger 
arises  from  the  wants  of  the  system,  the  natural  and  instinctive  sensa- 
tion soon  appears,  and  cannot  be  long  postponed  by  any  of  these  means. 
Hence,  it  has  been  proposed  to  make  a  distinction  between  appetite  and 
hunger;  applying  the  former  term  to  the  artificial,  the  latter  to  the 
natural,  desire.  In  these  respects,  there  is  certainly  a  wide  distinction 
between  them,  as  well  as  in  the  capriciousness,  which  occasionally  cha- 
racterizes the  former,  and  gives  rise  to  singular  and  fantastic  preferences. 

The  sensation  of  hunger  varies  in  intensity  according  to  different 
circumstances.  It  is  more  powerful  in  the  child  and  youth  than  in  one 
who  has  attained  his  full  height.  In  the  period  of  second  childhood,  it 
is  urgent, — probably  owing  to  the  diminished  power  of  assimilation 
requiring  that  more  aliment  should  be  received  into  the  stomach.  In 
disease,  the  sensation  is  generally  suppressed,  and  its  place  often  sup- 
plied by  loathing  or  disgust  for  food:  at  times,  again,  its  intensity  makes 


HUNGER.  555 

it  a  true  disease,  as  in  bulimia,  and  pica;  in  the  latter  of  which,  the 
appetite  is,  at  times,  irresistibly  directed  to  substances,  which  the  per- 
son never  before  relished,  or  are  not  edible, — as  chalk,  earth,  slate- 
pencil,  &c.  The  appetite  is  also  modified  by  exercise  or  inactivity,  and 
other  circumstances  extrinsic  and  intrinsic, — regular  exercise,  and  the 
exhilarating  passions;  a  cold  and  dry  atmosphere,  &c.,  augmenting  it, 
whilst  it  is  blunted  by  opposite  circumstances.  Long  continued  exer- 
tion, with  a  scanty  supply  of  nourishment,  if  not  continued  so  long  as 
to  injure  the  tone  of  the  stomach,  produces,  occasionally,  in  adults,  a 
voracious  appetite  and  rapid  digestion.  Mr.  Hunter  has  quoted,  in 
illustration  of  this  point,  the  following  extract  from  Admiral  Byron's 
narrative.  After  describing  the  privations  he  had  suffered  when  ship- 
wrecked on  the  coast  of  South  America,  the  Admiral  incidentally  refers 
to  their  effect  upon  his  appetite.  "The  governor  ordered  a  table  to  be 
spread  for  us  with  cold  ham  and  fowls,  which  only  we  three  sat  down 
to,  and  in  a  short  time  despatched  more  than  ten  men  with  common 
appetites  would  have  done.  It  is  amazing,  that  our  eating  to  that  excess 
we  had  done  from  the  time  we  first  came  among  these  kind  Indians  had 
not  killed  us,  as  we  were  never  satisfied,  and  used  to  take  all  opportu- 
nities for  some  months  after,  of  filling  our  pockets,  when  we  were  not 
seen,  that  we  might  get  up  two  or  three  times  in  the  night  to  cram 
ourselves."1 

Authors  have  distinguished  the  local  from  the  general  phenomena 
of  hunger;  but  many  of  their  assertions  on  these  points  appear  ima- 
ginative. We  are  told  by  M.  Adelon2  and  others,3  that  the  stomach 
becomes  contracted,  and  that  this  change  is  effected  by  the  action  of 
its  muscular  coat  alone; — the  mucous  or  lining  membrane  becoming 
wrinkled,  and  the  peritoneal  coat,  externally,  permitting  the  organ  to 
retire  between  its  laminae.  Such,  MM.  Tiedemann  and  Gmelin4  assert, 
is  the  result  of  their  observations.  M.  Magendie,5  however,  affirms, 
that  after  twenty-four,  forty-eight,  and  even  sixty  hours  complete  absti- 
nence, he  has  never  witnessed  this  contraction  of  the  organ.  It  had 
always  considerable  dimension,  especially  in  its  splenic  portion;  and 
not  until  after  the  fourth  or  fifth  day  did  it  appear  to  him  to  close 
upon  itself,  diminish  greatly  in  capacity,  and  slightly  change  its  posi- 
tion; and  these  effects  were  not  observed  unless  the  fasting  was  rigor- 
ously maintained. 

At  the  time  that  the  stomach  changes  its  shape  and  situation,  the 
duodenum  is  said  to  be  drawn  slightly  towards  it;  its  parietes  appear 
thicker, — and  the  mucous  follicles  and  nervous  papillae  project  more  into 
the  interior.  Its  cavity  is  void  of  food,  and  contains  only  a  little  saliva, 
mixed  with  bubbles  of  air;  a  small  quantity  of  mucus;  and,  according 
to  some,  a  little  bile  and  pancreatic  juice,  which  the  traction  of  the 
duodenum  has  caused  to  flow  into  it. 

Much  dispute  has  arisen  as  to  whether  the  circulation  of  the  blood  in 

1  Byron's  Voyage,  p.  181 ;  and  Hunter  on  the  Animal  Economy,  p.  196. 
3  Physiologic  de  1'Homme,  ii.  396. 

3  Rullier,  Art.  Faim,  in  Diet,  de  Medecine,  torn,  viii.,  Paris,  1823. 

4  Die  Verdauung  nach  Versuchen,  u.  s.  w.;  or  French  translation,  by  A.  J.  L.  Joardan, 
Paris,  1827.  6  Op.  citat.,  ii.  25. 


556  DIGESTION. 

the  stomach  experiences  any  mutation.  M.  Dumas1  was  of  opinion,  that 
when  the  organ  is  empty,  it  receives  less  blood  than  when  full;  either 
on  account  of  the  great  flexion  of  the  vessels  in  the  former  case,  or  on 
account  of  the  compression  experienced  by  the  nerves  in  consequence 
of  the  contracted  state  of  the  organ.  He  thinks  that,  under  such  cir- 
cumstances, a  part  of  the  blood  sent  to  it  reflows  into  the  liver,  spleen, 
and  omentum;  and  he  regards  these  organs  as  diverticula  for  the  blood 
of  the  stomach,  especially  as  the  liver  and  spleen  are  then  less  com- 
pressed, and  the  omentum  more  extensive,  owing  to  the  retraction  of 
the  stomach.  Bichat,  however,  denies  both  the  fact  and  its  explanation. 
He  affirms,  that  on  opening  animals  suffering  under  hunger,  he  never 
observed  the  vessels  of  the  stomach  less  full  of  blood,  the  mucous  mem- 
brane less  florid,  or  the  vessels  of  the  omentum  more  turgid.  Is  it  not 
true,  he  adds,  that  the  vessels  of  the  stomach  are  more  flexuous  when 
the  organ  is  empty?  being,  as  well  as  the  nerves,  connected  with  the 
serous  coat,  they  are  unaffected  by  changes  of  size  in  the  organ;  and 
besides,  the  retraction  of  the  stomach  could  never  be  great  enough  to 
compress  the  nerves.  He  denies,  moreover,  that  the  liver  and  spleen 
are  more  free,  and  the  omentum  larger,  whilst  the  stomach  is  empty, 
as  the  abdominal  parietes  contract  in  the  same  proportion  as  the  stomach. 
Magendie,2  however,  contests  this  last  assertion  of  Bichat;  and  affirms, 
on  the  faith  of  positive  experiments,  that  the  pressure  sustained  by  the 
abdominal  viscera  is  in  a  ratio  with  the  distension  of  the  stomach.  If 
the  stomach  be  full,  the  finger,  introduced  into  the  cavity  of  the  abdo- 
men through  an  incision  in  its  parietes,  will  be  strongly  pressed  upon, 
and  the  viscera  forced  towards  the  opening ;  whilst,  if  it  be  empty,  the 
pressure  as  well  as  the  tendency  of  the  viscera  to  escape  through  the 
opening  is  considerable.  During  the  state  of  vacuity  of  the  organ, 
he  remarked  that  the  different  reservoirs  in  the  cavity  of  the  abdomen, — 
the  bladder  and  gall  bladder, — were  more  easily  filled  by  their  proper 
fluids.  With  regard  to  the  quantity  of  blood  circulating  through  the 
stomach  in  the  empty  and  full  state, — he  is  disposed  to  believe,  that  the 
organ  receives  less  in  the  former  condition ;  but  that  in  this  respect  it 
does  not  differ  from  other  abdominal  viscera. 

The  general  effects,  said  to  be  produced  by  hunger,  in  contradistinc- 
tion to  the  local,  are; — debility  and  diminished  action  of  every  organ; 
the  circulation  and  respiration  are  less  frequent;  the  heat  of  the  body 
sinks;  the  secretions  diminish,  and  all  the  functions  are  exerted1  with 
more  difficulty,  if  we  except  absorption,  which  it  is  affirmed,  and  with 
much  probability,  is  augmented.  If  the  abstinence  be  so  long  protracted 
as  to  cause  death,  the  debility  of  the  functions  becomes  real,  and  not 
sympathetic.  Respiration  and  circulation  languish;  all  the  animal 
functions  totter;  whilst  absorption  continues,  and  the  blood  is  supplied 
by  the  decomposition  of  the  different  organs, — the  fat,  the  various 
liquid  matters  and  the  tissues  of  the  organs  being  successively  sub- 
jected to  its  action.  It  is  obvious,  however,  that,  with  the  drain  per- 
petually taking  place,  this  state  of  affairs  cannot  exist  long ;  the  blood 
becomes  diminished  in  quantity,  and  insufficient  in  every  respect  to 
vivify  the  organs;  the  functions  of  the  brain  are  perverted,  and,  in 

1  Principes  de  Physiologie,  Paris,  1806.  a  Precis,  &c.,  edit,  cit.,  ii.  26. 


HUNGER.  557 

many  instances,  furious  delirium  has  closed  the  scene;  whilst,  at  others, 
the  miserable  sufferer  has  sunk  passively  into  the  sleep  of  death.  Oc- 
casionally, again,  so  dreadfully  painful  are  the  sensations  caused  by  pro- 
tracted privation  of  food,  that  the  most  violent  antipathies  and  dearest 
affections  have  been  overcome;  and  numerous  instances  have  occurred 
in  which  the  sufferer  has  attacked  his  own  species,  friends,  children, 
and  even  his  own  person.  The  horrible  picture  of  the  shipwreck,  by 
Byron,1  is  not  a  mere  romance.  It  is  a  narrative  of  facts  that  have 
actually  occurred,  expanded  somewhat  by  the  imagination  of  the  poet. 

Dr.  James  Currie2  has  related  the  case  of  a  person,  who  died  of 
inanition  from  stricture  of  the  oesophagus,  the  particulars  of  which  may 
exemplify  the  phenomena  presented  by  some  of  those  who  perish  from 
abstinence.  The  records  of  such  cases  are  rare.  From  the  17th  of 
October  to-  the  6th  of  December,  the  patient  was  supported,  without 
the  aid  of  the  stomach,  by  means  of  broth  clysters;  and  was  immersed 
in  a  bath  of  milk  and  water.  At  one  period  he  had  a  parched  mouth : 
a  blister  discharged  only  a  thin,  coagulable  lymph;  and  the  urine  was 
scanty,  extremely  high-coloured,  and  intolerably  pungent.  The  heat  of 
the  body  was  natural  and  nearly  uniform  from  first  to  last;  and  the  pulse 
was  perfectly  natural  until  the  last  days.  His  sleep  was  sound  and 
refreshing;  spirits  even;  and  intellect  unimpaired,  until  the  four  last 
days  of  existence,  when  clysters  were  no  longer  retained.  Vision  was 
deranged  on  the  first  of  December,  and  delirium  followed  on  the  suc- 
ceeding day;  yet  the  eye  was  unusually  sensible,  and  the  sense  of  touch 
remarkably  acute.  The  surface  and  extremities  were  at  times  of  a 
burning  heat;  at  others,  clammy  and  cold.  On  the  fourth,  the  pulse 
became* feeble  and  irregular,  and  respiration  laborious ;  and,  in  ninety- 
six  hours  after  all  means  of  nutrition  as  well  as  medicine  had  been 
abandoned,  he  ceased  to  breathe.  He  was  never  much  troubled  by 
hunger.  Thirst  was,  at  first,  troublesome,  but  it  was  relieved  by  the 
tepid  bath.  This  was  a  case  in  which  the  patient  sank  tranquilly 
to  death.  In  others,  the  distressing  accompaniments  above  described, 
are  met  with;  and  the  death  is  that  of  a  furious  maniac. 

The  period  at  which  the  fatal  event  may  occur  from  protracted  absti- 
nence is  dependent  on  many  circumstances.  As  a  general  rule  the 
young  and  robust  will  expire  sooner  than  the  older;  and  this  will  have 
to  be  our  guidance  in  questions  of  survivorship,  where  several  individuals 
have  perished  together  from  this  cause.  The  picture,  drawn  by  Dante 
of  the  sufferings  and  death  of  Count  Ugolino  della  Gherardescha,  who 
saw  his  sons  successively  expire  before  him  from  hunger,  is  in  this  re- 
spect true  to  nature. 

"  Now  when  our  fourth  sad  morning  was  renew'd, 

Gaddo  fell  at  my  feet,  outstretch'd  and  cold, 

Crying : — '  Wilt  thou  not,  father !  give  me  food  ?' 
There  did  he  die ;  and  as  thine  eyes  behold 

Me  now,  so  saw  I  three  fall,  one  by  one, 

On  the  fifth  day  and  sixth ;  whence  in  that  hold, 
I,  now  grown  blind,  over  each  lifeless  son 

Stretch 'd  forth  mine  arms.     Three  days  I  called  their  names, 

Then  Fast  achieved  what  Grief  not  yet  had  done." 

"INFERNO,"  canto  xxxiii. 

1  Don  Juan,  canto  ii.,  58.  *  Medical  Reports,  &c.,  Amer.  edit.,  Philad.,  1808. 


558 


DIGESTION. 


In  some  experiments  on  inanition  undertaken  by  M.  Chossat,1  on 
pigeons  and  turtle  doves,  the  following  general  phenomena  were  ob- 
served. Commonly,  the  animal  remained  calm  during  the  first  half  or 
two-thirds  of  the  period.  It  then  became  more  or  less  agitated,  and 
this  state  continued  as  long  as  the  temperature  remained  elevated.  On 
the  last  day  of  life,  however,  the  restlessness  ceased,  and  gave  place  to 
stupor.  When  set  at  liberty,  it  sometimes  looked  round  with  astonish- 
ment, without  attempting  to  fly,  and  at  times  closed  its  eyes,  as  if  in  a 
state  of  sleep.  Gradually,  the  extremities  became  cold,  and  the  limbs 
so  weak  as  to  be  no  longer  able  to  sustain  it  in  the  standing  posture. 
It  fell  over  on  one  side,  and  remained  in  any  position  in  which  it  might 
be  placed,  without  attempting  to  move.  Respiration  became  slower 
and  slower;  the  general  weakness  increased,  and  the  insensibility  became 
more  profound;  the  pupils  dilated;  and  life  became  extinct, — at  times 
in  a  calm  and  tranquil  manner;  at  others,  after  convulsive  actions,  pro- 
ducing opisthotonic  rigidity  of  the  body. 

He  endeavoured  to  discover  the  effect  of  age  in  modifying  the  con- 
tinuance of  life  during  inanition,  but  was  unable  to  ascertain  the  rela- 
tive ages  of  the  turtle  doves,  the  subjects  of  his  experiments;  he 
endeavoured,  however,  to  form  some  estimate — although,  obviously,  a 
fallacious  one — from  their  relative  weights,  classing  them  as  "young," 
"middle-aged,"  or  "adult,"  according  as  their  weights  were  beneath 
120  grammes,  from  120  to  160,  or  above  160.  The  following  table  is 
interesting,  however,  by  showing  the  duration  of  life,  and  the  loss  of 
substance  during  inanition,  in  animals  of  different  weights. 


Weight  of  the  Body. 

Loss  of  the  Body. 

Duration 
of  life. 

Weight  at 
commence- 
ment. 

Weight  at 
death. 

Entire  abso- 
lute loss. 

Proportional 
loss  in  1000 
parts. 

Daily  propor- 
tional loss. 

Gram. 

Gram. 

Gram. 

a.  Young  . 
b.  Middle-aged 
c.  Old  .     .     . 

11042 
143-62 
189-36 

82-84 
91-60 
101-61 

27-58 
52-02 
87-75 

,    0250 
0-362 
0-463 

0-081 
0-059 
0-035 

3-07 
6-12 
13-36 

The  entire  absolute  loss,  and  the  proportionate  loss,  were  much 
greater  in  the  heavier  animals;  the  daily  loss  was  by  much  the  most 
rapid  in  the  lightest;  and  it  is  probable,  that  this  was  owing  to  the 
more  rapid  waste  which  takes  place  in  the  young. 

The  sensation  of  hunger  resembles  every  other  sensation  in  the  mode 
in  which  it  is  accomplished.  There  must  be  impression,  conduction, 
and  perception.  That  the  encephalon  is  the  organ  of  the  last  part  of 
the  process  is  proved  by  all  the  arguments  used  in  the  case  of  the 
internal  sensations  in  general.  Without  its  intervention  in  this,  as  in 
every  other  case,  no  sensation  can  be  accomplished.  The  stomach  is 
the  organ  in  which  the  impression  is  effected;  and  by  means  of  the 
nerves  this  impression  is  conveyed  to  the  spinal  marrow  and  encepha- 
lon. The  eighth  pair  or  pneumogastric  nerves  have  generally  been 

1  Recherches  Experimentales  sur  1'Inanition,  Paris,  1843;  noticed  in  Brit,  and  For.  Med. 
Rev.,  April,  1844,  p.  347. 


HUNGER.  559 

regarded  as  the  agents  of  this  transmission;  and  it  has  been  affirmed 
by  Baglivi,  Valsalva,  Haller,  Dumas,  Legallois,  Chaussier,  and  others, 
that  if  they  be  divided  in  the  neck,  although  the  stomach  may  be 
favourably  circumstanced,  in  other  respects,  for  the  developement  of  the 
impression  of  hunger,  and  the  encephalon  for  its  reception,  there  is  no 
sensation ;  but  MM.  Leuret  and  Lassaigne,1  Dr.  John  Reid,2  Nasse,3 
and  Longet,4  deny,  that  such  effect  follows  the  division  of  these 
nerves;  and  the  first  gentlemen  affirm,  that  horses  have  eaten  as  usual, 
and  apparently  with  the  same  appetite,  after  they  had  removed  several 
inches  of  the  pneumogastric  nerves;  and  even  continued  to  eat  after 
the  stomach  was  filled.  To  these  experiments  we  shall  have  occasion 
to  refer  hereafter.  They  by  no  means,  however,  exhibit  that  this  in- 
ternal sensation  differs  in  its  essence  from  others. 

A  difficulty,  which  the  physiologist  has  always  felt,  concerns  the 
precise  nature  of  the  action  of  impression.  Its  seat  is  clearly  in  the 
stomach.  This  was  shown  incontestably  by  a  case  of  fistulous  opening 
into  the  organ,  which  fell  under  the  care  of  Dr.  Beaumont,  and  to 
which  there  will  be  frequent  occasion  to  refer.  When  the  subject  of 
this  case  was  made  to  fast  until  his  appetite  was  urgent,  it  was  imme- 
diately assuaged  by  feeding  him  through  the  aperture.  To  the  stomach, 
indeed,  all  our  feelings  refer  the  sensation.  It  is  dependent  upon  some 
modification  occurring  in  the  very  tissue  of  the  viscus;  and  in  the 
nerves,  which,  as  has  been  shown,  are  the  sole  agents  in  all  phenomena 
of  sensibility.  These  nerves  are  spread  over  the  stomach,  so  that  the 
precise  seat  of  the  impression  cannot  be  as  accurately  defined  as  in  the 
case  of  the  organs  of  external  sense.  Moreover,  the  nerves  of  the 
stomach  proceed  from  two  essentially  different  sources, — the  eighth 
pair,  and  great  sympathetic.  The  question  consequently  arises: — on 
which  of  these  is  the  impression  made  ?  The  results  of  the  experiment 
of  cutting  the  eighth  pair  in  the  neck  would  appear  to  decide  in  favour 
of  the  former. 

As  to  the  proximate  or  efficient  cause  of  hunger,  we  cannot  expect 
to  arrive  at  any  satisfactory  conclusion.  It  is  a  sensation;  and,  like 
all  sensations,  inscrutable.  Theories,  however,  as  on  all  obscure  topics, 
have  been  numerous,  and  these  have  generally  been  of  a  mechanical  or 
a  chemical  nature.  Some  have  attributed  it  to  the  mechanical  friction 
of  the  parietes  of  the  stomach  against  each  other,  in  consequence  of  its 
contraction;  in  which  state,  they  affirm,  the  mucous  coat  is  rugous,  and 
its  papillae  and  follicles  prominent.  It  is  manifest,  however,  from  the 
structure  of  the  organ,  that  no  such  friction  can  take  place.  Yet  this 
view  was  embraced  by  Haller.5  Dr.  Fletcher6  ascribes  it  to  a  kind  of 
permanent  though  partial  contraction  of  the  muscular  fibres  of  the 
stomach; — "not  that  alternate  general  contraction  and  relaxation, 

1  Recherches  Physiologiques  et  Chimiques  pour  servir  &  THistoire  de  la  Digestion,  Paris, 
1825. 

a  Edinb.  Med.  and  Surg.  Journal,  April,  1839,  and  art.  Par  Vagum,  in  Cyclop,  of  Anat. 
and  Physiol.,  Pt.  xxviii.,  p.  899,  Lond.,  April,  1847. 

3  Untersuchungen  zur  Physiologie  und  Pathologic,  Bonn,  1835-6. 

4  Traite  de  Physiologie,  ii.  342,  Paris,  1850. 

5  Element.  Physiol.,  lib.  xix.,  sect.  2,  §  12,  Bern.,  1764. 

6  Rudiments  of  Physiology,  Part  iii.,  by  Dr.  Lewins,  p.  73,  Edinb.,  1837. 


560  DIGESTION. 

which  produces  a  sensible  motion  of  this  organ,  nor  that  permanent 
general  contraction,  which  would  serve  to  diminish  its  cavity,  but  that 
kind  of  permanent  contraction,  which  takes  place  in  certain  fibres  alone, 
and  perhaps  through  a  part  of  their  length  only,  and  by  which  these 
fibres  are,  as  it  were,  drawn  away  from  the  others,  or,  in  other  words, 
a  minor  degree  of  cramp."  Others,  again,  have  accounted  for  the 
sensation  by  the  action  of  the  gastric  juice,  which  is  supposed  to  Ijave  a 
tendency  to  irritate  the  internal  membrane.  In  proof  of  this,  they  refer 
to  a  case,  mentioned  by  Mr.  Hunter,  in  which  the  mucous  membrane, 
in  a  man  who  died  of  fasting,  was  found  corroded.  The  gastric  juice 
is,  however,  incapable  of  eroding  living  animal  matter;  and  the  nume- 
rous cases,  which  have  occurred  since  that  of  Hunter,  have  shown,  that 
the  corrosion  and  perforation,  which  we  meet  with  on  dissection,  are  to 
be  referred  to  an  action  after  death,  and  must,  consequently,  be  totally 
unconnected  with  the  sensation  felt  during  life.  We  have,  indeed,  no 
reason  for  believing  that  the  gastric  juice  can  ever  attain  a  state  of 
acridity,  and  affect  physically  the  surface  by  which  it  is  secreted.  It 
has  been  remarked,  that  it  is  a  law  of  the  animal  economy,  that  no 
secretion  acts  upon  the  part  over  which  it  is  destined  to  pass,  provided 
such  part  be  in  a  healthy  condition.  Yet  Sommering1  ascribes  the 
pain  from  long-continued  fasting  to  the  action  of  the  gastric  juice;  and 
Dr.  Wilson  Philip2  is  manifestly  induced  to  believe  that  its  influence  on 
the  stomach  is,  in  some  mode  or  other,  productive  of  the  sensation :  his 
remarks,  however,  tend  simply  to  show, — what  we  have  so  many  oppor- 
tunities for  observing,  that  the  sensation  can  be  postponed  by  exciting 
vomiting,  or  inducing,  for  the  time,  a  morbid  condition  of  the  stomach. 
The  unanswerable  objection,  however,  to  all  these  views  is  the  fact — 
repeatedly  proved  by  Dr.  Beaumont,3  and  which  the  author  had  an 
opportunity  of  observing — that,  in  the  fasting  state  there  is  little  or  no 
gastric  juice  in  the  cavity  of  the  stomach.  Dr.  Beaumont  thinks,  that 
the  sensation  of  hunger  is  produced  by  distension  of  the  vessels,  that 
secrete  the  solvent ;  but  such  distension,  if  it  exist — which  is  by  no 
means  proved — must  itself  be  consecutive  on  the  nervous  condition  that 
engenders  the  sensation :  the  efficient  cause  of  such  condition  has  still 
to  be  explained.  Bichat,  again,  attributed  it  to  the  lassitude  or  fatigue 
of  the  stomach,  occasioned  by  the  contraction  of  its  muscular  coat 
when  continued  beyond  a  certain  time.  In  answer  to  this,  it  may  be 
remarked,  that  if  any  thing  impedes  the  nutrition  of  the  body,  hunger 
continues,  although  the  stomach  may  be  distended.  This  happens  in 
cases  of  scirrhous  pylorus,  where  the  nutritive  mass  cannot  pass  into 
the  small  intestine,  to  be  subjected  to  the  action  of  the  chyliferous 
vessels,  and  the  losses  of  the  body  cannot,  therefore,  be  repaired ; — 
facts  which  would  seem  to  show,  that  hunger  is  a  sensation  excited  in 
the  stomach  by  sympathy  with  the  wants  of  the  constitution ;  and  that 
it  is  immediately  produced  by  some  inappreciable  alteration  in  the 
condition  of  the  nerves  of  the  organ.  It  appears,  from  the  experiments 

1  De  Corp.  Human.  Fabric,  torn,  vi.,  Traject.  ad  Mosnum,  1794-1801. 
3  Experimental  Inquiry  into  the  Laws  of  the  Vital  Functions,  2d  edit.,  Lond.,  1818. 
3  Experiments  and  Observations  on  the  Gastric  Juice,  and  the  Physiology  of  Digestion,  p. 
57,  Plattsburg,  1833. 


PREHENSION  OF  FOOD.  561 

of  M.  Magendie,1  that  when  the  cerebrum  and  a  great  part  of  the  cere- 
bellum were  removed  in  ducks,  the  instinct  of  seeking  food  was  lost  in 
every  instance,  and  the  instinct  of  deglutition  in  many :  food,  however, 
introduced  into  the  stomach,  was  found  to  be  digested. 

b.  Prehension  of  Food. 

The  arms  and  mouth  have  been  described  as  organs  of  prehension. 
It  is  scarcely  necessary  to  say,  that  the  hands  seize  the  food  and  convey 
it  to  the  mouth  under  ordinary  circumstances;  but  there  are  cases  in 
which  the  mouth  is  the  sole-or  chief  organ  of  prehension.  Most  animals 
are  compelled  to  use  the  mouth  only.  When  the  food  is  conveyed  to  it 
by  the  hands,  it  must  open  to  receive  it.  The  mode  in  which  this  is 
effected  has  given  rise  to  controversy;  and,  strange  to  say,  is  not  yet 
considered  determined.  Whilst  some  physiologists  have  asserted,  that 
the  lower  jaw  alone  acts  in  opening  the  mouth  moderately;  others  have 
affirmed,  -that  both  the  jaws  separate  a  little; — the  lower,  however, 
moving  five  or  six  times  as  much  as  the  upper.  That  the  latter  is  the 
correct  view  can  be  proved  by  positive  experiment.  If,  when  the  mouth 
is  closed,  we  place  the  flat  side  of  the  blade  of  a  knife  against  the  teeth 
of  both  jaws;  and,  holding  the  knife  immovably,  separate  the  jaws;  we 
find,  that  both  jaws  move  on  the  blade;  but  the  lower  to  a  much  greater 
extent  than  the  upper.  Now,  as  the  upper  jaw  is  fixed  immovably  to 
the  head,  the  whole  head  must,  of  necessity,  participate  in  this  move- 
ment; and  the  question  arises,  what  are  the  agents  that  produce  it? 
Some  attribute  it  to  a  slight  action  of  the  extensor  muscles  of  the  head; 
and  affirm,  that  whilst  the  depressors  of  the  lower  jaw  carry  it  down- 
wards, the  extensors  of  the  head  draw  the  head  slightly  backwards,  and 
thus  raise  the  upper  jaw. 

MM.  Magendie2  and  Adelon3  assert,  that  when  the  mouth  is  opened 
moderately,  the  upper  jaw  does  not  participate;  but,  that  if  the  motion 
be  "forced"  or  extensive,  it  participates  slightly.  The  experiment, 
however,  with  the  knife,  which  is  adduced  by  M.  Adelon  himself,  com- 
pletely overthrows  this  notion;  and  shows,  that  both  jaws  act,  whenever 
the  mouth  is  slightly  opened.  M.  Magendie  agrees  with  those  who  con- 
sider, that,  whenever  the  upper  jaw  is  raised,  it  must  be  by  the  head 
being  thrown  back  on  the  vertebral  column ;  and  he  properly  remarks, 
that  where  there  is  a  physical  impediment  to  the  depression  of  the  lower 
jaw,  the  mouth  must  be  opened  solely  by  the  retroversion  of  the  head 
on  the  spine.  M.  Ferrein4  conceived,  that  the  motion  of  the  upper  jaw  is 
occasioned  by  the  action  of  the  stylo-hyoideus  muscle,  and  the  posterior 
belly  of  the  digastricus;  and  he  affirms,  that  whilst  the  anterior  fasci- 
culus or  belly  of  the  digastricus  depresses  the  lower  jaw;  the  posterior 
belly  with  the  stylo-hyoideus  carries  the  head  backwards,  and,  with  it, 
the  upper  jaw.  The  attachments,  however,  of  these  muscles  sufficiently 
show,  that  they  cannot  be  the  agents :  the  mastoid  process,  to  which 
the  posterior  belly  of  the  digastric  muscle  is  attached,  is  near  the  arti- 
culation of  the  head  with  the  atlas;  whilst  the  styloid  process,  to  which 

1  Precis,  &c.,  ii.  168.  2  Op.  citat.,  ii.  43.  3  Op.  citat.,  ii.  408. 

4  Memoir,  de  1'Acad.  des  Sciences  pour  1744. 

VOL.  i.— 36 


562 


DIGESTION. 


the  stylo-hyoideus  is  attached,  is  anterior  to  the  articulation;  and  its 
effect  ought  to  be  to  depress  the  upper  jaw.  The  view  of  Professor 
Chaussier  is  the  most  probable.  He  ascribes  the  slight  elevation  of  the 
upper  jaw  to  the  mechanical  arrangement  of  the  joint  of  the  lower. 
The  temporo-maxillary  articulation  is  not  formed  by  a  single  condyle, 
but  by  two,  which  are  so  disposed,  that  the  lower  cannot  roll  downwards 
during  the  depression  of  the  lower  jaw  without  causing  the  upper  con- 
dyle to  roll  upwards,  and,  consequently,  to  elevate  slightly  the  upper 
jaw.  Under  ordinary  circumstances,  then,  the  jaws  cannot  be  at  all 
separated  without  both  participating ;  but  if  we  determine  to  fix  the 
upper  jaw  we  can  make  the  lower  the  sole  agent  in  the  movement. 

As  soon  as  the  food  is  introduced  into  the  mouth,  the  jaws  are  closed 
to  retain  it,  and  subject  it  to  mastication.  Frequently,  however,  they 
assist  in  the  act  of  prehension,  as  when  we  bite  a  fruit,  to  separate  a 
portion  from  it; — the  incisor  teeth  acting,  in  such  case,  like  scissors. 
This  is  chiefly  produced  by  the  contraction  of  the  muscles  that  raise 
the  lower  jaw;  and  it  is  probable,  that  the  action  of  the  stylo-hyoideus 

Fig.  247. 


Action  of  the  Lower  Jaw  in  Prehension. 

A.  Frontal  bone.  B.  Temporal.  C.  Parietal.  D.  Occipital.  E.  Coronoid  process  of  the  lower 
jaw,  to  which  the  temporal  muscle  is  attached.  F.  Condyloid  process  or  head  of  the  lower  jaw.  G. 
Lower  jaw.  H.  Mastoid process.  I.  Upper  jaw.  J.  Cheekbone.  K.  Orbit.  L.  Meatus  auditoriua 
externus.  L*.  Coronal  suture.  M.  Squamous  suture.  N.  Lambdoidal  suture,  g.  Lower  jaw  de- 
pressed. 

is  concerned  in  the  movement;  drawing  the  head  and  upper  jaw  with  it 
downwards  and  forwards.     The  levator  muscles  of  the  jaw  act  here  with 


ORAL  DIGESTION.  563 

great  disadvantage; — the  lower  jaw  representing  a  lever  of  the  third 
kind;  the  fulcrum  being  in  the  joint;  the  power  at  the  insertion  of  the 
levator  muscles ;  and  the  resistance  in  the  substance  between  the  teeth. 
The  arm  of  the  resistance  is,  consequently,  the  whole  length  of  the 
lever;  and  we  can  understand  why  we  are  capable  of  developing  so 
much  more  force,  when  the  resistance  is  placed  between  the  molares; 
and  why  old  people, — who  have  become  toothless,  and  are,  consequently, 
constrained  to  bite  with  the  anterior  part  of  the  jaws, — the  only  portion 
that  admits  of  contact, — cannot  bite  with  any  degree  of  strength. 

The  size  of  the  body,  put  between  the  incisor  teeth,  influences  the 
degree  of  force  that  can  be  brought  to  bear  upon  it.  When  small  the 
force  can  be  much  greater,  as  the  levator  muscles  are  inserted  perpen- 
dicularly to  the  lever  to  be  moved,  and  the  whole  of  their  power  is 
advantageously  exerted;  but  if  the  body  be  so  large,  that  it  can  scarcely 
be  received  into  the  mouth,  and  be  resisting  withal,  the  incisors  can 
scarcely  penetrate  it ; — the  insertion  of  the  levator  muscles  into  the 
jaw  being  rendered  very  oblique ;  and  the  greater  part  of  the  force  they 
develope  consequently  lost.  This  will  be  readily  seen  by  Figure  247. 
When  the  mouth  is  closed,  or  nearly  so,  the  masseter,  and  temporal 
muscles  represented  respectively  by  the  lines  B  E  and  J  /,  are  inserted 
nearer  the  perpendicular ;  but  when  the  lower  jaw  is  depressed,  so  that 
the  situation  of  these  muscles  is  represented  by  the  dotted  lines  B  e  and  J 
&,  the  direction  in  which  the  muscles  act  will  be  more  oblique,  and,  there- 
fore, more  disadvantageous.  When  the  muscles  of  the  jaws  are  incapa- 
ble, of  themselves,  of  separating  the  substance,  as  in  the  case  of  the 
apple,  the  assistance  of  the  muscles  of  the  hand  is  invoked ;  whilst  the 
muscles  on  the  posterior  part  of  the  neck,  which  are  inserted  into  the 
head,  draw  it  backwards;  and,  by  these  combined  efforts,  the  substance 
is  forcibly  divided. 

c.   Oral  or  Buccal  Digestion. 

The  changes,  effected  upon  the  food  in  the  mouth,  are  important 
preliminaries  to  the  function  that  has  to  be  executed  in  the  stomach 
and  duodenum.  As  soon  as  it  enters  the  cavity,  it  is  subjected  to  the 
action  of  the  organ  of  taste;  and  its  sapid  qualities  are  appreciated. 
By  its  stay  there,  it  also  acquires  nearly  the  temperature  of  the  cavity. 
This  is,  however,  a  change  of  little  moment,  unless  the  food  is  so  hot, 
that  it  would  injure  the  stomach,  if  passed  rapidly  into  it.  Under  such 
circumstances,  it  is  tossed  about  in  the  mouth,  until  it  has  parted  with- 
its  caloric  to  various  portions  of  the  parietes  of  the  cavity;  and  then, 
if  in  a  fit  state  for  the  action  of  deglutition,  it  is  transmitted  along  the 
oesophagus;  but  the  most  important  parts  of  oral  digestion  are  the 
movements  of  mastication  and  insalivation  by  which  solid  food  is  com- 
minuted, and  imbued  with  the  secretions  poured  into  the  interior  of  the 
mouth,  and  which  we  have  shown  to  be  of  a  very  compound  character. 

Under  the  sense  of  taste,  the  influence  of  the  agreeable  or  disagreea- 
ble character  of  the  food  upon  the  digestive  function  was  expatiated 
upon.  It  is  unnecessary,  therefore,  to  do  more  than  allude  to  the  sub- 
ject here.  We  find  that  whilst  a  luscious  aliment  excites  to  prolonged 
mastication,  and  the  salivary  glands  to  augmented  secretion,  the  mas- 


564  DIGESTION. 

ticatory  and  salivary  organs,  by  dividing  and  moistening  the  food,  per- 
mit the  organs  of  gustation  to  enjoy  the  savour  by  successive  applica- 
tions. 

When  the  food  is  received  into  the  month,  if  it  be  sufficiently  soft, 
it  is  commonly  swallowed  immediately ;  unless  the  flavour  is  delicious? 
when  it  is  detained.  If  solid,  and,  especially,  if  of  any  size  or  density  7 
it  is  divided  into  separate  portions,  or  chewed, — the  action  constituting 
mastication.  If  the  consistence  of  the  substance  be  moderate,  the 
tongue,  by  being  pressed  strongly  against  the  bony  palate,  is  sufficient 
to  effect  this  division;  bruising  it,  and  at  the  same  time,  expressing  its 
fluid  portions.  If  the  consistence  be  greater,  the  action  of  the  jaws 
and  teeth  is  required.  For  this  purpose,  the  lower  jaw  is  successively 
depressed  and  elevated  by  the  action  of  its  depressors  and  levators ; 
and  the  horizontal  or  grinding  motion  is  produced  at  pleasure  by  the 
action  of  the  pterygoids.  Whilst  these  muscles  are  acting,  the  tongue 
and  cheeks  are  incessantly  moving,  so  as  to  convey  the  food  between 
the  teeth,  and  insure  its  comminution.  Mastication  is  chiefly  effected 
by  the  molares.  There  is  advantage  in  using  them,  independently  of 
their  form,  in  consequence  of  the  arm  of  the  resistance  being  much 
shortened,  as  has  already  been  shown. 

The  teeth  are  well  adapted  for  the  service  they  have  to  perform. 
The  incisors,  as  their  name  imports,  are  used  for  cutting ;  hence  their 
coronas  come  to  an  edge ;  the  canine  teeth  penetrate  and  lacerate,  and 
their  coronas  are  acuminated;  whilst  the  molares  bruise  and  grind,  and 
their  touching  surfaces  are  tuberous.  The  first,  having  usually  no  great 
effort  to  sustain,  are  placed  at  the  extremity  of  the  lever ;  the  latter,  for 
opposite  reasons,  are  nearest  the  fulcrum.  To  preclude  displacement 
by  the  efforts  they  have  occasionally  to  sustain,  they  are  firmly  fixed  in 
the  alveoli  or  sockets;  and,  as  the  roots  are  conical,  and  the  alveoli 
accurately  embrace  them,  the  force,  as  in  the  case  of  the  wedge,  i& 
transmitted  in  all  directions,  instead  of  bearing  altogether  upon  the 
jaw,  which  it  would  do,  were  the  fangs  cylindrical.  The  molar  teeth, 
having  the  greatest  efforts  to  sustain,  are  furnished  with  several  roots; 
or  with  one  that  is  extremely  large. 

The  gums  add  materially  to  the  solidity  of  the  junction  of  the  teeth 
with  the  jaws.  They  are  themselves  formed  of  highly  resisting  mate- 
rials, so  as  to  withstand  the  pressure  of  hard  and  irregular  substances. 
Whenever  they  become  spongy,  and  fall  away  from  the  teeth,  the  latter 
become  loose ;  and  are  frequently  obliged  to  be  extracted,  in  conse- 
quence of  the  loose  tooth  acting  as  an  extraneous  body,  and  inflaming 
the  lining  membrane  of  the  alveolus.  The  arrangement  of  the  jaw  is 
well  adapted  to  the  function;  the  lower  jaw  passing  behind  the  upper 
at  its  anterior  part;  but  coming  in  close  contact  at  the  sides,  where 
mastication  is  chiefly  effected. 

During  the  whole  time  that  mastication  is  going  on,  the  mouth  is 
closed ; — anteriorly,  by  the  lips  and  teeth,  which  prevent  the  food  from 
falling  out  of  the  cavity;  and  posteriorly  by  the  velum  palati,  the 
anterior  surface  of  which  is  applied  to  the  base  of  the  tongue.  At  the 
same  time,  the  food  is  undergoing  insalivation  or  admixture  with  the 
various  fluids  poured  into  the  mouth,  and  particularly  with  the  saliva, 


ORAL  DIGESTION.  565 

the  secretion  of  which  is  augmented,  not  only  by  the  presence  of  food, 
but  even  by  the  sight  of  it,  especially  if  the  food  be  desirable; — giving 
rise  to  what  is  called  "mouth-watering."  It  is  probable,  that,  inde- 
pendently of  mental  association,  the  action  of  the  secretory  organs  is 
increased  by  the  agitation  of  the  organs  themselves  during  the  masti- 
catory movements.  It  has,  indeed,  been  asserted,  that  the  parotid 
glands  are  so  situate,  as  regards  the  jaws,  that  the  movement  of  the 
lower  jaw  presses  upon  them,  and  forces  out  the  saliva ;  but  MM. 
Bordeu  and  J.  Cloquet  have  demonstrated,  anatomically  and  by  ex- 
periment, that  this  is  not  the  case.1 

It  has  been  supposed  by  some,  that  admixture  with  saliva  communi- 
cates to  the  food  its  first  degree  of  animalization ;  or  in  other  words,  its 
first  approximation  to  the  substance  of  the  animal  it  has  to  nourish. 
Such  are  the  opinions  of  Professor  S.  Jackson2  and  M.  Yoisin.3  The 
former  asserts,  that  he  has  ascertained  positively,  that  the  saliva  exerts 
a  very  energetic  operation  on  the  food,  separating,  by  its  solvent  pro- 
perties, some  of  its  constituent  principles,  and  performing  a  species  of 
digestion.  MM.  Tiedemann  and  Gmelin,  too,  think  that  the  water,  and 
the  carbonates  and  acetates  of  potassa  and  soda,  and  the  chlorides  of 
potassium  and  sodium,  of  the  saliva,  contribute  to  soften  and  dissolve 
the  food ;  whilst  the  nitrogenized  materials,  the  salivary  and  albuminous 
matters,  communicate  to  it  a  first  degree  of  animalization.  It  is  more 
probable,  however,  that  the  great  use  of  mastication  and  insalivation  is 
to  give  the  food  the  necessary  consistence,  in  order  that  the  stomach 
and  small  intestine  may  exert  their  action  upon  it  in  the  most  favourable 
manner;  and  that,  consequently,  the  changes  effected  upon  it  in  the 
mouth,  are  chiefly  of  a  mechanical  character.  In  the  case  of  many 
substances — as  sugar,  salt,  &c. — a  true  solution  takes  place  in  the 
saliva;  and  this  probably  happens  to  sapid  bodies  in  general; — the  par- 
ticles being  separated  by  imbibing  the  fluid.  Krimer,4  of  Leipzig,  held 
in  his  mouth  a  piece  of  ham,  weighing  a  drachm,  for  three  hours.  At 
the  expiration  of  this  time,  the  ham  was  white  on  its  surface,  and  had 
increased  in  weight  twelve  grains.  Krimer,  it  may  be  remarked,  be- 
lieves, that  the  tears  assist  in  digestion,  and  that  they  flow  constantly 
by  the  posterior  nares  into  the  stomach.  It  would  seem,  too,  that  an 
important  action  of  the  saliva  is  the  conversion  of  starch  into  dextrin 
or  grape  sugar.  From  one  drachm  of  starch,  Dr.  Wright5  obtained  in 
twelve  hours,  at  a  temperature  of  98°,  by  admixture  with  saliva,  thirty- 
one  grains  of  sugar.  This  probably  takes  place  by  the  action  of  some 
nitrogenized  secretion,  like  pepsin  in  stomachal  digestion.  It  has  been 
affirmed,  indeed,  on  the  strength  of  numerous  and  varied  experiments 
detailed  before  the  French  Academy  of  Sciences,6  by  MM.  Bernard  de 
Yillefranche  and  Barreswil,  that  in  the  gastric  juice,  pancreatic  fluid, 
and  saliva,  an  organic  principle  exists,  which  is  common  to  them  all; 
and  that  it  is  the  nature  of  the  chemical  reaction  associated  with  it, 
which  alone  determines  their  power  of  digesting  the  different  aliment- 

*  Adelon,  op.  cit.,  ii.  418.  2  principies  of  Medicine,  p.  354,  Philad.,  1832. 

3  Nouvel  Aper^u  sur  la  Physiologie  du  Foie,  &c.,  Paris,  1833. 

4  Versuch  einer  Physiologie  des  Blutes,  Leipz.,  1820. 

*  Lond.  Lancet,  1841-2.  6  Comptes  Rendus,  7  Juiilet,  1845. 


566  DIGESTION. 

ary  principles.  In  an  alkaline  fluid,  all  three  have  the  power  of  trans- 
forming starch,  and  do  not  digest  meat;  whilst  in  an  acid  fluid  they 
dissolve  meat,  but  do  not  act  on  starch.  Hence,  they  think,  it  appears 
easy  to  transform  these  fluids  into  each  other,  and  to  make  for  example 
an  artificial  gastric  juice  from  pancreatic  fluid.  The  action  of  saliva, 
however,  is  said  to  be  less  energetic,  both  on  meat  and  starch,  than  the 
pancreatic  fluid.  For  the  organic  compound  in  the  saliva,  M.  Mialhe1 
proposes  for  it  the  name  animal  diastase  salivaire.  It  would  seem,  how- 
ever, from  the  experiments  of  MM.  Magendie2  and  Bernard,3  that  many 
substances  besides  saliva, — as  pieces  of  the  mucous  membrane  of  the 
mouth,  bladder,  rectum  and  other  parts,  various  animal  and  vegetable 
tissues,  and  even  morbid  products  effect  the  transformation  of  starch  into 
sugar;  but  that  the  gastric  fluid  does  not.  The  part  of  the  saliva, 
according  to  M.  Bernard,  which  appears  to  be  most  active  is  that 
secreted  by  the  small  glands  and  the  mucous  membrane  of  the  mouth; 
but  it  has  been  properly  observed,  by  Messrs.  Kirkes  and  Paget,4  that 
if  the  influence  of  saliva  in  aiding  the  digestion  of  farinaceous  food  be 
admitted,  we  have  yet  to  seek  for  the  corresponding  purpose  served  by 
the  saliva  of  the  carnivora,  which  consume  no  such  food;  and  on  this 
point  we  possess  at  present  no  information. 

It  is  probable,  however,  that  the  main  action  of  saliva  is  to  soften 
the  food;  for  when  substances  are  well  mixed  with  water,  they  are 
retained  in  the  mouth  for  a  short  time  only ;  and,  consequently,  in  an 
amylaceous  solution  there  is  no  opportunity  for  change  to  be  effected. 
Experiments,  instituted  by  M.  Lassaigne,5  by  a  committee  of  the 
Institute,  and  by  M.  Bernard6  show,  that  when  the  food  is  dry  a  con- 
siderable admixture  of  saliva  takes  place,  whilst  if  it  be  so  softened, 
that  mastication  is  not  needed,  it  absorbs  scarcely  any.  In  executing 
these  experiments,  the  aliment  was  weighed  before  giving  it  to  the 
animal;  the  esophagus  was  cut  across;  and  the  aliment,  after  having 
been  chewed  and  insalivated,  was  inserted  through  the  wound  in  the 
neck.  The  difference  in  weight  indicated  the  quantity  of  saliva  that 
had  been  added  to  it. 

According  to  Professor  Berard,7  these  experiments  teach  us :  First. 
That  dry  forage  absorbs  about  four  or  five  times  its  weight  of  saliva  and 
mucus.  Secondly.  That  dry  feculaceous  articles  (oats,  starch  and  bar- 
ley meal)  absorb  a  little  more  than  their  weight.  Thirdly.  That  green 
forage  (green  leaves  and  stalks  of  barley)  absorb  a  little  less  than  half 
their  weight;  and  fourthly ;  that  moist  feculaceous  articles  (starch  and 
bran)  to  which  sufficient  water  has  been  added  for  the  food  to  be  swal- 
lowed without  previous  mastication,  do  not  sensibly  absorb  any. 

Both  mastication  and  insalivation  are  of  moment,  in  order  that  diges- 
tion shall  be  accomplished  in  perfection;  and,  accordingly,  they  who 

1  Lancette  Fran§aise,  Avril,  1845;  and  Banking's  Abstract,  vol.  i.  Part,  ii.,  Amer.  edit., 
p.  270,  New  York,  1846. 

2  Comptes  Rendus,  1847,  p.  117. 

3  Canstatt  und  Eisenmann,  Jahresbericht  uber  die  Fortschritte  in  der  Biologic,  im  Jahre, 
1847,  s.  117. 

4  Manual  of  Physiology,  Amer.  edit.,  p.  162,  Philad.,  1849. 

5  Journal  de  Chimie  Medicale,  p.  472,  Paris,  1845.    ^ 

6  Archives  Generates  de  Medecine,  4e  serie,  torn.  xiii.  p.  1. 

7  Cours  de  Physiologic,  p.  721,  Paris,  1848. 


ORAL  DIGESTION. 


567 


swallow  food  without  due  mastication,  or  waste  the  saliva  by  constant 
and  profuse  spitting,  are  more  liable  to  attacks  of  dyspepsia,  or  imper- 
fect digestion.  It  is  proper,  however,  to  add,  that  Dr.  Budge,1  on 
extirpating  the  salivary  glands  in  animals,  did  not  find  that  they  sus- 
tained the  smallest  apparent  injury;  whence  he  conjectures,  that  certain 
glands  can  act  as  succedanea  to  others,  and  that  in  the  removal  of  the 
salivary  glands  the  pancreas  supplies  perhaps  the  fluid  usually  secreted 
by  the  other. 

A  table  given  by  Dr.-  Robert  Dundas  Thomson2  as  the  results  of  ex- 
periments on  two  cows,  signally  exhibits  the  beneficial  effects  of  a  proper 
grinding  of  the  food.  The  cows  were  fed  on  entire  barley  and  malt 
steeped  in  hot  water.  They  were  then  fed  on  crushed  barley  and  malt 
prepared  in  the  same  manner.  The  influence  of  the  finer  division  of 
the  grain  in  increasing  the  quantity  of  milk  is  strikingly  shown. 


Entire  barley  and  grass, 
Entire  malt  and  grass, 


BROWN  Cow. 
Milk  in  periods  of  five  days. 
Ibs. 


96 
95 


Crushed  barley,  grass  and  hay, 


Crushed  malt  and  hay, 


105 

110 

97 

96 


WHITE  Cow. 

Milk  in  periods  of  five  days. 

106  Ibs. 

94     " 

98     " 

104     " 


110 


The  table  exhibits,  that  with  the  entire  barley,  the  milk  diminished 
during  the  second  five  days  of  the  experiment,  whilst  with  the  crushed 
barley  it  had  a  tendency  to  increase  during  each  succeeding  period. 

The  degree  of  resistance,  and  sapidity  of  the  food,  apprise  us  when 
mastication  and  insalivation  have  been  sufficiently  exerted.  When  this 
is  the  case  it  is  subjected  to  the  next  of  the  digestive  processes.  Some 
physiologists  have  affirmed,  that  the  uvula  is  the  organ  which  judges 
when  the  food  is  adapted  for  deglutition.  M.  Adelon,  whose  views  are 
generally  worthy  of  great  favour  and  attention,  asserts,  "that  it  judges 
by  its  mode  of  sensibility,  of  the  degree  in  which  the  aliment  has  been 
prepared  in  the  mouth;  of  the  extent  to  which  it  has  been  chewed,  im- 
pregnated with  saliva,  and  reduced  to  paste;  and,  according  to  the 
impression  it  receives,  it  excites,  sympathetically,  the  action  of  all 
those  parts;  directs  the  convulsive  contraction  of  the  muscles  that  raise 
the  pharynx,  even  keeps  the  stomach  on  the  alert,  and  disposes  it  to 
receive  favourably  or  to  reject  the  food  passing  to  it."  Such  a  func- 
tion would  be  anomalous.  It  is,  indeed,  impossible  for  us  to  conceive, 
how  so  insignificant  an  organ  could  be  possessed  of  those  elevated 
attributes.  Observation,  also,  proves,  that  the  notion  is  the  offspring 
of  fancy.  M.  Magendie3  asserts,  that  he  has  known  several  persons  who 
had  entirely  lost  the  uvula,  either  by  venereal  ulceration  or  by  ex- 

1  Medicinische  Zeitung,  May  4,  1842;  cited  in   British  and  For.  Med.  Rev.,  July,  1842, 
p.  221. 

2  Experimental  Researches  on  the  Food  of  Animals,  Amer.  edit.,  New  York,  1846. 

3  Op.  cit.,  ii.  58. 


568  DIGESTION. 

cision,  and  yet  he  never  remarked  that  their  mastication  experienced 
the  slightest  modification,  or  that  they  swallowed  inopportunely.  Our 
experience  corresponds  with  that  of  M.  Magendie.  We  know  of  more 
than  one  individual  in  whom  there  is  not  the  slightest  vestige  of  uvula, 
yet  they  taste,  chew,  and  swallow  like  other  persons. 

d.  Deglutition. 

The  act  of  swallowing,  although  executed  with  extreme  rapidity, 
and  apparently  simple,  is  the  most  complicated  of  the  digestive  opera- 
tions, and  requires  the  action  of  mouth,  pharynx  and  oesophagus.  It 
has  been  well  analyzed  by  M.  Magendie, — first  of  all  in  a  thesis,  main- 
tained at  the  Ecole  de  Medecine  of  Paris,  in  1808,  and  subsequently, 
in  his  Precis  Elementaire  de  Physiologie^  To  facilitate  its  study,  he 
divides  it  into  three  stages.  In  the  first,  the  food  passes  from  the 
mouth  into  the  pharynx;  in  the  second,  it  clears  the  apertures  of  the 
glottis  and  nasal  fossse,  and  attains  the  oesophagus;  and,  in  the  third, 
it  clears  the  esophagus  and  enters  the  stomach. 

1.  When  the  food  has  been  sufficiently  masticated  and  imbued  with 
saliva,  it  is  collected  by  the  action  of  the  cheeks  and  tongue  upon  the 
upper  surface  of  the  last  organ ; — the  mass  being  more  or  less  rounded, 
and  hence  usually  termed  alimentary  bolus.     Mastication  now  stops; 
the  tongue  is  raised  and  applied  against  the  bony  palate  in  succession 
from  the  tip  to  the  root,  and  the  alimentary  bolus,  having  no  other 
way  of  escaping  from  the  force  pressing  it,  is  directed  towards  the 
pharynx.     Previous  to  this,  the  pendulous  veil  of  the  palate  had  been 
applied  to  the  base  of  the  tongue.     The  bolus  now  raises  it  to  the  hori- 
zontal position:  the  circumflexus  palati  muscles  render  the  velum  tense, 
so  that  the  food  cannot  pass  into  the  nasal  fossse ;  and  the  muscles  that 
constitute  the  pillars  of  the  fauces — palato-pharyngei  and  glosso-sta- 
phylini — contribute  to  this  effect.     By  this  combination  of  results,  the 
food  is  impelled  into  the  pharynx.     The  muscles,  which,  by  their  action, 
apply  the  tongue  to  the  roof  of  the  mouth  and  to  the  velum  palati,  are 
the  proper  muscles  of  the  organ,  aided  by  the  mylo-hyoidei.     In  this 
first  stage  of  deglutition,  the  motions  are  voluntary,  except  those  of  the 
velum  palati.     The  process  is  not  executed  with  rapidity,  and  is  easily 
intelligible.     Such  is  not  the  case  with  the  second  stage.     The  actions 
in  it  are  complicated,  and   executed  with  so  much  celerity,  that  they 
have  been  regarded  as  a  kind  of  convulsion. 

2.  The  distance,  over  which  the  bolus  has  to  travel,  in  the  second 
stage,  is  trivial ;  the  rapidity  of  its  course  is  owing  to  the  larynx  or 
superior  aperture    of  the  windpipe,   which   opens  into  the  pharynx, 
having  to  be  cleared  instantaneously,  otherwise  respiration  might  be 
arrested,  and  serious  effects  ensue.     The  mode,  in  which  the  second 
stage  is  accomplished,  is  as  follows.     As  soon  as  the  alimentary  bolus 
comes  in  contact  with  the  pharynx  all  is  activity ;  the  pharynx  con- 
tracts, embraces,  and  presses  the  bolus;  and  the  velum  pendulum,  drawn 
down  by  the  palato-pharyngei  and  glosso-staphylini  muscles,  fulfils  a 
similar  office.     At  the  same  time,  the  genio-glossus,  by  applying  the 

1  Edit,  cit.,  ii.  63. 


DEGLUTITION.  569 

tongue  to  the  palate,  from  the  tip  to  the  root,  raises  the  os  hyoides, 
the  larynx,  and,  with  it,  the  anterior  paries  of  the  pharynx.  The 
same  effect  is  directly  induced  by  the  contraction  of  the  mylo-hyoidei, 
and  genio-hyoidei  muscles ;  which,  instead  of  acting  as  depressors  of 
the  lower  jaw,  as  they  do  during  mastication,  take  the  jaw  as  their 
fixed  point,  and  are  levators  of  the  os  hyoides.  The  larynx  is  thus 
elevated,  carried  forwards,  and  meets  the  bolus  to  render  its  passage 
over  the  aperture  of  the  larynx  shorter,  and,  therefore,  more  speedy. 
To  aid  this  effect, — when  we  make  great  efforts  to  swallow,  the  head  is 
inclined  forwards  on  the  thorax.  Whilst  the  os  hyoides  and  the  larynx 
are  raised,  they  approach  each  other, — the  upper  margin  of  the  thyroid 
cartilage  passing  behind  the  body  of  the  hyoid  bone :  the  epiglottic 
gland  is  pushed  backward,  and  the  epiglottis  is  depressed,  and  inclined 
backwards  and  downwards,  so  as  to  cover  the  entrance  to  the  larynx. 
The  cricoid  cartilage  executes  a  rotatory  motion  on  the  inferior  cornua 
of  the  thyroid  cartilage,  which  occasions  the  entrance  of  the  larynx  to 
-become  oblique  from  above  to  below,  and,  of  course,  from  before  to 
behind.  The  bolus  thus  glides  over  its  surface  ;  and,  forced  on  by  the 
veil  of  the  palate,  and  by  the  constrictors  of  the  pharynx,  reaches  the 
oesophagus. 

At  one  time,  it  was  universally  believed,  that  the  epiglottis  is  the 
sole  agent  in  preventing  substances  from  passing  into  the  larynx. 
The  experiments  of  M.  Magendie1  have,  however,  demonstrated,  that 
this  is  the  combined  effect  of  the  motions  of  the  larynx  just  described, 
and  of  the  muscles,  whose  office  it  is  to  close  the  glottis;  so  that,  if 
the  laryngeal  and  recurrent  nerves  be  divided  in  an  animal,  and  the  epi- 
glottis be  left  in  a  state  of  integrity,  deglutition  is  rendered  extremely 
difficult; — the  principal  cause,  that  prevented  the  introduction  of  ali- 
ments into  the  glottis,  having  been  removed  by  the  section.  M.  Magen- 
die, and  MM.  Trousseau  and  Belloc2  refer  to  cases  of  individuals,  who 
were  totally  devoid  of  epiglottis,  and  yet  swallowed  without  any  diffi- 
culty,3 and  Magendie  remarks,  that  if,  in  laryngeal  phthisis  with  destruc- 
tion of  the  epiglottis,  deglutition  be  laboriously  and  imperfectly  accom- 
plished, it  is  owing  to  the  carious  condition  of  the  arytenoid  cartilages, 
and  to  the  lips  of  the  glottis  being  so  much  ulcerated  as  not  to  be  able 
to  close  the  glottis  accurately.  Whilst  the  bolus,  then,  is  passing  over 
the  top  of  the  larynx,  respiration  must  be  momentarily  suspended, 
owing  to  closure  of  the  glottis;  and  if,  from  distraction  of  any  kind, 
we  attempt  to  speak,  laugh,  or  breathe,  at  the  moment  of  deglutition, 
the  glottis  opens,  the  food  enters,  and  cough  is  excited,  which  is  not 
appeased,  until  the  cause  is  removed.  This  is  what  is  called,  in  com- 
mon language,  uthe  food  going  the  wrong  way."  As  soon  as  the  bolus 
has  cleared  the  glottis,  the  larynx  descends,  the  epiglottis  rises,  and 
the  glottis  opens  to  give  passage  to  the  air.  This  is  owing  to  the 
relaxation  of  the  muscles  that  had  previously  raised  the  larynx  and 

1  Memoire  sur  1'Usage  de  1'Epiglotte  dans  la  Deglutition,  Paris,  1813  ;  and  Precis,  &c.,  i.  67. 

2  A  Practical  Treatise  on  Laryngeal  Phthisis,  &c.  &c.;   Dr.  Warder's  translation,  p.  84, 
in  Dunglison's  American  Medical  Library,  Philad.,  1839. 

3  A  similar  case  is  given  by  Targioni,  in  which  neither  deglutition  nor  speech  was  im- 
paired; Morgagni,  xxviii.  13. 


570  DIGESTION. 

closed  the  glottis.  M.  Chaussier  thinks,  that  the  sterno-hyoidei  muscles 
now  act,  and  aid  in  producing  the  descent  of  the  parts.1  The  author 
had  an  excellent  opportunity  for  noticing  the  laryngeal  phenomena  of 
deglutition  in  a  man,  who  had  cut  his  throat,  and  in  whom  a  fistulous 
opening  remained,  which  permitted  the  inferior  ligaments  of  the  larynx 
to  be  seen  distinctly.  The  glottis  was  observed  to  be  firmly  closed.2 
M.  Longet,3  who  has  made  experiments  connected  with  this  subject  on 
animals,  is  disposed  to  think,  that  the  displacements  of  the  base  of  the 
tongue  and  epiglottis  are  the  two  most  important  conditions,'  and  that 
the  closed  glottis  is  only  the  last  obstacle  set  up  against  the  passage 
of  food  into  the  larynx;  but  he  evidently  assigns  too  much  importance 
to  the  epiglottis. 

The  velum  pendulum,  then,  protects  the  posterior  nares  and  the 
orifices  of  the  Eustachian  tube  from  the  entrance  of  the  food ;  and  the 
epiglottis,  the  elevation  of  the  larynx,  with  the  contraction  of  the  mus- 
cles that  close  the  glottis,  are  the  great  agents  in  preventing  it  from 
passing  into  the  larynx.  The  whole  of  this  second  stage  consists  of 
rapid  movements,  of  an  entirely  involuntary  character,  which,  accord- 
ing to  Bellingeri,4  are  under  the  presidency  of  the  palatine  filaments  of 
the  fifth  pair;  but  these  filaments  are  sensory;  the  motor  filaments 
being  probably  derived  from  the  pneumogastric ;  or,  according  to  M. 
Longet,  from  the  spinal.5 

3.  In  the  third  stage,  the  pharynx,  by  its  contraction,  forces  the  ali- 
mentary bolus  into  the  oesophagus,  so  as  to  somewhat  dilate  the  upper 
part  of  the  organ.  The  upper  circular  fibres  are  thus  excited  to  action, 
and  force  the  food  onward.  In  this  way,  by  the  successive  contraction 
of  the  circular  fibres,  it  reaches  the  stomach.  In  the  upper  part  of  the 
oesophagus,  the  relaxation  of  the  circular  fibres  speedily  follows  their 
contraction;  but  this  is  not  the  case  in  the  lowest  third,  the  circular 
fibres  remaining  contracted,  for  some  time  after  the  entrance  of  the 
bolus  into  the  stomach, — probably  to  prevent  its  return  into  the  oeso- 
phagus. The  passage  of  the  bolus  along  the  oesophagus  is  by  no  means 
rapid.  M.  Magendie6  affirms,  that  he  was  struck,  in  the  prosecution  of 
his  experiments,  with  the  slowness  of  its  progression.  At  times,  it  was 
two  or  three  minutes  before  reaching  the  stomach ;  at  others,  it  stopped 
repeatedly,  and  for  some  time.  Occasionally,  it  even  ascended  from 
the  inferior  extremity  of  the  oesophagus  towards  the  neck,  and  subse- 
quently descended  again.  When  any  obstacle  existed  to  its  entrance 
into  the  stomach,  this  movement  was  repeated  a  number  of  times,  before 
the  food  was  rejected.  Every  one  must  have  felt  the  slowness  of  the 
progression  of  the  food  through  the  oesophagus  when  a  rather  larger 
morsel  than  usual  has  been  swallowed.  If  it  stops,  we  are  in  the  habit 
of  aiding  its  progress  by  drinking  some  fluid,  or  by  swallowing  a  piece 
of  bread.  Occasionally,  however,  the  probang  is  necessary  to  propel  it. 
The  pain  produced  in  these  cases,  according  to  M.  Magendie,  is  owing 

-1  Adelon,  op.  citat.,  ii.  424. 

2  Dunglison's  American  Medical  Intelligencer,  Oct.,  1841,  p.  73. 

3  L'Examinateur  Medical,  17  Oct.,  1841 ;  and  Brit,  and  For.  Med.  Rev.,  Jan.,  1842,  p.  228. 
*  Dissert.  Inaugural.  Turin,  1823  ;  noticed  in  Edinb.  Med.  and  Surg.  Journ.  for  July,  1834. 
5  Traite  de  Physiologie,  ii.  337,  Paris,  1850.  6  Op.  citat.,  ii.  69. 


DEGLUTITION.  571 

to  the  distension  of  the  nervous  filaments,  that  surround  the  pectoral 
portion  of  the  canal.  In  the  case  of  a  female,  labouring  under  a  disease 
which  permitted  the  interior  of  the  stomach  to  be  seen,  M.  Halle  noticed, 
that  whenever  a  portion  of  food  passed  into  the  stomach,  a  sort  of  ring 
or  bourrelet  was  formed  at  the  cardiac  orifice,  owing  to  the  mucous 
membrane  of  the  oesophagus  being  forced  into  the  stomach  by  the  con- 
traction of  its  circular  fibres.1  The  mucous  fluid  pressed  out  from  the 
different  follicles,  by  the  passage  of  the  bolus,  materially  facilitates  its 
progress. 

Notwithstanding  the  facility  with  which  deglutition  is  accomplished, 
almost  every  part  of  it  is  uninfluenced  by  volition,  being  dependent 
upon  organization,  and  exerted  instinctively.  If  the  alimentary  mat- 
ter contained  in  the  mouth  be  not  sufficiently  masticated ;  or  if  it  has 
not  the  shape,  consistence,  and  dimensions,  it  ought  to  possess;  or 
if  the  ordinary  movements,  that  precede  mastication,  have  not  been 
executed, — whatever  effort  we  may  make,  deglutition  is  impractica- 
ble. We  constantly  meet  with  persons  who  are  unable  to  swallow 
the  smallest  pill ;  and  yet  can  swallow  a  much  larger  mass,  if  cer- 
tain preliminary  motions  be  executed,  which,  in  the  case  of  the  pill, 
are  inadmissible,  in  consequence  of  its  being  usually  of  a  nauseous 
character.  It  appears,  that  the  involuntary  parts  of  the  function  are 
excited  by  the  stimulation  of  the  aliment;  for,  if  we  attempt  to  swal- 
low the  saliva  several  times  in  succession,  we  find  after  a  time,  that 
the  act  is  impracticable,  owing  to  the  deficiency  of  saliva.  Every 
one  must  have  experienced  the  difficulty  of  deglutition,  when  the 
mouth  and  fauces  were  not  duly  moistened  by  their  secretions.  The 
involuntary  part  of  deglutition  is  under  the  control  of  the  reflex  system 
of  nerves.  An  impression  is  made  by  the  alimentary  matters  upon  the 
excitor  or  afferent  nerves,  which  impression  is  conveyed  to  the  gray 
matter  of  the  spinal  cord,  and  in  the  invertebrata  to  ganglia  corre- 
sponding to  it;  whence  it  is  reflected  to  the  muscular  fibres  that  have 
to  be  thrown  into  contraction.  The  portion  of  the  spinal  cord,  which 
serves  as  a  centre  for  the  reception  of  the  impression,  and  the  point  of 
departure  for  the  motor  influence,  is  the  medulla  oblongata;  and  the 
experiments  of  Dr.  John  Reid2  lead  to  the  inference,  that  the  glosso- 
pharyngeal,  which  is  chiefly  distributed  to  the  mucous  surface  of  the 
tongue  and  fauces,  is  the  excitor  nerve;  the  pharyngeal  branches  of  the 
pneumogastric,  the  motors.  It  would  seem,  however,  that  these  nerves 
do  not  alone  possess  the  function ;  for  after  they  have  been  divided,  the 
animal  is  still  capable  of  imperfect  deglutition.  The  associate  excitor 
or  afferent  nerves,  Dr.  Reid  concludes  to  be — the  branches  of  the  fifth 
pair,  that  are  distributed  to  the  fauces,  and  probably  also  those  of  the 
superior  laryngeal  distributed  to  the  pharynx : — the  associate  motor  or 
efferent  nerves  being  branches  of  the  hypoglossal,  that  are  distributed 
to  the  muscles  of  the  tongue,  and  to  the  sterno-hyoid,  sterno-thyroid, 
and  thyro-hyoid  muscles;  filaments  of  the  inferior  laryngeal  that  ramify 
on  the  larynx ;  some  of  the  branches  of  the  fifth  pair  that  supply  the 
levator  muscles  of  the  lower  jaw;  the  branches  of  the  portio  dura  that 

1  Op.  cit.,  ii.  70.  2'  Edinb.  Med.  and  Surg.  Journ.,  vol.  xlix. 


572  DIGESTION. 

ramify  upon  the  digastric  and  stylo-hyoid  muscles,  and  upon  the  muscles 
of  the  lower  part  of  the  face ;  and  probably  some  of  the  branches  of 
the  cervical  plexus,  which  unite  themselves  to  the  descendens  noni.  It 
must  be  admitted,  however,  that  this  part  of  the  physiology  of  deglu- 
tition is  obscure.1 

Some  individuals  are  capable  of  swallowing  air;  and,  according  to  M. 
Magendie,2  it  is  an  art  that  can  be  attained  by  a  little  practice.  In  the 
stomach,  the  air  acquires  the  temperature  of  the  viscus,  becomes  rarefied, 
and  distends  the  organ;  exciting,  in  some,  a  feeling  of  burning  heat; 
in  others,  an  inclination  to  vomit,  or  acute  pain.  He  thinks  it  pro- 
bable, that  its  chemical  composition  undergoes  change;  but,  on  this 
point,  nothing  certain  is  known.  The  time  of  its  stay  in  the  stomach 
is  variable.  Commonly,  it  ascends  into  the  oesophagus,  and  makes  its 
exit  through  the  mouth  or  nostrils.  At  other  times,  it  passes  through 
the  pylorus,  and  diffuses  itself  through  the  whole  of  the  intestinal  canal, 
as  far  as  the  anus, — distending  the  abdominal  cavity,  and  simulating 
tympanites.  M.  Magendie  refers  to  the  case  of  a  young  conscript,  who 
feigned  the  disease  in  this  manner. 

e.  Chy  unification. 

When  the  food  has  experienced  changes  impressed  upon  it  by  the 
preceding  process,  it  reaches  the  cavity  of  the  stomach,  where  it  is  re- 
tained for  several  hours,  and  undergoes  another  portion  of  the  digestive 
action,  being  converted  into  a  pultaceous  mass,  to  which  the  term  chyme 
has  been  applied;  whilst  the  process  has  been  called  chymification.  It 
does  not  seem,  that  all  physiologists  have  employed  these  terms  in  this 
signification;  some  have  confounded  chyle  with  chyme;  and  chylification 
with  chymification.  The  former  of  these  processes  is  distinctly  an  in- 
testinal act:  the  latter  is  exclusively  gastric. 

The  aliment,  as  it  is  sent  down  by  repeated  efforts  of  deglutition, 
descends  into  the  splenic  portion  of  the  stomach  without  difficulty,  as 
regards  the  first  mouthfuls.  The  stomach  is  but  little  compressed  by 
the  surrounding  viscera,  and  its  parietes  readily  separate  to  receive  the 
food;  but  when  it  is  taken  in  considerable  quantity,  the  distension  gradu- 
ally becomes  more  difficult,  owing  to  the  compression  of  the  viscera 
and  the  distension  of  the  abdominal  parietes.  The  accumulation  takes 
place  chiefly  in  the  splenic  and  middle  portions.  Dr.  Beaumont3  ob- 
served, that  when  a  piece  of  food  was  received  into  the  stomach,  the 
rugae  of  the  latter  gently  closed  upon  it ;  and  if  it  were  sufficiently  fluid, 
gradually  diffused  it  through  the  cavity  of  the  organ,  but  entirely  ex- 
cluded more  whilst  the  action  continued.  The  contraction  ceasing, 
another  quantity  of  food  was  received  in  the  same  manner.  It  was 
found,  in  the  subject  of  his  experiments,  that  when  the  valvular  portion 
of  the  stomach,  situate  at  the  fistulous  aperture,  was  depressed,  and 
solid  food  introduced,  either  in  large  pieces  or  finely  divided,  the  same 
gentle  contraction  or  grasping  motion  took  place,  and  continued  for 
fifty  or  eighty  seconds,  and  it  would  not  allow  of  another  quantity,  until 

1  Longet,  Traite  de  Physiologic,  ii.  334,  337,  Paris,  1850. 

2  Carpenter,  Human  Physiology,  ii.  146.     3- Experiments,  &c.,  on  the  Gastric  Juice,  p.  110. 


CHYMIFICATION.  573 

that  period  had  elapsed:  the  valve  could  then  be  depressed,  and  more 
food  put  in.  When  the  man  was  so  placed,  that  the  cardia  could  be 
seen,  and  was  permitted  to  swallow  a  mouthful  of  food,  the  same  con- 
traction of  the  stomach  and  grasping  of  the  bolus  were  invariably  ob- 
served to  commence  at  the  oesophageal  ring.  Hence,  when  food  is 
swallowed  too  rapidly,  irregular  contractions  of  the  muscular  fibres  of 
the  oesophagus  and  stomach  are  produced ;  the  vermicular  motions  of 
the  rugae  are  disturbed,  and  the  regular  process  of  digestion  is  inter- 
rupted. 

Whilst  the  stomach  is  undergoing  distension  by  food,  it  experiences 
changes  in  its  size,  situation,  and  connexion  with  the  neighbouring 
organs.  The  dilatation  does  not  affect  its  three  coats  equally.  The 
two  laminae  of  the  peritoneal  coat  separate,  and  permit  the  stomach  to 
pass  farther  between  them.  The  muscular  coat  experiences  a  true 
distension;  its  fibres  lengthen,  but  still  so  as  to  preserve  the  particu- 
lar shape  of  the  organ ;  whilst  the  mucous  coat  yields,  in  those  parts 
especially  where  the  rugse  are  numerous;  that  is,  along  the  great  curva- 
ture and  splenic  portion.  In  place,  too,  of  being  flattened  at  its  anterior 
and  posterior  surfaces,  and  occupying  only  the  epigastrium,  and  a  part 
of  the  left  hypochondrium,  it  assumes  a  rounded  figure.  Its  great  cul-de- 
sac  descends  into  the  left  hypochondre  and  almost  fills  it,  and  the  greater 
curvature  descends  towards  the  umbilicus,  especially  on  the  left  side. 
The  pylorus  preserves  its  position  and  connexion  with  the  surrounding 
parts; — being  fixed  down  by  a  fold  of  the  peritoneum.  It  is  chiefly 
forwards,  upwards,  and  to  the  left  side,  that  the  dilatation  occurs.  The 
posterior  surface  cannot  dilate  on  account  of  the  resistance  of  the  verte- 
bral column,  and  of  a  ligamentous  formation  which  prevents  the  stomach 
from  pressing  on  the  great  vessels  behind  it.  Its  cardiac  and  pyloric 
portions  are  also  fixed;  so  that  when  it  is  undergoing  distension,  a 
movement  of  rotation  takes  place,  by  which  the  great  curvature  is 
directed  slightly  forwards;  the  posterior  surface  inclined  downwards, 
and  the  superior  upwards.  A  wound  received  in  the  epigastric  region, 
will,  consequently,  penetrate  the  stomach  in  a  very  different  part,  ac- 
cording as  the  viscus  may  be,  at  the  time,  full  or  empty. 

The  dilatation  of  the  organ  produces  changes  in  the  condition  of  the 
abdomen  and  its  viscera.  The  total  size  of  the  abdominal  cavity  is 
augmented;  the  belly  becomes  prominent;  and  the  abdominal  viscera 
are  compressed, — sometimes  so  much  as  to  excite  a  desire  to  evacuate 
the  contents  of  the  bladder  or  rectum.  The  diaphragm  is  crowded  to- 
wards the  thorax,  and  is  depressed  with  difficulty;  so' that,  not  only  is 
ordinary  respiration  cramped;  but  speaking  and  singing  become  labo- 
rious. When  the  distension  of  the  organ  is  pushed  to  an  enormous 
extent,  the  parietes  of  the  abdomen  may  be  painfully  distended,  and 
the  respiration  really  difficult.  It  is  in  these  cases  of  over-distension, 
that  an  energetic  contraction  of  the  oesophagus  is  necessary;  hence  the 
advantage  of  the  strong  muscular  arrangement  at  its  lower  part.  In 
proportion  as  the  food  accumulates  in  the  stomach,  the  sensation  of 
hunger  diminishes;  and,  if  we  go  on  swallowing  additional  portions,  it 
entirely  disappears,  or  is  succeeded  by  nausea  and  loathing.  The  quan- 
tity, necessary  to  produce  this  effect,  varies  according  to  the  individual, 


574  DIGESTION. 

as  well  as  to  the  character  of  the  food;  a  very  luscious  article  sooner 
cloying  than  one  that  is  less  so.  A  due  supply  of  liquid  with  solid  ali- 
ment also  enables  us  to  prolong  the  repast  with  satisfaction. 

As  the  stomach,  when  distended,  presses  upon  the  different  viscera 
and  upon  the  abdominal  parietes,  it  is  obvious,  that  it  must  experience  a 
proportionate  reaction.  An  interesting  question  consequently  arises; — 
to  determine  the  causes,  which  oppose  the  passage  of  the  food  back  along 
the  oesophagus,  as  well  as  through  the  pylorus.  M.  Magendie1  found, 
in  his  vivisections,  that  the  lower  portion  of  the  oesophagus  experiences, 
continuously,  an  alternate  motion  of  contraction  and  relaxation.  The 
contraction  begins  at  the  junction  of  the  two  upper  thirds  with  the 
lowest  third ;  and  is  propagated,  with  some  rapidity,  to  the  termination 
of  the  oesophagus  in  the  stomach.  Its  duration,  when  once  excited,  is 
variable ;  the  average  being,  at  least,  half  a  minute.  When  thus  con- 
tracted, it  is  hard  and  elastic,  like  a  cord  strongly  stretched.  The  relaxa- 
tion, that  succeeds  the  contraction,  occurs  suddenly  and  simultaneously 
in  all  the  contracted  fibres ;  at  times,  however,  it  appears  to  take  place 
from  the  upper  fibres  towards  the  lower.  In  the  state  of  relaxation,  the 
oesophagus  is  remarkably  flaccid; — forming  a  singular  contrast  with  that 
of  contraction.  This  movement  of  the  oesophagus  is,  according  to  M. 
Magendie,2  under  the  dependence  of  the  eighth  pair  of  nerves.  When 
these  nerves  were  divided  in  an  animal,  the  oesophagus  was  no  longer 
contracted.  Still  it  was  not  relaxed.  Its  fibres,  deprived  of  nervous 
influence,  were  shortened  with  a  certain  degree  of  force;  and  the  canal 
remained  in  a  state  intermediate  between  contraction  and  relaxation. 

The  lower  part  of  the  oesophagus  of  the  horse,  for  an  extent  of  eight 
or  ten  inches,  is  not  contractile  in  the  manner  of  muscles.  M.  Ma- 
gendie3 found,  when  the  eighth  pair  of  nerves  was  irritated,  or  the 
parts  were  exposed  to  the  galvanic  stimulus,  that  no  contraction  was 
produced.  The  oesophagus  of  that  animal  is,  however,  highly  elastic ; 
and  its  lower  extremity  is  kept  so  strongly  closed,  that  for  a  long  time 
after  death,  it  is  difficult  to  introduce  the  finger;  and  considerable  pres- 
sure is  required  to  force  air  into  it.  M.  Magendie  considers  this  arrange- 
ment to  be  the  true  reason,  why  horses  vomit  with  such  difficulty  as  to 
occasionally  rupture  the  stomach  by  their  efforts.  The  alternate  mo- 
tions of  the  oesophagus,  which  we  have  described,  oppose  the  return  of 
the  food  from  the  stomach.  The  more  the.  organ  is  distended,  the  more 
intense  and  prolonged  is  the  contraction,  and  the  shorter  the  relaxation. 
The  contraction  commonly  coincides  with  inspiration ;  the  time  at  which 
the  stomach  is,  of  course,  most  strongly  compressed.  The  relaxation 
is  synchronous  with  expiration. 

The  pylorus  prevents  the  alimentary  mass  from  passing  into  the 
duodenum.  In  living  animals,  whether  the  stomach  be  filled  or  empty, 
this  aperture  is  constantly  closed  by  the  constriction  of  its  fibrous  ring, 
and  the  contraction  of  its  circular  fibres ;  and,  so  accurately  is  it  closed, 
that,  if  air  be  forced  into  the  s.tomach  from  the  oesophagus,  the  organ 
must  be  distended,  and  considerable  exertion  made  to  overcome  the 
resistance  of  the  pylorus.  Yet,  if  air  be  forced  from  the  small  intes- 

1  Precis,  &c.,  ii.  82.  2  Ibid.,  ii.  18.  3  i^rf.,  &  19. 


CHYMIFICATION.  575 

tine  in  the  direction  of  the  stomach,  the  pylorus  offers  no  resistance ; — 
suffering  it  to  enter  the  organ  under  the  slightest  pressure; — a  circum- 
stance that  accounts  for  the  facility  with  which  bile  enters  the  stomach; 
especially  when  there  exists  inverted  action  of  the  duodenum.  To  the 
pylorus,  however,  a  more  active  part  has  been  assigned  in  the  passage 
of  the  chyme  from  the  stomach  into  the  intestine.  "Nothing  in  the 
animal  economy,"  says  Dr.  Southwood  Smith,1  "is  more  curious  and 
wonderful  than  the  action  of  that  class  of  organs  of  which  the  pylorus 
affords  a  remarkable  example.  If  a  portion  of  undigested  food  present 
itself  at  this  door  of  the  stomach,  it  is  not  only  not  permitted  to  pass, 
but  the  door  is  closed  against  it  with  additional  firmness;  or,  in  other 
words,  the  muscular  fibres  of  the  pylorus,  instead  of  relaxing,  contract 
with  more  than  ordinary  force.  In  certain  cases,  where  the  digestion 
is  morbidly  slow,  or  where  very  indigestible  food  has  been  taken,  the 
mass  is  carried  to  the  pylorus  before  it  has  been  duly  acted  upon  by 
the  gastric  juice:  then,  instead  of  inducing  the  pylorus  to  relax,  in 
order  to  allow  of  its  transmission  to  the  duodenum,  it  causes  it  to  con- 
tract with  so  much  violence  as  to  produce  pain,  while  the  food,  thus  re- 
tained in  the  stomach  longer  than  natural,  disorders  the  organ:  and  if 
digestion  cannot  ultimately  be  performed,  that  disorder  goes  on  increas- 
ing until  vomiting  is  excited,  by  which  means  the  load  that  oppressed 
it  is  expelled.  The  pylorus  is  a  guardian  placed  between  the  first  and 
the  second  stomach,  in  order  to  prevent  any  substance  from  passing 
from  the  former  until  it  is  in  a  condition  to  be  acted  upon  by  the  latter; 
and  so  faithfully  does  this  guardian  perform  its  office,  that  it  often,  as 
we  have  seen,  forces  the  stomach  to  reject  the  offending  matter  by 
vomiting,  rather  than  allow  it  to  pass  in  an  unfit  state;  whereas,  when 
chyme,  duly  prepared,  presents  itself,  it  readily  opens  a  passage  for  it 
into  the  duodenum."  This  view  of  the  functions  of  the  pylorus  has 
antiquity  in  its  favour.  It  is,  indeed,  as  old  as  the  name,  which  was 
given  to  it  in  consequence  of  its  being  believed  to  be  a  faithful  porter 
or  janitor,  (rtva.copo$,  "a  porter;'5)  but  it  is  doubtless  largely  hypothetical. 
We  constantly  see  substances  traverse  the  whole  extent  of  the  intestinal 
canal,  without  having  experienced  the  slightest  change  in  the  stomach. 
Buttons,  half-pence,  &c.,  have  made  their  way  through,  without  diffi- 
culty ;  as  well  as  the  tubes  and  globes,  employed  in  the  experiments  of 
Spallanzani,  Stevens,  and  others.  There  are  certain  parts  of  fruits, 
which  are  never  digested,  yet  the  "janitor"  is  always  accommodating. 
Castor  oil  is  capable  of  being  wholly  converted  into  chyle ;  and  would 
be  so,  if  it  could  be  retained  in  the  stomach  and  small  intestines;  yet 
there  is  no  agent,  which  arrests  its  onward  progress.  Still,  from  these, 
and  other  circumstances,  M.  Broussais2  has  inferred,  that  there  is  an 
internal  gastric  sense,  which  exerts  an  elective  agency ;  detaining,  as  a 
general  rule,  substances  that  are  nutritive;  but  suffering  others  to  pass. 
The  presence  of  food  in  the  stomach  after  a  meal  soon  excites  the 
organ  to  action,  although  no  change  in  the  food  is  perceptible  for  some 
time.  The  mucous  membrane  becomes  more  florid,  in  consequence  of 

1  Animal  Physiology,  Library  of  Useful  Knowledge,  p.  41. 

2  Traite  de  Physiol.  appliquee  a  la  Pathologie ;  translated  by  Drs.  Bell  and  La  Roche,  p.  314, 
Philad..  1832. 


576  DIGESTION. 

the  larger  afflux  of  blood;  and  the  different  secretions  appear  to  take 
place  in  greater  abundance;  become  mixed  with  the  food,  and  exert  an 
active  and  important  part  in  the  changes  it  experiences  in  the  stomach. 
Direct  experiment  has  proved  that  such  augmented  secretion  actually 
occurs.  If  an  animal  be  kept  fasting  for  some  time,  and  then  be  made 
to  swallow  dry  food,  or  even  stones,  and  be  deprived  of  liquid  aliment, 
the  substances  swallowed  will  be  found, — on  killing  it  some  time  after- 
wards,— surrounded  by  a  considerable  quantity  of  fluid.  Such  is  not 
the  case  with  animals  killed  after  fasting.  The  stomach  then  contains 
no  fluid  matter.  The  augmented  secretion  in  the  former  case  must, 
therefore,  be  owing  to  the  presence  of  dry  food  in  the  stomach.  That 
it  is  not  simply  the  fluid  passed  down  by  deglutition, — the  salivary  and 
mucous  secretions,  for  example, — is  proved  by  the  fact,  that  the  same 
thing  occurs  when  the  oesophagus  has  been  tied.  Besides,  if  the  sto- 
mach of  a  living  animal  be  opened,  and  any  stimulating  substance  be 
applied  to  its  inner  surface,  a  secretion  is  seen  to  issue  in  considerable 
quantity  at  the  points  of  contact ;  and,  again,  if  an  animal  be  made  to 
swallow  small  pieces  of  sponge,  attached  to  a  thread  hanging  out  of  the 
mouth,  by  means  of  which  they  can  be  withdrawn,  they  become  filled 
with  the  fluids  secreted  by  the  stomach,  and,  on  withdrawing  them,  a 
sufficient  quantity  can  be  obtained  -for  analysis.  Such  experiments 
have  been  repeatedly  performed  by  MM.  Reaumur,1  Spallanzani,2  and 
others.  In  Dr.  Beaumont's  case3  the  collection  of  gastric  secretion  was 
obtained  by  inserting  an  elastic  gum  tube  through  the  opening:  in  a 
short  time  fluid  enough  was  secreted  to  flow  through  the  tube.  This 
admixture  with  the  fluids  of  the  mucous  membrane  of  the  stomach,  and 
the  secretions  continually  sent  down  from  the  mouth  by  the  efforts  of 
deglutition,  is  the  only  apparent  change  witnessed  for  some  time  after 
the  reception  of  solid  food.  Sooner  or  later,  according  to  circum- 
stances, .the  pyloric  portion  of  the  organ  contracts  sending  into  the 
splenic  portion  the  food  it  contains:  to  the  contraction  dilatation  suc- 
ceeds ;  and  this  alternation  of  movements  goes  on  during  the  whole  of 
digestion.  After  this  time  chyme  only  is  found  in  the  pyloric  portion 
mixed  with  a  small  quantity  of  unaltered  food.  This  motion  of  con- 
traction and  relaxation  has  been  called  peristole;  and  it  appears,  at 
first,  to  be  limited  to  the  pyloric  portion,  but  gradually  extends  to  the 
body  and  splenic  portion,  so  that,  ultimately,  the  whole  stomach  parti- 
cipates in  it.  It  consists  in  an  alternate  contraction  and  relaxation  of 
the  circular  fibres;  and  the  gentle  oscillation,  thus  produced,  not  only 
facilitates  the  admixture  of  the  food  with  the  gastric  secretions,  but 
continually  exposes  fresh  portions  to  their  action.  The  experiments  of 
Bichat  satisfied  him,  that  the  peristole  is  more  marked,  the  greater  the 
fulness  of  the  stomach.  He  made  dogs  swallow  forced-meat  balls,  in 
the  centre  of  which  he  placed  cartilage,  and  found,  that  when  the  sto- 
mach was  greatly  charged,  the  cartilages  were  pressed  out  of  the  balls. 
This  did  not  happen,  when  the  organ  contained  a  smaller  quantity  of 
food. 

1  Memoir,  de  1'Acad.  pour  1752.  2  Exper.  sur  la  Digestion,  Geneve,  1783. 

3  Experiments,  &c.,  on  the  Gastric  Juice,  p.  106. 


CHYMIFICATION.  577 

The  ordinary  course  and  direction  of  the  revolutions  of  the  food, 
according  to  Dr.  Beaumont,1  are  as  follows: — The  bolus,  as  it  enters 
the  cardia,  turns  to  the  left;  passes  the  aperture;  descends  into  the 
splenic  extremity,  and  follows  the  great  curvature  towards  the  pyloric 
end.  It  then  returns  in  the  course  of  the  lesser  curvature,  and  makes 
its  appearance  again  at  the  aperture,  in  its  descent  into  the  great  cur- 
vature to  perform  similar  revolutions.  That  these  are  the  revolutions 
of  the  contents  of  the  stomach,  he  ascertained  by  identifying  particular 
portions  of  food;  and  by  the  fact,  that  when  the  bulb  of  the  thermome- 
ter was  introduced  during  chymification,  the  stem  invariably  indicated 
the  same  movements.  Each  revolution  is  completed  in  from  one  to 
three  minutes,  and  the  motions  are  slower  at  first  than  when  chymifi- 
cation has  made  considerable  progress.  In  addition  to  these  move- 
ments, the  stomach  is  subjected  to  more  or  less  succussion  from  the 
neighbouring  organs.  At  each  inspiration  it  is  pressed  upon  by  the 
diaphragm;  and  the  large  arterial  trunks  in  its  vicinity,  as  well  as  the 
arteries  distributed  over  it,  subject  it  to  constant  agitation. 

It  has  been  already  remarked,  that  the  peristaltic  action  of  the  sto- 
mach,— and  the  action  extends  likewise  to  the  intestines, — is  effected 
by  the  muscular  coat  of  the  organ.  It  is,  however,  an  involuntary  con- 
traction, and  appears  to  be  little  influenced  by  the  nervous  system ; 
continuing,  for  instance,  after  the  division  of  the  eighth  pair  of  nerves; 
becoming  more  active,  according  to  M.  Magendie,2  as  animals  are  more 
debilitated,  and  even  at  death  ;  and  persisting  after  the  alimentary 
canal  has  been  removed  from  the  body.  MM.  Tiedemann  and  Gmelin,3 
however,  affirm,  that  by  irritating  the  plexus  of  the  eighth  pair  of 
nerves  situate  around  the  oesophagus  with  the  point  of  a  scalpel,  or 
touching  it  with  alcohol,  the  peristole  of  both  stomach  and  intestines 
can  be  constantly  excited  ;  and  Valentin  and  Dr.  John  Reid  state, 
that  distinct  movements  may  be  excited  in  the  stomach  by  irritating 
the  pneumogastric.  This  involuntary  function,  as  well  as  that  exerted 
by  the  heart  and  other  involuntary  organs,  affords  us  a  striking  instance 
of  the  little  nervous  influence,  which  seems  to  be  requisite  for  carry- 
ing on  many  of  those  functions  that  have  to  be  executed  independently 
of  volition  through  the  whole  course  of  existence  ;  and  which  appear  to 
be  excited  at  times,  in  a  reflex  manner,  by  the  presence  of  appropriate 
excitants  ; — of  food,  in  the  case  of  the  peristaltic  action  of  the  stomach ; 
of  blood,  in  that  of  the  heart,  &c. ;  and  yet  may  be  carried  on  in  the 
absence  of  all  nervous  influence,  as  in  the  cases  of  the  intestinal  canal, 
and  the  heart,  which  may  contract  for  a  long  time  after  they  have  been 
removed  from  the  body.  In  the  intestinal  canal,  the  movements  are 
doubtless  influenced  by  the  spinal  cord,  probably  through  the  sympa- 
thetic by  means  of  the  fibres  which  the  canal  derives  from  it ;  but 
although  influenced  by  the  spinal  cord,  they  are  not  dependent  upon  it 
for  contractility.  As  Dr.  Carpenter  has  remarked,  the  canal  is  ena- 
bled to  propel  its  contents  by  its  inherent  powers  ;  but — as  in  other 
instances — the  nervous  centres  exert  a  general  control  over  even  the 

1  Op.  citat,  p.  110.  a  Precis  Elementaire,  ii.  20. 

3  Die  Verdauung,  u.  s.  w.  or  French  edit.,  Recherches  sur  la  Digestion,  Paris,  1827. 

VOL.  i. — 37 


578  DIGESTION, 

organic  functions,  "  doubtless  for  the  purpose  of  harmonizing  them 
-with  each  other,  and  with  the  conditions  of  the  organs  of  animal  life."1 

The  gentle,  oscillatory  or  vermicular  motion  of  the  stomach,  and  the 
admixture  with  the  fluids,  secreted  by  its  internal  membrane,  as  well  as 
by  the  different  follicles,  &c.,  in  the  supra-diaphragmatic  portion  of  the 
alimentary  canal,  are  probably  the  main  agents  in  the  digestion  ope- 
rated in  the  stomach. 

Much  contrariety  of  sentiment  has  existed  regarding  the  precise 
organs  that  secrete  the  fluid  which  oozes  out  as  soon  as  food  is  placed 
in  contact  with  the  mucous  coat  of  the  stomach.  Whilst  some  believe 
it  to  be  exhaled  from  that  membrane  ;  others  conceive  it  to  be  secreted 
by  the  numerous  follicles,  seated  in  the  membrane  as  well  as  in  that  of 
the  lower  portion  of  the  oesophagus;  or  by  what  have  been  termed  gas- 
tric glands.  The  analogy  of  many  animals,  especially  of  birds,  would 
render  the  last  opinion  the  most  probable.  In  them  we  find,  in  the 
second  stomach,  the  cardiac  or  gastric  glands  largely  developed  ;  and  it 
is  probable,  that  they  are  the  great  agents  of  the  secretion  of  the  digest- 
ive fluid.  (See  Figs.  228  and  229.)  MM.  Tiedemann  and  Gmelin2  affirm, 
that  the  more  liquid  portion  of  the  gastric  fluid  is  exhaled,  and  that  the 
thicker,  more  ropy  and  mucous  portion  is  secreted  by  the  follicles, 
Rudolphi3  assigns  it  a  double  origin  ; — from  exhalants,  and  gastric 
glands;  whilst  MM.  Leuret  and  Lassaigne4  ascribe  its  formation  exclu- 
sively to  the  villi.  Dr.  Beaumont,5  who  had  an  excellent  opportunity 
for  experimenting  on  this  matter,  remarks,  that  on  applying  aliment,  or 
any  irritant,  to  the  internal  coat  of  the  stomach,  and  observing  the 
effect  through  a  magnifying-glass,  innumerable  minute,  lucid  points,  and 
very  fine  papillae,  could  be  seen  protruding,  from  which  a  pure,  limpid, 
colourless,  slightly  viscid  fluid  distilled,  which  was  invariably  and  dis- 
tinctly acid.  On  applying  the  tongue  to  the  mucous  coat  in  its  empty, 
unirritated  state,  no  acid  taste  could  be  perceived.  Although  no  aper- 
tures were  perceptible  in  the  papillae,  even  with  the  assistance  of  the 
best  microscope  that  could  be  obtained,  the  points,  whence  the  fluid 
issued,  were  clearly  indicated  by  the  gradual  appearance  of  innumera- 
ble very  fine,  lucid  specks,  rising  through  the  transparent  mucous  coat, 
and  seeming  to  burst,  and  discharge  themselves  upon  the  very  points 
of  the  papillae,  diffusing  a  limpid,  thin  fluid  over  the  whole  interior  gas- 
tric surface. 

A  like  difference  of  opinion  has  prevailed  regarding  the  chemical 
character  of  the  fluids  ;  and  this  has  partly  arisen  from  the  difficulty 
of  obtaining  them  identical.  The  true  fluid  secreted  by  the  gastric  fol- 
licles or  mucous  membrane  can  never,  of  course,  be  obtained  for  examina- 
tion in  a  state  of  purity.  It  must  always  be  mixed  not  only  with  the 
other  secretions  of  the  stomach,  but  with  all  those  transmitted  to  the 
organ,  by  the  constant  efforts  of  deglutition.  It  is,  consequently,  to 
this  mixed  fluid,  that  the  term  gastric  juice  has  really  been  applied ; 
although  it  is  more  especially  appropriated  to  the  particular  fluid,  pre- 
sumed to  be  secreted  by  the  stomach,  and  to  be  the  great  agent  in  diges- 

1  Human  Physiology,  p.  151,Lond.,  1842.  2  Op.  citat. 

3  Grundriss  der  Physiologie,  2er  Band,  2<e  Abtheilung,  s.  iii.,  Berlin,  1828. 

4  Recherches  sur  la  Digestion,  Paris,  1825.  5  Op.  citat.,  p.  103. 


CHYMIFICATION.  579 

tion.  To  the  nature  of  the  gastric  juice  and  its  effects  in  the  process 
of  digestion,  we  shall  have  occasion  to  recur  presently. 

It  is  probably  owing  to  the  quantity  of  fluid  secreted  by  the  stomach, 
that  it  is  so  largely  supplied  with  bloodvessels;  and  that  the  mucous 
membrane  is  more  injected,  during  the  presence  of  food  in  the  organ. 
Experiments,  by  Sir  Benjamin  Brodie1  and  others,  would  seem  to  show, 
that  the  secretion  is  under  the  influence  of  the  eighth  pair  of  nerves. 
Having  administered  arsenic  to  different  animals — on  some  of  which  he 
had  divided  these  nerves, — he  found,  that,  whilst  the  stomachs  of  those, 
in  which  the  nerves  wrere  entire,  contained  a  large  quantity  of  a  thin, 
mucous  fluid ;  in  those,  whose  nerves  were  divided,  the  organ  was  in- 
flamed and  dry.  Leuret  and  Lassaigne,2  however,  affirm,  that  divi- 
sion of  the  nerves  had  no  influence  on  the  secretion.  But  more  of  this 
presently. 

Before  entering  into  the  views  of  different  physiologists  on  chymifi- 
cation, — in  other  words,  into  the  theories  of  digestion, — it  will  be  well 
to  refer  to  the  physical  and  chemical  properties  of  the  chyme.  Whether 
the  changes  in  the  food  be  simply  physical  or  chemical,  or  whether  the 
first  stage  of  animalization  be  effected  within  the  stomach,  will  be  a 
topic  for  future  inquiry.  Chyme  is  a  soft,  homogeneous  substance,  of 
grayish  colour  and  acid  taste.  Such  are  its  most  common  characters: 
it  varies,  however,  according  to  the  food  taken,  as  may  be  observed, 
by  feeding  animals  on  different  simple  alimentary  substances,  and 
killing  them  during  digestion.  This  difference  in  its  properties  accounts 
for  the  discrepancy  observable  in  the  accounts  of  writers.  The  change 
wrought  on  the  aliments  is,  doubtless,  of  a  chemical  nature;  but  the 
new  play  of  affinities  is  controlled  by  circumstances  inappreciable  to 
us.  In  the  case  of  a  female  patient  at  the  hospital  La  Charite,  of 
Paris,  who  had  been  gored  by  a  bull,  and  had  a  fistulous  opening  in 
the  stomach,  the  food,  during  its  conversion  into  chyme,  appeared  to 
have  acquired  an  increase  of  its  gelatin;  a  greater  proportion  of  chlo- 
ride of  sodium;  phosphate  of  soda  and  phosphate  of  lime;  and  a  sub- 
stance, in  appearance,  fibrinous.3 

It  has  been  said,  again,  that  the  food  becomes  decarbonized  and 
more  nitrogenized ;  that  the  carbon  which  disappears  is  removed  by 
the  oxygen  of  the  air  swallowed  with  the  food,  or  by  that  contained  in 
the  food  itself;  and  that  the  nitrogen  proceeds  from  the  secretions  of 
the  stomach,  or  predominates  simply  because  the  food  is  decarbonized. 
M.  Adelon4  has  properly  remarked,  that  the  fact  and  the  explana- 
tion are  here  equally  hypothetical.  Generally,  the  chyme  possesses 
acid  properties.  MM.  de  Montegre,5  Magendie,6  and  Tiedemann  and 
Gmelin,7  always  observed  it  to  be  so.  Haller8  and  Marcet  found  it  to 
be  neither  acid  nor  alkaline.  In  the  chyme  examined  by  the  latter 
gentleman,  he  detected  albumen,  an  animal  matter,  and  some  salts, 

1  Philos.  Trans,  for  1814.  2  Op.  citat. 

3  Richerand's  Nouveaux  Elemens  de  Physiologic,  edit.   ISeme,  par  Berard,  aine,  p.  72, 
Bruxelles,  1837. 

4  Physiol.  de  1'Homme,  &c.,  edit,  cit.,  torn.  ii. 

5  Experiences  sur  la  Digestion,  Paris,  1824.  6  Op.  citat.,  ii.  p.  87. 

'  Op.  cit.  8  Element.  Physiol.,  xix.  1. 


580  DIGESTION. 

differing,  however,  slightly,  according  as  it  proceeded  from  animal  or 
vegetable  food.  In  the  latter  case,  it  afforded  four  times  as  much 
carbon  as  in  the  former,  but  less  saline  matter;  and  this  consisted  of 
lime  and  an  alkaline  chloride.  MM.  Leuret  and  Lassaigne1  analyzed 
the  chyme  from  the  stomach  of  an  epileptic,  who  died  suddenly  in  a 
fit,  five  or  six  hours  after  having  eaten.  It  was  of  a  white,  slightly- 
yellowish  colour ;  and  strong,  disagreeable  taste.  On  analysis,  it 
afforded  a  free  acid, — the  lactic;  a  white,  crystalline,  slightly  saccha- 
rine matter,  analogous  to  the  sugar  of  milk ;  albumen,  soluble  in 
water;  a  yellowish,  fatty,  acid  matter,  analogous  to  rancid  butter;  an 
animal  matter,  soluble  in  water,  having  all  the  properties  of  casein; 
and  a  little  chloride  of  sodium,  phosphate  of  soda,  and  much  phosphate 
of  lime.  Dr.  Prout2  affirms,  that  a  quantity  of  chlorohydric  acid  is 
present  in  the  stomach  during  the  process  of  digestion.  He  detected 
it  in  that  of  the  rabbit,  hare,  horse,  calf,  and  dog,  and  in  the  sour 
matter  ejected  by  persons  labouring  under  indigestion: — a  fact  which 
has  been  confirmed  by  Mr.  Children.  MM.  Tiedemann  and  Gmelin, 
and  Dr.  Beaumont,3  affirm,  that  the  secretion  of  acid  commences,  as 
soon  as  the  stomach  receives  the  stimulus  of  a  foreign  body,  and  that 
it  consists  of  chlorohydric  and  acetic  acids.  The  experiments  of  these 
gentlemen  were  not  confined  to  the  chymous  mass  obtained  from  digesti- 
ble food.  They  examined  the  fluids,  secreted  by  the  mucous  membrane 
when  indigestible  substances  were  sent  into  the  stomach,  and  the  acid 
character  was  equally  manifested.  These  experiments,  consequently, 
remove  an  objection,  made  by  Dr.  Bostock,4  regarding  the  detection 
of  the  chlorohydric  acid  by  Dr.  Prout; — that,  as  there  did  not  appear 
to  be  any  evidence  of  the  existence  of  this  acid  before  the  introduction 
of  food  into  the  stomach,  it  might  rather  be  inferred,  that  it  is,  in  some 
way  or  other,  developed  during  the  process  of  digestion.  In  all  Dr. 
Beaumont's  experiments,  the  chyme  was  invariably  and  distinctly  acid. 
The  principal  theories  on  chymification  have  been  the  following: — 
1.  Coetion,  or  elixation. — This  originated  with  Hippocrates,  and  was 
vaguely  used  by  him  to  signify  the  maceration,  and  maturation  expe- 
rienced by  the  food  in  the  stomach.  The  doctrine  was  embraced  by 
Galen  and  others,  who  ascribed  to  the  organ,  an  attracting,  retaining, 
concocting,  and  expelling  quality  effected  by  heat.5  In  proof  of  this, 
they  affirmed  that  the  heat  of  the  stomach  is  increased  during  chymi- 
fication ;  that  the  process  is  more  rapid  in  the  warm,  than  cold-blooded 
animal;  that  it  is  aided  by  artificial  heat,  and  continues  even  after 
death,  if  care  be  taken  to  keep  up  the  heat  of  the  body;  that  in  the  ex- 
periments on  artificial  digestion  made  by  Spallanzani,  heat  was  always 
necessary,  and  the  greater  the  degree  of  heat  the  more  easy  and  com- 
plete the  digestion. 

It  is  hardly  necessary  to  say  that  the  heat  of  the  stomach  is  totally 
insufficient  to  excite  any  coction  or  ebullition  in  the  physical  sense  of 

1  Rechercbes,  &c.,  p.  1 14. 

2  Phi  los.  Trans,  lor   1824;  and  Bridge  water  Treatise,  on  Chemistry,  &c.,  Amer.  edit.,  p. 
26S,  Philad.,  1834. 

3  On  the  Gastric  Juice,  &c,,  p.  105.  4  Physiology,  3d  edit.,  p.  569,  Lond.,  1836. 
5  Boerhaav.  Preelectiones  Academ.  Not.  Adv.,  §  86,  torn,  i.,  Getting.,  1740-1743. 


CHYMIFICATION.  581 

the  term,  and  this  applies  particularly  to  the  cold-blooded  animal,  which 
must  digest,  if  not  with  the  same,  with  due,  rapidity. 

2.  Putrefaction. — The  next  great  hypothesis  was  that  of  putrefac- 
tion^ which,  we  are  informed  by  Celsus,1  was  embraced  by  Phstonicus, 
a  disciple  of  Praxagoras  of  Cos,  who  flourished  upwards  of  three  hun- 
dred years  before  the  birth  of  Christ.     Of  late,  it  has  had  no  advocates, 
but  appears  to  have  been  the  view  embraced  by  Cheselden.2     The  rea- 
sons, urged  in  favour  of  it,  have  been; — the  putrescible  character  of 
the  materials  employed  as  food;  the  favourable  circumstances  of  a  heat 
of  98°  or  100°,  and  of  moisture;  and,  by  some,  the  foetor  of  the  ex- 
crements.    The  objections  are,  1.  That  when  the  contents  of  the  sto- 
mach are  rejected,  during  chymification,  they  exhibit  no  evidence  of 
putridity.     2.  That  in  all  the  experiments,  which  have  been  made  on 
the  comparative  digestibility  of  different  substances,  when  it  has  been 
necessary  to  kill  the  animals   at  different  stages  of  the  digestive  pro- 
cess, there  has  not  been  the  slightest  sign  of  putrefaction.     3.  That 
opportunities  frequently  occur,  for  witnessing  ravenous  fishes  and  rep- 
tiles with  an  animal  or  portion  of  an  animal, — too  large  to  be  entirely 
swallowed, — partly  in  the  stomach,  and  the  remainder  in  the  gullet  and 
mouth.     In  these  cases,  where  the  food  has  remained  in  this  situation 
some  days,  the  part  contained  in  the  throat  has  been  found  putrid, 
whilst  that  in  the  stomach  has  been  entirely  sweet;  and  lastly,  in  Spal- 
lanzani's  and  other  experiments,  to  be  detailed  presently,  it  was  found, 
when  food,  in  a  state  of  putridity,  was  taken  into  the  stomach,  or  mixed 
with  the  gastric  juice  out  of  the  stomach,  that  it  recovered  its  sweet- 
ness.    It  has  been  already  observed,  that  it  is  the  custom,  in  some 
countries,  to  eat  the  gibier  or  game  in  a  state  of  incipient  putrefaction ; 
yet  the  breath  is  not  tainted  by  it. 

3.  Trituration. — The  mathematical  physiologists, — Borelli,3  Hecquet,4 
Megallotti,5  Pitcairne,6  and  others — after  the  example  of  Erisistratus,7 
attempted  to  refer  the  whole  process  of  digestion  to  trituration,  ima- 
gining, that  the  food  is  subjected  in  the  stomach  to  an  action  similar 
to  that  of  the  pestle  and  mortar  of  the  apothecary,  or  of  the  millstone; 
and  that  the  chyle  is  formed  like  an  emulsion.     The  most  plausible 
arguments,  in  favour  of  this  view  of  the  subject,  are  drawn  from  the 
presumed  analogy  of  the  granivorous  bird,  whose  stomach  is  capable 
of  exerting  an  astonishing  degree  of  pressure  on  substances  submitted 
to  it.     There  is  no  analogy,  however,  between  the  human  stomach,  and 
the  gizzard  of  birds.     The  latter  is  a  masticatory  organ,  and  therefore 
possessed  of  the  surprising  powers  which  we  have  elsewhere  described ; 
whilst  mastication,  in  man,  is  accomplished  by  distinct  organs.     No 
comparison  can  be  instituted  between  the  gentle  oscillatory  motion  of 
the  stomach,  and  the  forcible  compression  exerted  by  the   digastric 
muscle  of  the  gizzard.     The  simple  introduction  of  the  finger  through 

1  De  Medicina,  cura  E.  Milligan,  edit.  2da,  p.  5,  Edinb.,  1831. 

2  Anatomy  of  the  Human  Body,  &c.,  8th  edit.,  p.  155,  Lond.,  1763. 

3  De  Motu  Animalium ;  Addit.  J.  Bernouillii,  M.D.,  Medit.  Mathem.  Muscul.,  Lugd.  Bat., 
1710. 

4  Traite  de  la  Digestion,  Paris,  1710.  5  Haller,  Elem.  Physiol.,  xix.  5. 
6  Works,  &c.,  Lond.,  1715.                                                    '  Cels.,  loc.  citat. 


582  DIGESTION. 

a  wound  of  the  abdomen  has  shown,  that  the  compression  exerted  by  it 
on  its  contents  is  totally  insufficient  to  bruise  any  resisting  substance. 
Moreover,  we  constantly  see  fruits, — as  raisins  and  currants, — passing 
through  the  whole  intestinal  canal  unchanged ;  whilst  worms  remain  in 
the  stomach — reside  there — unhurt ;  and,  we  shall  see  presently,  that 
the  experiments  of  Re'aumur  and  Spallanzani  proved  most  convincingly, 
that  digestion  is  effected  independently  of  all  pressure.  The  futility, 
indeed,  of  this  mode  of  viewing  the  subject  is  signally  illustrated  by 
the  fact,  that,  whilst  Pitcairne  estimated  the  power  of  the  muscular 
fibres  of  the  stomach  at  12,951  pounds,  Hales1  thought  that  twenty 
pounds  would  come  nearer  the  truth  ;  and  Astruc2  valued  its  compressive 
force  at  five  ounces  ! 

4.  Fermentation. — The  system  of  fermentation  had  many  partisans; 
amongst  whom  may  be   mentioned  Van  Helmont,3  Sylvius,4  Willis,5 
Boyle,6  Grew,7  Charleton,8  Lower,9  Raspail,10  &c.     Digestion,  in  this 
view,  was  ascribed  to  the  chemical  reaction  of  the  elements  of  the  food 
during  their  stay  in  the  stomach ; — the  action  being  excited  by  food 
that  had   already  undergone  digestion,  or  by  a  leaven  secreted  for  the 
purpose  by  the  stomach  itself.     In  favour  of  this  view,  it  was  attempted 
to  show,  that  air  is  constantly  generated  in  the  organ,  and  that  an  acid 
is  always  produced  as  the  result  of  fermentation, — the  formation  of 
chyme  being  referred  by  the  greater  number  of  physiologists  to  the 
food  undergoing  the  vinous  and  acetous  fermentations.     The  objections 
to  this  doctrine  of  fermentation  are  ; — that  digestion  ought  to  be  totally 
independent  of  the  stomach,  except  as  regards  temperature ;  and  the 
food  ought  to  be  converted  into  chyme,  exactly  in  the  same  manner, — 
if  it  were  reduced  to  the  same  consistence,  and  placed  in  the  same  tem- 
perature,— out  of  the  body;  which  is  not  found  to  be  the  case.     Bones 
are  speedily  reduced  to  chyme  in  the  stomach  of  the  dog,  although  they 
would  remain  unchanged  for  weeks,  in  the  same  temperature,  out  of  the 
body.     The  facts  of  the  voracious  fishes  before  mentioned  likewise  prove 
the  insufficiency  of  the  hypothesis ;  according  to  which,  digestion  ought 
to  be  accomplished  as  effectually  in  the  oesophagus  as  in  the  stomach. 
Yet  it  is  found  that,  whilst  the  portion  in  the  stomach  is  digested,  the 
other  may  be  unaltered,  or  be  putrid.     The  truth  is; — in  healthy  diges- 
tion, fermentation,  in  the  ordinary  acceptation  of  the  term,  does  not 
occur;  and,  whenever  the  elements  of  the  food  react  upon  each  other, 
it  is  an  evidence  of  imperfect  digestion;  hence,  fermentation  is  one  of 
the  most  common  signs  of  dyspepsia.         , 

5.  Chemical  solution. — The  theory  of  chemical  solution,  proposed  by 
Spallanzani,11  and  subjected  to  modifications,  has  met  with  more  favour 

1  Statical  Essays,  ii.  174,  4th  edit.,  Lond.,  1769. 

2  Traite  de  la  Cause  de  la  Digestion,  &c.,  Toulouse,  1714;  and  Haller,  loc.  citat. 

3  Ortus  Medicinse,  &c.,  Arnstel.,  1648.  4  Opera,  Genev.,  1781. 

5  Diatribae  duae  Medico-Philosophicse.  &c.,  Lond.,  1659. 

6  Works,  vol.  ii.,  Lond.,  1772. 

7  Comp.  Anat.  of  the  Stomach,  &c.,  Lond.,  1681.  8  (Econ.  Anim.  Exerc.  2. 

9  Tractatus  de  Corde,  &c.,  Amstel.,  1671. 

10  Chimie  Organique,  p.  356,  Paris,  1833. 

11  Dissertations  relative  to  the  Natural  History  of  Animals  and  Vegetables  :  sect.!.,  Lond., 
1789. 


CHYMIFICATION.  583 

from  physiologists  than  any  of  the  others  that  have  been  mentioned,  and 
may  be  regarded  as  established.  According  to  that  observer,  chymifi- 
cation  is  owing  to  the  solvent  action  of  a  fluid,  secreted  by  the  stomach, 
which  accumulates  in  that  viscus  between  meals  and  during  hunger,1 
and  acts  as  a  true  menstruum  on  the  substances  exposed  to  it.  This 
fluid, — to  which  he  gave  the  name  gastric  juice, — he  affirmed  to  be 
peculiar  in  each  animal,  according  to  its  kind  of  alimentation, — corre- 
sponding, as  regards  its  energy,  with  the  rest  of  the  digestive  apparatus, 
and  differing  in  its  source  in  the  series  of  animals ;  in  some,  proceed- 
ing from  the  follicles  of  the  oesophagus;  in  others  from  those  of  the  sto- 
mach ;  but  always  identical  in  the  same  animal ;  generally  transparent, 
yellowish;  of  a  saline  taste;  bitter;  slightly  volatile;  and  stronger  in 
animals  with  a  membranous  than  in  those  with  a  muscular  stomach,  and 
than  in  ruminant  animals.  To  obtain  the  juice,  Spallanzani  opened 
animals,  after  they  had  been  made  to  fast  for  a  time ;  and  collected  the 
juice  that  had  accumulated  in  their  stomachs ;  or  he  made  them  swallow 
tubes  pierced  with  holes,  and  filled  with  small  sponges.  By  withdraw- 
ing these  tubes,  by  means  of  a  thread  attached  to  them  and  suffered  to 
hang  out  of  the  mouth,  and  expressing  the  sponges,  he  obtained  the 
fluid  in  quantity  sufficient  for  examination.  To  determine  whether  this 
fluid,  obtained  from  fasting  animals,  was  destined  to  chymify  the  food, 
he  tried  the  following  experiments.  He  caused  numerous  animals  to 
swallow  tubes  filled  with  food,  but  pierced  with  holes,  so  that  the  juices 
of  the  stomach  might  be  able  to  get  into  their  interior;  and  found  that 
chymification  was  effected,  when  he  had  taken  the  precaution  to  chew 
the  substances  before  they  were  put  into  the  tubes,  or  to  triturate  them ; 
and  the  process  was  always  more  readily  accomplished,  the  more  easy 
the  access  of  the  fluids.  On  repeating  these  experiments  on  animals 
of  various  kinds,  with  a  muscular  or  membranous,  and  musculo-mem- 
branous  stomach ;  on  pullets,  turkeys,  ducks,  pigeons,  rooks,  frogs,  sala- 
manders, eels,  serpents,  sheep,  cats,  &c.,  he  obtained  the  same  results; 
and  hence  he  affirmed,  that  trituration  cannot  be  the  essence  of  chymi- 
fication. Reaumur,2 — originally  a  believer  in  the  doctrine  of  tritura- 
tion,— had  previously  arrived  at  the  same  conclusion,  by  experiments 
of  a  similar  kind.  Spallanzani  next  repeated  those  experiments  upon 
himself.  Having  well  chewed  different  articles  of  food,  he  enclosed 
them  in  wooden  tubes  pierced  with  holes,  and  swallowed  them ;  but,  as 
the  tubes  caused  pain  in  the  bowels,  he  substituted  small  bags  of  linen. 
The  substances  contained  in  bags  were  digested  without  the  bags  being 
torn;  a  fact,  which  proved,  that  digestion  must  have  been  accomplished 
by  means  of  a  fluid,  that  penetrated  them.  In  1777,  Dr.  Stevens3  re- 
peated these  experiments.  He  made  a  person  swallow  balls  of  metal, 
filled  with  masticated  food,  and  pierced  with  holes :  when  the  balls  were 
voided, — thirty-six  or  forty-eight  hours  afterwards, — they  were  entirely 
empty.  Lastly. — Spallanzani  was  desirous  of  seeing  whether  this  solvent 
juice  could  effect  digestion  out  of  the  body.  He  put  some  well-masti- 
cated food  in  small  glass  tubes,  and  mixed  gastric  juice  with  it.  These 

1  It  has  been  already  stated,  that  the  experiments  of  Dr.  Beaumont  have  satisfactorily 
proved  that  no  such  accumulation  takes  place  during  hunger. 

2  Memoir,  de  1'Acad.  pour  1752.  3  De  Alimentorum  Concoctione,  §  24. 


584  DIGESTION. 

tubes  he  placed  in  his  axilla,  in  order  that  they  might  be  exposed  to  the 
same  degree  of  heat  as  in  the  stomach ;  and  in  the  space  of  fifteen 
hours,  or  of  two  days, — more  or  less, — the  substances  appeared  to  be 
converted  into  chyme.  In  these  experiments  he  found  it  important  to 
employ  gastric  juice,  that  had  not  been  previously  used,  and  to  have  a 
sufficient  quantity  of  it. 

From  all  these  experiments,  Spallanzani  conceived  it  to  be  demon- 
strated, that  chymification  is  a  true  chemical  solution ;  and  he  endeavour- 
ed to  deduce  from  them  the  degree  of  digestibility  of  different  alimentary 
substances.  Similar  experiments  were  instituted  by  Dr.  Beaumont.1  In 
all  cases,  solution  occurred  as  perfectly  in  the  artificial  as  in  the  real 
digestions,  but  they  were  longer  in  being  accomplished,  for  reasons  which 
appear  sufficient  to  explain  the  difference.  In  the  former,  the  gastric 
secretion  is  not  continuous;  the  temperature  cannot  be  as  accurately 
maintained,  and  there  is  an  absence  of  those  gentle  motions  of  the 
stomach,  which  are  manifestly  so  useful  in  accomplishing  real  diges- 
tion. 

With  regard  to  the  precise  nature  of  the  gastric  juice  of  Spallanzani, 
we  have  already  observed  that  great  contrariety  of  sentiment  has  pre- 
vailed ;  and  that,  in  ordinary  cases,  it  is  impracticable  to  procure  it 
unmixed  with  the  other  secretions  of  the  digestive  mucous  membrane. 
Spallanzani  affirmed,  that  the  only  properties  he  detected  in  it,  were, — 
a  slightly  salt,  bitterish  taste;  it  was  neither  acid  nor  alkaline.  Gosse2 
found  it  vary  according  to  the  nature  of  the  animal, — whether  herbivor- 
ous or  carnivorous; — and  to  be  always  acid  in  the  former.  Dumas3 
held  the  same  sentiments,  and  maintained  from  experiments  on  dogs? 
that  it  was  acid  or  alkaline,  according  as  the  animal  had  fed  on  vege- 
table or  animal  diet.  He  declared  it,  moreover,  to  be  mawkish,  thick, 
and  viscid.  Viridet4  and  others  affirmed  that  it  was  always  acid.  Mr. 
Hunter5  was  not  inclined  to  suppose,  that  there  is  any  acid  in  the  gastric 
juice  as  a  component  or  essential  part  of  it,  "  although  an  acid  is  very 
commonly  discovered  even  when  no  vegetable  matter  has  been  introduced 
into  the  stomach/'  Scopoli6  analyzed  the  gastric  juice  of  the  rook,  and 
found  it  to  consist  of  water,  gelatin,  a  saponaceous  matter,  muriate  of 
ammonia,  and  phosphate  of  lime.  Carminati7  describes  it  as  salt,  bitter, 
and  frequently  acid;  and  MM.  Macquart8  and  Vauquelin,9in  the  gastric 
juice  of  the  ruminant  animal,  found  albumen  and  free  phosphoric  acid.10 
All  these  analyses  were  made  on  the  mixed  fluid,  to  which  the  term 
gastric  juice  has  been  applied.  That  such  a  mixed  fluid  does  exist  in 
the  stomach  at  the  time  of  chymification,  and  is  largely  concerned  in 
the  process,  is  proved  by  the  facts  already  mentioned,  as  well  as  by  the 
following.  M.  Magendie11  asserts,  that  one  of  his  pupils — M.  Pinel — 

Op.  citat.,  p.  139.  a  Experiences  sur  la  Digestion,  §  81,  Genev.,  1783. 

Principes  de  Physiologie,  Paris,  1806. 
Tractatus  Novus  de  Prima  Coctione,  &c.,  Genev.,  1691. 

Observations  on   Certain  Parts  of  the  Animal  Economy,  with  Notes  by  Prof.  Owen, 
Amer.  edit.,  p.  134.,  Philad.,  1840.  6  Jn  Spallanzani,  §  244. 

Ricerche  sulla  Natura,  &c.,  del  Succo  Gastrico,  Milano,  1785;  or  Journal  Phys.,  t.  xxiv. 
Mem.  de  la  Societe  de  Med.,  Paris,  1786.  9  Fourcroy,  Elem.  de  Chim.,  tom.iv. 

10  See  Burdach,  Die  Physiologie  als  Erfahrungsv/issenschaft,Y.  240  und431,Leips^  1835* 

11  Precis,  &c.,  ii.  11. 


CHYMIFICATION.  585 

could  procure,  in  a  short  time  after  swallowing  a  little  water  or  solid 
food,  as  much  as  half  a  pint.  M.  Pinel  "  possessed  the  faculty  of  vomit- 
ing at  pleasure."  In  this  way,  he  obtained  from  his  stomach,  in  the 
morning,  about  three  ounces  of  fluid,  which  was  analyzed  by  M.  Thenard, 
who  found  it  composed  of  a  considerable  quantity  of  water,  a  little 
mucus,  and  salts  with  a  base  of  soda  and  lime;  but  it  was  not  sensibly 
acid,  either  to  the  tongue  or  to  reagents.  On  another  occasion,  M. 
Pinel  obtained  two  ounces  of  fluid  in  the  same  manner.  This  was  ana- 
lyzed by  M.  Chevreul,  and  found  to  contain  much  water,  a  considerable 
quantity  of  mucus,  lactic  acid — united  to  an  animal  matter,  soluble  in 
water,  and  insoluble  in  alcohol, — a  little  muriate  of  ammonia,  chloride 
of  potassium,  and  some  chloride  of  sodium. 

Messrs.  Tiedemann  and  Gmelin1  procured  the  gastric  fluid  by  making 
animals,  that  had  fasted,  swallow  indigestible  substances,  as  flints.  It 
always  appeared  to  them  to  be  produced  in  greater  quantity,  and  to 
have  a  more  acid  character,  in  proportion  as  the  alimentary  matter  was 
less  digestible  and  less  soluble;  and  they  assign  it,  as  constituents, — 
chlorohydric  acid;  acetic  acid;  mucus;  no,  or  very  little,  albumen; 
salivary  matter;  osmazome;  chloride  of  sodium,  and  sulphate  of  soda. 
In  the  ashes,  remaining  after  incineration,  were,  carbonate,  phosphate, 
and  sulphate  of  lime,  and  chloride  of  calcium.  MM.  Leuret  and  Las- 
saigne2  assign  its  composition,  in  one  hundred  parts,  to  be, — water, 
ninety-eight;  lactic  acid;  muriate  of  ammonia;  chloride  of  sodium;  ani- 
mal matter  soluble  in  water;  mucus;  and  phosphate  of  lime,  two  parts. 
M.  Braconnot3  examined  the  gastric  juice  of  a  dog,  and  found  it  %to 
contain — free  chlorohydric  acid  in  great  abundance ;  muriate  of  ammo- 
nia; chloride  of  sodium  in  very  great  quantity;  chloride  of  calcium;  a 
trace  of  chloride  of  potassium;  chloride  of  iron;  chloride  of  magnesium; 
colourless  oil  of  an  acid  taste;  animal  matter  soluble  in  water  and  alco- 
hol, in  very  considerable  quantity;  animal  matter  soluble  in  weak  acids; 
animal  matter  soluble  in  water,  and  insoluble  in  alcohol  (salivary  matter 
of  Gmelin) ;  mucus ;  and  phosphate  of  lime.  In  the  winter  of  1832-3, 
the  author  was  favoured  by  Dr.  Beaumont,4  with  a  quantity  of  the  gas- 
tric secretion  obtained  from  the  individual  with  the  fistulous  opening 
into  the  stomach,  which  was  examined  by  himself,  and  his  friend,  the 
late  Professor  Emmet,  of  the  University  of  Virginia,  and  found  to  con- 
tain free  chlorohydric  and  acetic  acids,  phosphates,  and  chlorides,  with 
bases  of  potassa,  soda,  magnesia,  and  lime,  and  an  animal  matter — 
probably  pepsin — soluble  in  cold  water,  but  insoluble  in  hot.  The 
quantity  of  free  chlorohydric  acid  was  surprising:  on  distilling  the 
fluid,  the  acids  passed  over,  the  salts  and  animal  matter  remaining  in 
the  retort :  the  amount  of  chloride  of  silver  thrown  down  on  the  addi- 
tion of  the  nitrate  of  silver  to  the  distilled  fluid,  was  astonishing.  The 
author  had  many  opportunities  for  examining  the  gastric  secretion 
obtained  from  the  case  in  question.  At  all  times,  when  pure  or  un- 

1  Op.  cit.  2  Recherches,  &c.,  Paris,  1825. 

3  Journal  de   Chimie  Medicale,  torn,  ii.,  ser.  2,  1836,  and  Records  of  General   Science, 
Jan.,  1836. 

4  See  a  letter  from  the  author  to  Dr.  Beaumont,  in  Beaumont's  Experiments,  &c.,  on  the 
Gastric  Juice,  p.  77;  and  the  author's  Elements  of  Hygiene,  p.  216,  Philad.,  1S35. 


586  DIGESTION. 

mixed  except  with  a  portion  of  the  mucus  of  the  lining  membrane  of 
the  digestive  tube,  it  was  a  transparent  fluid,  having  a  marked  smell  of 
chlorohydric  acid ;  and  of  a  slightly  salt>  and  very  perceptibly  acid, 
taste.  It  matters  not,  therefore,  that  M.  Blondlot,1  in  his  experiments 
on  the  gastric  secretions  of  dogs  and  other  animals,  obtained  by  arti- 
ficial fistulous  openings  made  into  the  stomach,  did  not  find,  when  dis- 
tilled, that  they  exhibited  any  acid  reaction,  whflst  the  residue  in  the 
retort  was  always  strongly  acid.  The  results  referred  to  by  the  author 
as  regards  the  gastric  juice  of  man  were  positive  and  uniform ;  and 
established,  that  it  always  contains  a  large  quantity  of  chlorohydric 
acid.  After  this  it  seems  unnecessary  to  examine  into  the  statement  of 
M.  Blondlot,  that  the  true  and  almost  only  source  of  the  acidity  of 
healthy  gastric  fluid  is  the  presence  of  acid  phosphate  salts.  If,  at 
least,  we  admit  this  to  be  the  case  in  animals,  it  is  assuredly  not  so  in 
man.  The  remark  applies  equally  to  the  experiments  of  Dr.  R.  D. 
Thompson  on  the  gastric  secretions  of  the  sheep  and  pig.2  By  these 
observers,  the  results  obtained  from  the  examination  of  the  gastric 
secretions  in  man,  seem  to  have  been  passed  over,  and  they  have  de- 
duced their  inferences  from  those  of  animals,  which  may,  in  part, 
account  for  the  great  discrepancy  in  their  statements.3 

The  source  of  the  chlorine  or  chlorohydric  acid,  as  Dr.  Prout4  sug- 
gests, must  be  the  common  salt  existing  in  the  blood,  which,  he  con- 
ceives, is  decomposed  by  galvanic  action.  The  soda,  set  free,  remain- 
ing in  the  blood,  a  portion  being  "requisite  to  preserve  the  weak 
alkaline  condition  essential  to  the  fluidity  of  the  blood  ;"  but  the  larger 
part  being  directed  to  the  liver  to  unite  with  the  bile.  This  is  plausi- 
ble ;  but,  it  need  scarcely  be  added,  not  the  less  hypothetical.  Drs. 
Purkinje  and  Pappenheim5  are  of  a  similar  opinion  in  regard  to  the 
source  of  the  chlorohydric  acid.  From  their  galvanic  experiments  they 
think  it  follows,  that  the  juices  mixed  with  the  food  in  the  natural  way, 
saliva,  mucus,  the  portions  of  chloride  of  sodium  present  therein,  and 
still  more  the  gastric  mucous  membrane  itself,  develope  as  much  as  is 
required;  and  that  if  the  nervous  action  in  the  stomach  be  either  iden- 
tical with,  or  analogous  to,  galvanism,  it  would  be  sufficient  to  account 
for  the  secretion  of  the  quantity  of  chlorohydric  acid  requisite  for 
digestion,  without  the  assumption  of  a  special  organ  of  secretion. 

M.  Blondlot6  denies — and  Liebig7  formerly  did  likewise — that  in 
health  lactic  acid  exists  in  the  stomach.  In  certain  diseases,  accord- 
ing to  the  latter,  both  it -and  mucilage  are  formed  from  the  starch, 
and  sugar  of  the  food;  and  he  affirms,  that  the  property  possessed  by 
these  substances  of  passing,  by  contact  with  animal  substances,  in  a 

1  Traite  Analytique  de  la  Digestion,  Paris,  1844.     An  abstract  of  his  views  is  given  by 
Mr.  Paget,  Brit,  and  For.  Med.  Rev.,  Jan.,  1845,  p.  270. 

2  Ranlqng's  Abstract,  vol.  i.,  Pt.  2,  Amer.  edit.,  p.  271,  New  York.  1846. 

3  Carpenter,  Principles  of  Physiology,  4th  Amer.  edit.,  p.  494,  Philad.,  1850;  and  Kirkes 
and  Paget,  Manual  of  Physiology,  Amer.  edit.,  p.  170,  Philadelphia,  1849. 

4  Bridgewater  Treatise,  Amer.  edit.,  p.  268,  Philad.,  1834. 

6  Miiller's  Archiv.  fur  Anatomie,  u.  s.  w.  Heft  1,  1838,  noticed  in  Brit,  and  For.  Med. 
Rev.,  Oct.,  1838,  p.  529. 

6  Op.  cit. 

7  Animal  Chemistry,  Gregory's  and  Webster's  edit.,  p.  107,  Cambridge,  1842. 


CEYMIFICATION.  587 

state  of  decomposition,  into  lactic  acid,  has  induced  physiologists  with- 
out farther  inquiry,  to  assume  that  lactic  acid  is  produced  during  di- 
gestion. He  now,  however,  admits  its  existence  in  health,3  and  with 
Dr.  R.  D.  Thompson  and  MM.  Bernard  and  Barreswil  considers  it  to  be 
an  important  agent  in  the  digestive  process.  With  some  other  che- 
mists, he  denies  the  existence  of  free  chlorohydric  acid  in  the  stomach, 
and  believes,  that  when  it  is  obtained  by  the  simple  distillation  of  the 
gastric  juice  it  is  formed  by  the  reaction  of  the  lactic  and  phosphoric 
acids,  which  are  present  in  the  fluidr  on  the  chlorides ;  and  recently, 
Lehmann  found,  when  he  experimented  on  the  stomachs  of  dogs  placed 
in  vacuo  in  such  a  manner  as  to  cause  the  vapours  from  the  gastric 
juice  to  pass  through  a  tube  containing  a  solution  of  nitrate  of  silver, 
that  there  was  no  indication  of  free  chlorohydric  acid  until  the  fluid 
had  become  so  concentrated  as  to  permit  the  action  of  the  lactic  acid 
on  the  earthy  chlorides.  His  results  would  tend  to  confirm  the  later 
conclusions  of  Liebig,  as  well  as  those  of  MM.  Bernard  and  Barreswil,  as 
to  the  nature  of  the  acid  on  the  gastric  juice  of  certain  animals  at  least.2 
It  is  proper  to  remark,  however,  that  neither  Prout  nor  Braconnot 
could  detect  the  lactic  acid  in  the  gastric  juice ;  and,  moreover,  it  does 
not  appear  to  be  formed  in  artificial  digestion.3 

The  diversity  of  results  obtained  by  chemical  analysis;  the  difficulty 
of  comprehending  how  the  same  fluid  can  digest  substances  of  such 
opposite  character;  and  the  uncertainty  we  are  in,  regarding  the 
organs  concerned  in  its  production,  have  led  some  physiologists  to  doubt 
the  existence  of  any  such  gastric  juice  or  solvent  as  that  described  by 
Spallanzani.  M.  Montegre,4  for  example,  in  the  year  1812,  pre- 
sented to  the  French  Institute  a  series  of  experiments,  from  which  he 
concluded,  that  the  gastric  juice  of  Spallanzani  is  nothing  more  than 
saliva,  either  in  a  pure  state,  or  changed  by  the  chymifying  action  of 
the  stomach  and  become  acid.  As  M.  Montegre  was  able  to  vomit  at 
pleasure,  he  obtained  the  gastric  juice,  as  it  had  been  done  by  previous 
experimenters,  in  this  manner,  whilst  fasting.  He  found  it  frothy, 
slightly  viscid,  and  turbid;  depositing^  when  at  rest,  some  mucous 
flakes ;  and  commonly  acid;  so  much  so,  indeed,  as  to  irritate  the  throat, 
and  render  the  teeth  rough.  He  was  desirous  of  proving,  whether  this 
fluid  was  in  any  manner  inservient  to  chymification.  For  this  purpose, 
he  began  by  ejecting  as  much  as  possible  by  vomiting;  and,  afterwards, 
swallowed  magnesia  to  neutralize  what  remained.  On  eating  afterwards, 
the  food  did  not  appear  less  chymified,  nor  was  it  less  acid;  whence  he 
concluded,  that,  instead  of  the  fluid  being  the  agent  of  chymification,  it 
was  nothing  more  than  saliva  and  the  mucous  secretions  of  the  stomach, 
changed  by  the  chymifying  action  of  that  viscus.  To  confirm  himself 
in  this  view,  he  repeated,  with  it,  Spallanzani's  experiments  on  artificial 
digestion;  making,  at  the  same  sime,  similar  experiments  with  saliva: 

1  Chemistry  of  Food,  London,  1847. 

2  Archiv.  der  Phar-macie,  c.  p.  79,  cited  in  the  British   and  Foreign   iledico-Chirurgical 
Review,  p.  261,  Jan.,  1849. 

3  A  full  account  of  the  various  views  in  regard  to  the  gastric  acid  is  given  by  Frerichs> 
Art.  Verdauung,  Wagner's  Handworterbuch  der  Physiologic,  Slste  Lieferung,  s.  780,  Braun- 
schweig, 1849;  and  Berard,  Cours  de  Physiologic,  lie  Livraison,  p.  97,  Paris,  1849. 

4  Exper.  sur  la  Digestion,  p.  20,  Paris,  1824. 


588  DIGESTION. 

the  results  were  the  same  in  both  cases.  When  gastric  juice,  not  acid, 
was  put  into  a  tube,  and  placed  in  the  axilla, — as  in  Spallanzani's 
experiments, — in  twelve  hours  it  was  in  a  complete  state  of  putrefac- 
tion. The  same  occurred  to  saliva  placed  in  the  axilla.  Gastric  juice, 
in  an  acid  state,  placed  there,  did  not  become  putrid,  but  this  seemed 
to  be  owing  to  its  acidity;  for  the  same  thing  happened  to  saliva,  when 
rendered  acid  by  the  addition  of  a  little  vinegar;  and  even  to  the  gastric 
juice, — used  in  the  experiment  just  referred  to, — when  mixed  with  a 
little  vinegar.  Again: — he  attempted  artificial  digestions  with  the  gas- 
tric juice,  acid  and  not  acid;  fresh  and  old;  but  they  were  unsuccessful. 
The  food  always  became  putrid ;  but  sooner  when  the  juice  employed 
was  not  acid;  and,  if  it  sometimes  liquefied  before  becoming  putrid, 
this  was  attributed  to  the  acidity  of  the  juice,  as  the  same  effect  took 
place,  when  saliva,  mixed  with  a  little  vinegar,  was  employed.  M.  Mon- 
tegre,  moreover,  observed,  that  the  food  rejected  from  the  stomach 
was  longer  in  becoming  putrid,  in  proportion  to  the  time  it  had  been 
subjected  to  the  chymifying  action  of  the  stomach ;  and  he  concluded, 
that  the  fluid,  which  is  sometimes  contained  in  the  empty  stomach, 
instead  of  being  a  menstruum  kept  in  reserve  for  chymification,  is 
nothing  more  than  the  saliva  continually  sent  down  into  that  viscus, 
and  that  its  purity  or  acidity  depends  upon  the  chymifying  action  of 
the  stomach.1 

As  regards  the  fluid  met  with  in  the  stomach  of  fasting  animals,  M. 
Montegre's  remarks  may  be  true  in  the  main;  but  we  have  too  many 
evidences  in  favour  of  the  chemical  action  of  some  secretion  from  the 
stomach  during  digestion  to  permit  us  to  doubt  the  fact  for  a  moment. 
Besides,  some  of  Montegre's  experiments  have  been  repeated  with 
opposite  results.  MM.  Leuret  and  Lassaigne,2  and  Dr.  Beaumont3  per- 
formed those  relating  to  digestion  after  the  manner  of  Spallanzani,  and 
succeeded  perfectly ;  whilst  they  failed  altogether  in  producing  chymifi- 
cation with  saliva,  either  in  its  pure  state,  or  when  acidulated  with  vine- 
gar. By  steeping  the  mucous  membrane  of  an  animal's  stomach  in  an  acid 
liquor,  a  solution  is  obtained,  tp  which  Eberle4  gave  the  name  pepsin. 
This  solution  has  the  property  of  dissolving  organic  matter  in  a  much 
higher  degree  than  diluted  acids.  It  dissolves  coagulated  albumen, 
muscular  fibre,  and  animal  matters  in  general.  In  an  experiment,  one 
grain  of  the  digestive  matter  dissolved  one  hundred  grains  of  coagulated 
white  of  egg.  Eberle  thought  that  all  mucus  has  the  property,  when 
acidulated,  of  inducing  decomposition  and  subsequent  solution  of  the 
food;  but  it  would  appear,  that  no  other  mucus  than  that  of  the  gastric 
mucous  membrane,  when  acidulated,  possesses  it,5  and,  consequently, 
that  there  must  be  a  peculiar  substance,  pepsin,  which  may  be  regarded 
as  the  true  digestive  principle.6  This  principle  was  not  obtained  by 
Schwann  in  a  pure  state ;  but  M.  Wasmann7  would  appear  to  have  suc- 

1  Chaussier  and  Adelon,  in  Diet,  des  Sciences  Medicales,  xx.  422. 

2  Recherches  sur  la  Digestion,  Paris,  1825.  3  Op.  citat,  p.  139. 

4  Physiologic  der  Verdauung  nach  Versuchen,  u.  s.  w.,  Wurzburg,  1834;  Miiller,  Archiv. 
Heft  1,  1836,  or  London  Lancet,  p.  19,  March  31,  1838. 

5  Miiller,  Elements  of  Physiology,  by  Baly,  pp.  518  and  542,  London,  1838. 

6  Miiller  and  Schwann,  in  Miiller's  Archiv.  Heft  1,  1836;  and  Muller,  op.  citat. 

7  Journ.  de  Pharmacie;  and  American  Journal  of  Pharmacy,  for  Oct.  1840,  p.  192. 


CHYMIFICATION.  589 


ceeded  better.     A  solution,  containing  only  5oi(iu  Par*  °f  PePsin 
slightly  acidulated,  is  said  to  dissolve  the  white  of  an  egg  in  six  or  eight 
hours. 

Even  were  the  evidence  adduced  less  positive,  the  following  pheno- 
mena would  be  overwhelming  in  favour  of  the  existence  of  some  gastric 
secretion  concerned  in  the  digestive  changes  in  that  organ.  Besides 
the  fact  of  the  most  various  and  firm  substances  being  reduced  to  chyme 
in  the  stomach,  we  find  the  secretions  from  its  lining  membrane  possess- 
ing the  power  of  coagulating  albuminous  fluids.  It  is  upon  the  coagu- 
lating property  of  these  secretions,  that  the  method  of  making  cheese 
is  dependent.  Rennet,  employed  for  this  purpose,  is  an  infusion  of  the 
digestive  stomach  of  the  calf,  which,  on  being  added  to  milk,  converts 
the  albuminous  portion  into  curd;  and  it  is  surprising  how  small  a 
quantity  is  necessary  to  produce  this  effect.  Messrs.  Fordyce2  and 
Young,8  of  Edinburgh,  found  that  six  or  seven  grains  of  the  inner 
coat  of  a  calf's  stomach,  infused  in  water,  afforded  a  liquid,  which 
coagulated  more  than  one  hundred  ounces  of  milk,  —  that  is,  more  than 
six  thousand  eight  hundred  and  fifty-seven  times  its  own  weight  ;  and 
yet  its  weight  was  probably  but  little  diminished.  The  substance  that 
possesses  this  property  does  not  appear  to  be  very  soluble  in  water;  for 
the  inside  of  a  calf's  stomach,  after  having  been  steeped  in  water  for 
six  hours,  and  well  washed,  still  furnishes  a  liquor  or  infusion,  which 
coagulates  milk.  Liebig4  has  denied,  that  the  fresh  lining  membrane 
of  the  stomach  of  the  calf,  digested  in  weak  chlorohydric  acid,  gives  to 
that  fluid  the  power  of  dissolving  boiled  flesh  or  coagulated  white  of 
egg;  but  Dr.  Pereira5  affirms,  that  he  has  found,  by  experiment,  that  a 
digestive  liquor  can  be  prepared  from  the  fresh  undried  stomach  of  a 
calf.  This  has,  indeed,  been  shown  on  the  best  authority  long  ago. 
Mr.  Hunter,  for  example,  made  numerous  experiments  upon  the  coagu- 
lating power  of  the  secretions  of  the  stomach,  which  show,  that  it  is 
found  in  the  stomachs  of  animals  of  very  different  classes.  The  lining 
of  the  fourth  stomach  of  the  calf  is  in  common  use,  in  a  dried  state, 
for  the  purpose  mentioned  above;  and  it  has  been  proved,  that  every 
part  of  the  membrane  possesses  the  same  property.  Mr.  Hunter  found, 
by  experiment,  that  the  mucus  of  the  fourth  cavity  of  a  slink  calf,  made 
into  a  solution  with  a  small  quantity  of  water,  had  the  power  of  coagu- 
lating milk;  but  that  found  in  the  three  first  cavities  possessed  no  such 
power.  The  former,  even  after  it  had  been  kept  several  days,  and  was 
beginning  to  be  putrid,  retained  the  property.  The  duodenum  and 
jejunum,  with  their  contents,  likewise  coagulated  milk;  but  the  process 
was  so  slow  as  to  give  rise  to  the  suggestion,  that  it  might  have  occurred 
independently  of  the  intestines  employed  for  the  purpose.  He  found, 
that  the  inner  membrane  of  the  fourth  cavity  in  the  calf,  when  old 
enough  to  be  killed  for  veal,  had  the  same  property.  Portions  of  the 

1  Graham's  Elements  of  Chemistry,  Amer.  edit.,  p.  695,  Philad.,  1843,  and  Thomson's 
Animal  Chemistry,  p.  229,  Edinb.,  1843. 

2  A  Treatise  on  the  Digestion  of  Food,  p.  57,  2d  edit,  Lond.,  1791. 

3  Thomson's  System  of  Chemistry,  6th  edit,  iv.  596. 

4  Animal  Chemistry,  Webster's  Amer.  edit.,  Cambridge,  1842. 

5  Treatise  on  Food  and  Diet,  Amer.  edit,  p.  36,  New  York,  1843. 


590  DIGESTION. 

cuticular,  of  the  massy  glandular  part,  and  of  the  portion  near  the  pylo- 
rus of  the  boar's  stomach,  being  prepared  as  rennet,  it  was  found,  that 
no  part  had  the  effect  of  producing  coagulation  but  that  near  the  pylorus, 
where  the  gastric  glands  of  the  animal  are  especially  conspicuous.  The 
crop  and  gizzard  of  a  cock  were  salted,  dried,  and  afterwards  steeped  in 
water.  The  solution,  thus  obtained,  was  added  to  milk:  the  portion  of 
the  crop  coagulated  it  in  two  hours  ;  that  of  the  gizzard  in  half  an  hour. 
The  contents  of  a  shark's  stomach  and  duodenum  coagulated  it  instan- 
taneously. Pieces  of  the  stomach  were  washed  clean,  and  steeped  in 
water  for  sixteen  hours.  The  solution  coagulated  milk  immediately. 
Pieces  of  the  duodenum  produced  the  same  effect.  When  the  milk  was 
heated  to  96°,  the  coagulation  took  place  in  half  an  hour;  when  cold, 
in  an  hour  and  a  quarter.  The  stomachs  of  the  salmon  and  thornback, 
made  into  rennet,  coagulated  milk  in  four  or  five  hours. 

But  those  experiments  of  Mr.  Hunter  do  not  inform  us  of  the  par- 
ticular secretions  that  are  productive  of  the  effect.  They  would,  indeed, 
rather  seem  to  show,  that  it  is  a  general  property  of  the  whole  internal 
membrane.  To  discover  the  exact  seat  of  the  secretion,  and  especially 
whether  it  be  not  in  the  gastric  glands,  Sir  Everard  Home1  selected 
those  of  the  turkey ;  which,  from  their  size,  are  better  adapted  for  such 
an  experiment  than  those  of  any  other  bird,  except  the  ostrich.  A  young 
turkey  was  kept  a  day  without  food,  and  then  killed.  The  gastric  glands 
were  carefully  dissected  separately  from  the  lining  of  the  cardiac  cavity; 
cutting  off  the  duct  of  each  before  it  pierced  the  membrane,  so  that  no 
part  but  the  glands  themselves  were  removed.  Forty  grains,  by  weight, 
of  these  glands  were  added  to  two  ounces  of  new  milk;  and  similar  ex- 
periments were  made  with  rennet;  with  the  lining  of  the  cardiac  cavity 
of  the  turkey;  and  with  the  inner  membrane  of  the  fourth  cavity  of 
the  calf's  stomach.  Coagulation  and  separation  into  curds  and  whey 
were  first  effected  by  the  rennet.  Next  to  this,  and  simultaneously, 
came  the  gastric  glands,  and  the  fresh  stomach  of  the  calf;  and  lastly, 
the  cardiac  membrane  of  the  turkey.  From  these  experiments,  Sir 
Everard  concluded,  that  the  power  of  coagulation  is  in  the  secretion  of 
the  gastric  glands ;  and  that  the  power  is  communicated  to  other  parts, 
by  their  becoming  more  or  less  impregnated  with  it. 

The  marginal  figure,  copied  from  an  engraving  of  the  microscopic 
observations  of  Mr.  Bauer,  exhibits  the  gastric  glands  of  the  human 
oesophagus  magnified  fifteen  times.  These  glands  are  the  lining  of  the 
lower  part  of  the  oesophagus  ;  and  have  the  appearance  of  infundibular 
cells,  whose  depth  does  not  exceed  the  thickness  of  the  membrane. 
This  structure,  although  different  from  that  of  the  gastric  glands  of 
birds,  is  a  nearer  approach  to  it  than  is  to  be  met  with  in  any  part  of 
the  inner  surface  of  the  stomach  or  duodenum.  It  also  resembles  them, 
in  the  secretion  which  it  produces  coagulating  milk,  whilst  none  of  the 
inspissated  juices,  met  with  in  these  cavities,  according  to  Sir  Everard, 
affect  milk  in  the  same  way.  From  these  facts,  he  thinks,  there  can 
be  no  longer  any  doubt  entertained,  that  the  gastric  glands  have  the 
same  situation  respecting  the  cavity  of  the  stomach  as  in  birds.  Yet 

1  Lectures  on  Comparative  Anatomy,  i.  299,  Loud.,  1814,  and  iii.  134,  Lond.,  1823. 


CHYMIFICATION. 


591 


h 


M.  Montegre1  denies  that 
the  gastric  juice  has  any 
coagulating  power  ! 

In  some  experiments, 
undertaken  by  M.  J.  F. 
Simon2  with  a  view  to  de- 
termine, whether  the  sto- 
mach of  the  child  possesses 
the  same  properties  of 
coagulating  milk  as  that 
of  the  calf,  he  found  that 
cow's  milk  was  not  coagu- 
lated by  it,  but  that,  when 
a  quantity  of  the  colos- 
trum of  the  mother  of  a 

Child,     Which     died     When 

five  days  old,  was  obtained,  and  a  piece  of  calf's  stomach  was  intro- 
duced into  it,  the  milk  coagulated. 

Another  property,  manifestly  possessed  by  the  secretion  in  question, 
is  that  of  preventing  putrefaction,  or  of  obviating  it  in  substances  ex- 
posed to  its  action.  Montegre  and  Thackrah3  deny  it  this  property, 
but  there  can  be  no  doubt  of  its  existence.  Spallanzani,  Fordyce,  and 
others,  have  ascertained,  that  in  those  animals  which  frequently  take 
their  food  in  a  half  putrid  state,  the  first  operation  of  the  stomach  is 
to  disinfect,  or  remove  the  foetor  from  the  aliment  received  into  it. 
We  have  already  alluded  to  many  facts  elucidative  of  this  power. 
Helm  of  Vienna,4  in  the  case  of  a  female  who  had  a  fistulous  opening 
in  her  stomach,  observed,  that  substances  which  were  swallowed  in  a 
state  of  acidity  or  putridity,  soon  lost  those  qualities  in  the  stomach  ; 
and  the  same  power  of  resisting  and  obviating  putrefaction  has  been 
exhibited  in  experiments  made  out  of  the  body.  Nothing  could  be 
more  unequivocal,  as  regards  the  possession  of  this  property  by  the 
gastric  fluid,  than  the  experiments  of  Dr.  Beaumont  and  the  author,5 
with  the  secretion  obtained  from  the  subject  of  his  varied  investigations. 
In  the  presence  of  the  author's  friend,  N.  P.  Trist,  Esq.  —  then  consul 
of  the  United  States  at  Havana,  —  the  odour  of  putrid  food  was  as 
speedily  removed  by  it  as  by  chlorinated  soda,  employed  at  the  same 
time  on  other  portions.  The  explanation  of  this  property,  as  well  as 
that  of  coagulation,  has  been  a  stumbling-block  to  the  chemical  phy- 
siologist. "  We  can  only  say  concerning  it,"  says  Dr.  Bostock,6  "that 
it  is  a  chemical  operation,  the  nature  of  which,  and  the  successive  steps 
by  which  it  is  produced,  we  find  it  difficult  to  explain;  at  the  same 
time,  that  we  have  very  little,  in  the  way  of  analogy,  which  can  assist 
us  in  referring  it  to  any  more  general  principle,  or  to  any  of  the  es- 
tablished laws  of  chemical  affinity." 

1  Experiences  sur  la  Digestion,  Paris,  1824. 

2  Mailer's  Archiv.  Heft  1,  1839,  cited  in  Brit,  and  For.  Med.  Rev.,  Oct  ,  1839,  p.  549. 

3  Lectures  on  Digestion  and  Diet,  p.  14,  Lond.,  1824. 

4  Rudolphi,  Grundriss  der  Physiologic,  2er  Band,  2te  Abtheil.,  s.  114,  Berlin,  1828. 
s  See  the  author's  Elements  of  Hygiene,  p.  216,  Philad.,  1835. 

•  Edit,  citat.,  p.  571. 


592  DIGESTION. 

The  cases  of  what  are  termed  digestion  of  the  stomach  after  death 
afford  us,  likewise,  remarkable  examples  of  the  presence  of  some  power- 
ful agent  in  the  stomach;  as  well  as  of  the  resistance  to  chemical 
action,  offered  by  living  organs.  Powerful  as  the  action  of  the  gastric 
juice  may  be,  in  dissolving  alimentary  substances,  it  does  not  exert  it 
upon  the  coats  of  the  stomach  during  life.  Being  endowed  with  vitality, 
they  effectually  resist  it.  But  when  that  viscus  has  lost  its  vitality, 
its  parietes  yield  to  the  chemical  power  of  the  contained  juices,  and 
become  softened,  and,  in  part,  destroyed.  M.  Hunter1  found  the  lining 
membrane  of  the  stomach  destroyed,  in  several  parts,  in  the  body  of  a 
criminal,  who,  for  some  time  before  his  execution,  had  been  prevailed 
upon,  in  consideration  of  a  sum  of  money,  to  abstain  from  food.  Since 
Hunter's  time,  numerous  examples  have  occurred,  and  been  recorded 
by  Messrs.  Baillie,  Allan  Burns,  Haviland,  Grimaud,  Pascalis,  Cheese- 
man,  J.  B.  Beck,  Chaussier,  Yelloly,  Gardner,  Treviranus,  Godecke, 
Jager,  Carswell,  and  others.2  The  fact  is  of  importance  in  medical 
jurisprudence;  and,  until  a  better  acquaintance  with  the  subject,  would, 
doubtless,  have  been  set  down  as  strong  corroborative  evidence  in  cases 
of  suspected  poisoning.  It  is  now  established  that  solution  of  the  sto- 
mach may  take  place  after  death,  without  there  being  reason  for  sup- 
posing that  any  thing  noxious  had  been  swallowed. 

The  experiments  of  Drs.  Wilson  Philip3  and  Carswell4  are  corro- 
borative of  this  physiological  action  on  the  gastric  juice.  On  open- 
ing the  abdomen  of  rabbits,  that  had  been  killed  immediately  after 
having  eaten,  and  allowed  to  lie  undisturbed  for  some  time  before  ex- 
amination, the  former  found  the  great  end  of  the  stomach  soft,  eaten 
through,  and  sometimes  altogether  consumed'  the  chyme  being  covered 
only  by  the  peritoneal  coat,  or  lying  quite  bare  for  the  space  of  an 
inch  and  a  half  in  diameter:  and,  in  this  last  case,  a  part  of  the  con- 
tiguous intestines  was  also  destroyed;  whilst  the  cabbage,  which  the 
animal  had  just  taken,  lay  in  the  centre  of  the  stomach  unchanged,  if 
we  except  the  alteration  that  had  taken  place,  in  the  external  parts  of 
the  mass  it  had  formed,  in  consequence  of  imbibing  gastric  fluid  from 
the  half-digested  food  in  contact  with  it.  Why  the  perforation  takes 
place,  without  the  food  being  digested,  is  thus  explained  by  Dr.  Philip. 
Soon  after  death,  the  motions  of  the  stomach,  which  are  constantly 
carrying  on  the  most  digested  food  towards  the  pylorus,  cease.  The 
food  that  lies  next  to  the  surface  of  the  stomach,  thus  becomes  fully 
saturated  with  gastric  fluid;  neutralizes  no  more;  and  no  new  food 
being  presented  to  the  fluid  it  acts  on  the  stomach  itself,  now  deprived 
of  life,  and  equally  subjected  to  its  action  with  other  dead  animal  matter. 
It  is  extremely  remarkable,  however,  that  the  gastric  fluid  of  the  rab- 

1  Phil.  Transact.,  Ixii.;  and  Observations  on  certain  parts  of  the  Animal  Economy,  with 
notes  by  Prof.  Owen,  Amer.  edit.,  p.  144,  Philad.,  1840. 

2  Beck's  Medical  Jurisprudence,  6th  edit.,  ii.  311,  Albany,  1838;  Carswell's  Path.  Anat., 
No.  5,  Lond.,  1833;  and  T.  Wilkinson  King,  Guy's  Hospital  Reports,  vii.  139,  Lond.,  1842; 
and  a  case  communicated  to  the  author  by  Dr.  Thomas  M.  Flint,  in  which  the  stomach  had 
separated  from  the  oesophagus,  recorded  in  Med.  Examiner,  p.  715,  for  December,  1848. 

3  Treatise  on  Indigestion,  Lond.,  1821. 

4  Ibid,  and  Edinb.  Med.  and  Surg.  Journal,  Oct.,  1830;  and  art.  Perforation  of  the  Hollow 
Viscera,  in  Cyclopedia  of  Practical  Medicine,  P.  xvi.  p.  272,  Lond.,  1833. 


CHYMIFICATION.  593 

bit,  which,  in  its  natural  state,  refuses  animal  food,  should  so  completely 
digest  the  stomach,  as  not  to  leave  a  trace  of  the  parts  acted  upon. 
Dr.  Philip  remarks,  that  he  has  never  seen  the  stomach  eaten  through 
except  at  the  larger  end;  but,  in  other  parts,  the  external  membrane 
has  been  injured.  Mr.  A.  Burns,1  however,  affirms,  that  in  several 
instances  he  found  the  forepart  of  the  stomach  perforated,  about  an 
inch  from  the  pylorus,  and  midway  between  the  smaller  and  larger 
curvatures. 

From  all  these  facts,  then,  we  are  justified  in  concluding,  that  the 
food  in  the  stomach  is  subjected  to  the  action  of  a  secretion,  which  alters 
its  properties,  and  is  the  principal  agent  in  converting  it  into  chyme. 

But  many  physiologists,  whilst  they  admit,  that  the  change  effected 
in  the  stomach  is  of  a  chemical  character,  contend,  that  the  nature  of 
the  action  is  unlike  what  takes  place  in  any  other  chemical  process, 
and  is,  therefore,  necessarily  organic  and  vital,  and  appertaining  to 
vital  chemistry.  Such  are  the  sentiments  of  Messrs.  Fordyce,2  Brous- 
sais,3  Chaussier,  and  Adelon,4  and  others.  Dr.  Prout  suggests,  that 
the  stomach  must  have,  within  certain  limits,  the  power  of  organizing 
and  vitalizing  the  different  alimentary  substances;  so  as  to  render 
them  fit  for  being  brought  into  more  intimate  union  with  a  living  body, 
than  the  crude  aliments  can  be  supposed  to  be.  It  is  impossible,  he 
conceives,  to  imagine,  that  this  organizing  agency  of  the  stomach  can 
be  chemical.  It  is  vital,  and  its  nature  completely  unknown.  The 
physiologist  should  not,  however,  have  recourse  to  this  explanation, 
until  every  other  has  failed  him.  It  is,  in  truth,  another  method  of 
expressing  his  ignorance,  when  he  affirms,  that  any  function  is  executed 
in  an  organic  or  vital  manner  ;  nor  is  this  mode  of  explaining  the  con- 
version of  the  aliment  into  chyme  necessary  ;  the  secretion  of  the  mat- 
ters that  are  the  great  agents  of  chymification  is  doubtless  vital ;  but 
when  once  secreted,  the  changes,  effected  upon  the  food,  are  probably 
unmodified  by  any  vital  interference,  except  what  occurs  from  tempera- 
ture, agitation,  &c.,  which  can  only  be  regarded  as  auxiliaries  in  the 
function.  It  is  in  this  way,  that  digestion  is  influenced  by  the  nervous 
system. 

The  effect  of  the  different  emotions  on  the  digestive  function  is  often 
evinced,  and  has  already  been  alluded  to ;  but  the  importance  of  the 
nervous  influence  to  it  has  been  elucidated,  in  an  interesting  manner  to 
the  physiologist,  of  late  years  chiefly.  Baglivi,5  having  tied  the  nerves 
of  the  eighth  pair  in  dogs,  found  that  they  were  affected  with  nausea 
and  vomiting,  and  obstinately  refused  food.  Since  Baglivi's  time,  the 
same  results  have  been  obtained  by  many  physiologists.  M.  De  Blain- 
ville,  having  repeated  the  operation  on  pigeons,  found  the  vetch  in  their 
crops  entirely  unchanged,  and  chymification  totally  prevented.  Messrs. 
Legallois,6Brodie,7  Philip,8  Dupuy,  Clarke  Abel,  Hastings,9  and  others — 

1  Edinb.  Med.  and  Surg.  Journal,  vi.  132.     2  On  the  Digestion  of  Food,  2d  edit.,  Lond.,  1791. 

3  Traite  de  Physiologic,  &c.,  translated  by  Drs.  Bell  and  La  Roche,  p.  323. 

4  Diet,  des  Sciences  Medicates,  ix. 

5  Opera  Omnia,  Lugd.  Bat.,  1745.  «  Sur  le  Principe  de  la  Vie,  p.  214,  Paris,  1842. 
7  Phil.  Trans,  for  1814.  8  Experimental  Inquiry,  &c.,  Lond.,  1817. 

9  Journal  of  Science  and  Arts.,  vii.  ix.  x.  xi.  and  xii. 

VOL.  i.-— 38 


594  DIGESTION 

on  carefully  repeating  the  experiments — announced,  that,  after  this  ope- 
ration, the  digestive  process  was  entirely  suspended.1  The  result  of  these 
experiments  was,  however,  contested  by  several  physiologists  of  eminence, 
who  affirmed,  that,  after  the  division  of  the  eighth  pair,  digestion  continued 
nearly  in  the  natural  state,  or,  at  most,  was  only  slightly  impeded.  Mr. 
Broughton2  asserted,  that  he  had  made  the  section  on  eleven  rabbits? 
one  dog,  and  two  horses ;  and  that  digestion  was  not  destroyed.  M, 
Magendie3  expresses  his  belief,  that  the  arrest  of  chymification,  where  it 
was  observed,  was  owing  to  the  disturbance  of  respiration  caused  by 
the  division  of  the  nerves  ;  and  he  states  that  digestion  continued  when 
care  was  taken  to  cut  the  nerve  within  the  thorax,  lower  down  than 
the  part  which  furnishes  the  pulmonary  branch.  MM.  Leuret  and 
Lassaigne  assert,4  that  they  found  chymification  continue,  notwith- 
standing the  division  of  these  nerves  ;  and  Dr.  G.  C.  Holland5  thinks 
he  has  proved,  that  the  suspension  of  the  digestive  function  is  not  pro- 
duced by  the  influence  of  the  nerves  being  withdrawn  from  the  stomach, 
but  by  the  disturbance  of  the  circulatory  system  ;  for  when  the  natural 
conditions  of  this  system  were  maintained,  after  the  division  of  the 
nerves,  the  function  of  digestion  still  continued  to  be  properly  per- 
formed ;  showing  that  the  nervous  connexion  between  the  brain  and 
stomach  is  not  essential  to  the  process  of  digestion,  the  secretion  of  the 
gastric  solvent,  or  the  possession  of  contractility  by  the  muscular  fibres 
of  the  stomach. 

In  opposition  to  these  experiments,  those  of  M.  Dupuytren  may  be 
adduced.  He  divided,  separately,  the  portions  of  the  eighth  distri- 
buted to  the  pulmonary,  circulatory,  and  digestive  apparatuses,  and 
always  found,  when  the  section  was  made  below  the  pulmonary  plexus, 
that  chymification  was  suspended.  But  how  are  we  to  explain  the  dis- 
crepancy between  these  results,  and  those  of  Messrs.  Broughton  and 
Magendie  ?  M.  Adelon6  has  supposed,  that  as  the  eighth  pair  is  not  the 
only  nerve  distributed  to  the  stomach, — the  great  sympathetic  sending 
numerous  filaments  to  it, — these  filaments,  in  the  experiments  of  Messrs, 
Broughton  and  Magendie,  might  have  been  sufficient  to  keep  up  for 
some  time  the  chymifying  action  of  the  stomach ;  and,  again,  he  sug- 
gests, whether  the  nervous  influence  may  not  have  still  persisted  for  a 
time  after  the  section  of  the  nerve,  like  other  nervous  influences,  which, 
he  conceives,  continue  for  some  time  even  after  death ;  and  lastly,  he 
thinks  it  probable,  that,  in  the  cases  in  which  chymification  continued, 
the  experiment  was  badly  performed.  Most  of  these  reasons,  however, 
would  apply  with  as  much  force  to  the  experiments  on  the  other  side  of 
the  question.  Why  were  not  the  agency  of  the  great  sympathetic,  and 
the  continuance  of  the  nervous  influence  for  some  time  after  the  section 
of  the  nerve,  evidenced  in  the  experiments  of  Dupuytren,  Wilson  Philip, 
Hastings,  and  others  ? 

1  Ley,  in  App.  to  Laryngismus  Stridulus,  p.  447,  Lond.,  1836. 

2  Ibid.,  x.  292.  3  Precis,  &c.,  ii.  102. 

4  Edinburgh  Med.  and  Surg.  Journal,  xciii.  365 ;  and  Recherches  sur  la  Digestion,  Paris, 
1825. 

5  Inquiry  into  the  Principles,  &c.,  of  Medicine,  i.  444,  Lond.,  1834. 

6  Physiologic  de  1'Homme,  &c.,  2de  edit.,  vol.  ii.  Paris,  1829. 


CHYMIFICATION.  595 

More  recent  experiments  by  Messrs.  Wilson  Philip,1  Breschet,  Milne 
Edwards,  and  Vavasseur,2  have  shown,  that  the  mere  division  of  the 
nerves,  and  even  the  retraction  of  the  divided  extremities  for  the  space 
of  one-fourth  of  an  inch,  does  not  prevent  the  influence  from  being 
transmitted  along  them  to  the  stomach;  but  that  if  a  portion  of  the 
nerve  be  actually  removed,  or  the  ends  folded  back,  chymification  is 
wholly  or  partly  suspended.3  Most  of  the  experimenters  agree  with 
Sir  Benjamin  Brodie  in  the  opinion,  that  chymification  is  suspended 
owing  to  the  secretion  of  the  gastric  juice  having  been  arrested  by  the 
division  of  the  nerves  under  whose  presidency  it  is  accomplished.  MM. 
Breschet  and  Milne  Edwards,  however,  conceive,  that  the  effect  is 
owing  to  paralysis  of  the  muscular  fibres  of  the  stomach  produced  by 
the  section  of  the  nerves;  in  consequence  of  which  the  different  por- 
tions of  the  alimentary  mass  are  not  brought  properly  into  contact 
with  the  coats  of  the  stomach,  so  as  to  be  exposed  to  the  action  of  its 
secretions;  and  they  affirm,  that  when  the  galvanic  influence  is  made 
to  pass  along  the  part  of  the  nerve  attached  to  the  stomach,  its  effect 
is  to  restore  the  due  action  of  the  fibres;  and,  that  a  mechanical  irri- 
tant, applied  to  the  lower  end  of  the  divided  nerves,  produces  a  similar 
kind  of  change  on  the  food  in  the  organ;  from  which  they  conclude, 
that  the  use  of  the  par  vagum,  as  connected  with  the  functions  of  the 
stomach,  is  to  bring  the  alimentary  mass  into  necessary  contact  with 
the  gastric  secretions.  These  experiments  were  repeated  in  London  by 
Mr.  Cutler,  under  the  inspection  of  Dr.  Philip  and  Sir  B.  Brodie ;  but 
the  effects  of  mechanical  irritation  of  the  lower  part  of  the  divided 
nerve  did  not  correspond  with  those  observed  by  MM.  Breschet  and 
Milne  Edwards.4 

The  experiments  of  F.  Arnold,5  and  of  MM.  Bouchardat  and  San- 
dras6  lead  them  also  to  infer,  that  the  nerves  of  the  stomach  appear  to 
influence  chymification  in  so  far  as  the  process  depends  upon  the 
various  motions  of  the  organ. 

M.  Longet7  has  endeavoured  to  reconcile  these  discordant  results. 
Having  opened  many  dogs,  he  ascertained,  that  in  the  greater  number, 
irritation  of  the  pneumogastric  nerves  induced  contraction  of  the 
stomach.  Frequently,  during  his  experiments,  he  saw  the  stomach 
assume  the  hour-glass  form.  In  a  few  dogs,  the  movements  of  the 
stomach,  on  the  irritation  of  the  nerve,  were  scarcely  perceptible.  After 
repeating  his  experiments  on  forty  dogs,  he  recognised  that  the  differ- 
ence in  the  results  obtained  depended  on  the  condition  of  the  stomach 
itself.  Thus,  if  the  animal  was  opened  when  it  was  full,  irritation  of 
the  pneumogastric  nerves  caused  manifest  movement;  but,  when  empty, 
scarcely  any  was  excited:  the  movements,  in  fact,  were  feeble  in  pro- 

1  Philos.  Transact,  for  1822.  2  Archives  Generates  de  Med.,  Aout,  1823. 

3  Ware,  North  American  Medical  and  Surgical  Journal.,  Philad.,  1848. 

4  Bostock's  Physiology,  3d  edit.,  p.  523,  London,  1836. 

5  Lehrbuch  der  Physiologic  des  Menschen,  Zurich,  1836-7  ;  noticed  in  British  and  Foreign 
Medical  Review  for  Oct.,  1839,  p.  478. 

«  Annuaire  de  Therapeutique,  pour  1848,  p.  283,  Paris,  1848. 

7  Comptes  Rendus,  Fevr.,  1842.  See,  also,  Bischoff,  in  Mailer's  Archiv.,  Berlin,  1843,  and 
Prof.  E.  Weber,  art.  Muskelbewegung,  in  Wagner's  Handworterbuch  der  Physiologic,  15te 
Lieferung,  s.  41,  Braunschweig,  1846. 


596  DIGESTION. 

portion  to  the  time  .that  had  elapsed  from  the  period  of  chymification, 
or  of  filling  the  stomach.  M.  Longet  thinks,  that  these  facts  account 
for  the  different  results  arrived  at  by  experimentalists  in  regard  to  the 
influence  of  the  pneumogastric  nerves  over  the  movements  of  the 
stomach;  for,  if  the  same  experiments  were  made  when  the  stomach 
was  in  different  states,  they  might  readily  lead  to  opposite  conclusions. 
He  was  never  able  to  excite  any  movement  of  the  coats  of  the  stomach, 
by  irritating  or  galvanizing  the  filaments  of  the  great  sympathetic  or 
the  semilunar  ganglia. 

On  the  whole,  the  proposition  of  Dr.  Philip, — that  if  the  eighth  pair 
be  divided  in  such  a  manner  as  to  effectually  intercept  the  passage  of 
the  nervous  influence,  digestion  is  suspended, — is  generally  considered 
to  be  established;  although  it  must,  we  think,  be  admitted  with  Mr. 
Mayo,1  that  the  rationale  of  the  subject  remains  involved  in  great  un- 
certainty. Like  other  secretions,  that  of  the  gastric  juice,  although 
capable  of  being  modified  by  the  nervous  influence,  cannot  be  regarded 
as  immediately  dependent  upon  it.  The  secretion,  of  the  true  acid  cha- 
racter and  solvent  powers,  is  not  always  checked  by  the  section  of  the 
nerves,  and  the  experiments  of  Dr.  John  Reid2  and  others  have  suffi- 
ciently shown,  that  the  integrity  of  those  nerves  is  not  a  condition 
absolutely  necessary  for  secretion  in  the  stomach,  whilst  at  the  same 
time  they  prove,  that  the  amount  of  secretions  usually  poured  into  the 
interior  of  that  organ  may  be  modified  in  an  important  manner  by  causes 
acting  through  those  nerves.3  It". is  denied,  however,  by  Professor  J. 
Muller,  that  galvanism  has  any  influence  in  re-establishing  the  gastric 
secretion,  when  it  has  been  checked  by  their  division. 

Finally: — Dr.  Philip  found,  that  every  diminution  of  the  nervous 
influence, — the  section  of  the  medulla  spjnalis  at  the  inferior  part,  for 
example, — deprives  the  stomach  of  its  digestive  faculty;  and  MM. 
Edwards  and  Vavasseur  obtained  the  same  result  by  the  removal  of  a 
certain  portion  of  the  hemispheres  of  the  brain,  or  by  the  injection  of 
opium  into  the  veins  in  sufficient  quantity  to  throw  the  animal  into 
deep  coma.  Much  must,  of  course,  be  dependent  on  the  deranging 
influence  of  the  experiments.  By  means  of  the  fistulous  openings  into 
the  stomachs  of  dogs,  first  instituted  by  M.  Blondlot,  (see  page  586,)  M. 
Bernard4  undertook  fresh  experiments  on  this  unsettled  topic.  A  dog's 
digestion  was  watched  for  eight  days,  and  found  to  be  well  accomplished. 
On  the  ninth  day,  after  twenty-four  hours'  fast,  M.  Bernard  sponged 
out  the  stomach,  which  contracted  on  the  contact  of  the  sponge,  and 
at  once  secreted  a  large  quantity  of  gastric  fluid.  He  then  divided 
the  pneumogastric  nerves  in  the  middle  of  the  neck,  and  immediately 
the  mucous  membrane,  which  had  been  turgid,  became  pale,  as  if 
exsanguious;  the  movements  of  the  stomach  ceased;  the  secretion  of 
gastric  fluid  was  instantaneously  arrested,  and  a  quantity  of  neutral 
ropy  mucus  was  soon  produced  in  its  place.  After  this,  digestion  was 

1  Outlines  of  Human  Physiology,  4th  edit.,  p.  122,  Lond.,  1837. 

2  Edinb.  Med.  and  Surg.  Journal,  April,  1839;  and  art.  Par  Vagum,  in  Cyclop,  of  Anat. 
and  Physio!.,  pt.  xxviii.  p.  899,  Lond.,  April,  1847. 

3  Longet,  Traite  de  Physiologic,  ii.  339,  Paris,  1850. 

4  Gazette  Medicale  de  Paris,  1  Juin,  1844. 


CHYMIFICATION.  597 

not  duly  performed;  milk  was  no  longer  coagulated;  raw  meat  remained 
unchanged;  and  the  food,  consisting  of  meat,  milk,  bread,  and  sugar, 
which  the  dog  had  before  thoroughly  digested,  remained  for  a  long 
time  neutral,  and  at  length  acquired  acidity  only  from  its  transforma- 
tion into  lactic  acid.  In  the  stomachs  of  other  dogs,  after  the  division 
of  the  nerves,  he  traced  the  transformation  of  cane  sugar  into  grape 
sugar  in  three  or  four  hours ;  and  in  ten  or  twelve  hours,  the  trans- 
formation into  lactic  acid  was  complete.  In  others,  when  the  food  was 
not  capable  of  an  acid  transformation,  it  remained  neutral  to  the  last. 
In  no  case  did  any  part  of  the  food  pass  through  the  peculiar  changes 
of  chymification.  More  recently,  MM.  Bouchardat  and  Sandras,1  from 
the  results  of  a  series  of  experiments  instituted  by  them,  believe  they 
have  established,  that  stomachal  digestion  and  the  movements  of  the 
organ  are  interrupted  by  the  simultaneous  section  of  both  pneumogas- 
trics  on  a  level  with  the  larynx;  and  farther,  that  intestinal  digestion, 
and  the  production  and  absorption  of  a  very  laudable  chyle  persist  not- 
withstanding such  section;  and  M.  Longet2  concludes,  that  the  section  of 
the  pneumogastrics  seriously  affects  chymification,  chiefly  by  paralysing 
the  proper  movements  of  the  stomach,  but  partly  by  diminishing  the 
secretion  of  the  gastric  solvent;  and  lastly,  Professor  Berard,3  after 
examining  the  different  experiments  and  inferences  of  preceding  in- 
quirers, infers: — that  "the  mixed  cords  of  the  pneumogastrics  and  the 
branches  furnished  by  the  great  sympathetic  to  the  stomach  beneath 
the  diaphragm,  contribute  to  the  maintenance  of  the  contractility  of 
the  stomach  and  the  secretion  of  the  gastric  juice.  A  greater  share, 
however,  ought  to  be  assigned  to  the  cords  of  the  pneumogastric  than  to 
the  sub-diaphragmatic  branches  of  the  great  sympathetic.  Moreover, 
the  motor  influence  of  the  pneumogastric  appears  to  predominate  over 
the  secretory;  in  other  words,  the  resection  of  the  nerve  paralyses  the 
movements  more  than  it  diminishes  the  secretion." 

Of  all  these  theories  of  chymification,  that  of  chemical  action,  aided 
by  the  collateral  circumstances  to  be  mentioned  presently,  can  alone 
be  embraced;  yet,  how  difficult  is  it  to  comprehend,  that  any  one 
secretion  can  act  upon  the  immense  variety  of  animal  and  vegetable 
substances  employed  as  food !  The  discovery  of  the  chlorohydric  and 
acetic  acids  and  of  pepsin  in  the  secretion,  aids  us  in  solving  the  mys- 
tery expressed  by  the  well-known  pithy  and  laconic  observation  of  Dr. 
William  Hunter  in  his  lectures:  "Some  physiologists  will  have  it,  that 
the  stomach  is  a  mill ;  others,  that  it  is  a  fermenting  vat,  others,  again, 
that  it  is  a  stewpan  ; — but,  in  my  view  of  the  matter,  it  is  neither  a 
mill,  a  fermenting  vat,  nor  a  stewpan ; — but  a  stomach,  gentlemen,  a 
stomach." 

Allusion  has  been  already  made  to  pepsin — an  organic  compound 
thrown  off  from  the  stomach — which  is  an  active  agent  in  digestion. 
It  had  been  observed  in  the  experiments  of  Eberle  and  Schwann,  that 

1  Bouchardat,  Annuaire  de  Therapeutique,  de  Matiere  Medicate,  &c.,  pour  1848,  p.  306, 
Paris,  1848. 

2  Op.  cit.,  p.  340. 

3  Cours  de  Physiologie,  12e  livraison,  p.  235,  Paris,  1849. 


i 


598  DIGESTION. 

although  acids  alone  have  little  power  in  digesting  food,  they  act  ener- 
getically, when  combined  with  the  mucus  of  the  stomach.  Eberle 
thought,  that  the  acidulated  mucus  of  any  membrane  would  produce  the 
effect,  but  J.  Muller  and  Schwann  found  it  to  be  restricted  to  that  of  the 
stomach.  The  agency  of  pepsin  is  regarded  by  Liebig1  to  be  similar 
to  that  of  diastase  in  the  germination  of  seeds.  Both  are  bodies  in  a 
state  of  transformation  or  decomposition;  the  latter  effecting  the  solu- 
tion of  starch  by  its  conversion  into  sugar;  and  the  former  the  forma- 
tion of  alimentary  matter  into  chyme.  The  present  belief  amongst 
physiologists  and  chemists — from  all  these  experiments,  as  well  as 
those  of  Wasmann  and  others — is,  that  pepsin,  by  inducing  a  new 
arrangement  of  the  elementary  particles  or  atoms  of  alimentary  matter, 
disposes  it  to  dissolve  in  the  gastric  acids.  Chlorohydric  acid,  indeed, 
dissolves  wliite  of  egg  by -ebullition,  just  as  it  does  under  the  influence 
of  pepsin ;  so  that  pepsin  replaces  the  effect  of  a  high  temperature  in 
the  stomach.2  Liebig,  consequently,  does  not  believe,  that  the  digestive 
process  is  a  simple  solution,  but  a  species  of  fermentation,  not  identical, 
however,  with  any  of  the  known  processes  of  fermentation  occurring 
in  organic  matters  out  of  the  body.  It  differs  from  ordinary  fermen- 
tation in  being  unattended  with  the  formation  of  carbonic  acid ;  in  not 
requiring  the  presence  of  oxygen,  and  in  not  being  accompanied  by 
the  reproduction  of  the  ferment.3 

The  conclusions  of  MM.  Bernard  de  Villefranche  and  Barreswil,4 
from  numerous  and  varied  experiments  related  to  the  Academie  Royale 
des  Sciences,  of  Paris,  have  been  referred  to  already.  From  these,  it 
would  seem,  that  an  organic v  compound  of  like  nature  exists  in  the 
saliva,  gastric  juice,  and  pancreatic  fluid;  and  that  its  digestive  powers 
vary  according  as  it  is  associated  with  fluid  having  an  acid  or  an  alka- 
line reaction.  Thus  in  the  gastric  juice,  which  is  acid,  it  readily  dis- 
solves nitrogenized  substances, — fibrin,  gluten,  albumen,  &c.,  whilst  it 
is  altogether  without  action  on  starch.  These  gentlemen  affirm,  that 
if  we  destroy  this  acid  reaction,  and  render  the  gastric  juice  alkaline 
by  the  addition  of  carbonate  of  soda,  the  active  organic  matter  being 
in  presence  of  an  alkaline  fluid  changes  its  physiological  action,  and 
becomes  able  to  modify  starch  rapidly,  whilst  it  loses  the  power  of 
digesting  nitrogenized  substances.  As  the  saliva  and  pancreatic  juice 
are  alkaline,  it  wras  interesting  to  know  whether  a  change  in  the  chemi- 
cal reaction  of  these  fluids  would  produce  in  them  the  same  change  of 
properties  as  in  the  case  of  the  gastric  juice.  Experiment  proved  such 
to  be  the  fact.  By  rendering  the  pancreatic  fluid  or  saliva  acid,  their 
ordinary  action  was  inverted :  they  acquired  the  power  of  dissolving 
meat  and  other  nitrogenized  substances,  whilst  they  lost  their  influence 
on  starch. 

M.  Magendie  examined  the  gases  in  the  stomach  and  intestines  of 
executed  criminals,  and  obtained  the  following  results :  a,  in  the  case 
of  an  individual  who  had  taken  food  in  moderation  an  hour  previous  to 

1  Animal  Chemistry,  Gregory  and  Webster's  edit.,  p.  106,  Cambridge,  Mass.,  1842. 

2  Graham's  Elements  of  Chemistry,  Amer.  edit.,  by  Dr.  Bridges,  p.  696,  Philad.,  1843. 

3  Kirkes  and  Paget,  Manual  of  Physiology,  Amer.  edit.,  p.  173,  Philad.,  1849. 

4  Comptes  Rendus,  9  Decemb.,  1844,  and  7  Juillet,  1845. 


CHYMIFICATION.  599 

death ;  Z>,  in  the  case  of  one  who  had  eaten  two  hours  previously ;  and 
c,  in  the  case  of  one  who  had  done  so  four  hours  previous  to  execution. 

100  volumes  of  the  gas  contained 


Oxygen.  Azote.         Carbonic  Acid,  Inflammable  Gas, 

(  From  the  stomach,  11-00  71-45  14-00  3'55 

*«  J small  intestines,  OO'OO  20-03  24-39  55-33 

( large         do,  00-00  51-03  43-50  5'47 

( From  the  stomach,  00-00  00-00  00-00  00-00 

b,< small  intestines,  OO'OO  8-S5  40-00  51-15 

( large         do.  00-00  18-40  70-00  11-60 

t  From  the  stomach,  OO'OO  00-00  OO'OO  00  00 

c? small  intestines,  00-00  66'60  25-00  8-40 

( large         do,  OO'OO  45'96  42-86  IMS1 

From  these  results  it  appears,  that  when  the  execution  occurred  not 
longer  than  an  hour  after  a  meal,  oxygen  was  found  in  the  stomach  ;  and 
when  not  until  two  hours,  it  had  entirely  disappeared,  and  a  large  quan- 
tity of  nitrogen  was  found  in  the  intestines,  with  an  entire  absence  of 
oxygen ;  whence  it  is  inferred,  that  the  oxygen  of  the  air  is  separated 
from  the  nitrogen  in  the  stomach ;  and  the  former  is  employed  in  diges- 
tion. The  view  of  Liebig  is,  that  the  oxygen  occasions  a  molecular 
action  in  the  pepsin  or  animal  matter  in  the  stomach,  and  that  this  in- 
testine motion  is  communicated  to  the  molecules  of  the  albumen  or  pro- 
tein of  the  food,  so  that  the  latter  is  rendered  soluble  in  the  gastric 
acid.2  The  oxygen  he  refers  to  atmospheric  air  enclosed  in  the  saliva 
during  mastication,  and  in  that  way  introduced  into  the  stomach. 

Researches  into  the  phenomena  jof  digestion,  made  some  years  ago 
by  MM.  Bouchardat  and  Sandras,3  led  them  to  the  following  conclu- 
sions. First.  The  functions  of  the  stomach  in  digestion  consist  in  dis- 
solving, with  the  aid  of  chlorohydric  acid,  all  albuminous  matters,  as 
fibrin,  albumen,  casein,  and  gluten.  Secondly.  This  acid,  if  diluted 
with  5000  parts  of  water,  dissolves  the  same  matters  out  of  the  body, 
provided  they  are  not  cooked ;  but  if  boiled,  the  solution  has  no  action 
upon  them.  As  they  are  found,  however,  dissolved  in  the  stomach,  it 
is  probable  that  some  other  agency  is  at  work  than  simple  solution  by 
means  of  chlorohydric  acid;  but  the  presence  of  that  acid  appears  to 
be  indispensable.  Thirdly.  As  far  as  albuminous  matters  are  concerned, 
digestion  and  absorption  take  place  exclusively  in  the  stomach  through 
the  veins ;  the  intestines  present  scarcely  any  traces  of  those  matters 
although  they  exist  in  such  abundance  in  the  stomach.  Fourthly.  Solu- 
tion of  fecula  occurs  in  the  stomach.  This  principle  does  not  appear 
to  pass  into  the  state  of  sugar;  and  the  experiments  did  not  even  war- 
rant the  statement,  that  it  passes  into  that  of  soluble  starch;  but  they 
regard  its  transformation  into  lactic  acid  as  proved.  Fifthly.  The 
absorption  of  this  form  of  aliment  appears  to  take  place  less  exclusively 
from  the  stomach  than  that  of  albuminous  matters, — a  circumstance 
which  accords  with  the  special  arrangement  and  length  of  the  intestines 
of  animals  not  carnivorous.  Sixthly.  Fatty  matters  are  not  acted  on 

1  Liebig,  op.  cit.,  p.  289.  «  Ancell,  Lond.  Lancet,  Dec.  16,  1842,  p.  419. 

3  Annales  des  Sciences  Naturelles,  Oct.,  1842,  or  Edinb.  Med.  and  Surg.  Journal.,  Jan., 
1843. 


600  DIGESTION. 

in  the  stomach.  They  proceed  into  the  duodenum  forming  an  emulsion 
with  alkalies  furnished  by  the  liver  and  pancreas.  This  emulsion  is 
found  abundantly  throughout  the  whole  course  of  the  intestines. 
Seventhly.  The  chyle  appears  somewhat  less  abundant,  but  presents 
similar  characters  in  animals  that  are  killed  after  long  fasting;  as  in 
those  killed  after  having  taken  copious  meals  of  albuminous  matters  and 
fecula.  In  those,  however,  that  had  been  fed  on  fatty  matters  fat  was 
found  in  it  in  considerable  proportion. 

According  to  those  views — which  were  favourably  reported  upon  to 
the  Academic  Royale  des  Sciences  of  Paris,  by  MM.  Payen,  Magcndie, 
Flourens,  Milne  Edwards  and  Dumas,1  and  "the  authors  encouraged  to 
persevere  in  a  study  that  still  presents  so  many  problems  for  solution, 
and  into  which  they  have  but  entered,  although  they  have  already 
made  some  curious  observations," — most  articles  undergo  complete 
digestion  in  the  stomach ;  but  fat  requires  an  admixture  with  the  secre- 
tions poured  into  the  intestines,  and  is  taken  up  only  by  the  chyliferous 
vessels.  MM.  Bouchardat  and  Sandras  do  not,  however,  restrict  the 
agency  of  those  vessels  to  the  absorption  of  fat.  They  suggest — and 
it  can  only  be  regarded  as  a  suggestion — that  the  abdominal  glands 
prepare  for  the  chyliferous  vessels  and  thoracic  duct  a  chyle,  the  alka- 
line character  of  which  is  in  a  direct  ratio  with  the  acidity  developed 
in  the  stomach  during  digestion.  This  chyle — not  obtained  from  the 
food  but  by  a  true  process  of  secretion — enters  the  blood  through  the 
chyliferous  apparatus,  to  neutralize  the  acid,  that  is  indispensable  for 
the  solution  of  the  food  in  the  stomach  to  prepare  it  for  absorption  from 
that  organ. 

Should  the  views  of  MM.  Bouchardat  and  Sandras  be  established, 
they  would  modify  materially  former  notions  in  regard  to  the  physio- 
logy of  the  digestion  of  solids.  It  need  hardly  be  said,  however,  that 
a  succession  of  repeated  and  careful  experiments  tending  to  the  same 
results  will  be  necessary  before  they  can  be  regarded  as  worthy  of 
more  than  a  passing  notice.  Certain  of  the  positions  of  these  gentlemen 
have  received  support  from  the  investigations  of  M.  Blondlot.2  He  is 
of  opinion,  that  of  all  the  simple  alimentary  substances,  those  that  are 
fluid  at  the  ordinary  temperature  of  the  stomach,  and  those  that  are 
readily  soluble  in  its  secretions,  as  fluid  albumen,  sugar,  gum,  pectin, 
&c.,  are  at  once  absorbed  by  the  veins.  It  would  seem,  indeed,  that  in 
cases  of  scirrhus  of  the  pylorus,  and  where  a  cancerous  communication 
has  existed  between  the  stomach  and  colon,3  nutritious  matter  must 
necessarily  be  absorbed  from  the  stomach  :  except,  however,  in  such 
cases,  the  view,  that  digestion  can  be  accomplished  by  the  gastric  veins, 
independently  of  the  action  of  any  gastric  secretions,  can  scarcely  be 
maintained.4  It  would  seem,  moreover,  that  certain  aliments,  after 
having  experienced  the  necessary  stomachal  and  intestinal  changes,  are 
received  by  imbibition  into  the  veins  of  the  intestines.  MM.  Bouchardat 

1  Encyclographie  des  Sciences  Medicales,  Fevr.,  1843,  p.  159. 

2  Traite  Analytique  de  la  Digestion,  Paris,  1844. 

3  Such  a  case  is  given  by  Dr.  William  Waters,  in  Philadelphia  Med.  Examiner,  p.  201, 
April,  1845. 

4  A  Physiological  Essay  on  Digestion.     By  Nathan  R.  Smith,  M.D.,  &c.,  New  York,  1825. 


CHYMIFICATION.  601 

and  Sandras  affirm,  that  after  herbivorous  animals  have  been  fed  on 
farinaceous  substances,  more  dextrin,  grape  sugar  and  lactic  acid  are 
detected  in  the  blood  of  the  vena  porta  than  in  that  of  any  other  blood- 
vessel.1 Trommer,  also,  detected  grape  sugar  in  the  blood  of  the  portal 
vein,  but  not  in  that  of  the  hepatic  vein  in  animals  to  which  that  sub- 
stance had  been  given  with  their  food.2  The  bearing  of  such  observa- 
tions on  the  production  of  sugar  by  the  liver  will  be  shown  hereafter. 

In  conclusion: — Let  us  inquire  into  the  various  agencies  to  which 
the  food  is  exposed  during  the  progress  of  chymification.  First.  It 
becomes  mixed  with  the  secretions,  already  existing  in  the  stomach,  as 
well  as  with  those  excited  by  its  presence.  Secondly.  It  is  agitated  by 
the  peristaltic  motion  of  the  stomach  itself,  and  the  movement  of  the 
neighbouring  organs.  Thirdly.  It  is  exposed  to  a  temperature  of  at 
least  100°  of  Fahrenheit,  which,  during  the  ingestion  of  food,  does 
not  rise  higher:  exercise  elevates,  whilst  sleep,  or  rest,  or  a  recum- 
bent posture,  depresses  it.3  After  food  has  been  subjected  to  these 
influences,  the  conversion  into  chyme  commences.  This  always  takes 
place  from  the  surface  towards  the  centre:  the  nearer  it  lies  to  the 
surface  of  the  stomach,  the  more  it  is  acted  on;  and  the  part  that  is  in 
contact  with  the  lining  membrane  is  more  digested  than  any  other ; — 
appearing  as  if  corroded  by  some  chemical  substance  capable  of  dis- 
solving it. 

Dr.  Wilson  Philip4  asserts,  that  the  new  food  is  never  mixed  with 
the  old;  the  former  being  always  found  in  the  centre,  surrounded  on 
all  sides  by  the  latter.  If  the  old  and  new  be  of  different  kinds,  the 
line  of  separation  between  them  is  so  evident,  that  the  former  may  be 
completely  removed  without  disturbing  the  latter;  and  if  they  be  of 
different  colours,  the  line  of  demarcation  can  frequently  be  distinctly 
traced  through  the  parietes  of  the  stomach  before  they  are  laid  open. 
Dr.  Beaumont,5  however,  affirms,  that  this  statement  is  not  correct; 
that,  in  a  very  short  time,  the  food,  already  in  the  stomach,  and  that 
subsequently  eaten,  become  commingled.  In  the  subject  of  his  experi- 
ments, he  invariably  found  that  the  old  and  new  food,  if  in  the  same 
state  of  comminution,  were  readily  and  speedily  combftied. 

The  conversion  of  the  food  into  chyme,  it  has  been  conceived,  com- 
mences in  the  splenic  portion,  is  continued  in  the  body  of  the  viscus, 
and  completed  in  the  pyloric  portion.  On  this  point,  the  observations 
of  Dr.  Philip  differ  somewhat  from  those  of  M.  Magendie,6  the  former 
appearing  to  think,  that  chymification  is  chiefly  accomplished  in  the 
splenic  portion  and  middle  of  the  stomach;  whilst  the  latter  affirms, 
that  it  is  mainly  in  the  pyloric  portion  that  chyme  is  formed ; — the  ali- 
mentary mass  appearing  to  pass  into  it  by  little  and  little,  and  during 
its  stay  there  to  undergo  transformation.  He  further  affirms,  that  he 
has  frequently  seen  chymous  matter  at  the  surface  of  the  alimentary 

1  Gazette  M£dicale  de  Paris,  Jan.,  1845. 

2  Kirkes  and  Paget,  Manual  of  Physiology,  Amer.  edit.,  p.  191,  Philad.,  1849. 

3  Beaumont,  On  the  Gastric  Juice,  p.  274. 

4  Exper.  Inquiry,  ch.  vii.  sect.  1 ;  and  Treatise  on  Indigestion,  Lond.,  1821. 

6  Op.  citat.,  p.  89'.  6  Precis,  &c.,  edit.'cit.,  ii.  88. 


602  DIGESTION. 

mass  filling  the  splenic  half;  but  that  it  commonly  preserves  its  pro- 
perties in  this  part  of  the  organ. 

The  precise  steps  of  the  change  into  chyme  cannot  be  indicated. 
Some  of  the  results,  at  different  stages  of  the  process,  have  been  ob- 
served on  animals;  and  pathological  cases  have  occasionally  occurred, 
which  enabled  the  physiologist  to  witness  what  was  going  on  in  the 
interior  of  the  stomach ;  but,  with  perhaps  one  exception,  those  oppor- 
tunities have  not  been  much  improved.  Dr.  Burrows1  relates  a  case  of 
fistulous  opening  into  the  organ.  The  subject  of  the  case  was  not  seen 
by  him  until  twenty-seven  years  after  the  injury,  at  which  time  the  man 
was,  to  all  appearance,  healthy ;  but  he  was  drunken,  and  dissipated, 
and  the  following  year  died.  A  case  is  related  by  Schenk;2  and  Louis3 
refers  to  similar  cases  that  occurred  to  Foubert  and  Covillard.  Helm, 
of  Vienna,4  published  a  case,  to  which  reference  has  already  been  made ; 
and  one  of  an  interesting  character  occurred  at  the  Hospital  La  Charit£ 
of  Paris,  which  sheds  some  little  light  on  the  subject.5  The  aperture, 
which  was  more  than  an  inch  and  a  half  long,  and  an  inch  broad,  ex- 
posed the  interior  of  the  organ.  At  the  admission  of  the  female  into 
the  hospital,  she  ate  three  times  as  much  as  ordinary  persons.  Three 
or  four  hours  after  a  meal,  an  irresistible  feeling  compelled  her  to  re- 
move the  dressings  from  the  fistulous  opening,  so  as  to  allow  the  escape 
of  food  which  the  stomach  could  no  longer  contain, — when  the  contents 
came  out  quickly,  accompanied  by  more  or  less  air.  They  possessed  a 
faint  smell,  but  had  neither  acid  nor  alkaline  properties;  and  the  gray- 
ish paste,  of  which  they  consisted  when  diluted  with  distilled  water, 
did  not  affect  vegetable  blues.  Digestion  was  far  from  complete ;  yet, 
frequently  the  odour  of  wine  was  destroyed;  and  bread  was  reduced  to 
a  soft,  viscid,  thick  substance,  resembling  fibrin  recently  precipitated 
by  acetous  acid,  and  swimming  in  a  stringy  fluid  of  the  colour  of  com- 
mon soup.  Experiments,  made  on  this  half-digested  food,  at  the  Ecole 
de  Medecine,  showed  that  the  changes,  which  it  had  undergone,  were 
an  increase  of  gelatin;  the  formation  of  a  substance  like  fibrin;  and  a 
considerable  portion  of  chloride  of  sodium,  phosphate  of  soda  and 
phosphate  of  lime.  The  patient  could  never  sleep  until  she  had  emptied 
her  stomach,  and  washed  it  out  by  drinking  infusion  of  chamomile. 
In  the  morning,  it  contained  a  small  quantity  of  thick,  frothy  liquid, 
analogous  to  saliva,  which  did  not  affect  vegetable  blues;  with  matters 
of  greater  consistence,  and  some  opaque,  albuminous  flocculi  mingled 
with  the  liquid  portion.  The  results  of  chemical  experiments  on  this 
liquid  were  similar  to  those  obtained  on  the  analysis  of  saliva. 

But  the  most  interesting  case  in  its  observed  phenomena  is  one  that 
occurred  to  Dr.  Beaumont,6  of  the  United  States  Army,  now  of  Saint 
Louis,  which  the  author  had  an  opportunity  of  examining.  To  this 
case,  reference  has  already  been  made  repeatedly.  A  Canadian  lad, 

1  Transactions  of  the  Royal  Irish  Academy,  vol.  iv. 

2  Observ.  Medic.  Rar.  Nov.,  &c.,  lib.  iii.,Francof.,  1609. 

3  Memoir,  de  1' Academic  Royale  de  Chirurgie,  vol.  iv.  p.  213,  Paris,  1819. 

4  Rudolpbi,  Grundriss  der  Physiologic,  2ter  Band,  2te  Abtheil.,  s.  114,  Berlin,  1828. 
6  Richerand's  Elemens  de  Physiologic,  edit,  cit.,  p.  72. 

6  Op.  citat.,  Introduction,  p.  10;  and  the  Author's  Elements  of  Hygiene,  p.  216,  Philad., 
1835. 


CHYMIFICATION.  603 

Alexis  San  Martin,  eighteen  years  of  age,  received  a  charge  of  buck- 
shot in  his  left  side,  which  carried  away  integuments  and  muscles 
of  the  size  of  the  hand;  fracturing,  and  removing  the  anterior  half  of 
the  sixth  rib;  fracturing  the  fifth;  lacerating  the  lower  portion  of  the 
left  lobe  of  the  lung  and  the  diaphragm,  and  perforating  the  stomach. 
When  Dr.  Beaumont  saw  the  lad,  twenty-five  or  thirty  minutes  after 
the  accident,  he  found  a  portion  of  the  lung,  as  large  as  a  turkey's 
egg,  protruding  through  the  external  wound,  lacerated  and  burnt;  and, 
immediately  below  this,  another  protrusion,  which,  on  inspection,  proved 
to  be  a  portion  of  the  stomach,  lacerated  through  all  its  coats,  and  suf- 
fering the  food  he  had  taken  at  breakfast  to  escape  through  an  aperture 
large  enough  to  admit  the  forefinger.  It  need  scarcely  be  said,  that 
numerous  untoward  symptoms  occurred  in  the  cicatrization  of  so  formi- 
dable a  wound.  Portions  of  the  ribs  exfoliated;  abscesses  formed  to 
allow  the  exit  of  extraneous  substances;  and  the  patient  was  worn  down 
by  febrile  irritation.  Ultimately,  however,  the  care  and  attention  of 
Dr.  Beaumont  were  crowned  with  success,  and  the  instinctive  actions 
of  the  system  repaired  the  extensive  injury.  The  wound  was  received 
in  1822,  and  on  the  6th  of  June,  1823,  one  year  from  the  date  of  the 
accident,  the  injured  parts  were  sound,  and  firmly  cicatrized,  with  the 
exception  of  the  perforation  leading  into  the  stomach,  which  was  about 
two  inches  and  a  half  in  circumference.  Until  the  winter  of  1823-4, 
compresses  and  bandages  were  needed  to  prevent  the  escape  of  the  food. 
At  this  period,  a  small  fold  or  doubling  of  the  inner  coat  of  the  stomach 
appeared  forming  at  the  superior  margin  of  the  orifice,  slightly  pro- 
truding, and  increasing  in  size  until  it  filled  the  aperture.  This  val- 
vular formation  adapted  itself  to  the  opening  into  the  organ,  so  as  to 
completely  prevent  the  escape  of  the  contents,  when  the  stomach  was 
full;  but  it  could  be  readily  depressed  by  the  finger.  Since  the  spring 
of  1824,  San  Martin  has  enjoyed  general  good  health ;  he  is  active, 
athletic,  and  vigorous ;  eating  and  drinking  like  a  healthy  individual. 
From  the  summer  of  1825,  Dr.  Beaumont  had  been  engaged  in  the 
prosecution  of  numerous  experiments  upon  him ;  some  of  the  results 
of  which  he  has  given  to  the  world.  In  the  winter  of  1833,  he  was  in 
Washington,  when  the  author — at  the  time,  Professor  of  Medicine  in 
the  University  of  Virginia — was  politely  invited  to  examine  him  for 
physiological  purposes.  Many  of  the  results  of  this  examination  are 
given  by  Dr.  Beaumont,  and  have  already  been,  or  will  be,  referred  to 
in  the  present  work.  Dr.  Beaumont's  researches  into  the  comparative 
digestibility  of  different  alimentary  substances  belong  to  another  de- 
partment of  medical  science,  and  have  accordingly  received  attention 
from  the  author  elsewhere. 

What,  then,  it  may  be  asked,  are  the  changes  wrought  on  the  food  in 
the  stomach  by  the  gastric  secretions?  Dr.  Prout1  classes  them  under 
three  operations; — the  reducing,  converting,  and  organizing  and  vital- 
izing. The  first  of  these  is  probably  the  main  operation.  In  order  to 
decide,  whether  the  action  of  the  stomach  in  digestion  be  a  simple  solu- 
tion, or  a  total  or  partial  conversion,  certain  compounds  of  organization, 
easy  of  detection— as  gelatin,  albumen,  and  fibrin — were  introduced, 


604  DIGESTION. 

at  the  author's  suggestion,  into  the  stomach  through  the  fistulous  open- 
ing in  the  subject  of  Dr.  Beaumont's  case;  whilst  other  portions  were 
digested  artificially  in  gastric  juice  obtained  from  the  same  individual. 
The  solutions  presented  the  same  appearance,  and  were  similarly 
affected  by  reagents ;  and  in  all  cases,  whether  the  digestion  was  arti- 
ficial or  real,  the  proximate  principles  could  be  thrown  down  in  the 
state  of  gelatin,  fibrin  or  albumen,  as  the  case  might  be.  These  experi- 
ments, so  far  as  they  go,  justify  the  conclusion,  that  the  digestive 
process  in  the  stomach  is  a  simple  solution  or  division  of  alimentary 
substances,  and  an  admixture  with  the  mucous  secretions  of  that  organ, 
and  the  various  fluids  from  the  supra-diaphragmatic  portion  of  the 
digestive  tube.  With  regard  to  the  existence  of  the  other  gastric  opera- 
tions described  by  Dr.  Prout,  well-founded  doubts  may  be  entertained. 
To  his  proposition  that,  whatever  may  be  the  nature  of  the  food,  the 
general  composition  and  character  of  the  chyle  remain  always  the 
same,  no  objection  can  be  urged;  but,  admitting  its  accuracy,  it  by  no 
means  follows,  that  the  conversion  must  be  effected  in  the  stomach,  or 
that  any  organizing  or  vitalizing  powers  are  exerted  upon  the  chyme  in 
that  organ.  On  the  contrary,  it  appears  to  us,  that  the  essential  changes 
effected  on  solid  aliment  in  the  stomach  are  of  a  purely  physical  charac- 
ter, so  as  to  adapt  it  for  the  separation  of  the  chylous  portion  in  the 
intestines  by  organs  whose  vital  endowments  and  influences  cannot  be 
contested.  Dr.  T.  J.  Todd1  is  disposed  to  believe,  from  his  experiments 
on  artificial  digestion,  that  the  various  vegetable  and  animal  substances 
subjected  to  the  action  of  the  digestive  fluids  at  the  ordinary  tempera- 
ture of  the  atmosphere  are,  in  all  instances,  reduced — not  to  their 
cJiymical,  but  to  their  organic  elements  ;  and  he  is  of  opinion,  that  this 
applies  equally  to  digestion  in  the  stomach. 

From  what  has  been  already  shown  of  the  close  approximation  to 
each  other  in  chemical  composition  of  several  of  the  compounds  of  organi- 
zation, it  may  be  understood,  that  many  vegetable  principles  might  be 
converted  into  animal  principles  without  any  material  change  of  com- 
position. They  might  all  perhaps  be  changed  into  albumen,  from  which, 
as  elsewhere  seen,  fibrin  differs  but  little  except  in  its  organizable  power. 
Saccharine  matters — it  has  been  conceived — may  be  converted,  in  the 
digestive  tube,  partly  into  albumen,  and  partly  into  oleaginous  matter, 
the  nitrogen  of  the  former  being  furnished,  according  to  some,  by  the 
pepsin  or  by  some  highly  nitrogenized  substance  secreted  in  the  stomach 
or  duodenum  or  both;2  but  whether  such  conversion  really  occurs  is 
exceedingly  questionable.  The  oleaginous  matters  themselves  are  ab- 
sorbed by  simple  imbibition  as  an  emulsion  formed  by  their  union  with 
the  alkali  of  the  pancreatic  fluid.3 

On  the  whole,  in  the  present  state  of  our  knowledge  of  this  import- 
ant function,  we  are  perhaps  justified  in  concluding : — First.  That  by 
the  operation  of  the  gastric  secretions  the  nitrogenized  principles  of  the 
food,  whether  animal  or  vegetable,  are  dissolved  in  the  stomach.  Se- 

1  Brit.  Annals  of  Medicine,  Jan.,  1837. 

2  Prout,  on  the  Stomach  and  Urinary  Diseases,  p.  xxviii.,  note. 

3  Matteucci,  Lectures  on  the  Physical  Phenomena  of  Living  Beings,  by  Pereira,  Amer. 
edit.,  p.  110,  Philad.,  1848,  and  C.  Bernard,  Archives  Generates,  xix.  60,  cited  in  British  and 
Foreign  Medico-Chirurgical  Review,  p.  528,  April,  1849. 


CHYMIFICATION.  605 

condly.  That  amylaceous  matters  are  converted  into  saccharine,' and 
these  last  are  absorbed;  or  they  undergo  a  farther  change,  by  which 
they  are  partly  converted  into  lactic  acid,  and  partly  into  oleaginous 
matter,  and  are  absorbed  in  one  of  these  states.  Thirdly.  That  the 
oleaginous  principles  are  either  formed  into  an  emulsion  or  absorbed 
without  alteration ;  and  Fourthly.  That  with  the  exception  of  certain 
mineral  substances,  matters  that  cannot  be  reduced  to  either  of  these 
forms  are  rejected  as  excrement. 

In  proportion  as  the  food  is  digested,  it  passes  through  the  pylorus. 
After  the  layer,  that  lies  next  to  the  mucous  membrane,  has  experi- 
enced the  requisite  change,  and  is  propelled  onwards  by  the  muscular 
action  of  the  organ,  the  portion  lying  next  to  it  becomes  subjected  to 
the  same  process.  The  gastric  fluid,  at  the  same  time,  penetrates,  in 
a  greater  or  less  degree,  the  entire  alimentary  mass,  so  that,  when  the 
central  portion  comes  in  contact  with  the  surface  of  the  stomach,  its 
conversion  is  already  somewhat  advanced.  The  chyme,  thus  success- 
ively formed,  does  not  remain  in  that  organ,  until  the  whole  alimentary 
mass  has  undergone  chymification ;  but  as  it  is  completed,  it  is  trans- 
mitted, by  the  peristaltic  action,  through  the  pylorus  into  the  duode- 
num. In  the  early  stages  of  digestion,  the  passage  of  the  chyme  from 
the  stomach  is  more  slow  than  in  the  lateE.  At  first,  it  is  more  mixed 
with  the  undigested  portions  of  food,  and,  as  Dr.  Beaumont1  suggests, 
is  probably  separated  with  difficulty  by  the  powers  of  the  stomach.  In 
the  more  advanced  stages,  as  the  whole  mass  becomes  chymified,  the 
process  is  more  rapid,  and  is  accelerated  by  the  peculiar  contraction  of 
the  stomach,  already  described.  After  the  expulsion  of  the  last  parti- 
cles of  chyme,  the  organ  becomes  quiescent,  and  no  more  gastric  secre- 
tion takes  place,  until  a  fresh  supply  of  food  is  received,  or  some  me- 
chanical irritation  is  produced  in  its  inner  coat. 

The  time,  required  for  the  complete  chymification  of  a  meal,  is  stated 
by  the  generality  of  physiologists  to  be  about  four  or  five  hours.  In 
Dr.  Beaumont's  case,2  a  moderate  meal  of  meat,  with  bread,  &c.,  was 
digested  in  from  three  hours  to  three  hours  and  a  half.  We  believe 
that,  in  by  far  the  majority  of  cases,  a  longer  time  than  this  is  neces- 
sary ;  and  in  laborious  digestions,  the  presence  of  food  can  be  distin- 
guished by  eructations  for  more  than  double  the  time.  It  is  manifest, 
that  no  fixed  period  can  be  established  for  the  production  of  this  effect. 
It  must  vary,  according  to  the  digestive  capability  of  the  individual ; 
the  state  of  his  general  health  ;  and  the  relative  digestibility  of  the  ali- 
ments employed ;  all  which,  as  we  have  already  seen,  admit  of  great 
diversity. 

During  chymification,  only  a  very  small  quantity  of  air  is  found  in 
the  stomach  ;  sometimes,  none.  When  met  with,  it  is  near  the  cardiac 
orifice,  or  at  the  upper  part  of  the  splenic  portion.  The  experiments 
of  M.  Magendie,  on  this  point,  have  been  referred  to.  The  small  quan- 
tity of  air,  discovered  in  the  stomachs  of  animals,  disproves  the  idea  of 
M.  Chaussier,  that  we  swallow  a  bubble  at  each  effort  of  deglutition. 
If  so,  the  stomach  ought  to  be  always  inflated,  especially  after  eating, 

1  On  the  Gastric  Juice,  p.  96.  2  Ibid.,  p.  275. 


606  DIGESTION. 

which  is  not  the  case.  MM.  Leuret  and  Lassaigne1  found  the  air,  ob- 
tained from  the  stomach  of  a  dog  fed  on  meat,  to  consist  of  carbonic 
acid,  43  parts ;  sulphuretted  hydrogen,  2  parts ;  oxygen,  4  parts  ; 
nitrogen,  31  parts  ;  carburetted  hydrogen,  20  parts.  Whence  these 
gases  proceed  will  be  a  subject  of  future  inquiry. 

In  a  robust  individual,  chymification  is  effected  without  conscious- 
ness of  the  process.  He  finds,  especially  if  the  stomach  be  over-dis- 
tended, that  the  feeling  of  fulness  and  the  oppression  of  respiration, 
produced  by  the  distension  of  the  organ,  gradually  disappear.  It  is 
not  uncommon,  however,  for  slight  shivering  or  chilliness  to  be  felt  at 
this  time ;  for  the  sensations,  and  mental  and  moral  manifestations  to 
be  blunted ;  and  a  disposition  to  sleep  to  be  experienced.  "  This  con- 
centration of  the  whole  vital  activity,"  according  to  M.  Adelon,2  "  is 
so  natural  to  the  animal  economy,  that  there  is  always  danger  in  oppos- 
ing or  crossing  it  by  any  extraneous  or  organic  influence  ;  as  by  bath- 
ing, the  use  of  medicine,  violent  exercise,  mental  emotions,  intense 
intellectual  effort,  &c."  Gentle  exercise,  however,  would  seem  to  favour 
digestion.  Such  is  the  conviction  of  Dr.  Beaumont,3  from  his  observa- 
tions. In  the  subject  of  hrs  experiment,  he  found  the  temperature  of 
the  stomach  generally  raised  by  it  a  degree  and  a  half,  and  chymifica- 
tion expedited.  Where  digestion  is  imperfect,  the  signs,  already  men- 
tioned, will  be  accompanied  by  the  disengagement  of  air  and  conse- 
quent eructations  ;  a  sense  of  weight,  or  heat,  or  of  unusual  distension 
in  the  epigastric  region,  &c. ;  but  these,  as  well  as  the  developement  of 
sulphuretted  hydrogen,  discharged  by  eructation,  are  the  products  of 
ordinary  decomposition  or  fermentation,  and  appertain  to  the  morbid 
condition  of  the  function  or  to  indigestion.  Yet,  as  M.  Magendie4  has 
remarked,  it  does  not  seem,  that  these  laborious  digestions  are  much  less 
profitable  than  others.  The  fodfl,  habitually  received  into  the  stomach, 
contains  far  more  nutritive  matter  than  is  necessary  to  supply  the  wants 
of  the  system;  and, in  the  cases  in  question,  enough  chyle  is  always  sepa- 
rated in  the  small  intestine  to  supply  the  losses,  and  even  to  add  to  the 
bulk  of  the  body. 

It  has  been  already  remarked,  that  the  chyme,  first  formed,  does  not 
continue  in  the  stomach  until  the  whole  meal  has  undergone  chymifica- 
tion ;  but  that,  as  soon  as  it  has  experienced  the  necessary  changes,  it 
passes  through  the  pylorus  into  the  duodenum.  It  would  appear,  that 
the  accumulation  of  chyme  in  the  pyloric  portion  of  the  stomach  never 
exceeds  four  ounces  at  any  one  time.  M.  Magendie  states,  that,  in  the 
numerous  experiments,  in  which  he  has  had  an  opportunity  of  noticing 
it,  he  uniformly  found,  when  the  quantity  amounted  to  about  two  or  three 
ounces,  it  was  permitted  to  pass  through  the  pylorus  into  the  duodenum. 
This  passage  of  the  chyme  is  effected  by  the  peristaltic  action.  At  the 
commencement  of  digestion,  the  duodenum  contracts  inversely,  and  the 
pyloric  portion  of  the  stomach,  at  the  same  time,  drives  its  contents 
into  the  splenic.  This  movement  is,  however,  soon  followed  by  one  in 
an  opposite  direction  ;  and,  after  a  time,  the  inverted  action  ceases, 

1  Recherches  sur  la  Digestion,  Paris,  1825. 

2  Physiologic  de  I'Homme,  edit,  cit.,  ii.  433. 

3  On  the  Gastric  Juice,  p.  93.  •  4  Precis,  &c.,  ii.  104. 


.ACTION  OF  THE  SMALL  INTESTINE.  607 

and  the  movement  is  altogether  in  one  direction  ; — from  the  stomach 
towards  the  intestine.  The  movement  by  which  the  chyme  is  immedi- 
ately sent  into  the  duodenum,  is  thus  effected : — the  longitudinal  fibres, 
which  pass  from  the  cardiac  to  the  pyloric  orifice,  contract,  and  approxi- 
mate the  two  orifices  ;  the  pyloric  portion  then  contracts,  not  so  as  to 
direct  the  chyme  into  the  splenic  portion,  but  towards  the  duodenum  : 
in  this  manner,  the  chyme  passes  from  the  stomach  :  and,  as  fresh  por- 
tions are  formed,  they  are  successively  sent  onwards;  the  peristaltic 
action  becoming  more  and  more  marked  and  frequent,  and  extending 
over  a  larger  portion  of  the  organ,  as  chymification  approaches  its  ter- 
mination. As  the  chyme  is  discharged  into  the  small  intestine,  the 
stomach  gradually  returns  to  its  former  dimensions  and  situation. 

f.  Action  of  the  Small  Intestine. 

The  changes  in  the  alimentary  mass  in  the  small  intestine,  are  not 
less  important  than  those  already  considered.  They  consist  in  a  farther 
change  of  the  chyme  into  a  substance,  whence  chyle  can  be  extracted 
by  the  action  of  the  chyliferous  vessels  or  lacteals.  Whether  chyle 
be  separated  in  the  intestine,  in  a  state  fit  for  chyliferous  absorption, 
or  be  formed  by  those  vessels,  will  have  to  be  canvassed  hereafter.  In 
common  language,  however,  it  is  said  to  be  separated  there,  and  the 
process,  by  which  this  is  accomplished,  is  called  chylification. 

As  the  chyme  proceeds  into  the  duodenum,  it  readily  finds  space, 
until  towards  the  end  of  chymification,  when  the  intestine  not  unfre- 
quently  experiences  considerable  dilatation.  The  presence  of  the  ali- 
mentary mass  augments  the  secretion  from  the  mucous  membrane; 
and  occasions  a  greater  flow  of  the  biliary  and  pancreatic  juices.  MM. 
Leuret  and  Lassaigne1  found,  when  they  applied  vinegar,  diluted  with 
water,  to  the  external  surface  of  the  small  intestine  in  a  living  animal, 
that  a  considerable  quantity  of  serous  fluid  was  immediately  exhaled. 
The  same  application,  made  to  the  follicles  of  the  intestine,  excited 
the  secretion  of  a  greater  quantity  of  mucus;  and  its  application  to 
the  mouths  of  the  choledoch  and  pancreatic  ducts  caused  the  orifices 
to  dilate,  and  a  greater  discharge  of  bile  and  pancreatic  juice.  It  is 
in  this  local  manner  that  many  of  the  cholagogue  purgatives  produce 
their  effect.  Calomel  exerts  its  agency  on  the  upper  part  of  the  intes- 
tinal canal  more  especially;  and  the  irritation  it  induces  in  the  mucous 
membrane  at  the  mouth  of  the  ductus  communis  choledochus  is  propa- 
gated along  the  biliary  ducts  to  the  liver,  the  secretion  of  which  is 
thus  augmented, — but  not  by  any  specific  action  exerted  on  the  organ, 
as  has  been  often  imagined.  As  the  chyme  is  acid,  it  induces  the  same 
effects  on  the  follicles  as  the  acid  employed  in  the  experiments  of  MM. 
Leuret  and  Lassaigne. 

The  chyme  does  not  remain  so  long  in  the  intestine  as  food  does  in 
the  stomach.  The  successive  arrival  of  fresh  portions  propels  the  first 
onwards ;  and  the  same  effect  is  induced  by  the  peristaltic  action  of 
the  intestines, — an  involuntary,  muscular  movement  of  an  irregular, 
undulatory,  oscillatory  or  vermicular  character,  which  consists  in  an 

1  Recherches  sur  la  Digestion,  Paris,  1825. 


608  DIGESTION. 

alternate  contraction  and  dilatation  of  the  organ,  proceeding  generally 
from  above  to  below,  -so  as  to  propel  the  chyme  downwards.  When  it 
reaches  any  point  of  the  intestine,  its  contact  excites  the  contraction 
of  the  circular  fibres  of  the  part;  so  that  it  is  sent  forwards  to  another 
portion  of  the  canal;  the  circular  fibres  of  which  contract,  whilst  the 
former  are  relaxed;  and  this  occurs  successively  through  the  whole 
tract  of  the  intestines.  The  longitudinal  fibres,  by  their  contrac- 
tion, shorten  the  intestine,  and  in  this  manner  meet  the  chyme,  so 
as  to  facilitate  its  progress ;  but  their  effect  cannot  be  considerable. 
When  digestion  is  not  going  on,  the  peristaltic  action  occurs  only  at 
intervals;  always  slowly  and  irregularly;  and,  perhaps,  as  has  been 
suggested,  only  when  sufficient  mucous  secretion  has  collected  on  the 
inner  coat  of  the  intestine  to  provoke  it.  During  digestion,  it  is  much 
more  energetic  and  frequent,  and  more  marked  in  the  duodenum  and 
small  intestine  than  in  the  large;  occurring  not  continuously,  but  at 
intervals,  as  the  chyme  arrives  and  excites  it.  When  the  small  intes- 
tine is  surcharged,  it  may  take  place  in  several  parts  of  the  canal  at 
once;  and,  at  times,  the  action  is  inverted. 

The  secretions  poured  into  the  intestinal  canal  lubricate  it,  and 
facilitate  the  progress  of  the  chyme.  This  is  aided  by  the  free  and 
floating  condition  of  the  intestine;  and  by  the  agitation  of  the  diaphragm 
and  abdominal  muscles  in  respiration.  Yet  its  course  along  the  small 
intestine  is  slow.  The  chyme  is  not  transmitted  from  the  stomach 
continuously;  and  the  peristaltic  action  of  the  intestines  occurs  only  at 
intervals.  Moreover,  owing  to  the  convolutions  of  the  intestinal  canal, 
the  chyme  must,  in  many  cases,  proceed  against  its  own  gravity ;  and 
be  retarded  by  the  numerous  valvulse  conniventes,  which  bury  them- 
selves in  it,  when  the  canal  is  contracted  by  the  action  of  the  circular 
fibres.  All  these  circumstances  must  cause  it  to  proceed  slowly  along 
this  part  of  the  tube, — a  point  of  some  importance,  when  we  reflect, 
that  an  essential  change  is  effected  on  it  through  the  influence  chiefly 
of  the  bile  and  pancreatic  juice,  and  that  its  nutritive  portion  is  here 
absorbed.  In  the  duodenum,  the  course  of  the  chyme  is  slow.  In  the 
jejunum  it  is  more  rapid,  hence  the  name,  which  indicates,  that  it  is 
almost  always  found  "empty:"  in  the  ileum  again  it  is  slower  on  account 
of  the  greater  consistence  acquired  by  the  absorption  of  the  chylous 
portion.  Whilst  the  food  is  in  progress  along  the  small  intestine,  it 
experiences  the  change  in  its  physical  properties,  which  enables  the 
chyle  to  be  separated  from  it  by  absorption.  These  two  actions  have 
been  termed  respectively  chylification  and  the  absorption  of  chyle; 
although  by  some  the  former  term  has  been  applied  to  both  processes. 

Above  the  point,  at  which  the  common  choledoch  and  pancreatic 
ducts  open  into  the  duodenum,  no  change  is  observable  in  the  chyme. 
It  preserves  its  colour,  semi-fluid  consistence,  sour  smell,  and  slightly 
acid  taste;  having  been  simply  mixed  with  the  exhaled  and  follicular 
secretions  of  the  lining  membrane;  but,  immediately  after  it  has  passed 
the  part,  at  which  the  hepatic  and  cystic  bile  and  the  pancreatic  juice 
are  poured  into  the  intestine,  it  assumes  a  different  appearance;  its 
colour  is  found  to  be  changed;  it  becomes  yellowish;  of  a  bitter  taste; 
its  sour  smell  diminishes;  and  chyle  can  now  be  separated  by  the  lac- 


ACTION  OP  THE  SMALL  INTESTINE.  609 

teals.     Accordingly,  at  this  part  of  the  canal,  chyliferous  vessels  are 
first  perceptible. 

The  change  effected  upon  the  chyme  in  the  small  intestine  is  pro- 
bably,— like  that  produced  on  the  food  in  the  stomach, — of  an  entirely 
physical  character.  The  chyle  itself,  we  shall  endeavour  to  show 
hereafter,  is  formed  by  an  action  of  elaboration  and  selection  exerted 
by  the  chyliferous  vessels.  No  difference  is  observable  between  the 
chylous  and  excrementitious  portion  of  the  chyme  in  any  part  of  the 
small  intestine;  nor  can  it  be  separated  by  pressure  or  by  any  other 
physical  process.  M.  Magendie,1  indeed,  has  affirmed,  that  if  the 
chyme  proceeds  from  animal  or  vegetable  substances  that  contain  fat 
or  oil,  irregular  filaments  are  observed  to  form,  here  and  there,  on  the 
surface, — sometimes  of  a  flat,  at  others,  of  a  round  shape, — which 
speedily  attach  themselves  to  the  surface  of  the  valvulse,  and  appear 
to  be  brute  chyle;  but  this  is  not  observed  when  the  chyle  proceeds 
from  food,  that  does  not  contain  fat.  In  this  case,  a  grayish  layer,  of 
greater  or  less  thickness,  adheres  to  the  mucous  membrane,  and  appears 
to  contain  the  elements  of  chyle.  MM.  Leuret  and  Lassaigne2  state, 
that  if  an  animal  be  opened  while  digestion  is  going  on, — on  the  sur- 
face of  the  chyme,  between  the  pylorus  and  the  orifice  of  the  ductus 
communis  choledochus,  a  grayish-white,  homogeneous,  dense,  fluid,  and 
acid  substance  is  perceived  on  the  villi  of  the  intestine.  Neither  of 
these,  however,  is  chyle.  It  is  merely  the  substance  whence  chyle  is 
obtained  by  the  action  of  the  chyliferous  vessels.  The  fact,  mentioned 
by  M.  Magendie, — regarding  the  appearance  of  irregular  filaments,  when 
animal  or  vegetable  substances,  containing  fat  or  oil,  have  been  taken 
as  diet, — has  been  the  occasion  of  other  erroneous  deductions  of  a 
pathological  character.  Frank3  asserts,  that  he  was  requested  to  see  a 
prince,  who  was  attacked  with  epilepsy.  His  physician, — a  respectable 
old  practitioner, — assured  Frank,  that  he  could  make  his  patient  void 
thousands  of  filiform  worms  at  pleasure.  As  he  was  unable  to  define 
either  the  genus  or  species  of  these  worms, — the  quantity  of  which,  from 
his  account,  seemed  to  be  prodigious, — Frank  requested  to  be  a  witness 
of  the  phenomenon.  The  physician  administered  a  dose  of  castor  oil, 
which  produced  numerous  evacuations,  containing  thousands  of  whitish 
filaments  similar  to  small  eels ;  but  on  an  attentive  examination  of 
these  pretended  worms,  they  were  found  to  consist  entirely  of  the  castor 
oil,  in  a  state  of  fine  division. 

The  alteration  of  the  aliment  in  the  small  intestine  is  probably  of  a 
chemical  nature ;  yet  its  essence  is  impenetrable.  It  has,  accordingly, 
been  conceived  to  be  organic  and  vital.  The  same  remarks  are  appli- 
cable here  as  were  indulged  upon  the  supposed  organic  and  vital  action  of 
the  stomach  exerted  in  the  formation  of  chyme.  The  agents  of  this 
conversion  are: — the  fluids  secreted  from  the  mucous  membrane  of  the 
small  intestine,  and  the  biliary  and  pancreatic  juices,  aided  by  the  tem- 
perature of  the  parts,  and  the  peristole.  Haller4  was  of  opinion,  that 
the  first  of  these  is  a  principal  agent.  Reflecting  on  the  extensive 

1  Precis,  &c.,  ii.  III.  2  Op.  citat. 

3  De  Curandis  Hoininum  Morbis  Epitome,  lib.  vi.  p.  218.          4  Element.  Physiol.,  xix.  5. 

VOL.  i.— 39 


610  DIGESTION. 

surface  of  the  small  intestine,  on  the  number  of  arteries  distributed  to 
the  organ,  and  on  the  size  of  these  arteries,  he  asserted,  that  the  lining 
membrane  of  the  intestine,  at  the  time  of  chylification,  secretes  a  juice, 
•which  he  estimated  at  the  enormous  quantity  of  eight  pounds  in  the 
twenty-four  hours.  To  this  he  gave  the  name  succus  intestinalis,  and 
assigned  it  as  important  a  part  in  chylification  as  he  attributed  to  the 
gastric  juice  in  chymification.  It  is  probable,  however,  that  the  fluids 
secreted  by  the  mucous  membrane  of  this  portion  of  the  canal  resemble 
those  of  the  rest  of  the  intestinal  mucous  membrane;  and  that  their 
main  function  is  that  of  lubricating  the  intestine,  and  of  still  further 
diluting  the  chymous  mass.  MM.  Leuret  and  Lassaigne  endeavoured 
to  procure  some  of  them  by  making  animals,  whilst  fasting,  swallow 
small  sponges,  enveloped  in  fine  linen,  and  killing  them  twenty-four 
hours  afterwards.  Some  of  these  sponges  had  not  gone  further  than 
the  stomach,  and  were  filled  with  gastric  juice ;  others,  which  had 
reached  the  small  intestine,  had  imbibed  the  succus  intestinalis,  which 
•was  more  yellow,  and  manifestly  less  acid  than  the  gastric  secretion. 
On  attempting  to  dissolve  a  crumb  of  bread  in  each  of  these  juices, 
they  discovered  that  the  gastric  secretion  communicated  a  sour  smell  to 
the  bread ;  but  that  the  intestinal  secretion  allowed  the  bread  to  be 
precipitated,  and  dissolved  no  part  of  it.  From  this  experiment,  it  has 
been  concluded,  that  the  succus  intestinalis  is  not  a  great  agent  in  chyli- 
fication. The  deduction  is  probably  correct;  but  no  weight  can  be 
placed  upon  results  obtained  in  so  unsatisfactory  a  manner ;  for  it  is 
obvious,  that  no  certainty  could  exist  as  to  the  identity  between  the 
gastric  and  intestinal  juices  and  the  fluids  found  in  the  respective 
sponges. 

We  have  strong  reason  for  believing,  that,  even  if  food  should  escape 
the  action  of  the  stomach,  it  is  capable  of  being  digested  in  the  small 
intestine.  This  may  be  owing  to  some  of  the  true  gastric  juice  passing 
into  the  intestinal  canal,  and  impregnating  it;  or  it  may  be  a  similar 
secretion  from  follicles  seated  there.  The  lining  membrane  of  the  small 
intestine  possesses  the  property  of  coagulating  milk ;  and  pathological 
cases  occur  in  which  the  stomach  is,  to  all  appearance,  completely  dis- 
organized; yet  patients  survive  so  long  as  to  compel  us  to  presume, 
that  digestion  must  have  been  effected  elsewhere  than  in  that  organ. 
M.  Magendie1  placed  a  piece  of  raw  meat  in  the  duodenum  of  a  healthy 
dog.  At  the  expiration  of  an  hour  it  had  reached  the  rectum,  and  its 
weight  was  found  to  be  but  slightly  diminished ;  the  only  change  ap- 
peared to  be  at  its  surface,  which  was  discoloured.  In  another  experi- 
ment, he  fixed  a  piece  of  muscle  with  a  thread,  so  that  it  could  not  pass 
out  of  the  small  intestine.  Three  hours  afterwards,  the  animal  was 
opened.  The  piece  of  meat  had  lost  about  half  its  weight.  The  fibrin 
•was  especially  attacked;  and  what  had  resisted,  which  was  almost  all 
areolar  tissue,  was  extremely  fetid.  In  experiments  by  M.  Voisin,2 
aliment  was  introduced  into  the  small  intestines  of  animals, — in  one 
case  masticated  and  mixed  with  saliva;  in  another  without  any  prepara- 
tion. In  a  few  hours,  in  the  first  instance,  and  after  a  longer  period  in 

1  Precis,  &c.,  ii.  113.          2  Nouvel  Apergu  sur  la  Physiologie  du  Foie,  etc.,  Paris,  1833. 


ACTION  OF  THE  SMALL  INTESTINE.  611 

the  second,  the  food  was  as  completely  chymified  as  if  the  process  had 
taken  place  in  the  stomach.  The  same  experiments  were  repeated  upon 
animals  whose  pylorus  had  been  secured  by  ligature,  and  with  similar 
results.  One  of  them  lived  for  a  month  after  the  ligature,  nourished 
for  that  period  by  food  introduced  into  the  duodenum.  These  facts  ' 
sufficiently  show,  that  a  solvent  action  is  exerted  in  the  small  intestine. 

The  biliary  and  pancreatic  juices  are  usually  esteemed  great  agents 
in  chylification.  It  has  been  already  remarked,  that  the  chyliferous  ves- 
sels do  not  begin  to  appear  above  the  part  at  which  these  juices  are 
poured  into  the  duodenum ;  that  in  the  rest  of  the  small  intestine  they 
are  less  and  less  numerous  as  we  recede  from  the  duodenum  ;  and  that 
the  chyme  does  not  exhibit  any  marked  change  in  its  properties,  until 
after  its  admixture  with  those  fluids.  Direct  experiments  have  been 
made  for  the  purpose  of  testing  the  use  of  the  bile  in  digestion.  Sir 
Benjamin  Brodie  tied  the  ductus  communis  choledochus  in  young  cats, 
so  as  to  prevent  both  hepatic  and  cystic  bile  from  reaching  the  intes- 
tine. He  found,  that  chylification  was  interrupted,  and  there  were 
neither  traces  of  chyle  in  the  intestines  nor  in  the  chyliferous  vessels. 
The  former  contained  only  chyme,  similar  to  that  of  the  stomach,  which 
became  solid  at  the  termination  of  the  ileum ;  and  the  latter,  a  trans- 
parent fluid,  which  appeared  to  be  a  mixture  of  lymph,  and  of  the  more 
liquid  portion  of  the  chyme.  Mr.  Mayo,1  likewise,  found,  that  when 
the  ductus  communis  choledochus  was  tied  in  the  cat  or  dog,  and  the 
animals  were  killed  at.  various  intervals  after  eating,  there  was  no  trace 
whatever  of  chyle  in  the  lacteals.  M.  Magendie,2  however,  repeated 
these  experiments  on  adult  animals,  and  with  dissimilar  results.  The 
greater  part  died  of  the  consequences  of  opening  the  abdomen,  and 
of  the  operation  required  for  tying  the  duct.  But  in  two  cases,  in 
which  they  survived  some  days,  he  discovered  that  digestion  had  per- 
sisted ;  white  chyle  had  been  formed,  and  stercoraceous  matter  pro- 
duced. This  last  had  not  the  usual  colour ;  but  this,  as  he  remarks, 
is  not  surprising,  as  it  contained  no  bile.  The  experiment  was  repeated 
by  MM.  Leuret  and  Lassaigne,3  and  with  results  similar  to  those  ob- 
tained by  M.  Magendie.  In  the  duodenum  and  jejunum,  a  whitish  chyme 
adhered  to  the  parietes  of  the  organ ;  and  in  the  thoracic  duct  there 
was  a  fluid  of  a  rosy-yellow  colour,  which  afforded,  on  analysis,  the 
same  constituents  as  chyle;  although  the  subjects  of  the  operation  had 
been  kept,  for  some  time,  without  food. 

The  experiments  of  Messrs.  Tiedemann  and  Gmelin4  on  this  subject 
were  marked  by  the  usual  care  and  accuracy  of  those  observers.  They 
found,  that  the  animals  were  attacked  with  vomiting,  soon  after  the 
operation,  and  afterwards  with  thirst  and  aversion  for  food;  on  the 
second  or  third  day,  the  conjunctiva  became  yellow,  the  evacuations 
chalky,  and  very  fetid,  and  the  urine  yellow.  Some  of  the  animals 
died;  others  were  killed  :  of  the  latter,  some  had  previously  recovered 
from  the  jaundice,  owing  to  a  singular  recuperative  phenomenon,  noticed 

1  Lond.  Med.  and  Physical  Journal, Oct.,  1826  ;  and  Outlines  of  Physiology,  4th  edit,  p.  125, 
London,  1837.  2  Op.  citat.,ii.  117. 

3  Recherches  sur  la  Digestion,  p.  147,  Paris,  1825. 

4  Recherches  Experimentales,  &c.,  sur  la  Digestion,  ii.  53,  Paris,  182^. 


612  DIGESTION, 

by  Dr.  Blundell1  and  Sir  B.  Brodie  in  their  experiments— to  the  re- 
establishment  of  the  choledoch  duct,  by  the  effusion  of  lymph  around 
the  tied  part,  and  the  subsequent  dropping  off  of  the  ligature.  Like 
Sir  B.  Brodie,  Mayo,  Leuret  and  Lassaigne,  and  Voisin,  they  observed 
that  chymification  went  on  as  in  the  sound  animal. 

The  thoracic  duct  and  chyliferous  vessels,  in  animals  fed  a  short  time 
before  death,  always  contained  an  abundant  fluid,  which  was  generally 
of  a  yellowish  colour.  It  coagulated  like  ordinary  chyle;  the  crassa- 
mentum  acquired  the  usual  red  colour;  and  the  only  difference  between 
it  and  the  chyle  of  a  sound  animal  was,  that  after  tying  the  duc"t  it  was 
never  white.  They  conceived  the  reason  of  the  difference  to  be,  that 
the  white  colour  is  owing  to  fatty  matter  taken  up  from  the  food  by  the 
agency  of  the  bile,  which  possesses  the  power  of  dissolving  fat;  and 
may  probably,  therefore,  aid  in  effecting  its  solution  in  the  chyle  in  the 
radicles  of  the  chyliferous  vessels.  Sir  Benjamin  Brodie  and  Mr.  Mayo 
are  considered  to  have  been  misled  by  the  absence  of  the  white  colour^ 
usually  possessed  by  the  chyle,  but  which  is  wanting  in  ordinary  diges- 
tion, if  the  food  does  not  contain  fatty  matter.2  The  experiments  of 
Dr.  Beaumont  showed,  that  oil  undergoes  but  little  change  in  the  sto- 
mach, and  that  bile  is  probably  necessary  to  give  it  the  requisite  physical 
constitution,  in  order  that  chyle  may  be  separated  from  it.  Messrs. 
Tiedemann  and  Gmelin  restrict  the  agency  of  the  bile  in  chylifieation 
to  the  accomplishing  of  the  solution  of  the  fatty  matter,  and  to  the 
nitrogenizing  or  animalizing  of  food  that  does  not  contain  nitrogen. 
The  experiments  of  M.  Voisin  equally  show,  that  the  ligature  of  the 
choledoch  duct  does  not  prevent  the  formation  of  chyle,  provided  the 
passage  of  the  pancreatic  fluid  is  not  at  the  same  time  prevented.  In 
a  number  of  dogs,  a  ligature  was  applied  so  as  to  completely  prevent 
the  passage  of  bile  into  the  intestine.  Two  lived  three  months  after 
the  experiment;  three,  six  weeks;  and  five  died  shortly  after  the  appli- 
cation of  the  ligature.  In  no  instance  did  death  appear  to  be  owing 
to  the  suspension  of  digestion  or  assimilation.  Almost  all  the  animals 
had  begun  to  eat;  and,  in  the  majority,  food  perfectly  chymified  was 
found  in  the  duodenum ;  and  well  elaborated  chyle  in  the  chyliferous 
vessels.  It  would  appear,  therefore,  that  the  bile,  although  an  import- 
ant, is  not  an  essential  agent  in  digestion  in  the  duodenum.  This  is 
signally  corroborated  by  the  cases  of  two  infants,  four  or  five  months 
old,  recorded  by  Dr.  Blundell.  The  hepatic  ducts  in  both  cases  ter- 
minated blindly,  so  that  no  bile  entered  the  intestines;  the  evacuations- 
were  white  like  spermaceti,  and  the  skin  jaundiced.  Yet  they  grew 
rapidly,  and  throve  tolerably. 

No  certain  knowledge  exists,  whether  any  of  the  elements  of  the 
bile  are  absorbed  in  the  form  of  chyle ;  or  whether  it  acts  mainly  as  a 
precipitate,  and  is  thrown  off  with  the  excrement.  As  elsewhere  shown, 
however,  it  is  largely  excrementitious  or  depurative. 

As  to  the  mode  in  which  the  biliary  and  pancreatic  fluids  act  on  the 

1  Researches,  Physiological  and  Pathological,  London,  1825;  and  Elliotson's  Physiology, 
p.  124,  London,  1840. 

2  Edinb.  Med.  and  Surg.  Journal,  xciii.;  and  Mayo,  Outlines  of  Hwman  Physiology,  4th 
edit.,  p.  139,  London,  1837. 


ACTION  OF  THE  SMALL  INTESTINE.  613 

chyme,  we  have  not  had,  until  recently,  much  more  than  conjectures  to 
guide  us.  MM.  Tiedemann  and  Gmelin  suggest,  that  the  soda  of  the 
bile  unites  with  the  chlorohydric  and  acetic  acids  of  the  chyme ;  and 
simultaneously  the  latter  precipitates  the  mucus  of  the  bile  and  its 
colouring  principle  and  resin,  which  are  evacuated  with  the  excrements. 
The  majority  of  physiologists  believe,  that  bile  is  divided  into  two  parts, 
by  the  action  of  the  chyme;  the  one — containing  the  alkali,  salts,  and 
a  part  of  the  animal  matter — uniting  with  the  chyle;  the  other — con- 
taining the  coagulated  albumen,  the  coloured,  concrete,  acrid,  and  bitter 
oil — uniting  with  the  fseces,  to  be  discharged  along  with  them.  Ac- 
cording to  this. view,  the  action  of  the  bile  would  be  purely  chemical; 
a  part  would  be  recrementitial  or  taken  up  again;  and  a  part  excre- 
mentitial,  giving  to  the  excrements  their  smell  and  colour;  and,  accord- 
ing to  some,  the  necessary  stimulating  property  for  exciting  the  flow  of 
the  intestinal  fluids,  and  soliciting  the  peristaltic  action  of  the  intestines 
so  as  to  produce  their  evacuation.  It  is  more  than  doubtful,  however, 
whether  the  bile  have  any  such  influence  as  the  last.  It  is  a  law  in  the 
economy,  that  no  secretion  irritates  the  part  over  which  it  passes,  or  is 
naturally  destined  to  pass,  unless  such  part  is  in  a  morbid  condition  ;  and 
were  it  otherwise,  the  mucous  membrane  of  the  intestine  would  be  soon 
accustomed  to  the  stimulation ;  and,  the  effect  be  null.  MM.  Tiedemann 
and  Gmelin  further  suggest,  that  from  the  abundance  of  highly  nitro- 
genized  principles,  which  the  bile  contain's,  it  probably  contributes  to 
animalize  those  articles  of  food,  that  do  not  contain  nitrogen;  and  that 
it  may  tend  to  prevent  the  putrefaction  of  the  food  in  its  course  through 
the  intestines,  inasmuch  as  when  it  is  prevented  from  flowing  into  them, 
their  contents  appear  much  farther  advanced  in  decay  than  in  the 
healthy  state.  It  has  been  held  of  late,  that  bile  has  the  power  of 
transforming  saccharine  aliments  into  fat;  a  circumstance,  which  is 
favoured  by  the  discovery  of  H.  Meckel,1  that  when  sugar  is  mixed  with 
bile  out  of  the  body  a  part  of  it  is  converted  into  fatty  matter.  Ad- 
mixture with  the  pancreatic  juice  would  then  render  its  absorption  easy. 
(See  SECRETION  OF  BILE.) 

We  were  not  instructed  until  of  late  in  regard  to  the  precise  uses  of  the 
pancreatic  juice;  although  many  have  been  assigned  to  it,  which  being 
founded  in  ignorance  of  its  nature  and  properties,  it  would  be  a  waste 
of  time  to  notice.  Messrs.  Tiedemann  and  Gmelin  affirm,  that  it  yields 
to  the  chyme  the  richly  nitrogenized  principles,  that  enter  into  its  com- 
position; and,  consequently,  aids  in  assimilation.  In  testimony  of  this, 
they  remark,  that  the  pancreas  is  larger  in  herbivorous  than  in  carnivo- 
rous animals;  and  that,  in  proportion  as  the  chymous  matter  proceeds 
along  the  intestinal  canal,  it  exhibits  itself  less  rich  in  albumen  and 
other  nitrogenized  matters,  which  have  probably  been  abstracted  from 
it  by  absorption.  Dr.  Marcet2  discovered  in  the  chyme  of  the  small 
intestine  a  notable  development  of  albumen,  which  was  first  perceptible 
a  few  inches  from  the  pylorus,  and  did  not  exist  in  the  large  intestine; 
and  Messrs.  Tiedemann  and  Gmelin  found  in  the  intestinal  contents  of 

5  Henle  und  Pfeufer,  Zeitschrift  fur  rationelle  Medicin;  cited  by  Mr.  Paget  in  Report  in 
British  arid  Foreign  Medical  Review,  p.  261,  July,  1846. 
2  Medico-Chirurgical  Trans.,  vi.  618. 


614  DIGESTION. 

animals,  that  had  swallowed  pebbles  while  fasting,  more  albumen  than 
the  pancreatic  juice  could  account  for.  If  such  be  the  fact,  albumen 
must  be  either  developed  from  the  food,  or  secreted  from  the  mucous 
membrane. 

There  is  a  striking  resemblance  in  chemical  properties  between  the 
pancreatic  juice  and  saliva;  and  the  views  applicable  to  both  one  and 
the  other,  embraced,  as  the  result  of  numerous  experiments  by  MM. 
Bernard  and  Barreswil,  have  been  already  stated.  The  recent  experi- 
ments of  M.  C.  Bernard1  have  shed  important  light  on  this  matter. 
Exposure  of  fatty  bodies  to  the  pancreatic  juice  out  of  the  body  pro- 
duced at  once  a  complete  emulsion,  and  resolved  them  in£o  glycerin  and 
fatty  acid; — in  the  case  of  butter,  butyric  acid;  whilst  no  such  effect 
was  produced  on  such  bodies  by  admixture  with  other  fluids — saliva, 
gastric  juice,  or  serum  of  the  blood,  for  example.  These  experiments 
were  frequently  repeated  with  like  results  in  the  presence  of  distin- 
guished observers — MM.  Magendie,  B^rard,  Andral,  &c.  When  dogs 
to  which  fatty  substances  had  been  given  were  killed  during  digestion, 
these  substances  were  found  unaltered  until  they  came  in  contact  with 
the  pancreatic  fluid;  and  if  the  duct  of  the  pancreas  was  tied  all  change 
was  prevented.  It  would  seem,  therefore,  that  although  the  pancreatic 
fluid  resembles  the  saliva  in  many  respects — so  much  so,  indeed,  that 
the  pancreas  has  been  styled  "  the  abdominal  salivary  gland," — it  is  pos- 
sessed of  properties  as  a  digestive  fluid  which  the  saliva  has  not.  In  a 
remark  upon  a  subsequent  me'moire  by  M.  Bernard — the  commission, 
consisting  of  MM.  Magendie,  Milne  Edwards  and  Dumas — do  not  hesi- 
tate to  conclude,  that  M.  Bernard  has  completely  established  the 
physiological  office  of  the  pancreas  and  made  known  the  mechanism 
of  the  digestion  of  fatty  matters.2 

The  influence  of  the  temperature  of  the  interior  of  the  intestine,  and 
of  the  peristaltic  motion,  on  chylification,  can  be  looked  upon  as  only 
accessory  and  indirect. 

"Whilst  the  chyme  is  passing  through  the  small  intestine,  it  is  sub- 
jected to  the  action  of  the  chyliferous  vessels,  which  extract  from  it 
the  nutritious  part  or  chyle, — the  fluid  especially  destined  for  the  re- 
novation of  the  blood.  How  this  is  accomplished  will  be  treated  of 
under  the  head  of  Absorption.  In  proportion  as  this  absorption  is 
effected,  the  chyme  changes  its  properties.  In  the  commencement  of 
the  jejunum,  it  is  the  same  as  in  the  duodenum;  but,  lower  down,  the 
grayish  layer,  that  existed  at  its  surface,  is  observed  to  gradually  dis- 
appear. It  assumes  greater  consistence;  its  yellow  colour  becomes 
more  marked;  and,  in  the  ileum,  it  has  a  greenish  or  brownish  tint;  and 
from  being  acid  becomes  alkaline,  until,  at  the  lower  part  of  the  small 
intestine,  it  seems  to  be  the  useless  residue  of  the  alimentary  matter, 
and  the  various  secretions  from  the  upper  portion  of  the  digestive  ap- 
paratus. It  is  now  mere  excrementitious  matter  or  faeces,  although  not 
possessing  the  entire  fecal  odour.  Its  alkaline  character  has  generally 
been  ascribed  to  admixture  with  the  bile,  pancreatic  fluid,  and  the  secre- 

1  Archives  Generates,  xiv.;  translated  in  the  Provincial  Medical  and  Surgical  Journal  for 
March  31,  1849. 

2  Gazette  Medicale,  No.  9,  Paris,  1849. 


ACTION  OF  THE  LAKGE  INTESTINE.  615 

tion  from  the  intestinal  glandulae.  The  agency  of  the  bile  was  sup- 
posed to  be  through  its  free  soda,  or  the  carbonate  or  tribasic  phosphate 
of  soda.  The  bile,  however,  as  shown  elsewhere,  is  neutral;  and  accord- 
ingly it  has  been  suggested  as  more  probable,  that  the  chyme  is  made 
alkaline  by  the  ammonia,  which  is  one  of  the  products  of  the  spontaneous 
decomposition  of  bile  in  the  intestines.1  The  pancreatic  juice  is  cer- 
tainly also  alkaline. 

During  the  formation  of  chyle,  gases  are  almost  always  present  in 
the  small  intestine.  They  were  first  examined  by  Jurine;  but  chemical 
analysis  was  by  no  means  as  advanced  at  that  day  as  it  is  now ;  MM. 
Magendie2  and  Chevreul  have  more  recently  analyzed  those,  which  they 
found  in  the  small  intestines  of  three  criminals ;  all  young  and  vigorous. 
The  results  of  this  analysis  have  been  given  already  (p.  599).  The 
gases  might  originate  in  various  ways.  They  might  pass,  for  example, 
from  the  stomach  with  the  chyme.  There  is  this  objection,  however,  to 
the  view;  that  the  air  in  the  stomach  contains  oxygen  and  very  little 
hydrogen;  whilst  a  considerable  quantity  of  the  latter  gas  is  almost 
always  found  in  the  small  intestine,  and  never  oxygen.  Again,  they 
might  be  secreted  by  the  mucous  membrane  of  the  intestine.  So  far 
as  we  know,  however,  carbonic  acid  and  nitrogen  are  alone  exhaled 
from  the  tissues.  We  would  still  have  to  account  for  the  hydrogen. 
Lastly,  they  might  arise  from  the  reaction  of  the  elements  of  the  chyme 
upon  each  other,  and  this  has  been  considered  the  most  probable  origin. 
M.  Magendie3  has  frequently  seen  bubbles  of  gas  escaping  from  the 
chymous  mass,  between  the  mouth  of  the  ductus  communis  choledochus 
and  the  ileum;  but  never  from  that  of  the  ileum,  the  upper  part  of  the 
duodenum,  or  stomach;  and  he  affirms,  that  Chevreul,  in  prosecuting 
some  experiments,  found  that  when  the  mass  obtained  from  the  small 
intestine  was  suffered  to  ferment  for  some  time  in  a  stove,  at  the  tem- 
perature of  the  body,  the  same  gases  were  obtained  as  those  met  with 
in  the  small  intestine. 

When  the  food  has  attained  the  lower  part  of  the  ileum,  the  process 
of  chylification  has  been  accomplished,  and  the  residuary  matter  is 
transmitted,  by  the  peristaltic  action,  into  the  large  intestine.  The 
movement,  however,  recurs  irregularly  and  at  long  intervals.  In  the 
living  animal  it  can  rarely  be  perceived ;  but  may  be  noticed  in  one 
recently  killed,  and  appears  to  have  no  coincidence  with  that  of  the 
pylorus. 

g.  Action  of  the  Large  Intestine. 

The  large  intestine  acts  as  a  reservoir  and  excretory  canal  for  the 
faeces.  The  residue  of  the  alimentary  matter  is  sent  on  through  the 
valve  of  Bauhin  by  the  peristaltic  action  of  the  ileum.  This  valve,  we 
have  seen,  is  so  situate  at  the  point  of  union  between  the  ileum  and 
caecum  as  to  permit  a  free  passage  from  the  former  to  the  latter,  but 
to  prevent  return.  The  chymous  mass  is  sufficiently  soft  to  pass  rea- 
dily ;  and  the  quantity  of  mucus  poured  out  from  the  lining  membrane, 


1  Valentin,  Lehrbuch  der  Physiologie  des  Menschen,  i.  338,  Braunschweig,  1844. 

2  Precis,  ii.  115.  3  Ibid. 


117. 


616  DIGESTION. 

facilitates  its  course.  When  it  has  reached  the  large  intestine,  it  first 
accumulates  in  the  caecum,  which — being  cellular  or  pouched  like  the 
colon — necessarily  detains  it  for  some  time.  In  proportion,  however, 
as  the  caecum  becomes  filled,  the  peristaltic  action  is  extended  from 
the  small  intestine,  and  the  matter  is  sent  into  the  colon,  the  cells 
of  which  are  successively  filled ;  first,  those  of  the  ascending,  and 
then  those  of  the  transverse  and  descending  colon,  as  far  as  the  annu- 
lus  or  commencement  of  the  rectum.  The  whole  of  its  progress  through 
the  large  intestine  is  slowly  accomplished.  Independently  of  the 
pouched  arrangement,  which  retards  it,  a  part  of  the  colon  ascends,  so 
that  the  faecal  matter  must  often  proceed  contrary  to  gravity.  It 
becomes,  moreover,  more  and  more  inspissated  in  its  progress  towards 
the  outlet ;  and  the  peristaltic  action  recurs  at  greater  intervals  than 
in  the  upper  portions  of  the  tube.  The  importance  of  such  a  reservoir 
as  the  large  intestine  is  obvious.  Without  it,  we  should  be  subjected 
to  the  inconvenience  of  evacuating  the  faeces  incessantly. 

Before  the  excrementitious  matter  reaches  the  lower  portion  of  the 
small  intestine,  it  has  not  the  fecal  odour ;  but  acquires  it  after  having 
remained  there  for  a  short  time.  The  brownish-yellow  hue  becomes 
deeper;  but  its  consistence,  smell,  and  colour,  vary  considerably, 
according  to  the  character  of  the  alimentary  matter ;  the  mode  and 
degree  in  which  chymification  and  chylification  have  been  accomplished; 
the  habit  of  the  individual,  &c.  &c.  The  faecal  matter,  as  we  find  it, 
consists  of  the  excrementitious  part  of  the  food,  as  well  as  of  the  juices 
of  the  upper  part  of  the  canal,  that  have  been  subjected  to  the  digest- 
ive process ;  of  the  secretions,  poured  out  from  the  lower  part  of  the 
intestine,  and  also,  of  substances,  that  have  escaped  the  digestive 
actions  of  the  stomach  and  small  intestine,  and  are  often  perceptible  in 
the  evacuations.  The  peculiar  faecal  impregnation  is  probably  depend- 
ent upon  a  secretion  from  appropriate  follicles — those  of  Peyer,  for 
example  ;  and  we  can  thus  understand,  if  we  take  into  consideration 
the  digestion  of  the  different  secretions,  why  faecal  evacuations  may 
exist,  when  the  individual  has  not  eaten  for  some  time,  or  taken  but 
little  nourishment. 

Some  physiologists  have  believed,  that  chylification  takes  place  even 
in  the  large  intestines,  and  that  chylous  absorption  is  more  or  less 
effected  there.  M.  Viridet1  asserted,  that  the  caecum  is  a  second  sto- 
mach, in  which  a  last  effort  is  made  to  separate  from  the  food  the 
digestible  and  soluble  portions  it  may  still  contain.  In  herbivorous 
animals,  according  to  him,  an  acid  solvent  is  secreted  in  it.  MM. 
Tiedemann  and  Gmelin  seem  to  admit  the  fact ;  and  likewise  think, 
that  the  fluid,  secreted  by  the  inner  membrane  of  the  intestine,  assists 
in  the  assimilation  of  the  food  by  means  of  the  albumen  it  contains,  and 
that  faecal  matter  is  formed  there.  From  various  experiments  insti- 
tuted by  Professor  Schultz,2  of  Berlin,  he  infers,  that  the  food  in  the 
caecum  becomes  not  only  a  second  time  sour,  but  that  the  acid  chyme 
is  there  neutralized  by  the  access  of  bile  in  the  same  way  as  in  the  duo- 

1  Tractatus  Novus  de  Prima  Coctione,  &c.,  Genev.,  169J.. 

2  Lond.  Med.  and  Surg.  Journ.,  Oct.  31,  1835  ;  cited  in  Amer.  Journal  of  the  Medical  Sci- 
ences, Nov.,  1836,  p.  203. 


ACTION  OF  THE  LARGE  INTESTINE.  617 

denum.  M.  Blondlot,1  however,  states,  that  in  many  herbivorous  ani- 
mals and  granivorous  birds,  as  sheep,  goats,  pigeons  and  chickens,  the 
contents  of  the  caecum  were  never  acid  unless  sugar  in  some  form  had 
been  mixed  with  their  food.  The  acidity  of  the  caecum  which  then 
ensues,  he  thinks  is  the  result  of  that  part  of  the  starch  or  sugar,  which 
has  not  been  absorbed  in  the  small  intestine,  being  transformed  into 
lactic  acid.  The  fact  of  the  separation  of  chyle  in  the  caecum  and 
colon  is  proved  by  the  experiments  of  M.  Voisin,2  which  consisted  in 
introducing  food  into  these  intestines  after  the  ileo-caecal  valve  had 
been  closed  by  ligature. 

The  physical  characters  of  the  faeces  have  been  already  described. 
When  extruded,  they  have  the  shape  of  the  large  intestine,  or  of  the 
aperture,  through  which  they  have  been  evacuated.  If  the  form  of 
either  of  these  be  modified,  that  of  the  excrement  will  be  so  likewise. 
In  stricture  of  the  colon — especially  about  the  sigmoid  flexure — and  of 
the  rectum,  the  faeces  are  squeezed  through  the  narrowed  portions,  and 
often  evacuated  in  the  shape  of  ribands.  The  quantity  must,  of  course, 
vary  according  to  circumstances,  and  cannot  be  rigidly  estimated.  Ap- 
proximately, they  have  been  presumed  to  be,  in  the  adult  male,  from  a 
quarter  to  half  a  pound  in  the  twenty-four  hours,  the  evacuation  being 
usually  made  once  only  in  this  time.  The  biliary  secretion  appears  to 
modify  the  appearance  of  the  faeces  greatly.  If,  as  in  jaundice,  it  be 
prevented  from  flowing  into  the  intestine,  they  are  clay-coloured.  M. 
Adelon3  affirms,  that,  under  such  circumstances,  they  are  more  fre- 
quent. This  is  not  the  result  of  our  experience,  nor  does  it  appear  to 
be  deduced  from  his  own ;  as,  a  few  pages  before,  he  remarks,  "it  is 
certain,  that  if  the  bile  does  not  flow,  the  excrements  are  dry,  devoid  of 
colour,  and  there  is  constipation."  On  the  other  hand,  if  the  bile  flows 
in  too  great  quantity  the  faeces  are  darker  coloured.  It  is  doubtful, 
whether  the  varying  quantity  of  the  biliary  secretion  have  much  influ- 
ence on  the  number  of  evacuations,  unless  the  canal,  through  which  it 
has  to  pass,  is  in  a  morbid  condition.  Many  of  the  appearances  in  the 
faeces,  which  are  conceived  to  be  owing  to  a  morbid  condition  of  the 
biliary  secretion,  are  the  effect  of  admixture  with  products  of  morbid 
changes  in  the  stomach  or  intestines.  In  elucidation  of  this,  it  maybe 
observed,  that  the  green  evacuations  of  children  are  often  referred  to 
some  pathological  condition  of  the  biliary  secretion  ;  whereas  the  colour 
is  commonly  owing  to  unusual  formation  of  acid  in  the  stomach,  the 
admixture  of  which  with  healthy  bile  produces  the  colour  in  question. 

The  chemical  properties  of  the  faeces  have  been  repeatedly  inquired 
into.  They  must,  of  course,  vary  according  to  the  nature  of  the  food, 
its  quantity,  the  kind  of  digestion,  &c.  Human  faeces  were  examined 
by  Eawitz4  after  animal  and  vegetable  food  had  been  taken.  But  few 
fragments  of  muscular  tissue  were  met  with;  but  the  cells  of  cartilage 
and  fibre-cartilage — excepting  those  of  fish — were  found  unchanged. 
Elastic  fibres  and  fatty  matters,  which  had  escaped  absorption,  appeared 

1  Traite  Analytique  de  la  Digestion,  Paris,  1844. 

2  Nouvol  Aper§u  sur  la  Physiologie  du  Foie,  &c.,  Paris,  1833.  3  Op.  citat. 

4  Ueber  die  Einfachen  Nahrungsrnittel,  Breslau,  1846,  cited  by  Kirkes  and  Paget,  Manual 
of  Physiology,  Amer.  edit.,  p.  176,  Philad.,  1849. 


618  DIGESTION. 

to  be  unchanged;  for  fat  cells  were  sometimes  unaltered  in  the  faeces  ; 
and  crystals  of  cholesterin  might  generally  be  obtained  from  them 
especially  after  the  use  of  pork  fat  as  diet. 

Of  vegetable  aliments,  large  quantities  of  cell  membrane  were  unal- 
tered; and  starch  cells  were  commonly  deprived  of  only  part  of  their 
contents :  the  green  colouring  matter — chlorophyll — was  unaffected,  and 
the  walls  of  sap  vessels  and  spiral  vessels  were  usually  found  in  large 
quantities  in  the  faeces, — their  contents  having  been  probably  removed 
during  digestion. 

The  faeces  differ  in  each  animal  species.  Those  of  the  herbivora  con- 
tain less  animal  matter  than  those  of  the  carnivora  and  omnivora;  and 
the  agriculturist  is  well  aware,  that  the  excrements  of  all  animals  are  not 
equally  valuable  as  manure.  The  dung  of  the  pigeon  is  alkaline  and 
caustic;  and  hence  has  been  employed  in  tanning  for  softening  skins. 
The  excrement  of  dogs,  that  have  fed  only  on  bones,  is  white,  and  ap- 
pears to  be  almost  wholly  composed  of  the  earthy  matter  of  bone.  It 
has  not,  however,  been  examined  by  modern  chemists.  This  white  ex- 
crement is  the  album  graecum,  cynocoprus,  spodium  Grrsecorum,  album 
canis  or  stercus  caninum  album,  of  the  older  writers.  It  was  formerly 
employed  as  a  discutient  to  the  inside  of  the  throat  in  quinsies,  but  is 
now  justly  discarded. 

M.  Vauquelin,1  on  comparing  the  nature  and  quantity  of  the  earthy 
parts  of  the  excrements  of  fowls  with  those  of  the  food  on  which  they 
subsisted,  arrived  at  some  results  that  are  of  interest  to  the  physiolo- 
gist. He  found  that  a  hen  devoured,  in  ten  days,  11111*8-43  grains 
troy  of  oats.  These  contained  of  phosphate  of  lime  136*509  grains ; 
and  of  silica  219*548  grains;  in  the  whole  356*057  grains.  During 
these  ten  days  she  laid  four  eggs,  the  shells  of  which  contained  98*779 
grains  of  phosphate,  and  58*494  grains  of  carbonate  of  lime;  and  she 
passed  185*266  grains  of  silica.  The  fixed  parts,  thrown  out  of  the 
system  during  the  time,  consisted  of: — 

Phosphate  of  lime, 274-305  grains. 

Carbonate  of  lime, 511-911 

Silica, 185-266 


Given  out,  971-482 

Taken  in,  356-057 

Surplus, .         .         .         615-425 

The  quantity  of  fixed  matter,  therefore,  given  out  of  the  system  in 
ten  days,  exceeded  the  quantity  taken  in  by  this  last  amount. 

The  phosphate  of  lime,  taken  in,  amounted  to         ...         136*509  grains. 
That  given  out,  to 274-305 

137-796 

There  must,  consequently,  have  been  formed  137*796  grains  of  phos- 
phate of  lime,  besides  511*911  grains  of  the  carbonate.  The  inferences, 
deduced  from  these  experiments,  were,  that  lime,  and  perhaps  also  phos- 
phorus, is  not  a  simple  substance,  but  a  compound  formed  of  ingredients 

1  Annales  de  Chimie,  torn.  xxix.  p.  3. 


ACTION  OF  THE  LARGE  INTESTINE.  619 

that  exist  in  oats,  water,  or  air ;  the  only  substances  to  which  the  fowl 
had  access;  and  that  silica  must  enter  into  its  composition,  as  a  part 
had  disappeared.  Before,  however,  we  adopt  these  conclusions,  the 
experiments  ought  to  be  repeated  more  than  once.  The  chicken  should 
be  fed  on  oats  some  time  before  the  excrements  and  shells  are  subjected 
to  analysis;  as  the  carbonate  of  lime,  and  the  excess  of  phosphate  de- 
tected on  analysis,  might  have  proceeded,  not  only  from  the  food,  but 
from  earthy  matters  previously  swallowed.  Care  should  also  be  taken, 
that  it  has  no  access  to  any  calcareous  earth ;  and  we  must  be  certain, 
that  it  has  not  diminished  in  weight;  as,  in  such  case,  the  earth  may 
have  been  supplied  from  its  own  body.  These  precautions  are  the  more 
requisite,  seeing,  that  experiments  have  shown,  that  certain  birds  cannot 
produce  eggs  unless  they  have  access  to  calcareous  earth. 

There  are  some  very  remarkable  instances  of  chemical  changes,  in 
mysterious  actions,  more  immediately  concerned  in  the  decomposition 
and  renovation  of  the  frame ;  or,  in  what  has  been  abstractedly  termed — 
the  function  of  nutrition.  Dr.  Henry1  has  announced,  that  the  follow- 
ing substances  have  been  satisfactorily  proved  to  exist  in  healthy  urine; 
— water,  free  phosphoric  acid,  phosphate  of  lime,  phosphate  of  mag- 
nesia, fluoric  acid,  uric  acid,  benzoic  acid,  lactic  acid,  urea,  gelatin, 
albumen,  lactate  of  ammonia,  sulphate  of  potassa,  sulphate  of  soda, 
fluate  of  lime,  chloride  of  sodium,  phosphate  of  soda,  phosphate  of 
ammonia,  sulphur,  and  silex; — yet  we  have  no  proof  that  these  sub- 
stances are  obtained  from  any  other  source  than  the  food;  and  some  of 
them  are  with  difficulty  obtained  any  where.  Every  one  of  them  is 
necessary  for  the  constitution  of  the  urine ;  and  many  must  be  formed  by 
a  chemical  union  of  their  elements  under  the  vital  agency.  Some  are 
met  with  in  the  animal  body  exclusively.  Berzelius2  found,  in  100  parts 
of  human  fseces: — water,  73*3  ;  unaltered  residue  of  animal  and  vege- 
table substances,  7*0;  bile,  0-9;  albumen,  0-9;  peculiar  extractive  mat- 
ter, 2*7;  substance,  formed  of  altered  bile,  resin,  animal  matter,  &c., 
14;  salts,  1-2.  Seventeen  parts  of  these  salts  contained,  of  carbonate 
of  soda,  5;  chloride  of  sodium,  4;  sulphate  of  soda;  2  ;  ammoniaco-mag- 
nesian  phosphate,  2  ;  phosphate  of  lime,  4.  The  excrements  have  like- 
wise been  examined  by  MM.  Leuret  and  Lassaigne,  and  others ;  but 
none  of  the  analyses  have  shed  much  light  on  the  physiology  of  digestion. 
Analyses  of  the  ashes  of  firm  human  fseces  by  Enderlin3  yielded  the 
following  results: — chloride  of  sodium  and  alkaline  sulphate,  1-367; 
tribasic  phosphate  of  soda,  2-633 ;  phosphate  of  lime,  and  phosphate 
of  magnesia,  81-372  ;  phosphate  of  iron,  2-091 ;  sulphate  of  lime,  4-56  ; 
silica,  7-97. 

In  the  large  intestine,  gases  are  met  with,  along  with  the  faeces. 
These  were  examined  by  MM.  Magendie4  and  Chevreul  in  the  three  cri- 
minals already  referred  to  (page  599).  The  results  accord  with  those 
of  Jurine,5  obtained  long  ago,  as  regards  the  nature  of  the  gases;  but 

1  Elements  of  Chemistry,  9th  edit.,  ii.  435,  Lond.,  1823. 

2  Traite  de  Chimie,  trad,  par  Jourdan  et  Esslinger,  torn,  vii.,  and  Simon's  Animal  Che- 
mistry, Sydenham  Society  edit.,  ii.  372,  Lond.,  1846,  or  Amer.  edit.,  Philad.,  1846. 

3  Annalen  der  Chemie  und  Pharmacie,  Mars,  1844,  cited  by  Mr.  Paget,  Brit,  and  For.Med  . 
Rev.,  Jan,  1845,  p.  277. 

4  Precis,  &c.,  ii.  126.  «.  Memoir,  de  la  Soc.  Royale  de  Med.,  x.  72. 


620  DIGESTION. 

they  do  not  correspond  with  what  he  says  relating  to  the  carbonic  acid; 
the  quantity  of  which,  according  to  him,  goes  on  decreasing  from  the 
stomach  to  the  rectum.  The  analyses  of  MM.  Magendie  and  Chevreul 
show,  that  the  proportion  instead  of  decreasing,  increases.  Concerning 
the  origin  of  these  gases,  the  remarks  made  on  those  in  the  small  intes- 
tine are  equally  applicable  here. 

When  the  faecal  matter  has  accumulated  to  the  necessary  extent  in 
the  rectum,  its  expulsion  follows;  and  to  this  function  the  term  defeca- 
tion has  been  assigned.  The  faeces  collect  gradually  in  the  large  intes- 
tine, without  any  consciousness  on  the  part  of  the  individual.  Sooner 
or  later,  the  desire  or  want  to  evacuate  them  arises.  This  is  usually 
classed  among  the  internal  sensations  or  desires.  It  is,  however,  of  a 
mixed  character.  It  is  not  always  in  a  ratio  with  the  quantity  of  fcsces 
as  is  shown  by  the  fact,  that  occasionally  the  intestine  is  filled  without 
the  want  arising;  and,  if  they  be  unusually  thin  or  irritating,  the  desire 
is  developed,  when  an  extremely  small  quantity  is  present, — as  in  cases 
of  tenesmus.  The  period,  at  which  the  desire  returns,  is  variable, 
according  to  the  amount  and  character  of  the  food  employed,  as  well  as 
the  habit  of  the  individual.  Whilst  the  generality  of  persons  evacuate 
the  bowels  at  least  once  a-day, — and  this  at  a  period  often  regulated 
by  custom,— others  pass  a  week  or  two  without  any  alvine  discharge, 
and  yet  may  be  in  perfect  health.  Nay,  some  of  the  collectors  of  rare 
cases1  have  affirmed,  on  the  authority  of  Rhodius,  Panarolus,  Salmuth, 
and  others,  that  persons  may  remain  in  health,  with  the  bowels  moved 
not  oftener  than  once  a  month,  three  months,  half  a  year,  two  years, 
and  even  seven  years!  Sir  Everard  Home2 refers  to  the  case  of  General 
Grose,  who  was  in  the  Dutch  service,  under  the  Duke  of  Cumberland, 
in  the  Flanders  war;  and  who  for  thirty  years  had  no  passage  through 
the  bowels.  General  Gage  noticed  that  he  ate  heartily;  but  in  two 
hours  left  the  table  and  rejected  his  meal.  He  was  healthy,  and  capa- 
ble of  exercise  like  other  men.  Dr.  Heberden3  mentions  the  case  of  a 
person,  who  had  naturally  an  evacuation  once  a  month  only;  and  an- 
other who  had  twelve  evacuations  every  day  during  thirty  years,  and 
then  seven  every  day  for  seven  years,  and  grew  fat  rather  than  other- 
wise. A  young  lady  referred  to  by  M.  Pouteau,4  had  no  evacuation  for 
upwards  of  eight  years ;  although  during  the  last  year  she  ate  abundantly 
of  fruit,  and  drank  coffee,  milk,  tea,  and  broth  with  yolks  of  eggs;  but 
she  had  copious  greasy  sweats; — and  many  similar  extraordinary  cases 
have  been  recorded  by  Dr.  Chapman5  of  Philadelphia.  When  the  desire 
to  evacuate  has  once  occurred,  it  generally  persists  until  the  faeces  are 
expelled.  Sometimes,  however,  it  disappears  and  recurs  at  an  uncertain 
interval ;  and,  if  again  resisted,  may  become  the  source  of  pain,  and 
ultimately  command  implicit  obedience.  That  the  pressure  and  irrita- 
tion of  the  faeces  develope  the  sensation  is  evidenced  by  the  fact,  that 
the  momentary  relief  experienced  at  times,  when  the  desire  is  urgent, 

1  Art.  Cas  Rares,  in  Diet,  des  Sciences  M£dicales. 

2  Lect.  on  Comp.  Anat.,  v.  12,  Lond.,  1828.  3  Commentarii,  p.  14. 

4  CEuvres  Posthumes,  i.  27,  Paris,  1783. 

5  Lectures  on  the  more  important  Diseases   of  the  Thoracic  and  Abdominal  Viscera, 
p.  294,  Philad.,  1844. 


DEFECATION.  621 

is  usually  accompanied  by  a  manifest  upward  return  of  the  faecal  mat- 
ters from  the  sigmoid  flexure  into  the  colon. 

In  evacuating  the  faeces,  the  object  to  be  accomplished  is, — that  the 
contents  of  the  large  intestine  shall  be  pressed  upon  with" a  force  supe- 
rior to  the  resistance  presented  by  the  annulus  or  upper  extremity  of 
the  contracted  rectum,  and  the  muscles  of  the  anus.  The  contraction 
of  the  rectum  is  generally  insufficient  to  effect  this  last  object,  notwith- 
standing the  great  thickness  of  its  muscular  layer.  In  cases,  however, 
of  irritability  of  the  rectum,  the  sphincter  is  incapable  of  resisting  the 
force  developed  by  the  proper  muscular  fibres  of  the  gut.  Under  ordi- 
nary circumstances,  the  aid  of  the  diaphragm  and  abdominal  muscles 
is  invoked,  and  it  is  chiefly  through  these  muscles,  that  volitidn  influ- 
ences the  act  of  defecation, — suspending,  deferring,  or  accelerating  it, 
as  the  case  may  be.  After  a  full  inspiration,  the  muscles  that  close  the 
glottis  ;  and  the  expiratory  muscles, — especially  those  of  the  anterior 
part  of  the  abdomen,  contract  simultaneously.  The  air  cannot  escape 
from  the  lungs;  the  diaphragm  is  depressed  upon  the  abdominal  viscera, 
and  the  whole  thorax  presents  a  resisting  body;  so  that  all  the  expira- 
tory power  of  the  muscles  bears  upon  the  viscera,  and  presses  them 
against  the  vertebral  column.  In  this  way,  considerable  force  is 
exerted  upon  the  contents  of  the  colon  and  rectum;  the  resistance  of 
the  sphincter, — already  diminished  by  the  direct  exercise  of  volition, — 
is  surmounted;  it  yields,  and  the  faeces  are  extruded.  The  levator  ani 
and  ischio-coccygeus,  aided  by  the  transversus  perinei  muscle,  support 
the  anus  during  the  expulsory  efforts,  and  restore  it  to  its  place  after 
the  efforts  have  ceased.  Whilst  straining  is  effected  by  the  diaphragm 
and  abdominal  muscles,  the  longitudinal  muscular  fibres  of  the  rectum 
contract,  so  as  to  shorten  the  intestine,  and,  consequently,  the  space 
over  which  the  faeces  have  to  pass.  At  the  same  time,  the  circular 
fibres  contract  from  above  to  below,  so  as  to  propel  the  excrement 
downwards,  and  to  cause  the  mucous  membrane  to  extrude,  and  form  a 
ring  or  bourrelet,  like  that  which  occurs  at  the  cardiac  orifice  of  the 
stomach,  when  the  food  is  passing  from  the  oesophagus  into  that  organ. 
If  this  extrusion  occurs  to  a  great  extent,  it  constitutes  the  disease 
called  prolapsus  ani. 

Dr.  O'Beirne1  of  Ireland,  guided  by  the  following  facts  and  argu- 
ments ; — that  great  irritation  would  be  produced  in  the  sphincter  ani, 
and  bladder,  if  the  faeces  descended  readily  into  the  rectum ; — that  the 
difficulty  experienced  in  throwing  up  an  injection  is  inconsistent  with 
the  idea  of  the  gut  being  open,  and  proves  that  it  is  firmly  contracted 
and  closed; — that  when  the  surgeon  has  occasion  to  pass  his  finger  up 
the  rectum,  he  rarely  encounters  either  solid  or  fluid  fasces ; — that  the 
two  sphincter  muscles  of  the  anus  are  weakened  in  certain  diseases,  and 
divided  in  operations,  and  yet  it  rarely  happens,  that  the  power  of 
retaining  the  faeces  is  destroyed ; — that  on  passing  a  stomach-tube  to 
the  height  of  half  an  inch  up  the  rectum,  in  a  number  of  healthy  per- 
sons', it  was  found,  that  nothing  escaped,  and  that  the  tube  could  be 

1  New  Views  of  the  Process  of  Defecation,  &c.,  Dublin,  1S33;  reprinted  in  this  country, 
Washington,  1834. 


622  DIGESTION. 

moved  about  freely  in  a  space,  which,  on  introducing  the  finger,  was 
ascertained  to  be  the  pouch  of  the  rectum ;  but  that  from  the  highest 
part  of  the  pouch  to  the  upper  extremity  of  the  gut — generally  a 
distance  of  from  six  or  seven  to  eight  inches — it  could  not  be  passed 
upwards  without  meeting  with  considerable  resistance,  and  without 
using  a  degree  of  force  to  mechanically  dilate  the  intestine,  which  was 
plainly  felt  to  be  so  contracted  as  to  leave  no  cavity  for  this  extent; — 
that  when  the  instrument  reached,  in  this  way,  the  highest  point  of  the 
rectum,  the  resistance  to  its  passage  upward  was  felt  to  be  sensibly 
increased,  until,  at  length,  by  using  a  proportionate  degree  of  pressure, 
it  passed  rapidly  forward,  as  if  through  a  ring,  into  a  space  in  which 
its  extremity  could  be  moved  with  great  freedom,  and  as  instantly  a 
rush  of  flatus,  of  fluid  faeces,  or  of  both,  took  place  through  the  tube ; — 
and  that  in  every  instance,  where  the  tube  presented  the  least  appear- 
ance of  faeces  after  being  removed,  this  appearance  was  confined  to  that 
portion  which  had  entered  the  sigmoid  flexure: — guided  by  these  and 
other  facts,  Dr.  O'Beirne  properly  concluded,  that  in  the  healthy  and 
natural  state,  all  the  part  of  the  rectum  above  its  pouch  is  at  all  times, 
with  the  single  exception  of  a  few  minutes  previous  to  the  evacuation 
of  the  bowels,  firmly  contracted,  and  perfectly  empty,  at  the  same  time 
that  the  pouch  itself,  as  well  as  the  sigmoid  flexure  of  the  colon,  is 
always  more  or  less  open,  and  pervious, — and  that  the  sphincter  ani 
muscles  are  but  subsidiary  agents  in  retaining  the  faeces.  When  the 
faeces  are  firm,  considerable  muscular  effort  is  necessary  to  expel  them; 
but  when  they  are  of  a  softer  consistence,  the  contraction  of  the  rectum 
is  sufficient. 

The  sphincters — as  elsewhere  shown — afford  examples  of  reflex 
action.  After  sensation  and  volition  are  suspended,  they  contract 
under  direct  irritation.  Yet,  like  the  respiratory  muscles,  they  are  of 
a  mixed  character, — partly  voluntary  and  partly  involuntary.  They 
are  involuntary,  but  capable  of  being  aided  or  impeded  by  a  voluntary 
effort.  The  state  of  gentle  contraction,  in  which  they  constantly  are, 
is  evidently  dependent  upon  their  connexion  with  the  spinal  cord;  for 
the  experiments  of  Dr.  Marshall  Hall  have  exhibited,  that  it  ceases, 
when  the  connexion  is  destroyed. 

Air,  contained  in  the  intestinal  canal,  readily  moves  about  from  place 
to  place,  and  speedily  reaches  the  rectum  by  the  peristaltic  action 
alone.  Its  expulsion,  however,  is  commonly  accomplished  by  the  aid 
of  the  abdominal  muscles;  when  it  issues  with  noise.  If  discharged  by 
the  contraction  of  the  rectum  alone,  it  is  generally  in  silence.  Children 
are  extremely  subject  to  flatulence;  in  the  adult  it  is  not  so  common. 
Certain  kinds  of  diet  favour  its  production  more  than  others,  especially 
in  those  of  weak  digestive  powers,  of  which  condition  its  undue  evolu- 
tion is  generally  an  indication.  The  leguminous  and  succulent  vegeta- 
bles in  general  belong  to  this  class.  Where  digestion  is  tardily  accom- 
plished, they  give  occasion  to  the  copious  disengagement  of  gas.  Too 
often,  however,  the  disgusting  habit  of  constantly  discharging  air  stre- 
perously  from  the  bowels  is  encouraged,  rather  than  repressed;  and 
there  are  persons,  who  are  capable  of  effecting  the  act  almost  as  fre- 
quently as  they  attempt  it. 


LIQUIDS.  623 

The  noise,  made  by  the  air,  as  it  passes  backwards  and  forwards  in 
the  intestinal  canal,  constitutes  the  affection  called  borborygmus. 

So  much  for  the  digestion  of  solid  food.  In  so  delicate  and  compli- 
cated an  apparatus,  it  would  seem,  that  mischief  ought  more  frequently 
to  result  from  the  various  heterogeneous  substances  that  are  received 
into  the  digestive  tube.  Its  resistance,  however,  to  morbific  agencies 
is  astonishing.  In  the  Museum  of  the  Boston  Society  for  Medical 
Improvement1  an  open  penknife  is  preserved,  which  was  swallowed  by 
a  child  between  three  and  four  years  of  age,  and  passed  from  the  bowels 
after  the  expiration  of  fifty-one  hours;  the  child,  in  the  meantime,  play- 
ing about  as  usual,  and  not  seeming  to  suffer.  The  story  of  the  luna- 
tic, under  the  care  of  Dr.  Fox  of  Bristol,  who  swallowed  "some  inches" 
of  a  poker,  which  came  away  without  any  suffering,  is  regarded  as 
authentic;2  and  there  is  no  question  in  regard  to  the  authenticity  of  the 
case  of  the  sailor  recorded  by  Dr.  Marcet,3  who  swallowed  a  number  of 
clasp  knives  with  impunity,  but  ultimately  fell  a  victim  to  his  idle 
temerity, — having  swallowed,  in  the  whole,  thirty-seven! 

5.    DIGESTION  OF  LIQUIDS. 

In  inquiring  into  the  digestion  of  liquids,  we  shall  follow  the  same 
order  as  that  observed  in  considering  the  digestion  of  solids;  but  as 
many  of  the  acts  are  accomplished  in  the  same  manner,  it  will  not  be 
necessary  to  dwell  upon  them. 

Thirst  or  the  desire  for  drink  is  an  internal  sensation;  in  its  essence 
resembling  that  of  hunger,  although  not  referred  to  the  same  organs. 
It  arises  from  the  necessities  of  the  system ;  from  the  constant  drain  of 
the  fluid  portions  of  Ae  blood;  and  is  instinctive  or  essentially  allied  to 
organization.  The  sensation  differs  in  different  persons,  and  is  rarely 
alike  in  the  same.  Usually,  it  consists  of  a  feeling  of  dryness,  con- 
striction, and  heat  in  the  back  part  of  the  mouth,  pharynx,  CESophagus, 
and  occasionally  in  the  stomach;  and,  if  prolonged,  redness  and  tume- 
faction of  the  parts  supervene,  with  a  clammy  condition  of  the  mucous 
follicular — and  diminution  and  viscidity  of  the  salivary — secretions. 
These  phenomena  are  described  as  being  accompanied  by  restlessness, 
general  heat,  injected  eyes,  disturbed  mind,  acceleration  of  the  circula- 
tion, and  short  breathing,  the  mouth  being  frequently  and  largely  open, 
so  as  to  admit  the  air  to  come  in  contact  with  the  irritated  parts,  and 
thus  afford  momentary  relief. 

Thirst  is  a  very  common  symptom  of  febrile  and  inflammatory  dis- 
eases, in  which  fluid — especially  cold  fluid — is  desired  in  consequence 
of  the  local  relief  it  affords  to  the  parched  and  heated  membrane  of  the 
alimentary  canal.  It  is  also  developed  by  extraneous  circumstances: 
as  in  summer,  when  the  body  sustains  considerable  loss  of  fluid;  as  well 
as  in  those  diseases — dropsy,  diabetes,  &c. — which  produce  the  same 
effect.  There  are  many  other  circumstances,  however,  that  excite  it; — 

1  J.  B.  S.  Jackson,  A  Descriptive  Catalogue  of  the  Anatomical  Museum  of  the  Boston 
Society  for  Medical  Improvement,  p.  158,  Lond.,  1847. 

2  Southey,  The  Doctor,  iv.  297,  Lond.,  1837. 

3  Medico-Chirurgical  Transactions,  xii.  52,  Lond.,  1822. 


624  DIGESTION. 

long  speaking  or  singing;  certain  kinds  of  diet  as  the  saline  and  spicy, 
— and  especially  the  habit,  acquired  by  some,  of  drinking  frequently. 
Whilst  individuals,  thus  circumstanced,  may  need  several  gallons  a  day 
to  satisfy  their  wants; — others,  who  have,  by  resistance,  acquired  the 
habit  of  using  very  little  liquid,  may  be  enjoying  health  and  not  expe- 
riencing the  slightest  inconvenience  from  the  privation  of  liquid;  so  com- 
pletely are  we,  as  regards  the  character  and  quantity  of  our  aliment, 
the  creatures  of  habit.  This  privation,  it  is  obvious,  cannot  be  abso- 
lute or  pushed  beyond  a  certain  extent.  There  must  always  be  fluid 
enough  taken  to  administer  to  the  necessities  of  the  system. 

As  in  the  production  of  all  sensations,  three  acts  are  required  for 
accomplishing  that  of  thirst ; — impression,  conduction,  and  perception. 
The  last,  as  in  every  similar  case,  is  effected  by  the  brain;  and  the 
second  by  the  nerves  passing  between  the  part  impressed  and  that 
organ.  The  act  of  impression — its  seat  and  cause — will  alone  arrest  our 
attention,  and  it  will  be  found  that  we  are  still  less  instructed  on  these 
points  than  on  the  physiology  of  hunger.  Even  with  regard  to  the 
seat  of  the  impression,  we  are  in  a  state  of  uncertainty.  It  appears  to 
be  chiefly  in  the  back  part  of  the  mouth  and  fauces ;  but  whether  pri- 
marily there,  or  experienced  there  by  sympathy  with  the  condition  of 
the  stomach,  is  by  no  means  clear.  The  latter  opinion,  however, 
appears  the  more  probable.  In  a  remarkable  case,  published  by  Dr. 
Gairdner  of  Edinburgh,  it  was  found  impracticable  to  allay  thirst  by 
merely  supplying  the  mouth,  tongue,  and  fauces  with  fluid.  A  man 
had  cut  through  the  oesophagus.  An  insatiable  thirst  arose ;  several 
pailfuls  of  water  were  swallowed  daily,  and  discharged  through  the 
wound  without  removing  the  desire  for  drink;  but  on  injecting  water, 
mixed  with  a  little  spirit,  into  the  stomach,  if  was  soon  quenched. 
That  the  sensation  is  greatly  dependent  upon  the  quantity  of  fluid  cir- 
culating in  the  vessels  is  shown  by  the  fact,  mentioned  by  M.  Dupuytren, 
that  he  succeeded  in  allaying  the  thirst  of  animals,  by  injecting  milk, 
whey,  water  or  other  fluids  into  the  veins;  and  M.  Orfila  states,  that,  in 
his  toxicological  experiments,  he  frequently  allayed  in  this  way  the 
excessive  thirst  of  animals,  to  which  he  had  administered  poison;  and 
which  were  incapable  of  drinking,  owing  to  the  oesophagus  having  been 
tied.  He  found,  also,  in  his  experiments,  that  the  blood  of  animals 
was  more  and  more  deprived  of  its  watery  portions  as  the  abstinence 
from  liquids  was  more  prolonged.1 

Like  all  other  sensations,  that  of  thirst  arises  from  an  inappreciable 
modification  of  the  nerves  of  the  organ  :  hence,  all  the  hypotheses 
proposed  to  account  for  it  have  been  mere  fantasies  undeserving  of 
enumeration. 

The  prehension  of  liquids  differs  somewhat  from  that  of  solids.  The 
fluid  may  be  simply  poured  into  the  mouth,  or  a  vacuum  may  be  formed 
in  it:  the  pressure  of  the  atmosphere  then  forces  it  in.  When  we 
drink  from  a  vessel,  the  mouth  is  applied  to  the  surface  of  the  fluid; 
the  chest  is  then  dilated,  so  as  to  diminish  the  pressure  of  the  atmo- 
sphere on  the  portion  of  the  surface  of  the  liquid  intercepted  by  the 

1  Adelon,  Physiologie  de  t'Homme,  2de  6dit.,  ii.  525,  Paris,  1829. 


LIQUIDS.  625 

lips;  and  the  atmospheric  pressure  on  the  surface  of  the  fluid  in  the 
vessel  forces  it  into  the  mouth,  to  replace  the  air  that  has  been  drawn 
from  the  mouth  by  the  dilatation  of  the  thorax.  In  sucking,  the  mouth 
may  be  compared  to  an  ordinary  syringe;  the  nozzle  of  which  is  re- 
presented by  the  lips;  the  body  by  the  cheeks,  palate,  &c.,  and  the 
piston  by  the  tongue.  To  put  this  in  action,  the  lips  are  accurately 
adjusted  around  the  body  from  which  the  liquid  has  to  be  extracted. 
The  tongue  is  likewise  applied,  contracts,  and  is  carried  backwards; 
so  that  an  approach  to  a  vacuum  is  formed  between  its  upper  surface 
and  the  palate.  The  fluid,  no  longer  compressed  equally  by  the  atmo- 
sphere, is  displaced,  and  enters  the  mouth. 

As  neither  mastication  nor  insalivation  is  required  in  the  case  of 
liquids,  they  do  not  remain  long  in  the  mouth,  unless  their  temperature 
is  too  elevated  to  admit  of  their  being  passed  down  into  the  stomach 
immediately,  or  they  are  of  so  luscious  a  character,  that  their  prolonged 
application  to  the  organ  of  taste  affords  pleasure.  Their  deglutition  is 
effected  by  the  same  mechanism  as  that  of  solids ;  and,  as  they  yield 
readily  to  the  slightest  pressure,  with  less  difficulty.  Their  accumula- 
tion in  the  stomach  takes  place  in  much  the  same  manner.  They  arrive 
by  successive  mouthfuls;  and,  as  they  collect,  the  thirst  disappears 
with  all  its  local  and  general  attendants.  If,  however,  the  organ  be 
over-distended  a  disposition  to  vomiting  is  induced. 

The  changes,  which  liquids  undergo  in  the  stomach,  are  of  different 
kinds.  All  acquire  the  temperature  of  that  viscus,  and  become  mixed 
with  the  secretions  from  its  internal  surface,  as  well  as  from  that  of 
the  supra-diaphragmatic  portion  cf  the  digestive  tube.  Some,  however, 
undergo  the  operation  of  chymification ;  others  not.  To  the  latter 
class  belong, — water,  weak  alcoholic  drinks,  the  vegetable  acids,  &c. 
Water  experiences  the  admixture  already  mentioned ;  becomes  turbid, 
and  gradually  disappears,  without  undergoing  any  transformation. 
Part  passes  into  the  small  intestine;  the  other  is  directly  absorbed. 
When  any  strong  alcoholic  liquor  is  taken,  the  effect  is  different.  Its 
stimulation  causes  the  stomach  to  contract,  and  augments  the  secre- 
tion from  the  mucous  membrane  ;  whilst,  at  the  same  time,  it  coagu- 
lates all  the  albuminous  and  mucous  portions;  mixes  with  the  watery 
part  of  the  mucous  and  salivary  fluids,  and  rapidly  disappears  by  ab- 
sorption ;  hence,  the  speedy  supervention  of  inebriety,  or  death,  after 
a  large  quantity  of  alcohol  has  been  taken  into  the  stomach.  The 
substances,  that  have  been  coagulated  by  the  action  of  the  alcohol,  are 
afterwards  digested  like  solid  food.  We  can  thus  understand  the  good 
effects  of  a  small  quantity  of  alcohol,  taken  after  a  substance  difficult 
of  digestion, — a  custom  which  has  existed  from  high  antiquity,  and  has 
physiology  in  its  favour.  It  is,  in  such  cases, — to  use  the  language  of 
the  eccentric  Kitchener,1 — a  good  "peristaltic  persuader." 

Oil  remains  longer  in  the  stomach  than  any  other  liquid,  experiences 
little  change  there,  but  passes  into  the  small  intestine,  where  it  forms 
an  emulsion  and  enters  the  veins  and  chyliferous  vessels.  Milk,  as  is 

1  Directions  for  Invigorating  and  Prolonging  Life ;  or  the  Invalid's  Oracle,  &c.,  Amer. 
edit.,  from  the  6th  London,  by  T.  S.  Barrett,  New  York,  1831. 

VOL.  i.— 40 


626  DIGESTION. 

•well  known,  coagulates  in  the  stomach  soon  after  it  is  swallowed,  after 
which  the  clot  is  digested,  and  the  whey  absorbed.  Yet  the  existence 
of  coagula  in  the  stomach  is  constantly  regarded  by  the  unprofessional 
as  a  pathological  condition  !  Where  the  liquid,  aqueous  or  spirituous, 
holds  in  suspension  the  immediate  principles  of  animals  or  vegetables, 
as  gelatin,  albumen,  osmazome,  sugar,  gum,  fecula,  colouring  matter, 
&c.,  there  is  reason  to  believe  that  they  enter  immediately  into  the 
veins  of  the  stomach  and  small  intestine.  The  salts,  united  with  these 
fluids,  are  taken  up  along  with  them.  Red  wine,  according  to  M. 
Magendie,1  first  becomes  turbid  by  admixture  with  the  juices  formed  in 
or  carried  into,  the  stomach :  the  albumen  of  these  fluids  speedily 
undergoes  coagulation,  and  becomes  flocculent ;  and,  subsequently,  its 
colouring  matter — entangled,  perhaps,  with  the  mucus  and  albumen — 
is  deposited  on  the  mucous  membrane  of  the  stomach.  The  aqueous 
and  alcoholic  portions  soon  disappear. 

Liquids  reach  the  small  intestine  in  two  forms  ; — in  the  state  of 
chyme  ;  and  in  their  unaltered  condition.  In  the  former  case,  they 
proceed  like  the  chyme  obtained  from  solid  food.  In  the  latter,  they 
undergo  no  essential  change  ;  being  simply  united  with  the  fluids  poured 
into  the  small  intestine, — the  mucous  secretions,  bile  and  pancreatic 
juice.  Their  absorption  goes  on  as  they  proceed,  so  that  very  little,  if 
any,  attains  the  large  intestine.  The  mode  in  which  they  are  expelled 
is  the  same  as  in  the  case  of  solids. 

6.    ERUCTATION,  REGURGITATION,  AND  RUMINATION. 

Although  the  contraction  of  the  oesophagus  generally  prevents  the 
return  of  matters  from  the  stomach,  occasionally  this  occurs,  giving 
rise  to  eructation,  regurgitation,  or  vomiting. 

a.  Eructation. — Eructation  or  belching  is  the  escape  of  gas  from 
the  stomach.     If  air  exists  in  the  organ,  it  is  necessarily  situate  near 
the  cardiac  orifice.     When  the  aperture  relaxes,  it  passes  out,  and, 
unless   forced   back   by  the   contraction   of  the  oesophagus,  speedily 
reaches  the  pharynx,  causing  the  edges  to  vibrate,  hence  the  sound  by 
which  it  is  accompanied. 

b.  Ilegurgitation. — If,  instead  of  air,  liquid  or  solid  food  ascends 
from  the  stomach  into  the   mouth,  the  action  is  called  regurgitation. 
Of  this  we  have  an  instance  in  the  puking  of  the  infant  at  the  breast ; 
and  in  the  adult,  when  the  stomach  is  surcharged.     Occasionally,  too,  it 
occurs  when  the  organ  is  empty, — in  the  morning,  for  example  ; — when  it 
is  frequently  preceded  by  eructations,  by  which  the  air,  contained  in 
the  organ,  is  got  rid  of.     The  mode  in  which  it  takes  place  is  analo- 
gous to  that  of  eructation.     The  substances,  contained  in  the  stomach 
become  accidentally  engaged  in  the  cardiac  orifice,  during  the  open 
state  of  the  orifice,  and  the  relaxation  of  the  lower  part  of  the  oeso- 
phagus, owing  to  the  direct  pressure  of  the  stomach   on  its  contents, 
and  the  abdominal  muscles  contracting  and  compressing  that  viscus. 
When  they  have  once  passed  into  the  oesophagus,  the  latter  contracts 
upon  them  but  inversely,  or  from  below  to  above.     In  this  way  they 

1  Precis,  &c.,  ii.  143. 


VOMITING.  627 

ascend  into  the  pharynx,  and  ultimately  into  the  mouth.  Generally, 
regurgitation  takes  place  in  an  involuntary  manner;  but  there  are 
some  who  are  capable  of  effecting  it  at  will ;  and  can  discharge  the  con- 
tents of  their  stomachs  at  pleasure.  To  accomplish  this, — a  deep  inspi- 
ration is  taken,  by  which  the  diaphragm  is  forcibly  depressed  upon  the 
stomach  ;  the  abdominal  muscles  are  then  contracted  so  as  to  compress 
the  organ ;  and  this  effect  is  occasionally  aided  by  pressing  strongly 
with  the  hands  on  the  epigastric  region.  When  these  efforts  are  simul- 
taneous with  the  relaxation  of  the  lower  third  of  the  oesophagus,  the 
alimentary  matters  pass  into  the  oesophagus.  This  voluntary  regurgi- 
tation seems  to  be  what  is  called  vomiting  at  pleasure. 

c.  Rumination. — Some  individuals  have  taken  advantage    of  this 
power  to   chew  the  food  over  again,  and  subject  it  to  a  second  deglu- 
tition.    The  function  of  rumination  is  peculiar  to  certain  animals;  yet 
man  has  occasionally  possessed  it.     Peyer,1  as  well  as  Percy  and  Lau- 
rent,2 has  given  numerous  examples.     The  wife  of  &frotteur  or  rubber 
of  the  floors,  in  the  establishment  of  the  then  Duke  of  Orleans, — after- 
wards King  Louis  Philippe — could  bring  up  a  glassful  of  water  into  her 
mouth  immediately  after  she  had  swallowed  it.     Dr.  Copland3  appears 
to  have  seen  more  than  one  instance  of  human  rumination,  and  he  de- 
scribes it  as  an  affection  rather  to  be  courted  than  shunned,  so  far  as 
regards  the  sensations  of  the  individual.     Under  usual  circumstances, 
according  to  him,  rumination  commences  from  a  quarter  of  an  hour  to 
an  hour  and  a  half  after  a  meal.     The  process  is  never  accompanied 
with  the  smallest  degree  of  nausea,  pain,  or  disagreeable  sensation. 
The  returned  alimentary  bolus  is  attended  with  no  unpleasant  flavour; 
is  in  no  degree  acidulous  [  ?]  ;  is  agreeable  ;  and  masticated  with  addi- 
tional pleasure,  and  greater  deliberation  than  at  first.     The  whole  of 
the  food  swallowed  at  a  meal  is  not  returned  in  order  to  undergo  the 
process  ;  but  chiefly  the  part  that  has  been  insufficiently  masticated. 
The  more  fluid  portions   are  sometimes,  however,  regurgitated  along 
with  the  more  solid  ;  and  when  the  stomach  is  distended  by  a  copious 
meal  the  fluid  contents  are  frequently  passed  up  to  be  again  swallowed.4 

d.  Vomiting. — This  inverted  action  of  the  stomach,  preceded — as  it 
always  is — by  manifest  local  and  general  disturbance,  cannot  properly 
be  regarded  as  within  the  domain  of  physiology.     In  the  language  of 
Haller,  vomitus  totus  morbosus  est.     It  is,  however,  so  nearly  allied  to 
the  phenomena  we  have  just  considered,  and  has  engaged  so  much  of 
the  time  of  the  physiologist,  as  well  as  pathologist,  that  it  requires 
mention  here.    From  regurgitation  it  differs  essentially, — in  the  sensa- 
tion that  precedes  ;  the  retching  that  accompanies  ;  and  the  fatigue  that 
generally  succeeds  it ;  in  short,  whilst  in  regurgitation  no  indisposition 
may  be  felt,  in  vomiting  it  is  always  present  to  a  greater  or  less  extent. 

The  sensation  of  the  desire  to  vomit  is  termed  nausea.     It  is  an  in- 

1  Merycologia,  &c.,  Basil,  1685. 

2  Art.  Merycisme,  in   Diet,  des  Sciences  Medicales;  Berard,  Cours  de  Pbysiologie,  13te 
livraison,  p.  274,  Paris,  1849. 

3  Edition  ofDe  Lys's  translation  of  Richerand's  Physiology. 

4  An  interesting  case  of  rumination  is  cited  from  the  London  Lancet,  in  the  Philadelphia 
Med.  Examiner,  p.  315,  for  May,  1845. 


628  DIGESTION.. 

describable  feeling  of  general  indisposition ;  sometimes  accompanied 
with  one  of  circumgyration,  either  in  the  head  or  epigastric  region ; 
trembling  of  the  lower  lip,  and  copious  flow  of  saliva.  Along  with 
these  signs,  there  is  manifest  diminution  of  the  powers  of  the  vascular 
and  nervous  systems ;  hence  the  utility  of  nauseating  remedies  when 
these  systems  are  inordinately  excited.  The  causes,  which  produce 
nausea,  show  that  it  may  be  either  an  external  or  internal  sensation. 
Those,  that  occasion  it  directly  or  externally,  are  emetics;  too  great 
distension  of  the  stomach,  or  the  presence  of  food  that  disagrees  by  its 
quality  ;  morbid  secretions  ;  reflux  of  bile  from  the  duodenum,  &c.  All 
these  are  so  many  immediate  irritants,  which  develope  the  sensation,  as 
external  sensations  in  general  are  developed.  In  other  cases,  the  cause 
acts  at  a  distance.  Between  the  stomach  and  various  organs  of  the 
body,  such  extensive  sympathetic  relations  exist,  that  if  one  be  long 
and  painfully  affected,  the  stomach  sooner  or  later  sympathizes ;  and 
nausea,  or  vomiting,  or  both  are  induced.  In  many  instances,  indeed, 
the  cause  is  much  more  remote  than  this ;  the  sight  of  a  disgusting 
object,  an  offensive  smell,  or  a  nauseous  taste,  will  as  certainly  produce 
the  sensation  as  any  of  the  more  direct  agents.  To  this  class  of  causes 
belongs  the  nausea  produced  by  riding  in  a  carriage  with  the  back  to 
the  horses,  by  swinging,  and  particularly  by  sailing  on  the  ocean.  How 
the  motion,  which  obviously  excites  the  nausea  in  these  cases,  acts,  has 
been  the  subject  of  many  speculations,  especially  as  regards  sea-sickness. 
Darwin1  refers  it  to  an  association  with  some  affection  of  the  organs 
of  vision,  which,  in  the  first  instance,  produces  vertigo ;  and  M.  Bourru, 
in  his  French  translation  of  the  work  of  Gilchrist,  "  On  the  utility  of 
sea  voyages  in  the  cure  of  different  diseases," — ascribes  it  to  irritation 
of  the  optic  nerves,  caused  by  the  impossibility  of  fixing  the  eyes  on 
objects  soon  after  embarking.  The  objections  to  these  views  are,  that 
it  ought  to  be  prevented  by  simply  covering  the  eyes,  and  that  the  blind 
ought  to  be  exempt  from  it,  which  is  not  the  case.  Dr.  Wollaston2  at- 
tempted to  explain  it,  by  some  change  in  the  distribution  of  the  blood ; 
— the  descending  motion  of  the  vessel  causing  an  accumulation  in  the 
brain,  as  it  causes  the  mercury  to  rise  in  the  tube  of  a  barometer.  But 
the  explanation  is  too  physical.  The  mercury,  in  an  unyielding  tube, 
is  readily  influenced  by  the  motions  of  the  vessel ;  but  the  blood  in  the 
living  animal  is  circumstanced  far  otherwise.  It  is  under  the  influence 
of  a  vital  force,  which  interferes  greatly  with  the  action  of  purely  physi- 
cal causes.  Were  it  otherwise,  we  should  be  liable  to  alarming  accidents, 
whenever  the  body  is  exposed  to  the  slightest  concussion. 

The  generality  of  pathologists  consider,  that  the  first  effect  is  upon 
the  brain,  the  sensation  being  produced  consecutively  through  the  in- 
fluence of  that  organ  on  the  stomach;  and  it  is  difficult  not  to  accord 
with  this  view;  whilst  it  must  be  admitted,  that  the  precise  mode,  in 
which  it  is  effected,  is  beyond  our  cognizance — as  in  the  case,  indeed, 
of  every  other  phenomenon  of  the  nervous  system.  In  nausea,  pro- 
duced by  the  sight  of  a  disgusting  object,  we  have  this  catenation  of 
actions  somewhat  more  clearly  evidenced.  The  impression  is  manifestly, 

1  Zoonomia,  iv.  252,  3d  edit.,  Lond.,  1801.  2  Philos.  Transact,  for  1810. 


VOMITING.  629 

conveyed  to  the  brain  by  the  optic  nerves,  and  from  that  organ  the 
sensation  must  emanate.  It  is  probable,  too,  that  when  emetics  are 
injected  into  the  veins,  the  first  effect  takes  place  on  the  brain,  and  the 
stomach  is  affected  secondarily. 

When  the  state  of  nausea,  howsoever  induced,  continues  for  any 
length  of  time,  it  is  usually  followed  by  vomiting.  The  rejected  mat- 
ters are  generally  from  the  stomach;  but  if  the  retching  or  violent 
contractile  efforts  of  the  muscles  concerned  be  long  continued,  the  con- 
tents of  the  small  intestine  also  form  part ;  hence,  we  account  for  the 
universality  of  the  presence  of  bile  in  the  rejected  matters  after  an 
emetic  has  been  taken.  Its  presence  is,  therefore,  in  the  generality  of 
cases,  no  evidence  of  the  person's  being  what  is  termed  bilious.  The 
contents  of  the  small'  intestine  are  returned  into  the  stomach  by  the 
antiperistaltic  action.  The  longitudinal  fibres  take  their  fixed  point 
below,  and  contract  from  above  downwards ;  so  that  the  chymous  mass 
is  forced  towards  the  upper  part  of  the  canal,  whilst  the  circular  fibres 
contract  from  below  to  above.  In  cases  of  colica  ileus  or  iliac  passion, 
the  inverted  action  extends  through  the  whole  intestinal  canal;  so  that 
faecal  matters,  and  even  substances  injected  into  the  rectum,  pass  the 
ileo-csecal  valve,  and  are  discharged  by  the  mouth. 

Of  old,  it  was  universally  maintained,  that  vomiting  is  caused  by  the 
sudden  and  convulsive  inverted  contraction  of  the  stomach ;  and  they, 
who  admitted  that  the  diaphragm  and  abdominal  muscles  take  part  in 
the  action,  looked  upon  them  simply  as  accessories.  Francis  Bayle,1 
Professor  in  the  University  of  Toulouse,  in  1681,  appears  to  have  been 
the  first  who  suggested,  that  the  stomach  is  nearly  passive  in  the  act ; 
and  that  vomiting  is  caused  almost  exclusively  by  the  pressure  exerted 
upon  that  organ  by  the  diaphragm  and  abdominal  muscles.  His  reason 
for  the  belief  was  founded  on  the  fact,  that  having  introduced  his  finger 
into  the  abdomen  of  a  living  animal  whilst  it  was  vomiting  he  could  not 
perceive  any  contraction  of  the  stomach.  In  1686,  M.  Chirac  repeated 
the  experiment  with  similar  results ;  after  which,  the  views  of  Bayle 
were  embraced  by  many  of  the  most  eminent  physiologists  and  patho- 
logists, — Senac,  Van  Swieten,  and  Schwartz,2  and,  at  a  later  period, 
by  the  celebrated  John  Hunter,3  who  maintained,  that  the  contraction 
of  the  muscular  fibres  of  the  stomach  is  not  essential  to  the  act.  Many 
distinguished  physiologists  ranged  themselves  on  the  opposite  side. 
M.  Littre  maintained,  that  the  stomach  is  provided  with  considerable 
muscular  bands,  capable  of  powerful  contraction ;  and  that  vomiting, 
as  in  the  case  of  ruminant  animals,  is  often  caused  without  the  partici- 
pation of  the  abdominal  muscles.  We  have  seen,  however,  that  the 
rumination  of  animals  more  resembles  regurgitation.  M.  Lieutaud4 
argued,  that,  according  to  Bayle's  theory,  vomiting  ought  to  be  a  vo- 
luntary phenomenon;  that  the  stomach  is  too  deeply  seated  to  be  com- 
pressed, so  as  to  empty  it  of  its  contents,  by  the  neighbouring  muscles; 

1  Problemata  Medico-physica  et  Meclica,  Hagae  Comitis,  1678. 

2  Haller,  Elementa  Physiol.,  lib.  xix.  §  4,  Bern.,  1764. 

3  Observations  on  certain  parts  of  the  Animal  Economy,  with  Notes  by  Prof.  Owen,  Amer. 
edit.,  p.  121,  Philad.,  1840. 

4  Memoir,  de  1'Acad.  pour  1752,  p.  223. 

I 


630  DIGESTION. 

and  he  details  the  singular  case  of  a  female,  who,  whilst  labouring  under 
an  affection,  for  which  emetics  seemed  to  be  required,  resisted  the  action 
of  the  most  powerful  substances  of  that  nature.  After  her  death,  M. 
Lieutaud,  feeling  desirous  to  detect  the  cause  of  this  resistance,  had 
the  body  opened  in  his  presence:  the  stomach  was  found  enormously 
distended,  but  its  structure  unaffected.  He,  consequently,  inferred, 
that  the  stomach  had  become  paralysed  from  over-distension,  and  that 
the  effect  produced  was  similar  to  that,  so  often  met  with  in  the  bladder, 
when  it  has  been  long  and  largely  distended.  This  case  seemed  to  prove 
to  him,  that  the  stomach  is  most  concerned  in  the  act  of  vomiting,  as 
.  the  abdominal  muscles  and  diaphragm  appeared  healthy,  and  no  obstacle 
existed  to  their  contraction.  It  is  singular,  however,  that  emetics  should 
not  have  excited  the  contraction  of  the  diaphragm  and  abdominal  mus- 
cles; especially  as  there  is  reason  for  believing,  that  many  of  them  at 
least,  under  ordinary  circumstances,  are  taken  into  the  bloodvessels, 
and  affect  the  brain  first,  and  through  its  agency  the  muscles  con- 
cerned in  the  act  of  vomiting.  The  case  seems  to  have  been  one  of 
unusual  resistance  to  the  ordinary  effects  of  nauseating  substances,  and 
cannot  be  looked  upon  as  either  favourable  or  unfavourable  to  the  views 
of  Bayle.  We  find,  that  vomiting  does  not  follow  the  exhibition  of  the 
largest  doses  of  the  most  powerful  emetics,  if  the  energy  of  the  nervous 
system  be  suspended  by  the  inordinate  use  of  narcotics,  or  by  violent 
injuries  of  the  head.  M.  Lieutaud  farther  remarks,  that  according  to 
Bayle's  theory  vomiting  occurs  at  the  time  of  inspiration;  but  this 
cannot  be,  as  the  lower  part  of  the  oesophagus  is  then  contracted,  and 
if  the  vomited  matters  could  reach  the  pharynx,  they  would  pass  into 
the  larynx. 

Dr.  Marshall  Hall1  has  attempted,  and  successfully,  to  show,  that  the 
larynx  is  closed  during  vomiting;  and  has  concluded,  that  the  act  is  a 
modification  of  expiration, — or  that  the  muscles  of  expiration,  by  a  sud- 
den and  violent  contraction,  press  upon  the  contents  of  the  stomach,  and 
project  them  through  the  oesophagus.  Perhaps — as  Dr.  Hall  has  re- 
marked— no  act  affords  a  better  illustration  of  the  action  of  the  excito- 
motory  or  reflex  system  of  nerves  than  this.  If  the  upper  part  of  the 
throat  be  tickled  with  a  feather,  vomiting  results ;  but  if  the  feather  be 
passed  too  far  down,  deglutition  is  induced  and  not  vomiting.  The  ex- 
citor  nerves,  in  the  former  case,  are  the  glosso-pharyngeal,  and  perhaps 
the  fifth  pair.  When  vomiting  is  caused  by  an  emetic,  the  pneumogas- 
tric  is  the  excitor.  When  the  impression  is  first  made  on  the  brain, 
the  stimulus  must  be  conveyed  by  the  medulla  oblongata  and  medulla 
spinalis  to  the  muscles  concerned. 

Haller2  maintained  the  ancient  doctrine,  that  the  stomach,  alone,  is 
competent  to  the  operation.  His  views  were  chiefly  founded  on  his 
theory  of  irritability,  which  compelled  him  to  admit  contraction  wherever 
there  are  muscular  fibres;  and  on  certain  experiments  of  Wepfer,3  who 
asserted,  that  when  he  produced  vomiting  by  mineral  substances,  he 
observed  the  stomach  contract.  The  Academie  des  Sciences  of  Paris, 

1  Journal  of  Science  and  Arts,  xv.  388. 

2  LOG.  citat.  3  Cicutse  Aquaticse  Historia,  &c.,  Basil,  1679. 


VOMITING.  631 

unsatisfied  with  the  results  of  previous  observations,  appointed  M. 
Duverney1  to  examine  into  the  question,  experimentally  and  otherwise; 
who, — although  he  did  not  adopt  the  whole  theory  of  Chirac — confirmed 
the  accuracy  of  the  facts  on  which  it  rested.  He  demonstrated,  that 
the  stomach  is  but  little  concerned  in  the  act ;  and  that  it  is  chiefly  depend- 
ent upon  the  contraction  of  the  diaphragm  and  abdominal  muscles,  which 
enclose  the  stomach  as  in  a  press,  so  that  its  contents  are  compelled  to 
return  by  the  oesophagus.  On  the  other  hand,  in  1771,  M.  Portal,2  in 
his  lectures  at  the  College  of  France,  endeavoured  to  show,  that  the 
stomach  is  the  great  agent.  He  administered  to  two  dogs  arsenic  and 
nux  vomica,  which  produced  vomiting.  The  abdomen  was  immediately 
opened;  and,  according  to  Portal,  the  contractile  movements  of  the  sto- 
mach could  be  both  seen  and  felt;  and  it  was  noticed,  that  instead  of  the 
vomiting  being  dependent  upon  the  pressure  of  the  diaphragm  on  the 
stomach,  it  occurred  at  the  time  of  expiration;  and  was  arrested  during 
inspiration,  because  the  depressed  diaphragm  then  closes  the  inferior 
extremity  of  the  oesophagus  with  such  strength,  that  the  contents  can- 
not be  forced  into  the  oesophagus  when  we  press  upon  the  organ  with 
both  hands.  The  views  of  Portal  were  confirmed  by  the  experiments 
of  Dr.  Haighton.3  He  opened  several  animals  during  the  efforts  of 
vomiting;  and  states  that  he  distinctly  saw  the  contractions  of  the 
stomach. 

In  more  recent  times,  the  physiological  world  has  been  again  agitated 
with  this  question.  In  1813,  M.  Magendie4  presented  to  the  French 
Institute  the  results  of  a  series  of  experiments  on  dogs  and  cats, — 
animals,  that  vomit  with  facility.  Six  grains  of  tartrate  of  antimony 
and  potassa  were  given  to  a  dog,  and,  when  he  became  affected  with 
nausea,  the  linea  alba  was  divided,  and  the  finger  introduced  into  the 
abdomen  to  detect  the  state  of  the  stomach.  No  contraction  was  felt ; 
the  organ  appeared  simply  pressed  upon  by  the  liver  and  intestines 
crowded  upon  it  by  the  contracted  diaphragm  and  abdominal  muscles. 
Nor  was  any  contraction  of  the  stomach  perceptible  to  the  eye;  on  the 
contrary,  it  appeared  full  of  air,  and  three  times  its  usual  size.  The 
air  manifestly  came  from  the  oesophagus,  as  a  ligature,  applied  round 
the  cardia,  completely  shut  it  off.  From  this  experiment,  M.  Magendie 
inferred,  that  the  stomach  is  passive  in  vomiting.  A  solution  of  four 
grains  of  tartrate  of  antimony  and  potassa  in  two  ounces  of  water  was 
injected  into  the  veins  of  a  dog;  and,  as  soon  as  nausea  took  place,  an 
incision  was  made  into  the  abdomen,  and  the  stomach  drawn  out  of  the 
cavity.  Although  the  retching  continued,  the  viscus  remained  immova- 
ble ;  and  the  efforts  were  vain.  If,  on  the  other  hand,  the  anterior  and 
posterior  surfaces  of  the  stomach  were  pressed  upon  by  the  hands, 
vomiting  occurred,  even  when  no  tartrate  was  administered, — the  pres- 
sure provoking  the  contraction  of  the  diaphragm  and  abdominal  muscles, 
and  thus  exhibiting  the  close  sympathetic  connexion,  existing  between 
those  acts.  A  slight  pull  at  the  oesophagus  was  attended  with  a  similar 

1  Memoir  de  l'Acad£m.  pour  1700,  Hist.,  p.  27. 

2  Cours  d' Anatomic  Medicale,  Paris,  1804. 

3  Memoirs  of  the  Lond.  Med.  Society,  vol.  ii. 

4  Memoire  sur  le  Vomissement,  Paris,  1813;  and  Precis  Elementaire,  edit,  cit.,  ii.  152. 


632  DIGESTION. 

result.  In  another  dog,  the  abdomen  was  opened;  the  vessels  of  the 
stomach  tied;  and  the  viscus  extirpated.  A  solution  of  two  grains  of 
tartrate  of  antimony  and  potassa  in  an  ounce  and  a  half  of  water  was 
then  injected  into  the  veins  of  the  animal,  when  nausea  and  fruitless 
efforts  to  vomit  supervened.  The  injection  was  repeated  six  times:  and 
always  with  the  same  results. — In  another  dog,  the  stomach  was  extir- 
pated, and  a  hog's  bladder  fitted  to  the  esophagus  in  its  stead,  con- 
taining a  pint  of  water,  which  distended  but  did  not  fill  it.  The  whole 
was  then  put  into  the  abdomen;  the  parietes  of  which  were  closed  by 
suture.  A  solution  of  tartrate  of  antimony  and  potassa  was  now  in- 
jected into  the  jugular  vein:  nausea — and,  afterwards,  vomiting — super- 
vened, and  the  fluid  was  forced  from  the  bladder. — In  another  dog,  the 
phrenic  nerves  were  divided ;  by  which  three-fourths  of  the  diaphragm 
were  paralysed;  the  dorsal  being  the  only  nerves  of  motion  remaining 
untouched.  When  tartrate  of  antimony  and  potassa  was  injected  into 
the  veins  of  this  animal,  but  slight  vomiting  occurred;  and  this  ceased, 
when  the  abdomen  was  opened,  and  the  stomach  forcibly  pressed  upon. — 
In  another  dog,  the  abdominal  muscles  were  detached  from  the  sides 
and  linea  alba ; — the  only  part  of  the  parietes  remaining  being  the 
peritoneum.  A  solution  of  tartrate  of  antimony  and  potassa  was  now 
injected  into  the  veins:  nausea  and  vomiting  supervened;  and,  through 
the  peritoneum,  the  stomach  was  observed  immovable;  whilst  the  dia- 
phragm pressed  down  the  viscera  so  strongly  against  the  peritoneum, 
that  it  gave  way,  and  the  linea  alba  alone  resisted. — In  a  final  experi- 
ment, he  combined  the  two  last.  He  cut  the  phrenic  nerves  to  paralyse 
the  diaphragm ;  and  removed  the  abdominal  muscles.  Vomiting  was 
no  longer  excited. 

From  these  different  results,  M.  Magendie  decided,  that  vomiting 
takes  place  independently  of  the  stomach;  and,  on  the  other  hand, 
that  it  cannot  occur  without  the  agency  of  the  diaphragm  and  abdominal 
muscles ;  and  he  concluded,  that  the  stomach  is  almost  passive  in  the 
act ; — that  the  diaphragm  and  abdominal  muscles,  especially  the  first, 
are  the  principal  agents ; — that  air  is  constantly  swallowed  at  the  time 
of  vomiting,  to  give  the  stomach  the  bulk  which  is  necessary,  in  order 
that  it  may  be  compressed  by  those  muscles;  and  lastly,  that  the  dia- 
phragm and  abdominal  muscles  are  largely  concerned  in  vomiting,  as  is 
indicated  by  their  evident  and  powerful  contractions,  and  by  the  fatigue 
felt  in  them  afterwards.  In  corroboration  of  his  view,  M.  Magendie 
refers  to  cases  of  scirrhous  pylorus,  in  which  there  is  constant  vomiting, 
although  a  part  of  the  tissue  of  the  stomach  has  become  of  cartilaginous 
hardness,  and,  consequently,  incapable  of  contraction. 

Clear  as  the  results  obtained  by  this  practiced  experimenter  seem  to 
be,  they  have  been  controverted ;  and  attempted  to  be  overthrown  by 
similar  experiments.  Soon  after  the  appearance  of  his  memoir,  M. 
Maingault1  laid  before  the  Society  of  the  Faculte  de  MSdecine  of 
Paris,  a  series  of  experiments,  from  which  he  deduced  very  different 
results.  In  all,  vomiting  was  produced  without  the  aid  of  the  diaphragm 
and  abdominal  muscles.  The  vomiting  was  excited,  by  pinching  a  por- 

1  Memoire  sur  le  Vomissement,  Paris,  1813. 


VOMITING.  633 

tion  of  intestine,  which  acts  more  speedily  than  the  injection  of  sub- 
stances into  the  veins.  The  abdomen  of  a  dog  was  opened,  and  a  ligature 
passed  round  a  portion  of  intestine,  which  was  returned  into  the  abdo- 
men, and  the  wound  closed  by  suture:  vomiting  took  place.  All  the 
abdominal  muscles  were  next  extirpated, — the  skin,  alone,  forming  the 
parietes  of  the  cavity.  This  was  brought  together,  and  the  vomiting 
continued.  On  another  dog,  three-quarters  of  the  diaphragm  were 
paralysed  by  the  section  of  the  phrenic  nerves.  The  abdomen  was 
now  opened,  and  a  ligature  placed  round  a  portion  of  intestine.  Vomit- 
ing occurred.  Lastly; — these  two  experiments  were  united  into  one. 
The  abdominal  muscles  were  cut  crucially,  and  removed ;  the  phrenic 
nerves  divided;  and  the  diaphragm  was  cut  away  from  its  fleshy  portion 
towards  its  tendinous  centre ;  leaving  only  a  portion  as  broad  as  the 
finger  under  the  sternum.  The  integuments  were  not  brought  together; 
yet  vomiting  continued. 

As  these  results  were  obtained  on  numerous  repetitions  of  the  experi- 
ment, M.  Maingault  conceived  himself  justified  in  deducing  inferences 
opposite  to  those  of  M.  Magendie,  namely, — that  the  contraction  of  the 
diaphragm  and  abdominal  muscles  is  only  accessory  to  the  act  of 
vomiting;  that  the  action  of  the  stomach  is  its  principal  cause; — that 
the  latter  is  not  a  convulsive  contraction,  which  strikes  the  eye,  but  a 
slow,  antiperistaltic  action ;  and  that  the  only  convulsive  movement  is 
the  contraction  of  the  oesophagus,  which  drags  the  stomach  upwards. 
He  adduces,  moreover,  various  considerations  in  favour  of  his  deduc- 
tions. If  the  stomach,  he  asks,  be  passive,  why  does  it  possess  nerves, 
vessels,  and  muscular  fibres?  Why  is  vomiting  more  energetic,  when 
the  stomach  is  pinched  nearer  to  its  pyloric  orifice?  Why  are  the  rugae 
of  the  mucous  membrane  of  the  stomach,  during  vomiting,  directed  in 
a  divergent  manner  from  the  cardiac  and  pyloric  orifices  towards  the 
middle  portion  of  the  organ  ?  If  the  diaphragm  does  all,  why  do  we 
not  vomit  whenever  that  muscle  contracts  forcibly  ?  Why  does  not  the 
diaphragm  produce  the  discharge  of  urine  in  paralysis  of  the  bladder? 
Why  is  vomiting  not  a  voluntary  phenomenon?  And,  lastly,  how  is  it 
that  it  occurs  in  birds,  which  have  no  diaphragm  ? 

The  minds  of  physiologists  were  of  course  distracted  by  these  conflict- 
ing results.  M.  Richerand1  embraced  the  views  of  M.  Magendie ;  and 
affirmed,  that  he  had  never  observed  contraction  of  the  stomach ;  and 
that  it  seemed  to  him  the  least  contractile  of  any  part  of  the  intestinal 
canal.  With  regard  to  the  experiments  of  M.  Maingault,  he  con- 
sidered, that  the  stomach  had  not  been  wholly  separated  from  the  sur- 
rounding muscles;  that  the  action  of  the  pillars  of  the  diaphragm,  and 
the  spasmodic  constriction  of  the  hypochondres  are  sufficient  to  com- 
press the  viscus;  that  nothing  is  more  difficult  to  effect  than  the  section 
of  the  phrenic  nerves  below  their  last  root ;  and,  moreover,  such  section 
does  not  entirely  paralyse  the  diaphragm,  as  the  muscle  still  receives 
twigs  from  the  intercostal  nerves  and  great  sympathetic ;  that  the  car- 
dia,  being  more  expanded  than  the  pylorus,  the  passage  of  substances 
through  it  is  rendered  easy;  and  that  it  is  incorrect  to  say,  that  the 

1  Nouveaux  Elemens  de  Physiologie,  7eme  edit.,  Paris,  1817, 


634  ,  DIGESTION. 

cardiac  orifice,  during  inspiration,  is  closed  between  the  pillars  of  the 
diaphragm.  Again,  to  object  that,  according  to  the  theory  of  M.  Ma- 
gendie,  vomiting  ought  to  be  a  voluntary  phenomenon,  is  a  feeble 
argument;  for  it  is  admitted,  that  the  muscles,  which,  at  the  time, 
compress  the  stomach,  act  convulsively.  If  the  diaphragm,  in  paraly- 
sis of  the  bladder,  cannot  effect  the  excretion  of  the  urine,  it  is  because 
that  reservoir  is  not  favourably  situate  as  regards  the  muscle;  and, 
lastly,  the  arguments  deduced  from  birds,  that  they  are  capable  of 
vomiting,  although  they  have  no  diaphragm,  is  equally  insufficient,  for 
it  is  not  absolutely  necessary  that  it  should  be  a  diaphragm,  but  any 
muscle  that  can  compress  the  stomach. 

When  the  Memoir  of  M.  Maingault  was  presented  to  the  society  of 
the  Faculte  de  Medecine,  M.  Legallois  and  Professor  Be'clard  were 
named  reporters.  The  experiments  were  repeated  before  them  by  M. 
Maingault ;  but,  instead  of  appearing  contradictory  to  those  of  Ma- 
gendie,  these  gentlemen  declared,  that  they  were  not  sufficiently  mul- 
tiplied, nor  sufficiently  various,  to  lead  to  any  positive  conclusion. 
MM.  Legallois  and  Be'clard  subsequently  repeated  and  varied  them; 
and  instituted  others,  from  which  they  deduced  corollaries,  entirely 
conformable  to  those  of  M.  Magendie;1  and  lastly,  M.  Bdgin2  boldly 
affirms,  "without  fear  of  being  contradicted  by  facts,  that  there  is  no 
direct  or  authentic  experiment,  that  demonstrates  the  activity  of  the 
stomach  during  vomiting:" — and  he  adds,  "I  have  repeated  the  greater 
part  of  the  experiments  of  Magendie;  he  has  performed  all  in  presence 
of  a  great  number  of  spectators,  of  whom  I  was  one ;  and  I  can  say, 
with  the  commissioners  of  the  Academie  des  Sciences,  that  I  have  seen, 
examined,  touched,  and  my  conviction  is  full  and  entire."  Still,  many 
eminent  physiologists  have  adhered  to  the  idea,  that  the  stomach  is 
the  main  agent  in  vomiting ;  and  among  these  was  M.  Broussais.3  He 
manifestly,  however,  confounded  the  phenomena  of  regurgitation  with 
those  of  vomiting ;  which,  we  have  endeavoured  to  show,  are  distinct. 

A  case  of  wound  of  the  left  hypochondrium  with  escape  of  the  sto- 
mach was  described  to  the  Academie  Royale  de  M6decine,  by  M. 
Lupine,  and  reported  upon  by  MM.  Lagneau,  Gimelle,  and  Be'rard,4 
which  confirms  the  views  adopted  by  M.  Magendie.  During  the  whole 
of  the  period,  that  the  stomach  remained  out  of  the  abdominal  cavity, 
there  was  no  apparent  contraction  of  the  muscular  fibres  of  the  organ, 
and  none  of  its  contents  were  expelled,  although  the  patient  made 
violent  efforts  to  vomit.  As  soon,  however,  as  the  stomach  had  been 
returned  into  the  abdomen,  the  efforts  were  followed  by  the  expulsion 
of  its  contents.  M.  Ldpine  confirms  the  observations  of  Magendie  in 
another  point.  After  each  act  of  vomiting,  the  patient  appeared  to 
swallow  air.  "I  observed  him,"  says  M.  Le'pine,  "execute  repeated 

1  Bulletin  de  la  Faculte  et  de  la  Societe  de  Med.,  1813,  No.  x.,  and  CEuvres  de  Legallois, 
Paris,  1824. 

2  Traite  de  Therapeutique,  Paris,  1825. 

3  Traite  de  Physiologic,  etc.,  Drs.  Bell  and  La  Roche's  translation,  p.  345,  Philad.,  1832. 

4  Bulletin   de  TAcademie   Royale  de    Medecine,    1844.     See  the  cases  cited  in  Philad. 
Med.  Examiner,  April  20,  1844,  p.  92;  also  a  case  of  Wound  of  Abdomen,  in  Amer.  Journ. 
of  the  Med.  Sciences,  Oct.,  1846,  p.  379. 


ABSORPTION.  635 

acts  of  deglutition,  each  of  which  was  accompanied  by  a  noise,  that 
seemed  to  be  owing  to  the  passing  back  of  air." 

On  the  whole,  we  are,  perhaps,  justified  in  concluding,  that  the 
ancient  doctrine  regarding  vomiting  is  full  of  error,  and  ought  to  be 
discarded ;  that  the  inverted  action  of  the  stomach,  although  not  ener- 
getic, is  necessary, — that  the  pressure,  exerted  on  the  parietes  of  the 
stomach  by  the  diaphragm  and  abdominal  muscles,  is  a  powerful  cause, 
— and  that  the  more  or  less  complete  paralysis  of  the  diaphragm,  or 
destruction  of  the  abdominal  muscles,  renders  vomiting  more  feeble 
and  more  slow  in  manifesting  itself.  The  deep  inspiration  preceding 
the  act  of  vomiting,  is  terminated  by  the  closure  of  the  glottis:  after 
this  the  diaphragm  cannot  move  without  expanding  or  compressing  the 
air  in  the  lungs.  It,  consequently,  presents  a  resisting  surface,  against 
which  the  stomach  may  be  pressed  by  the  contracting  abdominal  mus- 
cles. The  order  of  the  phenomena  seems  to  be  as  follows.  The  brain 
is  affected  directly  or  indirectly  by  the  cause  exciting  vomiting ; — 
through  the  brain  and  medulla,  the  glottis  is  closed,  and  the  diaphragm 
and  abdominal  muscles  are  thrown  into  appropriate  contraction,  and 
press  upon  the  stomach;  this  organ  probably  contracts  from  the 
pylorus  towards  the  cardia;  and,  by  the  combination  of  efforts,  the 
contents  are  propelled  into  the  oesophagus,  and  out  of  the  mouth. 
These  efforts  are  repeated  several  times  in  succession,  and  then  cease, 
— to  reappear  at  times.  Whilst  the  rejected  matters  pass  through  the 
pharynx  and  mouth,  the  glottis  closes ;  the  velum  palati  rises  and  be- 
comes horizontal  as  in  deglutition  ;  but  owing  to  the  convulsive  action 
of  the  parts,  these  apertures  are  less  accurately  closed,  and  more  or 
less  of  the  vomited  matter  passes  into  the  larynx  or  nasal  fossae.  On 
account  of  the  suspension  of  respiration  impeding  the  return  of  blood 
from  the  upper  parts  of  the  body,  and  partly  owing  to  the  force  with 
which  the  blood  is  sent  through  the  arteries,  the  face  is  flushed,  or 
livid,  the  perspiration  flows  in  abundance,  and  the  secretion  of  tears  is 
largely  augmented. 


CHAPTER  II. 

ABSORPTION. 

IN  the  consideration  of  the  preceding  functions,  we  have  seen  the 
alimentary  matter  subjected  to  various  actions  and  alterations ;  and  at 
length,  in  the  small  intestine,  possessed  of  the  necessary  physical  con- 
stitution for  the  chyle  to  be  separated  from  it.  Into  the  mode  in  which 
this  separation, — which  we  shall  find  is  not  simply  a  secerning  action, 
but  one  of  vital  elaboration, — is  effected,  we  have  now  to  inquire.  It 
constitutes  the  function  of  absorption,  and  its  object  is  to  convey  the 
nutritive  fluid,  formed  from  the  food,  into  the  current  of  the  circula- 
tion. Absorption  is  not,  however,  confined  to  the  formation  of  this 
fluid.  Liquids  can  pass  into  the  blood  directly  through  the  coats  of 
the  containing  vessel,  without  having  been  subjected  to  any  elabora- 
tion; and  the  different  constituents  of  the  organs  are  constantly  sub- 


636  ABSORPTION. 

jected  to  the  absorbing  action  of  cells,  by  which  their  decomposition  is 
effected,  and  their  elements  conveyed  into  the  blood;  whilst  antago- 
nizing cells  elaborate  from  the  blood,  and  deposit  fresh  particles  in  the 
place  of  those  that 'have  been  removed.  These  various  substances, 
— bone,  muscle,  hair,  nail,  as  the  case  may  be, — are  never  found,  in 
their  compound  state,  in  the  blood ;  and  the  inference,  consequently,  is 
that  at  the  very  radicles  of  the  absorbents  and  exhalants,  the  sub- 
stance on  which  absorption  or  exhalation  has  to  be  effected,  is  reduced 
to  its  constituents,  and  this  by  an  action,  to  which  we  know  nothing 
similar  in  physics  or  chemistry:  hence,  it  has  been  inferred,  that  the 
operation  is  one  of  the  acts  of  vitality. 

All  the  various  absorptions  may  be  classed  under  two  heads: — the 
external  and  the  internal;  the  former  including  those  that  take  place 
on  extraneous  matters  from  the  surface  of  the  body  or  its  prolongation 
— the  mucous  membranes;  and  the  latter,  those  that  are  effected  inter- 
nally, on  matters  proceeding  from  the  body  itself,  by  the  removal  of 
parts  already  deposited.  By  some  physiologists,  the  action  of  the  air 
in  respiration  has  been  referred  to  the  former  of  these ;  and  the  whole 
function  of  absorption  has  been  defined; — the  aggregate  of  actions,  by 
which  nutritive  substances — external  and  internal — are  converted  into 
fluids,  which  serve  as  the  basis  of  arterial  blood.  The  function  of  respi- 
ration will  be  investigated  separately.  Our  attention  will,  at  pre- 
sent, be  directed  to  the  other  varieties;  and,  first  of  all  to  that  which 
occurs  in  the  digestive  tube. 

I.    DIGESTIVE  ABSORPTION. 

The  absorption,  effected  in  the  organs  of  digestion,  is  of  two  kinds; 
according  as  it  concerns  liquids  of  a  certain  degree  of  tenuity,  or  solids. 
The  former,  it  has  been  remarked,  are  subjected  to  no  digestive  action, 
but  disappear  chiefly  from  the  stomach,  and  in  part  from  the  small 
intestine.  The  latter  undergo  conversion,  before  they  are  fitted  to  be 
taken  up  from  the  intestinal  canal. 

a.  Absorption  of  Chyle  or  Ghylosis. 

1.    ANATOMY  OF  THE  CHYLIFEROUS  APPARATUS. 

In  the  lower  animals,  absorption  is  effected  over  the  whole  surface  of 
the  body,  both  as  regards  the  materials  necessary  for  nutrition  and  the 
supply  of  air.  No  distinct  organs  for  the  performance  of  these  func- 
tions are  perceptible.  In  the  upper  classes  of  animals,  however,  we 
find  an  apparatus,  manifestly  intended  for  the  absorption  of  chyle,  and 
constituting  a  vascular  communication  between  the  small  intestine  and 
left  subclavian.  Along  this  channel,  the  chyle  passes,  to  be  emptied 
into  that  venous  trunk. 

The  chyliferous  apparatus  consists  of  chyliferous  vessels,  mesenteric 
glands,  and  thoracic  duct.  The  chyliferous  vessels  or  lacteals,  arise 
from  the  inner  surface  of  the  small  intestine; — in  the  villi,  which  are  at 
the  surface  of,  and  between,  the  valvulse  conniventes.  Prof.  E.  H.  Weber1 
has,  however,  seen  them  distributed  in  the  interspaces  between  the 

1  Mutter's  Archiv.,  u.  s.  w.,  s.  400,  Berlin,  1847. 


CHYLIFEROUS  APPARATUS. 


637 


villi;    the  lacteals  Fig.  249. 

and  bloodvessels 
forming  a  close  net- 
work ;  but  he  could 
not  detect  them  in 
the  parietes  of  the 
follicles  of  Lieber- 
klihn.  Their  ori- 
gin is  almost  im- 
perceptible ;  and, 
accordingly,  the 
nature  of  their 
arrangement  has 
given  occasion  to 
much  diversity  of 
sentiment  amongst 
anatomists.  Lie- 

berktihn1      affirms,  Chyliferous  Vessels. 

that,  by  the  micro- 
scope, it  may  be  shown  that  each  villus  terminates  in  an  ampullula  or 
oval  vesicle,  which  has  its  apex  perforated  by  lateral  orifices,  through 
which  the  chyle  enters.  The  doctrine  of  open  mouths  of  lacteals  and  lym- 
phatics was  embraced  by  Hewson,2  Sheldon,3  Cruikshank,4  Hedwig,5  and 
Bleuland,6and  by  some  of  the  anatomists  and  physiologists  of  the  present 
day  ;7  but,  on  the  other  hand,  it  has  been  contested  by  Mascagni,8  and 
others;  whilst  Rudolphi,9Meckel,10and  numerous  others11  believed,  that 
the  lacteals  have  not  free  orifices ;  but  that  in  the  villi,  in  which  ab- 
sorption is  effected,  a  spongy  or  sort  of  gelatinous  tissue  exists,  which 
accomplishes  absorption,  and,  being  continuous  with  the  mouths  of 
chyliferous  vessels,  conveys  the  product  of  absorption  into  them. 
Bichat  conceived  them  to  commence  by  a  kind  of  sucker  or  absorbing 
mouth,  the  action  of  which  he  compared  to  that  of  the  puncta  lachry- 
malia  or  of  a  leech  or  cupping-glass;  and  lastly, — from  the  observation, 
often  made,  that  different  coloured  fluids,  with  which  the  lymphatics 
have  been  injected,  have  never  spread  themselves,  either  into  the  areo- 
lar  tissue,  or  the  parenchyma  of  the  viscera, — M.  Mojon,12  of  Genoa, 
affirmed,  that  lymphatics  have  no  patulous  orifice,  and  that  they  take 

1  Dissert,  de  Fabric.  Villor.  Intest.  passim.  Lugd.,  Bat.,  1745. 

2  Experimental  Inquiries;  edited  by  Falconer,  Lond.,  1774,  1777,  and  1780,  or  Hewson's 
Works,  Sydenham  Society's  edit.,  p.  181,  Lond.,  1846. 

3  The  History  of  the  Absorbent  System,  &c.,  p.  1,  Lond.,  1784. 

4  Anatomy  of  the  Absorbing  Vessels,  2d  edit.,  Lond.,  1790. 

5  Disquisit.  Ampull.  Lieberkxihnii,  Lips.,  1797. 

6  Exper.  Anatom.,  1784;  and  Descript.  Vasculor.  in  Intestinor  Tennium  Tunicis,  Ultra]., 
1797. 

7  See  Henle,  Allgemeine  Anatomic,  u.  s.  w.  s.  569,  Leipz.,  1841. 

8  Vasorum  Lymphaticorum  Corporis  Humani  Historia,  &c.,  Senis,  1787;  and  Prodrome 
d'un  Opera  sul  Sistemo  de  Vase  Linfatice,  Siena,  1784. 

9  Anatomisch.  Pliysiologisch.  Abhandlung.,  Berlin,  1802. 

10  Handbuch,  u.  s.  w.  translated  by  Jourdan  and  Breschet,'  p.  179,  Paris,  1805. 

11  F.Arnold,  Lehrbuch  der  Physiologic  des  Menschen,  Zurich,  1836-7;  noticed  in  Brit, 
and  For.  Med.  Rev.,  Oct.,  1839,  p.  479. 

12  Journal  de  la  Societe  des  Sciences  Physiques,  &c.  Nov.,  1833. 


638 


ABSORPTION. 


their  ^  origin  from  a  cellular  filament,  which  progressively  becomes  a 
villosity,  an  areolar  spongiole,  a  capillary,  and,  at  length,  a  lymphatic 


Fig.  250. 


Chyliferous  Apparatus. 

A,  A.  A  portion  of  the  jejunum.  6,  6,  ft,  b.  Superficial  lacteals.  e,  c,  c.  Mesentery,  d,  d,  d.  First 
row  of  mesenteric  glands,  e,  e,  e.  Second  row.  /,/.  Receptaculum  chyli.  g.  Thoracic  duct.  h. 
Aorta,  t,  t.  Lymphatics. 

trunk; — the  absorbent  action  of  these  vessels  being  a  kind  of  imbibition. 
Lastly,  Professor  Muller1  affirms,  that  he  has  never  perceived  any 
opening  at  the  extremity  of  the  villi:  in  his  earlier  examinations,  he 
was  unable  to  see  appearances  of  foramina  on  any  part  of  their  sur- 
face, but  he  has  observed,  in  portions  of  the  intestines  of  the  sheep 
and  the  ox,  which  had  been  exposed  for  some  time  to  the  action  of 
water,  that  over  the  whole  surface  of  the  villi  indistinct  depressions 
were  scattered,  which  might  be  regarded  as  oblique  openings.  He 
adds,  however,  that  he  makes  this  observation  with  great  hesitation 
and  distrust. 

1  Handbuch  der  Physiologic,  u.  s.  w.,  and  Baly's  translation,  p.  269,  Lond.,  1838. 


CHYLIFEROUS  APPARATUS. 


639 


Fig.  251. 


Fig.  252. 


Section 
Villus. 


of  Intestinal 
(Gerlach.) 


a.  Artery,  b.  Vein.  c. 
Lymphatic.  —  Magnified 
250  diameters. 


Intestinal  Villus  with  the 
commencement  of  a 
Lacteal.  (Krause.) 


All  these  are  mere  speculations,  too  often  entirely  gratuitous ;  and 
the  view,  that  they  never  open  by  free  orifices  on  the  surface  of  the 
intestine,  as  was  formerly  imagined,  is  entirely  in  accordance  with  the 
results  of  modern  histological  inquiries. 

The  marginal  illustration,  Fig.  252,  from  Krause  exhibits  the  appear- 
ance presented  by  the  incipient 
chyliferous  vessels  in  the  villi 
of  the  jejunum  of  a  young  man, 
who  had  v  been  hanged  soon 
after  taking  a  full  meal  of  fa- 
rinaceous food.  The  chylife- 
rous vessel  issuing  from  each 
villus  appeared  to  arise  by  seve- 
ral small  branches,  in  some  of 
which  free  extremities  could 
be  traced,  whilst  others  anas- 
tomosed with  each  other.  The 
arrangement  of  the  different 
anatomical  constituents  is  well 
seen  in  Fig.  251,  which  re- 
presents an  injected  intestinal 
villus  of  a  cat,  which  was  killed 
during  digestion.  When  they 
become  perceptible  to  the  eye, 
they  are  observed  as  in  Fig. 
249,  communicating  frequently  with  each  other;  and  forming  a  minute 
network,  first  between  the  muscular  and  mucous  membranes,  and  after- 
wards between  the  muscular  and  peritoneal,  until  they  terminate  in 
larger  trunks,  a,  a,  a,  a.  When  they  attain  the  point  at  which  the 
peritoneal  coat  quits  the  intestine,  they  also  leave  it;  creep  for  an  inch 
or  two  in  the  substance  of  the  mesentery;  and  enter  a  first  row  of 
mesenteric  glands.  From  these  they  issue,  of  a  greater  size  and  in  less 
number;  proceed  still  farther  along  the  mesentery,  and  reach  a  second 
row,  into  which  they  enter.  From  these,  again,  they  issue,  larger  and 
less  numerous;  anastomosing  with  each  other;  and  proceeding  towards 
the  lumbar  portion  of  the  spine,  where  they  terminate  in  a  common 
reservoir, — the  reservoir  of  Pecquet,  receptaculum  seu  cisterna  cliyli, 
(Figs.  250  and  253) — which  is  the  commencement  of  the  thoracic  duct. 
This  reservoir  is  situate  about  the  third  lumbar  vertebra;  behind  the 
right  pillar  of  the  diaphragm,  and  the  right  renal  vessels.  The  chy- 
liferous vessels  generally  follow  the  course  of  the  arteries;  but  some- 
times proceed  in  the  spaces  between  them.  They  exist  in  the  lower 
part  of  the  duodenum,  throughout  the  whole  of  the  jejunum,  and  in  the 
upper  part  of  the  ileum.  M.  Voisin1  affirms,  that  all,  or  at  least  the 
major  part,  of  them  pass  through  the  substance  of  the  liver,  before 
they  empty  their  contents  into  the  thoracic  duct.  After  proceeding  a 
certain  distance,  they  anastomose,  he  says,  with  each  other,  enlarge  in 
size,  and  are  collected  together  so  as  to  form  a  kind  of  plexus  below  the 

1  Nouvel  Apergu  sur  la  Physiologic  du  Foie,  &c.,  Paris,  1833. 


640  ABSORPTION. 

lobe  of  Spigelius,  towards  which  they  converge.  From  this  point,  they 
penetrate  the  substance  of  the  liver,  through  which  they  ramify  with 
great  minuteness,  and  finally  empty  themselves  into  the  receptaculum 
chyli.  To  prove,  that  the  chyliferous  vessels  do  pass  through  the  liver, 
he  put  a  ligature  around  the  duct  below  the  diaphragm,  in  a  dog  which 
had  eaten  largely,  and  when  digestion  was  in  full  activity.  The  chy- 
liferous vessels  were  observed  to  swell,  and  their  whitish  colour  was 
distinctly  perceived.  They  could  be  traced,  without  much  difficulty, 
from  the  interior  of  the  intestinal  canal,  through  the  mesenteric  glands, 
as  far  as  their  entrance  into  the  liver. 

The  chyliferous  vessels  are  composed  of  two  coats;  the  outer  of  a 
fibrous  and  firm  character;  the  inner  very  thin,  epithelial,  and  gene- 
rally considered  to  form,  by  its  duplicatures,  valves.  These  are, of  a 
semilunar  form,  arranged  in  pairs,  and  with  the  convex  side  towards 
the  intestine.  Their  arrangement  has  appeared  to  be  well  adapted  for 
permitting  the  chyle  to  flow  from  the  intestine  to  the  thoracic  duct, 
and  for  preventing  its  retrograde  course ;  but  M.  Magendie1  affirms,  that 
their  existence  is  by  no  means  constant.  These  reputed  valves  are 
considered  by  M.  Mojon2  to  be  true  sphincters.  By  placing  the  lymph- 
atic vessels  on  a  glass  plate,  and  opening  them  through  their  entire 
length,  he  observed  by  the  microscope,  that  they  are  formed  of  circular 
fibres,  which,  by  diminishing  the  size  of  the  vessel  at  different  points, 
give  rise  to  the  nodosities  observed  externally.  If  the  ends  of  a 
varicose  lymphatic  be  drawn  in  a  contrary  direction,  these  nodosities 
disappear,  as  well  as  the  supposititious  valves.  Mojon  observed,  more- 
over, that  the  fibrous  membrane  of  the  lymphatics  has  longitudinal,  as, 
•well  as  oblique,  filaments  passing  from  one  narrow  portion  to  another. 
The  longitudinal  fibres  have  their  two  extremities  attached  to  the  trans- 
verse fibres,  which,  according  to  him,  constitute  the  sphincters  or 
contractors  of  the  lymphatics.  He  explains  the  difficulty  often  ex- 
perienced in  attempting  to  inject  the  lymphatic  vessels  in  a  direction 
contrary  to  the  course  of  the  lymph,  by  the  circumstance,  that  the 
little  pouches  formed  by  the  sphincters,  and  the  relaxation  or  disten- 
sion of  their  parietes  on  filling  them  with  injected  matter,  diminish  the 
calibre  of  the  tube,  and  can  even  close  it  entirely.  The  smallest  lacteals 
appear  to  be  destitute  of  valves;  but  valves  are  perceptible  in  those  of 
less  than  one-third  of  a  line  in  diameter,  and  they  have  the  same 
structure  as  those  of  the  veins.  The  minute  lacteals  in  the  villi  are 
said  to  consist  of  a  single  membrane  with  elongated  cell-nuclei,  corre- 
sponding to  the  longitudinal  fibrous  membrane  of  the  veins,  but  not  lined 
by  epithelium.  Some  anatomists  describe  an  external  coat,  formed  of 
condensed  areolar  tissue,  which  unites  the  chyliferous  vessels  to  the 
neighbouring  parts. 

The  mesenteric  glands  or  ganglions  are  small,  irregularly  lenticular 
organs;  varying  in  size  from  the  sixth  of  an  inch  to  an  inch;  nearly 
one  hundred  in  number,  and  situate  between  the  two  laminae  of  the 
mesentery.  In  them,  the  lymphatic  vessels  of  the  abdomen  termi- 

1  Precis  Elementaire,  2de  edit.,  i?.  177,  Paris,  1825. 

2  Op.  citat.  and  Arner.  Journal,  &c.,  for  Aug.  1834,  p.  465. 


CHYLIFEROUS  APPARATUS. 


641 


nate;  and  the  chyliferous  vessels  traverse  Fig.  253. 

them  in  their  course  from  the  intestine  to  the 
thoracic  duct.  Their  substance  is  of  a  pale  rosy 
colour;  and  their  consistence  moderate.  By 
pressure,  a  transparent  and  inodorous  fluid 
can  be  forced  from  them;  which  has  never  been 
examined  chemically.  Anatomists  differ  with 
regard  to  their  structure.  According  to  some, 
they  consist  of  a  pellet  of  chyliferous  ves- 
sels, folded  a  thousand  times  upon  each  other; 
subdividing  and  anastomosing  almost  ad 
infinitum;  united  by  areolar  tissue,  and 
receiving  a  number  of  bloodvessels.  In 
the  opinion  of  others,  again,  cells  exist  in 
their  interior,  into  which  the  afferent  chy- 
liferous vessels  open ;  and  whence  the  effe- 
rent set  out.  These  are  filled  with  a  milky 
fluid,  carried  thither  by  the  lacteals  or  ex- 
haled by  the  bloodvessels.  Notwithstand- 
ing the  labours  of  Nuck,1  Hewson,  Aber- 
nethy,  Mascagni,  Cruikshank,  Haller,2 
B£clard,3  and  other  distinguished  anato- 
mists, the  texture  of  these,  as  well  as  of  the 
lymphatic  glands  or  ganglions  in  general,  is 
not  demonstrated.  The  chyliferous  and  san- 
guiferous  vessels  become  extremely  minute 
in  their  substance ;  and  the  communication 
between  the  afferent  and  efferent  vessels  is 
very  easy;  as  mercurial  injections  pass 
readily  from  the  one  to  the  other.  Accord-  Thoracic  Duct. 

1.  Arch  of  aorta.  2.  Thoracic  aorta.  3.  Abdominal  aorta;  showing,  its  principal  branches  divided 
near  their  origin.  4.  Arteria  innominata,  divided  into  right  carotid  and  right  subclavian  arteries.  5. 
Left  carotid.  6.  Left  subclavian.  ,7.  Superior  cava,  formed  by  the  union  of  8,  the  two  venae  inno- 
minatae;  and  these  by  the  junction  9  of  internal  jugular  and  subclavian  vein  at  each  side.  10.  Greater 
vena  azygos.  11.  Termination  of  the  lesser  in  greater  vena  azygos.  12.  Receptaculum  chyli ;  seve- 


ral lymphatic  trunks  are  seen  opening  into  it.  13.  Thoracic  duct,  dividing  opposite  middle  of  dors 
vertebrae  into  two  branches  which  soon  reunite  ;  course  of  duct  behind  arch  of  aorta  and  left  subcla- 
vian artery  is  shown  by  a  dotted  line.  14.  The  duct  making  its  turn  at  root  of  the  neck  and  receiving 
several  lymphatic  trunks  previously  to  terminating  in  posterior  aspect  of  junction  of  internal  jugular 
and  subclavian  vein.  15.  Termination  of  trunk  of  ductus  lymphaticus  dexter. 

ing  to  Mr.  Goodsir,  the  absorbent  vessels  within  the  chyliferous  and 
lymphatic  glands  lay  aside  all  but  their  internal  coat ;  and  the  epi- 
thelium, instead  of  forming  a  thin  lining  of  flat  transparent  scales,  as 
in  the  extra-glandular  lymphatics,  acquires  an  opaque  granular  aspect, 
and  is  converted  into  a  thick  irregular  layer  of  spherical  nucleated 
corpuscles,  measuring  on  an  average  s^^th  part  of  an  inch  in  dia- 
meter, so  as  to  suggest  the  idea  of  lymph  or  chyle  corpuscles  generated 
on  the  internal  membrane  after  the  ordinary  manner  of  epithelium 
cells,  and  about  to  be  thrown  off  into  the  vessel.  This  layer,  according 
to  Mr.  Goodsir,  is  thickest  in  those  lymphatics  that  are  situated  towards 


1  Adenologia,  Lugd.  Bat.,  1696. 
3  Addit.  a  Bichat,  p.  128,  Paris,  1821. 
VOL.  I. — 41 


2  Element.  Physiol.,  lib.  ii.  §  3,  Lausar.,  1757. 


642 


ABSORPTION. 


Fig.  254. 


Fig.  255. 


Diagram  of  a  lymphatic  gland,  showing 
the  intra-glandular  network,  and  the  tran- 
sition from  the  scale-like  epithelia  of  the 
extra-glandular  lymphatics,  to  the  nu- 
cleated cells  of  the  intra-glandular. 


Portion  of  the  intra-glandular  lymphatic, 
showing  along  the  lower  edge  the  thick- 
ness of  the  germinal  membrane,  and  upon 
it,  the  thick  layer  of  glandular  epithelial 
cells. 


tlie  centre  of  the  gland,  becomes  gradually  thinner  towards  the  afferent 
and  efferent  vessels,  and  passes  continually  into  the  ordinary  epithe- 
lium. 

The  thoracic  duct,  g,  Fig.  250,  and  13,  Fig.  253,  is  formed  by  the 
junction  of  the  chyliferous  trunks  with  the  lymphatic  trunks  from  the 
lower  extremities.  The  receptaculum  chyli,  already  described,  forms 
its  commencement.  After  passing  from  under' the  diaphragm,  the  duct 
proceeds,  in  company  with  the  aorta,  along  the  right  side  of  the  spine, 
until  it  reaches  the  fifth  dorsal  vertebra;  where  it  crosses  over  to  the 
left  side  behind  the  oasophagus.  It  then  ascends  behind  the  left  carotid 
artery ;  runs  up  to  the  interstice  between  the  first  and  second  vertebrae 
of  the  chest;  where,  after  receiving  the  lymphatics,  which  come  from 
the  left  arm  and  left  side  of  the  head  and  neck,  it  suddenly  turns  down- 
wards, and  terminates  at  the  angle  formed  by  the  meeting  of  the  sub- 
clavian  and  internal  jugular  veins  of  the  left  side. 

To  observe  the  chyliferous  apparatus  to  the  greatest  advantage,  it 
should  be  examined  in  an  individual  recently  executed,  or  killed  sud- 
denly two  or  three  hours  after  having  eaten ;  or  in  an  animal,  destroyed 
for  the  purpose  of  experiment,  under  similar  circumstances.     The  lac- 
teals  are  then' filled  with  chyle,  and  may  be  readily  recognised,  especially 
if  the  thoracic  duct  has  been  previously  tied.     These  vessels  were  un- 
known to  the  ancients.     The  honour  of  their  discovery  is  due  to  Gaspard 
Aselli,1  of  Cremona,  who,  in  1622,  at  the  solicitation  of  some  friends, 
undertook  the  dissection  of  a  living  dog,  which  had  just  eaten,  in  order 
to  demonstrate  the  recurrent  nerves.     On  opening  the  abdomen,  he 
perceived  a  multitude  of  white,  very  delicate  filaments  crossing  the 
mesentery  in  all  directions.     At  first,  he  took  them  to  be  nerves;  but 
having  accidentally  cut  one,  he  saw  a  quantity  of  a  white  liquor  exude, 
analogous  to  cream.     Aselli  also  noticed  the  valves,  but  he  fell  into  an 
important  error  regarding  the  destination  of  the  lacteals ;  believing  them 
to  collect  in  the  pancreas,  and  from  thence  proceed  to  the  liver.     In 
1628,  the  human  lacteals  were  discovered.     Gassendi2  had  no  sooner 
heard  of  the  discovery  of  Aselli,  than  he  spoke  of  it  to  his  friend 
Nicholas-Claude-Fabrice  de  Peiresc,  senator  of  Aix;  who  seems  to  have 
been  a  most  zealous  propagator  of  scientific  knowledge.     He  immedi- 

1  De  Lactibus  seu  Lacteis  Venis,  &c.,  Mediol.,  1627;  also,  in  Collect.  Oper.  Spigelii,  edit. 
Van  der  Linden;  and  in  Manget.  Theatr.  Anatom. 

2  Vita  Peirescii,  in  Op.  omnia,  v.  300. 


CHYLE.  643 

ately  bought  several  copies  of  the  work  of  Aselli,  which  had  only  ap- 
peared the  year  previously;  and  distributed  them  amongst  his  profes- 
sional friends.  Many  experiments  were  made  upon  animals,  but  the 
great  desire  of  De  Peiresc  was,  that  the  lacteals  should  be  found  in  the 
human  body.  Through  his  interest,  a  malefactor,  condemned  to  death, 
was  given  up,  a  short  time  before  his  execution,  to  the  anatomists  of 
Aix;  who  made  him  eat  copiously;  and,  an  hour  and  a  half  after  execu- 
tion, opened  the  body,  in  which,  to  the  great  satisfaction  of  De  Peiresc, 
the  vessels  of  Aselli  were  perceived  in  the  clearest  manner.  Afterwards, 
in  1634,  John  Wesling1  gave  the  first  graphic  representation  of  them  as 
they  exist  in  the  human  body;  and  subsequently  pointed  out  more  clearly 
than  his  predecessors  the  thoracic  duct  and  lymphatics.  Prior  to  the 
discovery  of  the  chyliferous  and  lymphatic  vessels,  the  veins,  which 
arise  in  immense  numbers  from  the  intestines,  and,  by  their  union  with 
other  veins,  form  the  vena  porta,  were  esteemed  the  agents  of  absorp- 
tion; and,  even  at  the  present  day,  they  are  considered,  by  some  physio- 
logists, to  participate  with  the  chyliferous  vessels  in  the  function; — 
with  what  propriety  we  shall  inquire  hereafter. 

2.  CHYLE. 

The  chyle,  as  it  circulates  in  the  chyliferous  vessels,  has  only  been 
submitted  to  examination  in  comparatively  recent  times.  It  varies  in 
different  parts  of  its  course.  The  best  mode  of  obtaining  it  is  to  feed 
an  animal;  and,  when  digestion  is  in  full  progress,  to  strangle  it,  or 
divide  the  spinal  marrow  beneath  the  occiput.  The  thorax  must  then 
be  opened  through  its  whole  length,  and  a  ligature  be  passed  round  the 
aorta,  oesophagus,  and  thoracic  duct,  as  near  the  neck  as  possible.  If 
the  ribs  of  the  left  side  be  now  turned  back  or  broken,  the  thoracic  duct 
is  observed  lying  against  the  oesophagus.  By  detaching  the  upper 
part,  and  cutting  into  it,  the  chyle  flows  out.  A  small  quantity  only 
is  thus  obtained;  but,  if  the  intestinal  canal  and  chyliferous  vessels  be 
repeatedly  pressed  upon,  the  flow  may  be  sometimes  kept  up  for  a  quarter 
of  an  hour.  It  is  obviously  impossible,  in  this  way,  to  obtain  the  chyle 
pure;  inasmuch  as  the  lymphatics,  from  various  parts  of  the  body,  are 
constantly  pouring  their  fluid  into  the  thoracic  duct. 

From  the  concurrent  testimony  of  various  experimenters,  chyle  is  a 
liquid  of  a  milky- white  appearance;  limpid  and  transparent  in  herbi- 
vorous animals,  but  opaque  in  the  carnivorous;  neither  viscid  nor  glu- 
tinous to  the  touch;  of  a  consistence,  varying  somewhat  according  to 
the  nature  of  the  food;  a  spermatic  smell;  sweet  taste,  not  dependent 
on  that  of  the  food;  neither  acid  nor  alkaline;  and  of  a  specific  gravity 
greater  than  distilled  water,  but  less  than  the  blood.  Magendie,2  Tiede- 
mann  and  Gmelin,3  and  Miiller,4  however,  state  it  to  possess  a  saline 
taste ;  to  be  clammy  on  the  tongue ;  and  sensibly  alkaline.  Its  milky 
colour  is  generally  supposed  to  be  owing  to  oily  matter  which  occurs  in 
it  in  the  form  of  globules  of  various  sizes,  from  ^gi^th  to  20*00^  °f 
an  inch  in  diameter,  and  which  are  more  abundant  in  the  chyle  of  man 

1  Syntagm.  Anatom.,  viii.  170.  2  Precis,  &c.,  ii.  172. 

3  Die  Verdauung  nach  Versuchen,  i.  353,  Heidelb.,  1826 :  or  French  translation,  by  Jourdan, 
Paris,  1827. 

4  Elements  of  Physiology,  by  Baly,  p.  258,  London,  1838. 


644  ABSORPTION. 

and  of  the  carnivora,  than  in  that  of  the  herbivora.  Mr.  Gulliver1  has, 
however,  affirmed,  that  the  colour  is  due  to  an  immense  multitude  of 
minute  particles,  which  he  regards  as  forming  the  matrix  or  molecular 
base  of  the  chyle.  These  are  generally  spherical  and  extremely  small, — 
their  diameter  being  estimated  at  from  sgj^th  to  sittsijth  of  an  inch* 
They  are  of  a  fatty  nature,  and  their  number  appears  to  be  dependent 
upon  the  amount  of  fatty  matter  in  the  food.  Their  fatty  nature  is 
shown  by  their  solubility  in  ether,  and,  when  the  ether  evaporates,  by 
their  forming  drops  of  oil.  As,  however,  they  do  not  run  together,  it 
has  been  suggested,  that  each  molecule  consists  of  oil  coated  with  albu- 
men, a  view  which  is  supported  by  the  fact,  that  when  water  or  dilute 
acetic  acid  is  added  to  chyle,  many  of  the  molecules  are  lost  sight  of, 
and  oil  drops  appear  in  their  place;  as  if  the  envelopes  of  the  mole- 
cules had  been  dissolved,  and  their  oily  contents  had  run  together.2 

The  chemical  character  of  the  chyle  of  animals  has  been  examined 
by  Emmert,3  Yauquelin,4  Marcet,5  Prout,6  Simon,7  and  Nasse  ;8  and  is 
found  to  resemble  greatly  that  of  the  blood.  In  a  few  minutes  after 
its  removal  from  the  thoracic  duct  it  becomes  solid  ;  and,  after  a  time? 
separates,  like  the  blood,  into  two  parts ;  a  coagulum,  and  a  liquid. 
The  coagulum  is  an  opaque  white  substance  ;  of  a  slightly  pink  hue  ; 
insoluble  in  water  ;  but  readily  soluble  in  the  alkalies,  and  alkaline  car- 
bonates. M.  Vauquelin  regards  it  as  fibrin  in  an  imperfect  state,  or  as 
intermediate  between  that  principle  and  albumen  ;  but  M.  Brande9  thinks 
it  more  closely  allied  to  the  caseous  matter  of  milk  than  to  fibrin.  The 
analyses  of  Drs.  Marcet  and  Prout  agree,  for  the  most  part,  with  that 
of  M.  Vauquelin.  The  existence  of  fibrin  in  it  can  scarcely  be  doubted. 

Like  blood,  again,  chyle  often  remains  for  a  long  time  in  its  vessels 
without  coagulating,  but  coagulates  rapidly  on  being  removed  from 
them.10 

Dr.  Prout  has  detailed  the  changes,  which  the  chyle  experiences  in 
its  passage  along  the  chyliferous  apparatus.  In  each  successive  stage, 
its  resemblance  to  blood  was  found  to  be  increased.  Another  point  of 
analogy  with  blood  is  the  fact,  observed  by  Mr.  Bauer,nand  subsequently 
by  MM.  Prdvost  and  Dumas,12  and  others,  that  the  chyle,  when  examined 
by  the  microscope,  contains  globules  ;  differing  from  those  of  the  blood 
in  their  being  of  a  smaller  size,  the  average  being  ^g^oth  of  an  inch, 
and  devoid  of  colouring  matter.  The  nature  and  source  of  these  glob- 
ules, as  well  as  of  those  of  the  lymph  which  resemble  them  in  all  respects, 
is  not  determined.  They  have  been  supposed  to  be  the  nuclei  or  pri- 
mordial cells  from  which  all  the  tissues  originate,13  and  to  be  the  source 
of  the  blood  globule. 

1  Gerber's  General  Anatomy,  by  Gulliver,  Appendix,  p.  88,  London,  1842. 

2  Kirkes  and  Paget,  Manual  of  Physiology,  Amer.  edit.,  p.  207,  Philad.,  1849. 

3  Annales  de  Chimie,  torn.  Ixxx.  p.  81. 

4  Ibid.,  Ixxx.  113;  and  Annals  of  Philosophy,  ii.  220. 

5  Medico-Chirurg.  Transactions,  vol.  vi.  618,  London,  1815. 

6  Thomson's  Annals  of  Philosophy,  xiii.  121,  and  263. 

7  Animal  Chemistry,  Sydenham  Soc.  edit.,  p.  354,  London,  1845,  or   Amer.  edit.,  Philad., 
1846.  8  Wagner's  Handworterbuch,  u.  s.  w.,  i.  235,  art.  Chyle  ;  and  Simon,  op.  cit. 

9  Phil.  Transact,  for  1812.  '°  Bouisson,  Gazette  Medicale  de  Paris,  1844. 

11  Sir  E.  Home,  op.  cit.,  Hi.  25.         12  Biblioth.  Universelle  de  Geneve,  p.  221,  Juillet,  1821. 

13  Gulliver,  in  Gerber's  Anatomy,  p.  83,  note. 


CHYLE.  645 

Although  chyle  has  essentially  the  same  constituents,  whatever  may 
be  the  food  taken,  and  separates  equally  into  a  clot  and  serous  portion, 
the  character  of  the  aliment  may  have  an  effect  upon  the  relative  quan- 
tity of  those  constituents,  and  thus  exert  an  influence  on  its  compo- 
sition. That  it  scarcely  ever  contains  adventitious  substances  will  be 
seen  hereafter  ;  but  it  is  obvious,  that  if  an  animal  be  fed  on  diet  con- 
trary to  its  nature,  the  due  proportion  of  perfect  chyle  may  not  be 
formed  ;  and  that,  in  the  same  way,  different  alimentary  articles  may 
be  very  differently  adapted  for  its  formation.  MM.  Leuret  and  Las- 
saigne,1  indeed,  affirm,  that  in  their  experiments  they  found  the  chyle 
differ  more  according  to  the  nature  of  the  food  than  to  the  animal  spe- 
cies ;  but  that,  contrary  to  their  expectation,  the  quantity  of  fibrin  in 
it  bore  no  relation  to  the  more  or  less  nitrogenized  character  of  the  ali- 
ment. They  assign  it,  as  constituents,  fibrin,  albumen,  fatty  matter, 
soda,  chloride  of  sodium,  and  phosphate  of  lime. 

Messrs.  Tiedemann  and  Gmelin  have  communicated  the  following 
data  in  regard  to  the  influence  of  diet  on  the  chyle.  The  experiments 
were  made  on  dogs,  and  the  chyle  was  taken  from  the  thoracic  duct. 
First*  After  taking  cheese,  the  chyle  coagulated  slightly.  The  clot 
was  little  more  than  a  pale  red  transparent  film,  and  the  serum  slightly 
milky.  It  contained  water,  950-3  ;  clot,  1-71 :  residue  of  serum,  48-0. 
Secondly.  After  the  use  of  starch,  the  chyle  was  of  a  pale  yellowish- 
white  colour,  and  coagulated  rapidly.  It  contained  water  930*0  ;  clot 
and  residue  of  serum,  70-0.  The  clot  was  of  pale  red  colour.  Thirdly. 
After  taking  flesh,  and  bread  and  milk,  it  was  of  a  reddish- white  colour, 
and  coagulated  rapidly,  the  clot  being  of  a  pale  red  tint,  and  the  serum 
very  milky.  It  consisted  of  water,  915-3  ;  clot,  2-7  ;  residue  of  serum, 
83-8.  Fourthly.  After  the  use  of  milk  it  presented  a  milky  appearance, 
and  the  clot  was  transparent,  and  of  a  pale  red  colour.  Fifthly.  After 
bread  and  milk,  it  contained  water,  961-1 ;  clot  1/9  ;  residue  of  serum, 
37*0.  Sixthly.  After  flesh,  bread,  and  milk,  it  was  of  a  yellowish  red 
colour;  coagulated  firmly,  separating  into  a  bright  red  clot,  and  turbid  yel- 
low serum;  and  contained  water,  933*5;  clot,  5-6;  residue  of  serum,  60-9.2 

The  chief  object  of  Dr.  Marcet's  experiments  was  to  compare  the 
chyle  from  vegetable,  with  that  from  animal  food,  in  the  same  animal. 
The  experiments  made  on  dogs  led  him  to  the  following  results.  The 
specific  gravity  of  the  serous  portion  is  from  1-012  to  1*021,  whether 
it  be  formed  from  animal  or  vegetable  diet.  Vegetable  chyle,  when  sub- 
jected to  analysis,  furnishes  three  times  more  carbon  than  animal 
chyle.  The  latter  is  highly  disposed  to  become  putrid  ;  and  this  change 
generally  commences  in  three  or  four  days  ;  whilst  vegetable  chyle  may 
be  kept  for  several  weeks,  and  even  months,  without  being  putrid.3 
Putrefaction  attacks  rather  the  coagulum  of  the  chyle  than  its  serous 
portion.  The  chyle  from  animal  food  is  always  milky  ;  and,  if  kept  at 
rest,  an  unctuous  matter  separates  from  it,  similar  to  cream,  which  swims 
on  the  surface.  The  coagulum  is  opaque,  and  has  a  rosy  tint.  On  the 

1  Recherches  sur  la  Digestion,  Paris,  1825.  2  Simon,  op.  cit,  p.  358. 

3  M.  Thenard  has  properly  remarked,  that  the  difference  in  the  time  of  putrefaction  of 
these  two  substances,  appears  very  extraordinary.  It  is,  indeed,  inexplicable.  Traite  de 
Chitnie  Elementaire,  &c.,  5eme  edit.,  Paris,  1827. 


646  ABSORPTION. 

other  hand,  chyle  from  vegetable  food  is  almost  always  transparent,  or 
nearly  so,  like  ordinary  serum.  Its  coagulum  is  nearly  colourless,  and 
resembles  an  oyster ;  and  its  surface  is  not  covered  with  the  substance 
analogous  to  cream.  M.  Magendie,1  too,  remarks,  that  the  proportion 
of  the  three  substances,  into  which  chyle  separates  when  left  at  rest ; — 
namely,  the  fatty  substance  on  the  surface,  the  clot,  and  the  serum, 
varies  greatly  according  to  the  nature  of  the  food ; — that  the  chyle, 
proceeding  from  sugar,  for  example,  has  very  little  fibrin ;  whilst  that 
from  flesh  has  more ;  and  that  the  fatty  matter  is  extremely  abundant 
when  the  food  contains  fat  or  oil ;  whilst  scarcely  any  is  found  if  the 
food  contains  no  oleaginous  matter.  Lastly: — the  attention  of  Dr. 
Prout2  has  been  directed  to  the  same  comparison.  He  found,  on  the 
whole,  less  difference  between  the  two  kinds  of  chyle  than  had  been 
noticed  by  Dr.  Marcet.  In  his  experiments,  the  serum  of  chyle  was  ren- 
dered turbid  by  heat,  and  a  few  flakes  of  albumen  were  deposited ;  but, 
when  boiled,  after  admixture  with  acetic  acid,  a  copious  precipitation 
ensued.  To  this  substance,  which  thus  differs  slightly  from  albumen, 
Dr.  Prout  gave  the  inexpressive  name  of  incipient  albumen.  The  fol- 
lowing is  a  comparative  analysis,  by  him,  of  the  chyle  of  two  dogs,  one 
of  which  was  fed  on  animal,  and  the  other  on  vegetable  substances. 
The  quantity  of  pure  albumen,  it  will  be  observed,  was  much  less  in 
the  latter  case. 

Vegetable  Food.    Animal  Food. 

Water 93-6  89-2 

Fibrin 0-6  0-8 

Incipient  albumen             4-6  4'7 

Albumen,  with  a  red  colouring  matter      .         .         .             O4  4-6 

Sugar  of  milk a  trace. 

Oily  matter a  trace.  a  trace. 

Saline  matters 0-8  0-7 

100-0  100-0 

The  difference  between  the  chyle  from  food  of  such  opposite  cha- 
racter, as  indicated  by  these  experiments,  is  insignificant,  and  indicative 
of  the  great  uniformity  in  the  action  of  the  agents  of  absorption. 
Researches  by  Messrs.  Macaire  and  Marcet,3  tend,  indeed,  to  establish 
the  fact,  that  both  the  chyle  and  the  blood  of  herbivorous  and  carnivo- 
rous quadrupeds  are  identical  in  their  composition,  in  as  far,  at  least, 
as  regards  their  ultimate  analysis.  They  found  the  same  proportion  of 
nitrogen  in  it,  whatever  kind  of  food  the  animal  consumed  habitually ; 
and  this  was  the  case  with  the  blood,  whether  of  the  carnivora  or  herb- 
ivora ;  but  it  contained  more  nitrogen  than  the  chyle.  These  results 
are  not  so  singular,  now  that  we  know  that  the  animal  and  vegetable 
compounds  of  protein  are  almost  identical  in  composition.  (See  page 
545.) 

All  the  investigations  into  the  nature  of  the  chyle  exhibit  the  inac- 
curacy of  the  view  of  Roose,4  that  chyle  and  milk  are  identical. 

1  Op.citat.,  p.  174. 

.  2  Annals  of  Philosophy,  xiii.  22,  and  Bridge-water  Treatise,  Amer.  edit.,  p.  272,  Philad., 
1834. 

3  Memoir,  de  la  Societe  de  Physique  et  de  1'Histoire  Naturelle  de  Geneve,  v.  389. 

*  Weber's  Hildebrandt's  Handbuch  der  Anatomic,  i.  102,  Braunschweig,  1830. 


CHYLOSIS.  647 

With  regard  to  the  precise  quantity  of  chyle,  formed  after  a  meal, 
•we  know  nothing  definite.  When  digestion  is  not  going  on,  there  can 
of  course  be  none  formed  except  from  the  digestion  of  the  secretions  of 
the  digestive  tube  itself;  and,  after  an  abstinence  of  twenty-four  hours, 
the  contents  of  the  thoracic  duct  are  chiefly  lymph.  During  digestion, 
the  quantity  of  chyle  formed  will  bear  some  relation  to  the  amount  of 
food  taken,  the  nutritive  qualities  of  the  food,  and  the  digestive  powers 
of  the  individual.  M.  Magendie,1  from  an  experiment  made  on  a 
dog,  estimated,  that  at  least  half  an  ounce  was  conveyed  into  the  mass 
of  blood,  in  that  animal,  in  five  minutes :  and  the  flow  was  kept  up,  but 
much  more  slowly,  as  long  as  the  formation  of  chyle  continued.  In 
experiments  on  a  cat,  Professor  F.  Bidder2  found  the  amount  that  passed 
through  the  thoracic  duct  in  the  twenty-four  hours,  to  be  in  proportion 
to  the  weight  of  the  body  as  1  to  5-34;  or  about  that  which — as  else- 
where shown — the  mass  of  blood  has  been  generally  conceived  to  bear 
to  the  weight  of  the  body.  In  dogs,  the  proportion  was  as  1  to  6*66. 
It  is  difficult,  however,  to  establish  an  average  amount  where  so  many 
elements  have  to  enter  into  the  calculation  and  so  much  variation  must 
occur,  according  to  the  greater  or  less  amount  of  aliment  taken  and 
numerous  other  circumstances;3  but  that  so  large  a  quantity  passes  as 
is  stated  by  these  observers,  almost  exceeds  belief. 

3.    PHYSIOLOGY   OF   CHYLOSIS. 

The  facts  referred  to, — regarding  the  anatomical  arrangement  of  the 
chyliferous  radicles  and  mesenteric  glands, — will  sufficiently  account 
for  the  obscurity  of  our  views  on  many  points  of  chylosis.  The  diffi- 
culty in  detecting  the  extremities  of  the  chyliferous  radicles  has  been 
the  source  of  different  hypotheses ;  and,  according  as  the  view  of  open 
mouths  or  of  spongy  gelatinous  tissue  has  been  embraced,  the  chyle  has 
been  supposed  to  enter  immediately  into  the  vessels,  or  to  be  received 
through  the  medium  of  this  tissue ;  or,  again,  to  pass  through  the 
parietes  of  the  vessels  by  imbibition.  Let  it  be  borne  in  mind,  how- 
ever, that  the  action  of  absorption  is  seen  only  by  the  "mind's  eye;" 
and  that  chyle  does  not  seem  to  exist  any  where  but  in  the  chyliferous 
vessels.  In  the  small  intestine,  we  see  a  chymous  mass,  possessing  all 
the  properties  we  have  described,  but  containing  nothing  resembling 
true  chyle;  whilst,  in  the  smallest  lacteal  that  can  be  detected,  it 
always  possesses  the  same  essential  properties.  Between  this  impercep- 
tible portion  of  the  vessel,  then,  and  its  commencement, — including  the 
latter, — the  elaboration  must  have  been  effected.  MM.  Leuret  and 
Lassaigne,4  indeed,  affirm,  that  they  have  detected  chyle  in  the  chymous 
mass  within  the  intestine,  by  the  aid  of  the  microscope.  They  state, 
that  globules  appeared  in  it  similar  to  those  that  are  contained  in  chyle, 
and  that  their  dissemination  amongst  so  many  foreign  matters  alone 
prevents  their  union  in  perceptible  fibrils.  These  globules  they  regard 

1  Op.  citat.,  ii.  183. 

2  Muller's  Archiv.  fur  Anat.,  s.  46,  Berlin,  1845. 

3  Prof.  Th.  L.  W.  Bischoff,  Muller's  Archiv.,  s.  125,  Berlin,  1846. 

*  Recherches  Physiologiques  et  Chimiques,  pour  servir  a  1'Histoire  de  la  Digestion,  p.  60, 
Paris,  1825. 


648  ABSORPTION. 

as  true  chyle, — for  the  reason,  that  they  observed  similar  globules  in 
artificial  digestions;  and,  on  the  other  hand,  never  detected  them  in  the 
digestive  secretions.  In  their  view,  consequently,  chyliferous  absorption 
is  confined  to  the  separation  of  chyle,  ready  formed  in  the  intestine, 
from  the  excrementitious  matters  united  with  it.  But  we  must  have 
stronger  evidence  to  set  aside  the  overwhelming  testimony  in  favour  of 
an  action  of  selection  and  elaboration  by  the  absorbents  of  all  organ- 
ized bodies — vegetable  as  well  as  animal.  The  nutriment  of  the  vege- 
table may  exist  in  the  soil  and  the  air  around  it;  but  it  is  subjected  to 
a  vital  agency  the  moment  it  is  laid  hold  of,  and  is  decomposed  to  be 
again  combined  to  form  sap.  A  like  action  is  doubtless  exerted  by  the 
chyliferous  radicles;1  and  hence  all  the  modes  of  explaining  this  part 
of  the  function,  under  the  supposition  of  their  being  passive,  mechanical 
tubes,  are  inadequate.  Boerhaave2  affirmed,  that  the  peristaltic  motion 
of  the  intestines  has  a  considerable  influence  in  forcing  chyle  into 
the  mouths  of  the  chyliferous  vessels;  whilst  Dr.  Young3  is  disposed  to 
ascribe  the  whole  effect  to  capillary  attraction;  and  he  cites  the  lachry- 
mal duct  as  an  analogous  case,  the  contents  of  which,  he  conceives, — 
and  we  think  with  propriety, — are  entirely  propelled  in  this  manner. 

The  objections  to  these  views,  as  regards  the  chyliferous  vessels,  are 
sufficiently  obvious.  The  chyle  must,  according  to  them,  exist  in  the 
intestines ;  and,  if  that  of  Boerhaave  were  correct,  we  ought  to  be  able 
to  obtain  it  from  the  chyme  by  pressure.  As  the  chyle  is  not  present, 
ready  formed,  in  the  intestine,  the  explanations  by  imbibition  and  by 
capillary  attraction  are  equally  inadmissible.  There  is  no  analogy 
between  the  cases  of  the  lachrymal  duct  and  the  chyliferous  vessels ; 
even  if  it  were  admitted,  that  the  latter  have  open  mouths,  which  is 
not  the  case.  In  another  part  of  this  work,  it  was  affirmed,  that 
the  passage  of  the  tears  through  the  puncta  lachrymalia,  and  along 
the  lachrymal  ducts,  is  one  of  the  few  cases  in  which  capillary  attrac- 
tion can  be  invoked,  with  propriety,  for  the  explanation  of  functions 
executed  by  the  human  frame.  In  that  case  there  is  no  conversion 
of  the  fluid.  It  is  the  same  on  the  conjunctiva  as  in  the  duct;  but, 
in  the  case  of  the  chyliferous  vessels,  a  new  fluid  is  formed:  there 
must,  therefore,  have  been  an  action  of  selection  exerted;  and  this 
very  action  would  be  the  means  of  the  entrance  of  the  new  fluid  into 
the  mouths  of  the  lacteals.  If,  therefore,  we  admit,  in  any  form,  the 
doctrine  of  capillary  tubes,  it  can  only  be,  when  taken  in  conjunction 
with  that  of  the  elaborating  agency.  "  As  far  as  we  are  able  to  judge," 
says  Dr.  Bostock,4  "when  particles,  possessed  of  the  same  physical 
properties,  are  presented  to  their  mouths  (the  lacteals),  some  are  taken 
up,  while  others  are  rejected ;  and  if  this  be  the  case,  we  must  con- 
ceive, in  the  first  place,  that  a  specific  attraction  exists  between  the 
vessel  and  the  particles,  and  that  a  certain  vital  action  must,  at  the 
same  time,  be  exercised  by  the  vessel  connected  with,  or  depending 

1  F.  Arnold,  Lehrbuch  der  Physiologie  des  Menschen,  Zurich,  1836-7  j  noticed  in  Brit.and 
For.  Med.  Review,  Oct.,  1839,  p.  479. 

2  Prelect.  Academ.  in  Prop.  Instit.  Rei  Med.,  §  103. 

3  Medical  Literature,  p.  42,  Lond.,  1813. 
<  Physiology,  edit,  cit.,  622,  Lond.,  1836. 


CHYLOSIS.  649 

upon,  its  contractile  power,  which  may  enable  the  particles  to  be 
received  within  the  vessel,  after  they  have  been  directed  towards  it. 
This  contractile  power  may  be  presumed  to  consist  in  an  alternation  of 
contraction  and  relaxation,  such  as  is  supposed  to  belong  to  all  vessels 
that  are  intended  for  the  propulsion  of  fluids,  and  which  the  absorbents 
would  seem  to  possess  in  an  eminent  degree."  This  is  specious;  but  it 
would  be  not  the  less  hypothetical  if  the  chyliferous  vessels  had  open 
mouths,  and  we  have  seen  they  have  not. 

By  other  physiologists,  absorption  is  presumed  to  be  effected  by 
virtue  of  the  peculiar  sensibility  or  insensible  organic  contractility  or 
irritability  of  the  mouths  [?]  of  the  absorbents ;  but  these  terms,  as  M. 
Magendie1  has  remarked,  are  the  mere  expression  of  our  ignorance, 
regarding  the  nature  of  the  phenomenon.  The  separation  of  the 
chyle  is,  doubtless,  a  chemical  process;  seeing  that  there  must  be  both 
an  action  of  decomposition  and  recomposition ;  but  it  is  not  regulated 
solely  by  the  same  laws  as  those  that  govern  inorganic  chemistry. 

Professor  Goodsir,2  with  almost  all  modern  physiologists,  has  referred 
the  function  to  the  agency  of  cells.  Having  fed  a  dog  with  oatmeal, 
butter,  and  milk,  he  examined  the  intestinal  villi  three  hours  after- 
wards; when  the  chyliferous  vessels  were  turgid  with  chyle,  and  the 
intestine  was  full  of  milky  chyme  mingled  with  a  bilious-looking  fluid. 
In  the  white  portion  of  the  fluid,  which  was  situate  principally  towards 
the  mucous  membrane,  numerous  epithelium  cells  were  found ;  some 
of  which  had  evidently — from  their  form — been  detached  from  the 
surface  of  the  villi ;  whilst  others  have  been  thrown  off  from  the  inte- 
rior of  the  follicles  of  Lieberkuhn.  The  villi  were  turgid,  and  destitute 
of  epithelium  except  at  their  bases.  Each  villus  was  covered  by  a 
very  fine,  smooth  membrane,  continuous  with  what  Mr.  Bowman  terms 
the  "basement  membrane"  of  the  mucous  surface,  which  is  reflected 
into  the  follicles.  The  villi  were  semitransparent  except  at  their  free 
or  bulbous  extremities,  where  they  were  white  and  nearly  opaque. 
The  summit  of  each  villus  was  crowded  beneath  the  enveloping  mem- 
brane with  a  number  of  perfectly  spherical  vesicles,  varying  in  size 
from  j^o  <5tn  to  2^0 otn  °f  an  inc^  >  tn^  matter  in  the  interior  of  which 
had  an  opalescent  milky  appearance.  At  the  part  where  the  vesicles 
approached  the  granular  texture  of  the  substance  of  the  villus,  minute 
granular  or  oily  particles  were  situate  in  great  numbers.  The  trunks 
of  two  lacteals  could  be  easily  traced  up  the  centre  of  each  villus;  and 
as  they  approached  the  vesicular  mass,  they  subdivided  and  looped; 
but  in  no  instance  could  they  be  seen  to  communicate  directly  with 
any  of  the  vesicles.  These  vesicles,  in  Mr.  Goodsir's  opinion,  can 
scarcely  be  considered  in  any  other  light  than  cells,  whose  lives  have 
but  a  very  brief  duration,  which  select  from,  and  appropriate  the  ma- 
terials in  contact  with  the  surface  of  the  villi  into  their  own  substance, 
and  then  liberate  them,  by  solution  or  disruption  of  the  cell-wall,  in  a 
situation  where  they  can  be  absorbed  by  the  lacteals.  When  the  in- 
testine contains  no  more  chyme,  the  developement  of  new  vesicles 

1  Precis,  &c.,  ii.  179. 

2  Edinb.  New  Philosophical  Journal,  July,  1842;  and  Anatomical  and  Pathological  Ob- 
servations,  p.  4,  Edinb.,  1845. 


650  ABSORPTION. 

ceases;  the  lacteals  empty  themselves,  and  the  villi  become  flaccid. 
During  the  interval  of  repose,  the  epithelium  is  renewed  for  the  protec- 
tion of  the  surface  of  the  villi,  and  for  the  secretion  function  of  the 
follicles  of  Lieberkuhn.  It  is  considered  by  Mr.  Goodsir,  that  the 
epithelium  cells  have  their  origin  in  certain  nuclei,  which  he  has  de- 
tected scattered  through  the  basement  membrane. 

These  views  were  embraced  by  Dr.  Carpenter;  but  they  are  by  no 
means  established.  It  is  denied,  indeed,  by  Reichert,1  from  his  own  and 
Bidder's  observations,  that  the  epithelium  is  ever  so  shed  from  the  diges- 
tive canal,  in  or  after  any  act  of  digestion,  as  to  leave  any  portion  of 
the  subjacent  mucous  membrane  uncovered  or  raw ;  and  Prof.  E.  H. 
Weber2  distinctly  observed  the  chyliferous  vessels  filled  with  chyle, 
although  the  mucous  membrane  was  covered  with  epithelium.  The 
materials  of  the  chyle,  therefore,  to  enter  the  vessels  must  have  passed 
through  the  epithelium.  During  absorption,  he  noticed  the  prismatic 
cells  of  the  cylinder  epithelium  experiencing  change  of  form  and  colour, 
and  in  rabbits  and  frogs  becoming  tumid,  and  containing  chyle  cor- 
puscles. In  man,  beneath  the  epithelium  is  a  second  layer  of  cells, 
which  are  neither  conical,  cylindrical,  nor  prismatic,  but  round;  many 
of  which  are  filled  with  an  opaque  white ;  and  others  with  a  transparent, 
oleaginous  fluid;  so  that  different  cells  appeared  to  absorb  different 
fluids. 

It  has  already  been  said,  that  chyle  always  possesses  the  same 
essential  properties;  that  it  may  vary  slightly  according  to  the  food, 
and  the  digestive  powers  of  the  individual;  but  rarely  if  ever  contains 
any  adventitious  substance, — the  function  of  the  chyliferous  vessels 
being  restricted  to  the  formation  of  chyle.  The  facts  and  arguments, 
in  favour  of  this  view  of  the  subject,  will  be  given  hereafter. 

The  course  of  the  chyle  is,  as  we  have  described,  along  the  chylife- 
rous vessels,  and  through  the  mesenteric  glands  into  the  receptaculum. 
chyli  or  commencement  of  the  thoracic  duct ;  along  which  it  passes  into 
the  subclavian  vein.  The  chief  causes  of  its  progression  are, — first  of 
all,  the  inappreciable  action,  by  which  the  chyliferous  vessels  form  and 
receive  the  chyle  into  them.  This  formation  being  continuous,  the 
fresh  portions  must  propel  those  already  in  the  vessels  towards  the 
mesenteric  glands,  in  the  same  way  as  the  ascent  of  sap  in  plants, 
during  the  spring,  appears  to  depend  on  the  constant  absorbing  action 
of  the  roots.3  It  is  probable,  too,  that  the  vessels  themselves  are  con- 
tractile:4 such  is  the  opinion  of  Messrs.  Sheldon,5  Schneider,  Cruik- 
shank,6  and  J.  Miiller.  M.  Mandl7  affirms,  that  it  can  no  longer  be 
doubted;  and  that  the  irritability  continues  even  for  several  hours  after 
death.  M.  Mojon8  considers,  that  when  the  longitudinal  fibres,  which 
he  has  observed  in  the  lymphatics,  contract,  they  draw  one  sphincter 
nearer  to  another,  whilst  the  oblique  fibres  diminish  the  diameter.  All 

•  Muller's  Archiv.,  1844.  2  Ibid.,  s.  401,  Berlin,  1847. 

3  Breschet,  Le  Systeme  Lymphatique,  Paris,  1836. 

4  Miiller's  Handbuch,  u.  s.  w.,  and  Baly's  translation,  i.  284,  Lond.,  1838. 

5  History  of  the  Absorbent  System,  p.  28,  Lond.,  1784.  6  Op.  citat.,  c.  12. 
7  Manuel  d'Anatomie  generate,  p.  211,  Paris,  1843. 

*  Journ.  de  la  Societe  des  Sciences  Physiques,  etc.,  Nov.,  1 833. 


CHYLOSIS.  651 

these  fibres,  taking  their  point  d'appui  in  the  circular  fibres,  dilate  the 
superior  sphincters  by  drawing  the  circumference  downwards.  By  this 
method,  the  fluid  that  enters  a  lymphatic  irritates  the  vessel,  which 
contracts  upon  itself,  diminishes  its  cavity,  and  sends  on  the  fluid 
through  the  open  sphincter.  A  kind  of  peristaltic  action,  he  conceives, 
— and  in  this  view  he  is  confirmed  by  MM.  Lacauchie,1  Gruby,  and 
Delafond,2 — exists  in  the  lymphatics  similar  to  that  of  the  intestines, 
which  may  be  observed  very  distinctly,  he  says,  in  the  lacteal  vessels 
of  the  mesentery  of  animals,  if  opened  two  or  three  hours  after  they 
have  been  well  fed. 

Moreover,  that  the  lacteals  and  lymphatics  are  possessed  of  a  power 
of  contraction  is  corroborated — it  is  argued — by  the  following  reasons. 
First.  They  are  small;  and  tonic  contractions  are  generally  admitted 
in  all  capillary  vessels.  Secondly.  The  ganglions  or  glands,  which  cut 
them  at  intervals,  would  destroy  the  impulse  given  by  the  first  action 
of  the  radicles;  and  hence  require  some  contraction  in  the  vessels  to 
transport  the  chyle  from  one  row  of  these  ganglions  to  another.  Thirdly. 
If  a  chyliferous  vessel  be  opened  in  a  living  animal,  the  chyle  spirts 
out,  which  could  not  be  eifected  simply  by  the  absorbent  action  of  the 
chyliferous  radicles;  and,  Fourthly r,  in  a  state  of  abstinence,  these  ves- 
sels are  found  empty;  proving,  that  notwithstanding  there  has  been  an 
interruption  to  the  action  of  chylous  absorption,  the  whole  of  the  chyle 
has  been  propelled  into  the  receptaculum  chyli.  It  is  obvious,  however, 
that  most  of  these  reasons  would  apply  as  well  to  the  elasticity  as  to 
the  muscularity  of  the  outer  coat  of  these  vessels.3  A  more  forcible 
argument  is  derived  from  an  experiment  by  Lauth.4  He  killed  a  dog 
towards  the  termination  of  digestion;  and  immediately  opened  its  abdo- 
men, when  he  found  the  intestines  marbled,  and  the  chyliferous  vessels 
filled  with  chyle.  Under  the  stimulation  of  the  air,  the  vessels  began 
to  contract,  and,  in  a  few  minutes,  were  no  longer  perceptible.  The 
result  he  found  to  be  the  same,  whenever  the  dissection  was  made  within 
twenty-four  hours  after  death ;  but,  at  the  end  of  this  time,  the  irrita- 
bility of  the  vessels  was  extinct;  and  they  remained  distended  with 
chyle,  notwithstanding  the  admission  of  air.  These  experiments  lead 
to  a  deduction,  in  the  absence  of  less  direct  proof,  scarcely  doubtful; — 
that  the  chyliferous  vessels  possess  a  contractile  action,  by  the  aid  of 
which  the  chyle  is  propelled  along  the  vessels.  In  addition  to  these 
propelling  causes,  the  pulsation  of  the  arteries  in  the  neighbourhood  of 
the  vessels,  and  the  pressure  of  the  abdominal  muscles  in  respiration 
have  been  invoked.  The  former  has  probably  less  effect  than  the  latter. 
It  is  not,  indeed,  easy  to  see  how  it  can  be  possessed  of  any.  Of  the 
agency  of  the  latter  we  have  experimental  evidence.  If  the  thoracic 
duct  be  exposed  in  the  neck  of  a  living  animal,  and  the  course  of  the 
chyle  be  observed,  it  will  be  found  accelerated  at  the  time  of  inspira- 
tion, when  the  depressed  diaphragm  forces  down  the  viscera,  or  when 
the  abdomen  of  the  animal  is  compressed  by  the  hands.  We  shall  find, 
too,  hereafter,  that  the  mode  in  which  the  thoracic  duct  opens  into  the 

1  Comptes  Rendus,  15  Mai,  1843.  2  Ibid.,  5  Juin,  1843. 

3  Adelon,  Physiologie,  etc.,  iii.  31.  4  Essai  sur  les  Vaisseaux  Lymphat.,  Strasb.,  1824. 


652  ABSORPTION. 

subclavian  exerts  considerable  effect  on  the  progress  of  the  chyle.  We 
have  reason  to  believe  that  its  course  is  slow.  It  has  been  already 
stated,  that  in  an  experiment  on  a  dog,  which  had  eaten  animal  food  at 
discretion,  M.  Magendie1  found  half  an  ounce  of  chyle  discharged  from 
an  opening  in  the  thoracic  duct  in  five  minutes.  Still,  as  he  judiciously 
remarks,  the  velocity  will  be  partly  dependent  upon  the  quantity  of 
chyle  formed.  If  much  enters  the  thoracic  duct,  it  will  probably  pro- 
ceed faster  than  under  opposite  circumstances.  In  the  commencement 
of  the  thoracic  duct  it  becomes  mixed  with  lymph;  and  under  the  head 
of  lymphatic  absorption  we  shall  show  how  they  proceed  together  into 
the  subclavian,  and  the  effect  produced  by  the  circumstances  under 
which  the  thoracic  duct  opens  into  that  venous  trunk. 

It  has  been  a  subject  of  inquiry,  whether  chyle  varies  materially  in 
different  parts  of  its  course ;  and  what  is  the  precise  modification, 
impressed  upon  it  by  the  action  of  the  mesenteric  glands.  The  experi- 
ments of  Reuss,  Emmert,3  and  others,  seem  to  show,  that  when  taken 
from  the  intestinal  side  of  the  glands  it  is  of  a  yellowish- white  colour; 
does  not  become  red  on  exposure  to  the  air,  and  coagulates  but  imper- 
fectly, depositing  only  a  small,  yellowish  pellicle.  It  is  said,  indeed, 
that  chyle,  drawn  from  the  chyliferous  vessels,  which  traverse  the  intes- 
tinal walls,  contains  albumen  in  a  state  of  solution,  but  no  fibrin,  and 
abounds  in  oleaginous  matter ;  whilst  that  from  the  other  side  of  the 
glands,  and  near  the  thoracic  duct,  is  of  a  reddish  hue  :  contains  chyle 
globules,  coagulates  entirely,  and  separates  into  a  clot  and  serum.  M. 
Vauquelin,3  too,  affirms,  that  it  acquires  a  rosy  tint  as  it  advances  in 
the  apparatus  ;  and  that  the  fibrin  becomes  gradually  more  abundant. 
These  circumstances  have  given  rise  to  the  belief,  that  as  it  proceeds 
it  becomes  more  and  more  animalized,  or  transformed  into  the  nature 
of  the  being.  This  effect  has  generally  been  ascribed  to  the  mesenteric 
glands ;  and  it  has  been  presumed  by  some  to  be  produced  by  the  exha- 
lation of  a  fluid  into  their  cells  from  the  numerous  bloodvessels  with 
which  they  are  furnished.  Others,  again,  consider,  that  the  veins  of 
the  glands  remove  from  the  chyle  every  thing  that  is  noxious  ;  or  purify 
it.  From  the  circumstance,  that  the  rosy  colour  is  more  marked  on 
the  thoracic,  than  on  the  intestinal  side  of  the  glands  ;  that  the  fluid 
is  richer  in  fibrin  after  having  passed  through  those  glands ;  and  that 
the  rosy  colour  and  fibrin  are  less  when  the  animal  has  taken  a  large 
proportion  of  food,  MM.  Tiedemann  and  Gmelin4  infer,  that  it  is  to  the 
action  of  the  glands,  that  the  chyle  owes  those  important  changes  in  its 
nature; — the  fluid,  in  its  passage  through  them,  obtaining,  from  the 
blood  circulating  in  them,  new  elements,  which  animalize  it. 

There  is  much  probability  in  the  view,  that  some  nitrogenized  mate- 
rial is  secreted  from  the  lining  membrane  of  the  chyliferous  vessels,  in 
the  mesenteric  glands  especially,  through  the  agency  of  the  nucleated 
cells  described  by  Professor  Goodsir,  which  may  be  a  great  agent  in 
the  changes  effected  on  the  chyle  in  its  course.  At  the  same  time — as 

1  Precis,  &c.,  ii.  183. 

2  Reil's  Archiv.,  viii.  s.  2;  and  Annales  de  Chimie,  Ixxx.  81. 

3  Annales  de  Chimie,  Ixxxi.  113  ;  and  Annals  of  Philosophy,  ii.  220. 

4  Die  Verdauung  nach  Versuchen,  u.  s.  w.,or  Jourdau's  translat.,  Paris,  1827. 


CHYLOSIS.  653 

has  been  well  observed1 — an  important  source  of  fallacy  attends  all  deduc- 
tions founded  upon  the  differences  observed  in  the  chyle  in  the  several 
parts  of  its  course  through  the  lacteals, — which  is,  that  we  cannot  be  at 
all  sure  how  far  this  may  not  be  dependent  upon  an  actual  interchange 
of  ingredients  with  the  blood,  by  imbibition  through  the  very  thin 
parietes  of  the  contiguous  vessels.  The  whole  question,  as  Dr.  Carpen- 
ter properly  remarks,  offers  a  wide  scope  for  farther  inquiry. 

The  following  table,  slightly  modified  from  one  by  Gerber,2  exhibits 
concisely  the  relative  proportions  of  the  three  main  ingredients  of  the 
chyle — fat,  albumen,  and  fibrin — in  various  parts  of  the  absorbent  sys- 
tem ;  and  affords  some  idea  of  its  change  in  the  process  of  assimilation. 

f  Fat  in  maximum  quantity  (numerous  fat  or  oil  glob- 

I.  In  the  afferent  or  peripheral  lac-    I        ules). 

teals  (from  the  intestines  to  the  -\    Albumen  in  minimum  quantity  (few  or  no  chyle  cor- 
mesenteric  glands).  puscles}. 

^  Fibrin  almost  entirely  wanting. 

II.  In  the  efferent  or  central  lacteals   f  F*  in  medium  Tantity  (few^r  oil  globules) 
(from  the  mesenteric  glands  to  the  \    AUnunm  m  m"«num  quantity  (chyle  corpuscles  very 

,          •     ,       x  1        numerous,  but  imperfectly  developed), 

thoracic  duct).  ^   ^^  m  m'edium  g^J 

C  Fat  in  minimum  quantity  (fewer  or  no  oil  globules). 

Ill    In  the  thoracic  duct  j    Albumen  in  medium  quantity  (chyle  corpuscles  nume- 

1        rous  and  more  distinctly  cellular). 
^  Fibrin  in  maximum  quantity. 

In  another  place,  various  hypotheses,  that  have  been  indulged  re- 
garding the  functions  of  the  spleen,  will  be  noticed.  It  is  proper,  how- 
ever, to  refer,  here,  to  one  which  has  been  proposed  by  MM.  Tiede- 
mann  and  Gmelin.  They  consider  the  organ  a  dependent  ganglion  of 
the  absorbent  system,  which  prepares  a  fluid  destined  to  be  mixed  with 
the  chyle  to  effect  its  animalization ;  and  assert,  that  the  chyle  coagu- 
lates little  or  not  at  all  before  it  has  passed  through  the  mesenteric 
glands  ;  but,  after  this,  fibrin  begins  to  appear,  and  is  much  more  abund- 
ant after  the  addition  of  the  lymph  from  the  spleen,  which  contains  a 
large  quantity  of  fibrin.  Before  passing  the  mesenteric  glands,  the 
chyle  contains  no  red  particles ;  but  it  does  so  immediately  afterwards, 
and  more  particularly  after  it  is  mixed  with  the  lymph  from  the  spleen, 
which  abounds  with  them,  and  with  fibrin.  M.  Voisin,3  who,  as  we  have 
seen,  considers  that  the  chyliferous  vessels  ramify  in  the  substance  of 
the  liver,  is  of  opinion  that,  by  the  action  of  the  liver,  a  species  of  puri- 
fication is  produced  in  the  chyle,  by  which  the  latter  is  better  fitted  to 
mingle  with,  and  form  part  of,  the  blood ;  but  neither  his  anatomical 
nor  physiological  views  on  the  subject  have  met  with  much  countenance. 

Prior  to  the  discovery  of  the  chyliferous  vessels,  the  mesenteric  veins 
were  regarded  as  agents  of  chylous  absorption  ;  and  as  these  veins  ter- 
minate in  the  vena  portse,  which  is  distributed  to  the  liver,  this  last  was 
considered  the  first  organ  of  sanguification ;  and  to  impress  upon  the 
chyle  a  primary  elaboration.  In  this  view,  the  great  size  of  the  organ 
compared  with  the  small  quantity  of  bile  furnished  by  it,  and  the  excep- 
tion, which  the  mesenteric  veins  and  vena  portse  present  to  the  rest  of 

1  Carpenter,  Human  Physiology,  2d  Amer.  edit.,  p.  426,  Philad.,  1845. 

2  Ibid.,  p.  427. 

3  Nouvel  Aper£u  sur  la  Physiologic  du  Foie,  &c.,  Paris,  1833. 


654  ABSORPTION. 

the  venous  system, — as  well  as  the  large  size  of  the  liver  in  the  foetus, 
although  not  effecting  any  biliary  secretion,  and  the  fact  of  its  receiv- 
ing immediately  the  nutritive  fluid  from  the  placenta  were  accounted 
for.  The  idea  of  the  agency  of  the  mesenteric  veins  is  now  nearly 
exploded,  but  not  altogether  so.  There  are  yet  physiologists,  and  of 
no  little  eminence,  who  esteem  them  participators  in  the  functions  of 
chylosis  with  the  chyliferous  vessels  themselves. 

Some  of  the  arguments,  based  on  fallacious  data,  used  by  these  gen- 
tlemen, are: — First.  The  mesenteric  veins  form  as  much  an  integrant 
part  of  the  villi  of  the  intestine  as  the  chyliferous  vessels;  and  they 
have  also,  free  orifices  [?]  in  the  cavity  of  the  intestine.  Lieberkiihn,,1 
by  throwing  an  injection  into  the  vena  portae,  observed  the  fluid  ooze 
out  of  the  villi  of  the  intestine;  and  M.  Ribes2  obtained  the  same  result 
by  injecting  spirit  of  turpentine  coloured  black.  These  experiments — 
it  need  hardly  be  said — are  insufficient  to  establish  the  fact  of  open 
mouths.  Situate,  as  those  vessels  are,  in  an  extremely  loose  tissue, 
which  affords  them  but  little  support,  the  slightest  injecting  force  might 
be  expected  to  rupture  them.  Secondly.  Chyle  has  often  been  found 
in  the  mesenteric  veins.  Swammerdam  asserts,  that,  having  placed  a 
ligature  around  these  veins  in  a  living  animal,  whilst  digestion  was 
going  on,  he  saw  whitish,  chylous  striae  in  their  blood ;  and  Tiedemann 
and  Gmelin  affirm,  that  they  have  often,  in  their  experiments,  observed 
the  same  appearance.  If  the  fact  of  the  identity  of  these  striae  with 
chyle  were  well  established,  we  should  have  to  bend  to  the  weight  of 
evidence.  This  is  not,  however,  the  case.  No  other  reason  for  the 
belief  is  afforded  than  their  colour.  The  arguments  against  the  me- 
senteric veins  having  the  power  of  forming  chyle  we  think  irresistible. 
A  distinct  apparatus  exists,  which  scarcely  ever  contains  any  thing 
but  chyle;  and  consequently,  it  would  seem  unnecessary,  that  the 
mesenteric  veins  should  participate  in  the  function,  especially  as  the 
fluid  which  circulates  in  them  is  most  heterogeneous ;  and,  as  we  shall 
see,  a  compound  of  various  adventitious  and  other  absorptions.  Grant- 
ing, however,  that  these  striae  are  true  ehyle,  it  would  by  no  means  fol- 
low absolutely,  that  it  should  be  formed  by  the  mesenteric  veins.  A  com- 
munication may  exist  between  the  chyliferous  vessels  and  these  veins. 
Wallaeus3  asserts,  that  having  placed  a  ligature  on  the  lymphatic  trunks 
of  the  intestine,  chyle  passed  into  the  vena  portae.  Rosen,  Meckel,4 
and  Lobstein  affirm,  that  by  the  use  of  injections  they  detected  this 
inosculation.  Lippi5  states,  that  the  chyliferous  vessels  have  numerous 
anastomoses  with  the  veins,  not  only  in  their  course  along  the  mesentery 
before  they  enter  the  mesenteric  glands,  but  also  in  the  glands  them- 
selves. Tiedemann  and  Gmelin  concur  in  the  existence  of  this  last 
anastomosis,  and  MM.  Leuret  and  Lassaigne  found  that  a  ligature  ap- 
plied round  the  vena  portae  occasioned  the  reflux  of  blood  into  the  tho- 

1  Dissert,  de  Fabric.  Villor.  Intestin.,  Lugd.  Bat,  1745. 

2  Memoir,  de  la  Societe  Medicale  d'Emulation,  viii.  621. 

a  Medica  Omnia,  &c.,  ad  Chyli  et  Sanguinis  Circul.,  Lond.,  1660. 

4  Diss.  Epist.  ad  Haller.  de  Vasis  Lymph.,  &c.,  Berol.,  1757 ;  Nov.  Exper.  de  Finibus  Ve- 
namm  et  Vaa.  Lymph.,  Berol.,  1772 ;  and  Manuel  d'Anatomie,  &c.,  French  edit.,  by  Jourdan, 
i.  179. 

5  Illustrazioni  Fisiologiche  e  Patologiche  del  Sistema  Linfatico-Chilifero,  Firenze,  1825. 


CHYLOSIS.  655 

racic  duct.  Professors  Meckel,  E.  H.  Weber,  Rudolphi,  and  J.  Miiller 
doubt,  however,  the  existence  of  an  actual  open  communication  between 
the  lymphatics  and  minute  veins  in  the  glands.  Meckel  states,  as  a 
reason  for  his  questioning  this,  that  when  the  seminal  duct  of  the  epi- 
didymis  of  the  dog  is  injected,  the  veins  also  are  filled;  and  Miiller1 
observes,  that  when  glands  are  injected  from  their  excretory  duct,  the 
small  veins  of  the  gland  also  frequently  become  filled  with  mercury; 
and  the  cases  in  which  this  occurred  to  him  were  always  those  in  which 
the  ducts  had  not  been  well  filled, — their  acini  not  distended.  Thirdly. 
That  the  ligature  of  the  thoracic  duct  has  not  always  induced  death, 
or  has  not  induced  it  speedily;  and,  consequently,  the  thoracic  duct  is 
not  the  only  route  by  which  the  chyle  can  pass  to  be  inservient  to  nu- 
trition. In  an  experiment  of  this  kind  by  M.  Duverney,  the  dog  did 
not  die  for  fifteen  days.  M.  Flandrin  repeated  it  on  twelve  horses, 
which  appeared  to  eat  as  usual,  and  to  maintain  their  flesh.  On  killing 
and  opening  them  a  fortnight  afterwards,  he  satisfied  himself  that  the 
thoracic  duct  was  not  double.  Sir  Astley  Cooper  performed  the  expe- 
riment on  several  dogs:  the  majority  lived  longer  than  a  fortnight,  and 
none  died  in  the  first  two  days;  although,  on  dissection,  the  duct  was 
found  ruptured,  and  chyle  effused  into  the  abdomen.  The  experiments 
of  M.  Dupuytren  have  satisfactorily  accounted  for  these  different  re- 
sults. He  tied  the  thoracic  duct  in  several  horses.  Some  died  in  five 
or  six  days,  whilst  others  continued  apparently  in  perfect  health.  In 
those  that  died  in  consequence  of  the  ligature,  it  was  impossible  to 
throw  any  injection  from  the  lower  part  of  the  duct  into  the  subclavian. 
It  was,  therefore,  presumable,  that  the  chyle  had  ceased  to  be  poured 
into  the  blood,  immediately  after  the  duct  was  tied.  On  the  other 
hand,  in  those  that  remained  apparently  unaffected,  it  was  always  easy 
to  send  mercurial  or  other  injections  from  the  abdominal  portion  of  the 
duct  into  the  subclavian.  The  injections  followed  the  duct  until  near 
the  ligature,  when  they  turned  off,  and  entered  large  lymphatic  vessels, 
•which  opened  into  the  subclavian ;  so  that,  in  these  cases,  the  ligature 
of  the  thoracic  duct  did  not  prevent  the  chyle  from  passing  into  the 
venous  system ;  and  thus  we  can  understand  why  the  animals  should 
not  have  perished.2 

From  every  consideration,  then,  it  appears  that  the  chyliferous  ves- 
sels are  the  sole  organs  concerned  in  chylosis;  and  we  shall  see  pre- 
sently, that  they  refuse  the  admission  of  other  substances,  which  must, 
consequently,  reach  the  circulation  through  a  different  channel. 

The  views  of  MM.  Bouchardat  and  Sandras — who  believe,  that  the 
absorption  of  the  nutritive  portion  of  most  aliments  takes  place  in  the 
stomach, — fatty  matters  only  being  absorbed  by  these  vessels,  and  that 
they  moreover  absorb  a  fluid  of  an  alkaline  character  designed  to  neu- 
tralize the  acidity  developed  in  the  stomach  during  digestion,  as  well  as 
those  of  Matteucci  and  Bertrand  in  regard  to  the  absorption  of  the 
same  substances,  have  been  given  already. 

1  Handbuch,  u.  s.  w.;  and  Baly's  translation,  p.  273,  Lond.,  1838. 

2  Richerand's  Elemens  de  Physiologic,  edit,  cit.,  p.  90. 


656  ABSORPTION. 

b.  Absorption  of  Drinks. 

It  has  been  stated,  that  a  wide  distinction  exists  between  the  gastric 
and  intestinal  operations  that  are  necessary  in  the  case  of  solid  and 
liquid  food.  Whilst  the  former  is  converted  into  chyme  and  passes  into 
the  small  intestine,  to  have  its  chylous  part  separated  from  it;  the  latter 
is  usually  absorbed  from  the  stomach  or  small  intestine. 

The  chyliferous  vessels,  we  have  seen,  are  agents  and  exclusive  agents 
of  the  absorption  of  chyle — the  nutritive  product  from  the  digestion  of 
solids.  What,  then,  are  the  agents  of  the  absorption  of  liquids  ?  There 
are  but  two  sets  of  vessels  on  which  we  can  rest  for  a  moment.  These 
are  the  lacteals  or  lymphatics  of  the  digestive  tube;  and  the  veins  of 
the  same  canal.  But,  it  has  been  seen,  the  chyliferous  vessels  refuse 
the  admission  of  everything  but  chyle.  It  would  necessarily  follow, 
then,  that  the  absorption  of  liquids  must  be  a  function  of  the  veins. 
Such  is  the  conclusion  of  most  physiologists,  and  on  inferences  that  are 
logical.  The  view  is  not,  however,  universally  admitted;  some  assign- 
ing the  function  exclusively  to  the  lacteals;  others  sharing  it  between 
them  and  the  veins.  Let  us  inquire  into  the  facts  and  arguments  ad- 
duced in  support  of  these  different  opinions.  The  advocates  for  the 
exclusive  agency  of  the  chyliferous  vessels  affirm,  First,  That  whatever 
is  the  vascular  system,  that  effects  the  absorption  of  drinks,  it  must  com- 
municate freely  with  the  cavity  of  the  intestine;  and  that  the  chyliferous 
vessels  do  this.  Secondly,  That  this  system  of  vessels  is  the  agent  of 
chylous  absorption: — a  presumption,  that  it  is  likewise  the  agent  of  the 
absorption  of  drinks.  Thirdly,  That  every  physiologist,  who  has  ex- 
amined the  chyle,  has  described  its  consistence  to  be  in  an  inverse  ratio 
with  the  quantity  of  drink  taken;  and,  lastly,  that  when  coloured  and 
odorous  substances  have  passed  into  the  intestine,  they  have  been  found 
in  the  chyliferous  vessels  and  not  in  the  mesenteric  veins.  The  experi- 
ments, adduced  in  favour  of  this  last  position  are,  however,  so  few  and 
inadequate,  that  it  is  surprising  they  could  have,  for  a  time,  so  com- 
pletely overturned  the  old  theory.  This  effect  was  greatly  aided  by  the 
zeal  and  ability  of  the  Hunters,  and  of  the  Windmill  Street  School  in 
general,  who  were  the  great  improvers  of  our  knowledge  regarding  the 
anatomy  of  the  lymphatic  system.  John  Hunter,1 — who  was  one  of  the 
first  that  positively  denied  absorption  by  the  veins,  and  maintained  that  of 
the  lymphatics, — instituted  the  following  ingenious  and  imposing  experi- 
ment. He  opened  the  abdomen  of  a  living  dog;  laid  hold  of  a  portion 
of  intestine,  and  pressed  out  the  matters  it  contained  with  his  hand. 
He  then  injected  warm  milk  into  it,  which  he  retained  by  means  of  liga- 
tures. The  veins,  belonging  to  the  portion  of  intestine,  were  emptied 
of  their  blood  by  puncturing  their  trunks;  and  were  prevented  from 
receiving  fresh  blood,  by  the  application  of  ligatures  to  the  correspond- 
ing arteries.  The  intestine  was  returned  into  the  cavity  of  the  abdo- 
men ;  and,  in  the  course  of  half  an  hour,  was  again  withdrawn  and 
scrupulously  examined;  the  veins  were  still  found  empty,  whilst  the 

1  Observations  on  certain  parts  of  the  Animal  Economy,  by  John  Hunter,  F.  R.  S.,  with 
notes  by  Richard  Owen,  F.R.S.,  Bell's  Library  edit.,  p.  307,  Philad.,  1840. 


OF  DRINKS.  657 

chyliferous  vessels  were  full  of  a  white  fluid.  Mr.  Hunter  subsequently 
repeated  the  experiment  with  odorous  and  coloured  substances,  but 
without  being  able  to  detect  them  in  the  mesenteric  veins.  It  may  be 
remarked,  also,  that  Musgrave,1  Lister,2  Blumenbach,3  Seiler  and  Fici- 
nus  assert,4  that  they  have  detected  substances,  which  had  been  thrown 
into  the  intestines  of  animals,  in  the  chyle  of  the  thoracic  duct.  The 
experiments  of  Hunter,  however,  are  those,  on  which  the  supporters 
of  this  view  of  the  question  principally  rely. 

Physiologists,  who  believe  in  the  absorption  of  liquids  by  the  mesen- 
teric veins,  adduce  similar  arguments  and  much  more  numerous  experi- 
ments. They  affirm,  that  the  mesenteric  veins,  like  the  chyliferous 
vessels,  form  constituent  portions  of  the  villi; — that  if  the  chyliferous 
system  is  manifestly  an  absorbent  apparatus,  the  same  may  be  said  of 
the  venous  system; — that  if  the  chyle  has  appeared  more  fluid  after 
much  drink  has  been  taken,  the  blood  of  the  mesenteric  veins  was  seen 
by  Boerhaave  to  be  more  fluid  under  like  circumstances;  and,  lastly, 
against  the  experiments  of  Hunter,  numerous  others  have  been  cited, 
showing  clearly,  that  liquids,  injected  into  the  intestine,  have  been 
found  in  the  mesenteric  veins,  whilst  they  could  not  be  detected  in  the 
chyliferous  vessels. 

To  the  first  experiment  of  Hunter  it  has  been  objected; — that  in  his 
time  the  art  of  performing  physiological  experiments  was  imperfect; 
and  that,  in  order  to  deduce  useful  inferences  from  it,  we  ought  to 
know,  whether  the  animal  was  fasting,  or  digestion  was  going  on  at 
the  time  it  was  opened;  that  the  lymphatics  ought  to  have  been  ex- 
amined at  the  commencement  of  the  experiment,  to  see  whether  they 
were  full  of  chyle,  or  empty;  as  well  as  the  milk,  to  notice  whether  it 
had  experienced  any  change  during  its  stay  in  the  intestine;  and  lastly, 
that  the  reasons  ought  to  have  been  assigned  for  the  belief,  that  the 
lacteals  were  filled  with  milk  at  the  end  of  the  experiment,  and  not 
with  chyle.  Moreover,  the  experiment  has  been  repeated  several 
times  by  MM.  Flandrin  and  Magendie,5 — careful  and  accurate  ob- 
servers,— yet,  in  no  case,  was  the  milk  found  in  the  chyliferous  vessels. 
The  first  experiment  of  Hunter  cannot,  therefore,  be  looked  upon  as 
satisfactory.  Some  source  of  fallacy  must  have  occurred,  otherwise 
a  repetition  of  the  experiment  should  have  been  attended  with  like  re- 
sults. We  shall  find,  hereafter,  that  in  another  experiment,  by  that 
distinguished  individual,  a  source  of  illusion  existed,  of  which  he  was 
not  unaware,  that  was  sufficient  to  account  for  the  appearance  he 
noticed. 

The  experiments  of  Hunter  with  odorous  and  coloured  substances 
have  been  repeated  by  many  physiologists,  and  found  even  less  con- 
clusive than  that  with  the  milk.  M.  Flandrin,  who  was  professor  in  the 
Veterinary  School  at  Alfort,  in  France,  thought  that  he  could  detect, 
in  horses,  an  herbaceous  odor  of  the  blood  of  the  mesenteric  veins,  but 
not  of  the  chyle.  He  gave  a  horse  a  mixture  of  half  a  pound  of  honey, 
and  the  same  quantity  of  asafcetida;  and,  whilst  the  smell  of  the  latter 

1  Philosoph.  Transact,  for  1701,  p.  996.  2  Philosoph.  Transact.,  1701,  p.  SIP. 

3  Institut.  Physiol ,  §  422.  *  Journal  Complement,  xviii.  327. 

5  Precis,  &c.,  edit,  citat.,  ii.  201. 

VOL.  i. — 42 


658  ABSORPTION. 

was  distinctly  perceptible  in  the  venous  blood  of  the  stomach  and 
intestine,  no  trace  of  it  existed  in  arterial  blood  and  chyle.  Sir  Everard 
Home1  having  administered  tincture  of  rhubarb  to  an  animal,  round 
whose  thoracic  duct  he  had  placed  a  ligature,  found  the  rhubarb  in  the 
bile  and  urine.  M.  Magendie  gave  to  dogs,  whilst  digesting,  a  quantity 
of  alcohol  diluted  with  water;  and  solutions  of  camphor,  and  other 
odorous  fluids:  on  examining  the  chyle,  half  an  hour  afterwards,  he 
could  not  detect  any  of  those  substances;  but  the  blood  of  the  mesen- 
teric veins  exhaled  the  odour,  and  afforded  the  substances  by  distilla- 
tion. He  gave  to  a  dog  four  ounces  of  a  decoction  of  rhubarb;  and,  to 
another,  six  ounces  of  a  solution  of  prussiate  of  potassa  in  water.  Half 
an  hour  afterwards,  no  trace  of  these  substances  could  be  detected  in 
the  fluid  of  the  thoracic  duct ;  whilst  they  could  be  in  the  urine.  On 
another  dog,  he  tied  the  thoracic  duct,  and  gave  it  two  ounces  of  a 
decoction  of  nux  vomica.  Death  occurred  as  speedily  as  in  an  animal 
in  which  the  thoracic  duct  was  pervious.  The  result  was  the  same, 
when  the  decoction  was  thrown  into  the  rectum,  where  no  proper  chy- 
liferous  vessels  exist.  Having  tied  the  pylorus  in  dogs,  and  conveyed 
fluids  into  their  stomachs,  absorption  equally  took  place,  and  with  the 
same  results.  Lastly,  with  M.  Delille,2  he  performed  the  following 
experiment  on  a  dog,  which  had  eaten  a  considerable  quantity  of  meat, 
in  order  that  the  chyliferous  vessels  might  be  easily  perceived.  An 
incision  was  made  through  the  abdominal  parietes ;  and  a  portion  of  the 
small  intestine  drawn  out,  on  which  two  ligatures  were  applied  at  a  short 
distance  from  each  other.  The  lymphatics,  which  arose  from  this  portion 
of  the  intestine,  were  very  white,  and  apparent  from  the  chyle  that 
distended  them.  Two  ligatures  were  placed  around  each  of  them;  and 
they  were  divided  between  the  ligatures.  Every  precaution  was  taken, 
that  the  portion  of  intestine  drawn  out  of  the  abdomen  should  have  no 
connexion  with  the  rest  of  the  body  by  lymphatics.  Five  mesenteric  ar- 
teries and  veins  communicated  with  this  portion  of  the  intestine.  Four  of 
the  arteries  and  as  many  veins  were  tied,  and  cut  in  the  same  manner  as 
the  lymphatics.  The  two  extremities  of  the  portion  of  intestine  were 
now  divided,  and  separated  entirely  from  the  rest.  A  portion,  an  inch 
and  a  half  long,  thus  remained  attached  to  the  body  by  a  mesenteric 
artery  and  vein  Only.  These  two  vessels  were  separated  from  each 
other  by  a  distance  of  four  fingers'  breadth ;  and  the  areolar  coat  was 
removed  to  obviate  the  objection,  that  lymphatics  might  exist  in  it. 
Two  ounces  of  a  decoction  of  nux  vomica  were  now  injected  into  this 
portion  of  intestine,  and  a  ligature  was  applied  to  prevent  the  exit  of 
the  injected  liquid.  The  intestine,  surrounded  by  fine  linen,  was 
replaced  in  the  abdomen  ;  and,  in  six  minutes,  the  effects  of  the  poison 
were  manifested  with  their  ordinary  intensity  : — every  thing  occurred 
as  if  the  intestine  had  been  in  its  natural  condition.  M.  Segalas3  per- 
formed a  similar  experiment,  leaving  the  intestine,  however,  communi- 
cating with  the  rest  of  the  body  by  chyliferous  vessels  only.  On  inject- 
ing a  solution  of  half  a  drachm  of  alcoholic  extract  of  nux  vomica  into 
the  intestine;  the  poisoning,  which,  in  the  experiment  of  M.  Magendie, 

1  Lectures  on  Comparative  Anatomy,  i.  221,  Lond.,  1814. 

2  Precis,  &c.,  ii.  203. 

3  Magendie's  Journal  de  Physiologic,  torn.  ii. ;  and  Precis,  &c.,  ii.  208. 


OF  DRINKS.  659 

took  effect  in  six  minutes,  had  not  occurred  at  the  expiration  of  half  an 
hour ;  but  when  one  of  the  veins  was  untied  and  the  circulation  re- 
established, it  supervened  immediately.  Westrumb1  mixed  rhubarb, 
turpentine,  indigo,  prussiate  of  potassa,  and  acetate  of  lead  with  the 
food  of  rabbits,  sheep,  and  dogs.  They  were  detected  in  the  veins  of 
the  intestines  and  in  the  urine,  but  not  in  the  chyle.  The  same  facts 
were  observed  by  Mayer2  when  rhubarb,  saffron,  and  prussiate  of  potassa 
were  introduced  into  the  stomach.  MM.  Tiedemann  and  Gmelin  like- 
wise observed  that  the  absorption  of  different  colouring  and  odorous 
substances  from  the  intestinal  canal  was  effected  exclusively  by  the 
veins.  Indigo,  madder,  rhubarb,  cochineal,  litmus,  alkanet,  camboge, 
verdigris,  musk,  camphor,  alcohol,  spirits  of  turpentine,  Dippel's  animal 
oil,  asafoetida,  garlic,  the  salts  of  lead,  mercury,  iron,  and  baryta,  were 
found  in  the  venous  blood,  but  never  in  the  chyle.  The  prussiate  of 
potassa  and  sulphate  of  potassa  were  the  only  substances,  which,  in 
their  experiments,  had  entered  the  chyliferous  vessels. 

Such  are  the  chief  facts  and  considerations  on  which  the  believers  in 
the  chyliferous  absorption  and  venous  absorption  of  drinks  rest  their 
respective  opinions.  The  strength  is  manifestly  with  the  latter.  Let 
it  be  borne  in  mind,  that  no  sufficient  experiments  have  been  made,  to 
encourage  the  idea,  that  any  thing  is  contained  in  the  chyliferous  ves- 
sels except  chyle;  and  that  nearly  all  are  in  favour  of  absorption  by 
the  mesenteric  veins.  An  exception  to  this,  as  regards  the  chyliferous 
and  lymphatic  vessels,  seems  to  exist  in  the  case  of  certain  salts.  The 
prussiate  and  the  sulphate  of  potassa — we  have  said — were  detected  in 
the  thoracic  duct  by  MM.  Tiedemann  and  Gmelin  ;  the  sulphate  of  iron 
and  the  prussiate  of  potassa  were  found  there  by  Messrs.  Harlan,  Law- 
rence, and  Coates3  of  Philadelphia ;  and  the  last  of  these  salts  by  Dr. 
Macneven  of  New  York.  "  I  triturated,"  says  Dr.  Macneven,4  "  one 
drachm  of  crystallized  hydrocyanate  of  potassa  with  fresh  butter  and 
crumbs  of  bread,  which  being  made  into  a  bolus  the  same  dog  swallowed 
and  retained.  Between  three  and  four  hours  afterwards,  Dr.  Anderson 
bled  him  largely  from  the  jugular  vein.  A  dose  of  hydrocyanic  acid 
was  then  administered,  of  which  he  died  without  pain,  and  the  abdomen 
was  laid  open.  The  lacteals  and  thoracic  duct  were  seen  well  filled 
with  milk-white  chyle.  On  scratching  the  receptaculum,  and  pressing 
down  on  the  duct,  nearly  half  a  teaspoonful  of  chyle  was  collected.  Into 
this  were  let  fall  a  couple  of  drops  of  the  solution  of  permuriate  of  iron, 
and  a  deep  blue  was  the  immediate  consequence."  Professor  J.  Muller* 
placed  a  frog  with  its  posterior  extremities  in  a  solution  of  prussiate  of 
potassa,  which  reached  nearly  as  high  as  the  anus,  and  kept  it  so  for 
two  hours.  He  then  carefully  washed  the  animal,  and  having  wiped 
the  legs  dry  tested  the  lymph  taken  from  under  the  skin  with  a  persalt 
of  iron ;  it  immediately  assumed  a  bright  blue  colour,  while  that  of  the 
serum  of  the  blood  was  scarcely  affected  by  the  test.  In  a  second 

1  De  Phsenomenis,  quae  ad  Vias  sic  dictas  Lotii  clandestinas  referuntur,  Getting.,  1819. 

2  Meckel's  Archiv.,  Band.  iii. 

3  Philad.  Journ.  of  Med.  and  Phys.  Sciences,  vol.  ii.;  and  Harlan's  Medical  and  Physical 
Researches,  p.  458,  Philad.,  1835. 

4  New  York  Med.  and  Phys.  Journ.,  June,  1822. 

5  Handbuch  der  Physiologic,  u.  s.  w.  Baly's  translation,  p.  279,  Lond.,  1838. 


660  ABSORPTION. 

experiment,  in  which  the  frog  was  kept  only  one  hour  in  the  solution, 
the  salt  could  not  be  detected  in  the  lymph.  These  exceptions  are 
strikingly  corroborative  of  the  rule.  Of  the  various  salts  employed, 
only  those  mentioned  appear  to  have  been  detected  in  the  chyle  of  the 
thoracic  duct.  It  is,  therefore,  legitimately  presumable,  that  they 
entered  adventitiously,  and  probably  by  simple  mechanical  imbibition: 
— the  mode  in  which  venous  absorption  seems  to  be  effected. 

The  property  of  imbibition,  possessed  by  animal  tissues,  has  already 
been  the  subject  of  remark  (page  65).  It  was  then  shown,  that  they 
are  not  all  equally  penetrable;  and  that  different  fluids  possess  different 
penetrative  powers.  This  view  is  confirmed  by  the  experiments  of 
MM.  Tiedemann  and  Gmelin  on  the  subject  under  discussion.  Although 
various  substances  were  placed  in  the  same  part  of  the  intestinal  canal, 
they  were  not  all  detected  in  the  blood  of  the  same  vessels.  Indigo 
and  rhubarb,  for  example,  were  found  in  the  blood  of  the  vena  portse. 
Camphor,  musk,  spirit  of  wine,  spirit  of  turpentine,  oil  of  Dippel, 
asafoetida,  garlic,  not  in  the  blood  of  the  intestines,  but  in  that  of  the 
spleen  and  mesentery;  prussiates  of  iron,  lead,  and  potassa  in  that  x>f 
the  veins  of  the  mesentery ;  those  of  potassa,  iron,  and  baryta  in  that 
of  the  spleen  ;  prussiate  of  potassa,  and  sulphates  of  potassa,  iron,  lead, 
and  baryta  in  that  of  the  vena  portae  as  well  as  in  the  urine;  whilst 
madder  and  camboge  were  found  in  the  latter  fluid  only. 

Experiments  by  MM.  Flandin  and  Danger1  confirm  the  general  rule 
of  the  absorption  of  poisons  from  the  digestive  canal  by  the  branches 
of  the  vena  portse,  and  the  diversity  of  locality  in  which  they  are  met 
with.  Their  latest  examinations  were  made  on  the  absorption  of  the 
salts  of  lead,  which  they  detected  in  the  digestive  tube,  liver,  spleen, 
kidneys,  and  lungs,  but  not  in  the  blood,  heart,  brain,  muscles,  or 
bones. 

The  evidence  in  favour  of  the  action  of  the  chyliferous  vessels  being 
restricted  to  the  absorption  of  chyle,  whilst  the  intestinal  veins  take 
up  other  matters,  is  not,  however,  considered  by  some  to  be  as  incon- 
clusive as  it  is  by  us.  M.  Adelon,2  for  example,  concludes,  that,  as 
the  sectators,  on  both  sides,  employ  absolutely  the  same  arguments, 
we  are  compelled  to  admit,  that  the  two  vascular  systems  are  under 
exactly  similar  conditions;  and  both,  consequently,  participate  in  the 
function.  We  have  seen,  that  whatever  may  be  the  similarity  of  argu- 
ments, the  facts  are  certainly  not  equal.3  It  is  proper,  however,  to 
remark,  that  chemical  analysts  experience  great  difficulty  in  detecting 
inorganic  substances  when  these  are  mixed  with  certain  of  the  com- 
pounds of  organization;  and  this  may  account  for  such  substances  not 
having  been  discovered  in  the  thoracic  duct,  even  when  present  there. 

With  regard  to  the  mode  in  which  the  absorption  of  fluids  is  effected, 
a  difference  of  opinion  has  existed,  and  chiefly  as  regards  the  question, 
— whether,  as  in  the  case  of  the  chyle,  any  vital  elaboration  be  con- 
cerned, or  whether  the  fluid,  when  it  attains  the  interior  of  the  vessel, 
be  the  same  as  without.  The  arguments  in  favour  of  these  different 

1  Gazette  Medicale.  3  Fevr.,  1844. 

2  Physiologic  de  I'Homme,  edit,  cit.,  iii.  111. 

3  Bollock's  Physiol.,  3d  edit.,  p.  607,  Lond.,  1836. 


OF  DKINKS.  661 

views  will  be  detailed  under  the  head  of  Venous  Absorption.  We  may 
merely  observe,  at  present,  that  water, — the  chief  constituent  of  all 
drinks, — is  an  essential  component  of  every  circulating  fluid ; — that 
we  have  no  evidence  that  any  action  of  elaboration  is  exerted  upon  it: 
and  that  the  ingenious  and  satisfactory  experiments  of  Prof.  J.  K. 
Mitchell,1  of  Philadelphia,  have  shown,  that  it  penetrates  most,  if  not 
all,  animal  tissues  better  than  any  other  liquid;  and,  consequently, 
passes  through  them  to  accumulate  in  any  of  its  own  solutions.  It  is 
probably  in  this  way, — that  is,  by  imbibition, — that  all  venous  absorp- 
tions are  effected. 

But  it  has  been  said : — if  fluids  pass  so  readily  through  the  coats  of 
the  veins, — by  reason  of  the  extensive  mucous  surface,  with  which 
they  come  in  contact,  a  large  quantity  of  extraneous  and  heterogeneous 
fluid  must  enter  the  abdominal  venous  system  when  we  drink  freely, 
and  the  composition  of  the  blood  be  consequently  modified;  and,  if  it 
should  arrive,  in  this  condition,  at  the  heart,  the  most  serious  conse- 
quences might  result.  It  has,  indeed,  been  affirmed  by  a  distinguished 
member  of  the  profession2  in  this  country,  in  a  more  ingenious  than 
forcible  argument  to  support  a  long-cherished — but  now  almost  univer- 
sally abandoned — hypothesis,  that  "it  must  at  least  be  acknowledged, 
that  no  substance,  in  its  active  state,  does  reach  the  circulation,  since 
it  is  shown,  that  a  small  portion  even  of  the  mildest  fluid,  as  milk  or 
mucilage,  oil  or  pus,  cannot  be  injected  into  the  bloodvessels  without 
occasioning  the  most  fatal  consequences."  But  the  effects  are  here 
greatly  dependent  on  the  mode  in  which  the  injection  is  made.  If  a 
scruple  of  bile  be  sent  forcibly  into  the  crural  vein,  the  animal  gene- 
rally perishes  in  a  few  moments.  The  same  occurs,  if  a  quantity  of 
atmospheric  air  be  rapidly  introduced  into  a  venous  trunk.  The  ani- 
mal, according  to  Sir  Charles  Bell,3  dies  in  an  instant,  when  a  very 
little  air  is  blown  in ; — and  there  is  no  suffering  nor  struggle,  nor  any 
stage  of  transition,  so  immediately  does  the  stillness  of  death  take  pos- 
session of  every  part  of  the  frame.  In  this  way,  according  to  Beau- 
chene,  Larrey,  Dupuytren,  Warren  of  Boston,  Mott  and  Stevens  of 
New  York,  Delpech,  and  others,  operations  at  times  prove  fatal; — the 
air  being  drawn  in  by  the  divided  veins.  If,  however,  the  scruple  of 
bile,  or  the  same  quantity  of  atmospheric  air  be  injected  into  one  of 
the  branches  of  the  vena  portae,  no  apparent  inconvenience  is  sustained. 
M.  Magendie4  concludes,  from  this  fact,  that  the  bile  and  atmospheric 
air,  in  their  passage  through  the  myriads  of  small  vessels  into  which  the 
vena  portas  divides  and  subdivides  in  the  substance  of  the  liver,  become 
thoroughly  mixed  with  the  blood,  and  thus  arrive  at  the  vital  organs 
in  a  condition  to  be  unproductive  of  mischief.  This  view  is  rendered 
the  more  probable  by  the  fact,  that  if  the  same  quantity  of  bile  or  of 
air  be  injected  very  slowly  into  the  crural  vein,  no  perceptible  incon- 
venience is  sustained.  Dr.  Blundell5  injected  in  this  manner  five 
drachms  into  the  femoral  vein  of  a  very  small  dog,  with  only  tempo- 

1  American  Journal  of  the  Medical  Sciences,  vii.  44,  58. 

2  Chapman,  Elements  of  Therapeutics,  6th  edit.,  p.  47,  Philad.,  1831. 

3  Animal  Mechanics,  P.  ii.  p.  42,  London,  1829. 

*  Precis  Elementaire,  2de  edit.,  ii.  433.  6  Medico-Chirurg.  Trans,  for  1818,  p.  65. 


662  ABSORPTION. 

rary  inconvenience;  and,  subsequently,  three  drachms  of  expired  air, 
without  much  temporary  disturbance ;  and  M.  Lepelletier1  affirms,  that 
in  the  amphitheatre  of  the  Ecole  Pratique  of  Paris,  in  the  presence  of 
upwards  of  two  hundred  students,  he  injected  thrice  into  the  femoral 
vein  of  a  dog,  of  middle  size,  at  a  minute's  interval,  three  cubic  inches 
of  air,  without  observing  any  other  effect  than  struggling,  whining, 
and  rapid  movements  of  deglutition ;  and  these  phenomena  existed  only 
whilst  the  injection  was  going  on.  Since  that  he  has  often  repeated 
the  experiment  with  -identical  results, — "  proving,"  he  observes,  "  that 
the  deadly  action  of  the  air  is,  in  such  case,  mechanical,  and  it  is  pos- 
sible to  prevent  the  fatal  effects  by  injecting  it  so  gradually,  that  the 
blood  has  power  to  disseminate,  and  perhaps  even  to  dissolve  it  with 
sufficient  promptitude  to  prevent  its  accumulation  in  the  cardiac  cavi- 
ties." From  the  experiments  of  Mr.  Erichsen,  however,  the  cause  of 
death  in  such  cases,  would  appear  to  be  asphyxia. 

As  liquids  are  frequently  passed  off  by  the  urinary  organs  soon  after 
they  have  been  swallowed,  it  has  been  believed  by  some, — either  that 
there  are  vessels  which  form  a  direct  communication  between  the  sto- 
mach and  bladder ;  or  that  a  transudation  takes  place  through  the 
parietes  of  the  stomach  and  intestine,  and  that  the  fluids  proceed 
through  the  intermediate  areolar  tissue  to  the  bladder.  Both  these 
views,  we  shall  hereafter  show,  are  devoid  of  foundation. 

In  animals,  in  which  the  cutis  vera  is  exposed,  or  the  cuticle  very 
thin,  nutritive  absorption  is  effected  through  that  envelope.  In  the 
polypi,  medusae,  radiaria,  and  vermes,  absorption  is  active,  and  accord- 
ing to  Zeder  and  Rudolphi,2  entozoa,  that  live  in  the  midst  of  animal 
humours,  imbibe  them  through  the  skin.  A  few  years  ago,  Jacobson3 
instituted  experiments  on  the  absorbing  power  of  the  helix  of  the  vine 
(Limagon  des  vignes).  A  solution  of  prussiate  of  potassa  was  poured 
over  the  body.  This  was  rapidly  absorbed,  and  entered  the  mass  of 
blood  in  such  quantity,  that  the  animal  acquired  a  deep  blue  colour 
when  sulphate  of  iron  was  thrown  upon  it.  In  the  frog,  toad,  sala- 
mander, &c.,  cutaneous  absorption  is  so  considerable,  that  occasionally 
the  weight  of  water,  taken  in  this  way,  is  equal  to  that  of  the  whole 
body.  We  shall  see,  hereafter,  that  the  nutrition  of  the  ftetus  in  utero 
is  mainly,  perhaps,  accomplished  by  nutritive  absorption  effected  through 
the  cutaneous  envelope. 

II.    ABSORPTION  OF  LYMPH  OR  LYMPHOSIS. 

This  function  is  effected  by  agents,  that  strongly  resemble  those  con- 
cerned in  the  absorption  of  chyle.  One  part  of  the  vascular  apparatus 
is,  indeed,  common  to  both, — the  thoracic  duct.  We  are  much  less 
acquainted,  however,  with  the  physiology  of  lymphatic,  than  of  chy- 
liferous,  absorption. 

1  Physiologie  Medicate  et  Philosophique,  i.  494,  Paris,  1831. 

2  Entozoorum  Histor.,  i.  252,  275,  Berlin,  1829. 

3  Memoir,  de  TAcad.  des  Sciences  de  Berlin,  1825,  and  Tiedemann,  Traite  Complet  de 
Physiologie  de  1'Homme,  edit.  Fr.,p.  242,  Paris,  1831. 


OF  DRINKS. 


663 


1.    ANATOMY  OF  THE  LYMPHATIC  APPARATUS. 

The  lymphatic  apparatus  consists  of  lymphatic  vessels,  lymphatic 
glands  or  ganglia,  and  thoracic  duct.  The  latter,  however,  does  not 
form  the  medium  of  communication  between  all  the  lymphatic  vessels 
and  the  venous  system. 

1.  Lymphatic  vessels. — These  vessels  exist  in  almost  all  parts  of  the 
body ;  and  have  the  shape  of  cylindrical,  transparent,  membranous 
tubes,  of  small  size,  anastomosing  freely  with  each  other,  so  as  to 
present,  everywhere,  a  reticular  arrangement.  They  are  never,  accord- 
ing to  Professor  Muller,  so  small  as  the  arterial  and  venous  capillaries, 
and  are,  almost  without  exception,  visible  to  the  naked  eye.  Gr.  R. 
Treviranus  asserts,  that  their  walls,  like  the  areolar  membrane  and 
other  tissues,  are  made  up  of  minute  elementary  cylinders,  of  a  diame- 
ter of  from  0-001  to 

0-006      millimetres,  Fig- 256- 

placed  in  a  series, 
side  by  side  and  end 
to  end,  so  as  to  con- 
stitute tubes  which 
form  networks,  and 
open  into  larger  lym- 
phatic trunks.  They 
are  extremely  nu- 
merous; more  so, 
however,  in  some 
parts  than  others. 
They  have  not  been 
found  in  the  brain, 
spinal  marrow,  eye, 
or  internal  ear, 
bones,  cartilages,  or 
any  non-vascular 
parts ;  but  this  is  not 
a  positive  proof,  that 
they  do  not  exist  in 
some  of  them.  It 
may  be,  that  they  are 
so  minute  as  to  es- 
cape observation.  In 
their  progress  to- 
wards the  venous 
system,  they  go  on 
forming  fewer  and 


Vessels  and  Lymphatic  Glands  of  Axilla. 

1.  The  axillary  artery.    2.  Axillary   vein.    3.  Brachial   artery.    4. 
tewer      trunks!      yet    Brachial  vein.    5.  Primitive  carotid  artery.    6.  Internal  jugular  vein. 
1  •  -i-i       7.  Subcutaneous  lymphatics  of  arm  at  its  upper  part.    8.  Two  or  three 

always  remain  Small.     Of  the  most  inferior  and  superficial  glands  into  which  the  superficial 
TV)i<;     nnifnrmitv     in     lymphatics  empty.    9.  Deep-seated  lymphatics  which  accompany  bra- 
111- j      in    chial  artery.    10.  Lymphatics  and  glands  which  accompany  infra-scapu- 


s 


to    lar  bloodvessels.     11.  Glands  and  lymphatics  accompanying  thoracica 
lri  lonSa  artery.     12.   Deeper-seated   lymphatics.     13.   Axillary  chain   of 

When  an  ar-    glands.     14.  Acromial  branches  of  lymphatics.     15.  Jugular  lymphatics 
and  glands.    16,  17.  Lymphatics  which  empty  into  subclavian  vein  near 
a    its  junction  with  right  internal  jugular  vein. 


664 


ABSORPTION. 


branch,  its  size  is  sensibly  diminished;  and  when  a  vein  receives  a  branch, 
it  is  enlarged  ;  but  when  a  lymphatic  ramifies,  there  is  generally  little 
change  of  size,  whether  the  branch  given  off  be  large  or  small. 

The  lymphatics  consist  of  two  planes, — the  one  superficial,  the  other 
deep-seated.  The  former  creep  under  the  outer  covering  of  the  organ, 
or  of  the  skin,  and  accompany  the  subcutaneous  veins.  The  latter  are 
seated  more  deeply  in  the  interstices  of  the  muscles,  or  even  in  the 
tissue  of  parts;  and  accompany  the  nerves  and  great  vessels.  These 
planes  anastomose  with  each  other. 

This  arrangement  occurs  not  only  in  the  limbs,  but  the  trunk,  and  in 
every  viscus.  In  the  trunk,  the  superficial  plane  is  seated  beneath  the 
skin;  and  the  deep-seated  between  the  muscles  and  the  serous  membrane 
that  lines  the  splanchnic  cavities.  In  the  viscera,  one  plane  occupies 
the  surface;  the  other  appears  to  arise  from  the  parenchyma. 

The  two  great  trunks  of  the  lymphatic  system,  in  which  the  lym- 
phatic vessels  of  the  various  parts  of  the  body  terminate,  are  the  tho- 
racic duct,  and  the  great  lymphatic  trunk  of  the  right  side.  The 
course  of  the  thoracic  duct  has  been  described  already.  It  is  formed 
of  three  great  vessels; — one,  in  which  all  the  lymphatics  and  lacteals 
of  the  intestines  terminate;  and  the  other  two,  formed  by  the  union  of 
the  lymphatics  of  the  lower  half  of  the  body.  Occasionally,  the  duct 
consists  of  several  trunks,  which  unite  into  one  before  reaching  the  sub- 

clavian  vein;  but  more  fre- 
quently it  is  double.  In  ad- 
dition to  the  lymphatics  of  the 
lower  half  of  the  body,  the 
thoracic  duct  receives  a  great 
part  of  those  of  the  thorax, 
and  all  those  from  the  left  half 
of  the  upper  part  of  the  body. 
At  its  termination  in  the  sub- 
clavian,  there  is  a  valve  so  dis- 
posed as  to  allow  the  lymph  to 
pass  into  the  blood;  and  to 
prevent  the  reflux  of  the  blood 
into  the  duct.  We  shall  see, 
however,  that  its  mode  of  ter- 
mination in  the  venous  system 
possesses  other  advantages. 
The  great  lymphatic  trunk  of 
the  right  side  is  formed  by  the 
absorbents  from  that  side  of 
the  head  and  neck,  and  from 


Fig.  257. 


Lymphatic  Vessels  and  Glands  of  the  Groin  of  the 
Right  Side. 


1.  Saphena  magna  vein.    2.  Veins   on   the  surface  of  -j^g  right  arm.    It  is  Very  short, 
abdomen.     3.  External  pudic  vein.    4.  Lymphatic  ves-  .       °.      ,  ,  •       i» 

sels  collected  in  fasciculi  and  accompanying  the  saphena  being  little  more  than  an  inch, 
vein  on  its  inner  side.    5.  External  trunks  of  the  same  •,   __„._.!.•-..,    ^.-4.    _    «110v+.«>, 

set  of  vessels.    6.  Lymphatic  gland  which  receives  all  and  SOmetimCS    not    a    quarter 

these  vessels.     It  is  placed  on  the  termination  of  the.  sa-  nf  an  inf»V)     in   IpTlD-fh  hilt  of 

phena  vein.     7.   Efferent  trunks  from  this  gland;    they  (  Cn>  IU  *««gN«| 

become  deep-seated  and  accompany  the  femoral  artery,  a  diameter  nearly  aS  great  aS 

8.  One  of  the  more  external  lymphatic  glands  of  the  groin.  ,  •       J       ±          \  1 

9.  A  chain  of  four  or  five  inguinal  glands,  which  receive  the     tllOraClC    UUCt.       A    ValVO 
the  lymphatics  from  the  genitals,  abdomen,  and  external  i          Pv-i«t^    at    thp    mouth     of 
portion  of  the  thigh.  aiso     6X1SIS    at    tne    mOUin     01 


LYMPHOSIS.  665 

this  trunk,  which  has  a  similar  arrangement  and  office  with  that  of  the 
left  side. 

The  lymphatics  have  been  asserted  to  be  more  numerous  than  the 
veins;  by  some,  indeed,  the  proportion  has  been  estimated  at  fourteen 
superficial  lymphatics  to  one  superficial  vein;  whence  it  has  been  de- 
duced, that  the  capacity  of  the  lymphatic  is  greater  than  that  of  the 
venous  system.  This  must  be  mere  matter  of  conjecture.  The  same 
may  be  said  of  the  speculations  that  have  been  indulged  regarding  the 
mode  in  which  the  lymphatic  radicles  arise, — whether  by  open  mouths 
or  by  some  spongy  mediate  body.  The  remarks  made  regarding  the 
chylous  radicles  apply  with  equal  force  to  the  lymphatic. 

It  has  been  a  matter  of  some  interest  to  determine,  whether  the 
lymphatic  vessels  have  other  communications  with  the  venous  system 
than  by  the  two  trunks  just  described;  or,  whether,  soon  after  their 
origin,  they  do  not  open  into  the  neighbouring  veins, — an  opinion  held 
by  many  of  those,  who  believe  in  the  doctrine  of  absorption  by  the 
lymphatics  exclusively,  to  explain  why  absorbed  matters  are  found  in 
the  veins.  Several  of  the  older,  as  well  as  more  modern,  anatomists, 
have  professed  this  opinion;  whilst  it  has  been  strenuously  combated  by 
Sommering,  Rudolphi,1  and  others.  Vieussens  affirmed,  that,  by  means 
of  injections,  lymphatic  vessels  were  distinctly  seen  originating  from 
the  minute  arteries,  and  terminating  in  small  veins.  Sir  William  Bli- 
zard2  asserts,  that  he  twice  observed  lymphatics  terminating  directly 
in  the  iliac  veins.  Mr.  Braey  Clarke3  found  that  the  trunk  of  the 
lymphatic  system  of  the  horse  had  several  openings  into  the  lumbar  veins. 
M.  Ribes,4  by  injecting  the  supra-hepatic  veins,  saw  the  substance  of 
the  injection  enter  the  superficial  lymphatics  of  the  liver.  M.  Alard5 
considers  that  the  lymphatic  and  venous  systems  communicate  at  their 
origins.  Vincent  Fohmann6  thinks,  that  the  lymphatic  vessels  com- 
municate directly  with  the  veins,  not  only  in  the  capillaries,  but  in  the 
interior  of  the  lymphatic  glands.  Lauth,7  of  Strasburg, — who  went  to 
Heidelberg  to  learn  from  Fohmann  his  plan  of  injecting, — announced 
the  same  facts  in  1824.  By  this  anatomical  arrangement,  Lauth  ex- 
plains how  an  injection,  sent  into  the  arteries,  reaches  the  lymphatics, 
without  being  effused  into  the  areolar  tissue;  the  injection  passing  from 
the  arteries  into  the  veins,  and  thence,  by  a  retrograde  route,  into  the 
lymphatics.  M.  Beclard  believed,  that  this  communication  exists  at  least 
in  the  interior  of  the  lymphatic  glands;  and  he  supported  his  opinion 
by  the  fact,  that  in  birds,  in  which  these  glands  are  wanting,  and  are 
replaced  by  plexuses,  the  lymphatic  vessels  in  the  plexuses  are  distinctly 
seen  opening  into  the  veins.  Lippi8  has  made  these  communications  the 

1  Grundriss  der  Physiologie,  u.  8.  w.,  2ter  Band,  2te  Abtheilung,  s.  247,  Berlin,  1828. 

2  Physiological  Observations  on  the  Absorbent  System  of  Vessels,  Lond.,  1787. 

3  Rees's  Cyclopedia,  art.  Anatomy,  Veterinary.  4  Magendie,  Precis,  etc.,  ii.  238. 

5  Du  Siege  et  de  la  Nature  des  Maladies,  ou  nouvelles  considerations  touchant  la  veritable 
action  du  Systeme  Absorbant,  etc.,  Paris,  1821. 

6  Ueber  die  Verbindung  der  Saugadern  mit  den  Venen,  Heidelb.,  1821,  und  Das  Sauga- 
dersystem  der  Wirbelthiere,  Heft  1,  Heidelb.,  1824;  and  Mem.  sur  les  communications  des 
vaisseaux  lymphatiques  avec  les  veines,  Liege,  1832. 

7  Essai  sur  les  Vaisseaux  Lymphatiques,  Strasbourg,  1824. 

8  Illustrazioni  Fisiologiche,  etc.,  Firenz.,  1825. 


666 


ABSORPTION. 


subject  of  an  express  work.  According  to  him,  the  most  numerous 
exist  between  the  lymphatic  vessels  of  the  abdomen,  and  the  vena  cava 
inferior  and  its  branches.  So  numerous  are  they,  that  every  vein  re- 
ceives a  lymphatic  vessel,  and  the  sum  of  all  would  be  sufficient  to  form 
several  thoracic  ducts.  Opposite  the  second  and  third  lumbar  vertebrae, 
the  lymphatic  vessels  are  manifestly  divided  into  two  orders: — some 
ascending,  and  emptying  themselves  into  the  thoracic  duct;  others 
descending  and  opening  into  the  renal  vessels  and  pelves  of  the  kid- 
neys. Lippi  admits  the  same  arrangement,  as  regards  the  chyliferous 
vessels;  and  he  adopts  it  to  explain  the  prompt- 
Fig-  258-  itude  with  which  drinks  are  evacuated  by  the 
urine. 

Subsequent  researches  have  not,  in  general, 
confirmed  the  statements  of  Lippi.  G.  Rossi,1 
indeed,  maintains,  that  the  vessels,  which  Lippi 
took  for  lymphatics,  were  veins.  It  would  ap- 
pear,  however,  that  when  Rossi  was  in  Paris,  he 
was  unable  to  demonstrate,  when  requested  to  do 
so  by  M.  Breschet,  the  very  things,  that  he  had 
previously  figured  and  described.  Panizza,  too, 
affirms,  that  no  direct  union  or  continuity  be- 
tween the  venous  capillaries  and  lymphatics  has 
ever  been  made  manifest  to  the  eye,  either  in 
the  human  subject  or  the  lower  animals:2  and,  on 
the  whole,  the  observations  of  Lippi  as  to  the 
alleged  termination  of  lymphatics  in  various 
veins  of  the  abdomen  have  generally  been 
either  rejected  as  erroneous  or  held  to  refer  to 
deviations  from  the  normal  condition.3  It  is 
proper  to  remark,  however,  that,  recently,  Dr. 
A.  Nuhn,4  Prosector  at  Heidelberg,  has  main- 
tained, that  there  is  a  regular  communication 
between  the  abdominal  lymphatics  and  veins, 
and  describes  three  cases  of  the  kind  which  fell 
under  his  own  observation.  In  two  of  these  the 
lymphatics  opened  into  the  renal  veins ;  in  the 
third  into  the  vena  cava.  The  article  contains 
a  good  history  of  the  views  of  different  observ- 
ers on  the  communication  between  the  ab- 
sorbents and  veins. 

Lymphatics.  We  are  perhaps  justified  in  concluding  with 

a,  a,  «,  a.  Afferent  and  effe-  Panizza,  that  anatomy  has  not   hitherto   suc- 
rent  lymphatic  vessels  proceed-  cceded  in  determining,  with  physical  certainty, 

ing  towards  thoracic  duct,    b,  b.    .  .  <=>'         .-   r    J  ,,  t      X 

Lymphatic  glands.  The  arrows  in  what  relation  the  sanguiierous  and  lymphatic 

indicate  the  direi:~ u:~u 

the  chyle  passes. 


h  systems  stand  to  each  other,  at  their  extreme 


1  Omodei's  Annali  Universali,  Jan.,  1826. 

2  Osservazioni  Antropo-zootomico  fisiologicbe,  Pavia,  1833;  and  Breschet's  Systeme  Lym- 
phatique,  Paris,  1836. 

3  Quain's  Human  Anatomy,  by  Quain  and  Sharpey,  Amer.  edit.,  by  Dr.  Leidy,  ii.  43, 
Philad.,  1849. 

4  Miiller's  Archiv.  fur  Anatomie,  u.  s.  w.,  Heft  2,  s.  173,  Berlin,  1848. 


LYMPHATIC  APPARATUS. 


667 


Fig.  259. 


ramifications.1    M.  Magendie2  conceives  the  most  plausible  view  regard- 

ing the  lymphatics  to  be:  —  that  they  arise  by  extremely  fine  roots  in 

the  substance  of  the  membranes  and  areolar  tissue,  and  in  the  paren- 

chyma of  organs,  where  they  appear  continuous  with  the  final  arterial 

ramifications;  —  as  it  frequently  happens,  that  an  injection  sent  into  an 

artery  passes  into  the  lymphatics  of  the  part  to  which  it  is  distributed. 

By  some,  they  are  described  as  commencing  either  in  closely  meshed 

networks,  interspersed  among 

the  bloodvessels  of  the  several 

tissues,  or  else  in  pointed  closed 

tubes  or  processes,  as  shown  in 

the  marginal  figure  of  the  lymph 

and  bloodvessels  in  a  part  of 

the  tail  of  the  tadpole;  —  the 

bloodvessels  being  denoted  by 

the  corpuscles  in  them.  In  this 

state,  many  of  the  extremities 

of  the   lymphatics   appear  to 

communicate  with   pointed  or 

star-shaped  cells;  but  this,  ac- 

cording to  Messrs.  Kirkes  and 

Paget,3  may  be  peculiar  to  the 

embryonic  state,  as  no  similar 

cells  are  seen  in  the  adult;  nor 

is  there  any  appearance  of  the 

existence  of  cells  for  the  elabo- 

ration   of   lymph,    similar    to 

those  described  as  existing  in 


the  intestinal  villi. 

mi  /»      i         i 

The  structure   of  the   lym- 


Bloodvessels  and  .Lymphatics  irom  the  iailoitne 

Tadpole. 

phatic  vessels  is  like  that  of 
the  lacteals.  They  have  the  same  number  and  character  of  coats;  the 
same  crescentic  valves  or  sphincters,  occurring  in  pairs,  and  giving 
them  the  knotted  and  irregular  appearance,  for  which  they  are  remark- 
able; —  every  contraction  indicating  the  presence  of  a  pair  of  valves,  or 
sphincter.  The  minutest  lymphatics  seem,  however,  to  be  destitute  of 
valves  :  but  they  are  discernible  in  those  of  less  than  one-third  of  a  line 
in  diameter,  and  have  the  same  structure  as  those  of  the  veins.  In 
man,  each  lymphatic,  before  reaching  the  venous  system,  passes  through 
a  lymphatic  gland  or  ganglion,  formerly  called  a  conglobate  gland. 
These  organs  are  extremely  numerous;  and  in  shape,  structure,  and 
probably  in  function,  resemble  entirely  the  mesenteric  glands.  They, 
therefore,  do  not  demand  distinct  notice.  They  exist  more  particularly 
in  the  axillae,  neck,  neighbourhood  of  the  lower  jaw,  beneath  the  skin 
of  the  nape  of  the  neck,  in  the  groins,  and  pelvis  in  the  neighbourhood 
of  the  great  vessels.  The  connexion  between  the  lymphatics  and  those 

1  See,  on  both  sides  of  this  subject,  Mailer's  Handbuch,  u.  s.  w.,  Baly's  translation,  p.  273, 
Lond.,  1838;  and  Weber's  Hildebrandt's  Handbuch  der  Anatomic,  iii.  113,  Braunschweig, 
1831.  2  Precis,  &c.,  ii.  194. 

3  Manual  of  Physiology,  Amer.  edit.,  p.  205,  Philad.,  1849. 


668  ABSORPTION. 

glands  is  the  same  as  that  between  the  chyliferous  vessels  and  mesen- 
teric  glands. 

M.  Chaussier  includes  in  the  lymphatic  system  certain  organs,  whose 
uses  in  the  economy  are  not  manifest, — the  thymus  gland,  the  thyroid, 
the  supra-renal  capsules,  and  perhaps  the  spleen.  These  he  considers 
to  be  varieties  of  the  same  species,  and  terms  them  all  glandiform  gan- 
glions. 

The  thy mus  gland  is  a  body  consisting  of  distinct  lobes,  situate  at  the 
upper  and  anterior  part  of  the  thorax  behind  the  sternum.  It  has  been 
considered  to  belong  more  particularly  to  foetal  existence,  and  will  be 
investigated  hereafter.  The  thyroid  gland  is,  also,  a  located  organ, 
situate  at  the  anterior  part  of  the  neck  beneath  the  skin  and  subcuta- 
neous muscles,  and  resting  on  the  anterior  and  inferior  part  of  the 
larynx,  and  first  rings  of  the  trachea.  It  is  formed  of  lobes,  which  sub- 
divide into  lobules  and  granula  ;  is  of  a  red,  and  at  times  yellow  colour; 
and  presents,  internally,  cells  or  vesicles,  filled  with  a  viscid  and  colour- 
less or  yellowish  fluid.  Collected  on  the  point  of  a  knife  after  incising 
the  gland,  it  appears  like  weak  solution  of  gum,  and  is  almost  devoid 
of  the  ropiness  of  white  of  egg.  Put  into  common  rectified  spirit  it 
seems  to  lose  only  a  little  water  ;  becomes  solid,  but  not  opaque  ;  and 
loses  but  little.  The  same  effects  result  in  the  cells  when  the  gland  is 
boiled  for  a  quarter  of  an  hour :  no  apparent  solution  occurs.  The 
thyroid  gland  has  no  excretory  duct;  and,  consequently,  it  is  difficult 
to  imagine  its  use.  It  is  larger  in  the  foetus  than  in  the  adult,  and  has 
been  supposed  to  be,  in  some  way,  inservient  to  foetal  existence.  It 
continues,  however,  through  life ;  receives  large  arteries,  as  well  as  a 
number  of  nerves  and  lymphatics,  and  hence,  it  has  been  supposed,  fills 
some  important  office  through  the  whole  of  existence.  This,  however, 
is  conjectural.  Mr.  King1  has  affirmed,  what  had  been  already  imagined 
by  many,  that  the  absorbent  vessels  of  the  thyroid  convey  its  peculiar 
secretion  to  the  great  veins  of  the  body.  It  is  the  seat  of  goitre  or 
bronchocele,  the  swelled  neck,  Derbyshire  necTc,  papas,  &c.,  as  it  has 
been  termed  in  different  quarters  of  the  globe, — a  singular  affection, 
which  is  common  at  the  base  of  lofty  mountains  in  all  parts  of  the 
world  ;  and  for  the  cure  of  which,  we  have  a  valuable  remedy  in  iodine. 
The  eutrophic  agency  of  this  drug  is  particularly  exerted  on  the  thy- 
roid, and  it  affords  an  additional  instance,  to  the  many  already  known, 
of  remedial  agents  exerting  their  properties  upon  a  particular  organ, 
without  our  being  able,  in  the  slightest  degree,  to  account  for  the  pre- 
ference. Iodine  stimulates,  perhaps,  the  absorbent  vessels  of  the  gland 
to  augmented  action ;  it  certainly  modifies  the  nutrition  of  the  organ ;  and 
the  consequence  is  absorption  of  the  morbid  deposit.  Lastly;  the  supra- 
renal or  atrabiliary  capsules  or  glands  are  small  bodies  in  the  abdo- 
men, behind  the  peritoneum,  and  above  each  kidney,  which  are  larger 
in  the  foetus  than  in  the  adult.  The  arteries  distributed  to  them  are 
of  considerable  size.  These  bodies  consist  of  small  sacs,  with  thick 
parenchymatous  parietes ;  are  lobular  and  granular, — the  internal 
cavity  being  filled,  according  to  Sir  Everard  Home,2  with  a  viscid  fluid 

1  Guy's  Hospital  Reports,  i.  437,  Lond.,  1836,  and  Sir  Astley  Cooper,  ibid.,  p.  448. 

2  Lect.  on  Comp.  Anat.,  v.262,  Lond.,  1828. 


"LYMPH.  669 

pulp  or  oil,  which  is  reddish  in  the  foetus,  yellow  in  childhood,  and 
brown  in  old  age.  Under  the  microscope,  the  pulp  is  found  to  consist 
of  minute  oil-like  spheroids,  of  very  unequal  size,  varying  from  24oootn 
to  g^o^th  of  an  inch  in  diameter.1  They  continue  during  life  :  but  with 
their  uses  we  are  unacquainted.  By  the  ancients,  they  were  believed 
to  be  the  secretory  organs  of  the  imaginary  atrabilis  ;  hence  their  name. 
Sir  Everard  Home  considers  that  they  act  like  a  filter,  "  by  which  any 
oil  left  in  the  arterial  branches  that  are  near  the  kidneys  may  be  sepa- 
rated and  prevented  from  making  its  escape  by  the  tubse  uriniferse  of 
these  glands."  Dr.  Carpenter2  thinks  the  only  function  that  can  be 
assigned  them  with  anything  like  probability  is  that  of  serving  as  a 
means  of  conveying  into  the  veins  the  blood  sent  through  the  renal 
artery,  when,  from  any  cause,  the  secreting  function  of  the  kidneys  is 
partly  or  wholly  checked,  and  their  capillary  circulation  stagnates  in 
consequence. 

All  these  bodies  are  probably  concerned  in  lymphosis ;  but  at  the 
same  time — as  shown  hereafter, — they  may  act  under  special  circum- 
stances as  diverticula  to  the  blood  and  hence  merit  the  name — now 
generally  assigned  to  them — of  vascular  glands. 

2.    LYMPH. 

Lymph  may  be  procured  in  two  ways,  either  by  opening  a  lymphatic 
vessel,  and  collecting  the  fluid  that  issues  from  it, — but  this  is  an  un- 
certain method, — or  by  making  an  animal  fast  four  or  five  days,  and 
obtaining  the  fluid  from  the  thoracic  duct.  This  has  been  considered 
pure  lymph  ;  but  it  must  be  mixed  with  the  product  of  the  digestion  of 
the  different  secretions  from  the  portion  of  the  digestive  tube  above  the 
origin  of  the  chyliferous  vessels.  Chyle  itself  is  nothing  more  than 
lymph  of  the  intestines,  containing  matter  absorbed  from  the  digested 
food ;  and  in  the  intervals  of  digestion  lymph  alone  is  found  in  the  chy- 
liferous vessels. 

The  fluid,  obtained  as  above-mentioned,  is  of  a  rosy,  slightly  opa- 
line tint;  a  markedly  spermatic  odour,  and  saline  taste.  At  times,  it 
is  of  a  decidedly  yellowish  colour  ;  at  others,  of  a  madder  red  ;  circum- 
stances which  may  have  given  occasion  to  erroneous  inferences  from 
experiments  made  on  the  absorption  of  colouring  matters.  Its  specific 
gravity  has  been  found,  by  some,  to  be  1022-28  :  by  others,  1-037.  Its 
colour  is  affirmed  to  be  more  rosy  in  proportion  to  the  length  of  time 
the  animal  has  fasted.  When  examined  by  the  microscope,  it  exhibits 
globules  or  corpuscles  like  those  of  the  chyle  ;  and,  like  the  chyle,  bears 
considerable  analogy,  in  its  chemical  composition,  to  the  blood.  Both 
may,  indeed,  without  impropriety,  be  regarded  as  rudirnental  blood. 

Bodies  similar  to  these  lymph  corpuscles  are  seen  mingled  with  the 
blood,  occupying  generally  the  space  between  the  main  current  and  the 
parietes  of  the  vessel.  Some,  however,  regard  them  as  blood  corpus- 
cles in  process  of  solution  or  disintegration ;  and  M.  MandP  thinks  they 
do  not  exist  in  the  fluid  during  life,  but  are  owing  to  the  coagulation  of 

1  Gulliver,  in  Gerber's  General  Anatomy,  p.  103. 

«  Principles  of  Human  Physiology,  §  710,  Lond.,  1842. 

3  Anatom.  Microscop.,  i.  15. 


670  ABSORPTION. 

its  fibrin.  More  recently,  he  has  stated,  that  from  experiments  made 
with  M.  Breschet,  it  was  evidently  impracticable  to  procure  pure  lymph 
by  opening  the  lymphatic  hearts  of  frogs.  Blood  globules  always 
existed  in  it;  and  this,  he  thinks,  throws  doubts  on  the  view,  that  lymph 
corpuscles  are  transformed  into  blood  corpuscles. 

When  left  at  rest,  lymph  separates  into  two  portions; — the  one  a 
liquid,  nearly  like  the  serum  of  the  blood;  the  other  a  coagulum  or  clot 
of  a  deeper  rosy  hue;  in  which  is  a  multitude  of  reddish  filaments,  dis- 
posed in  an  arborescent  manner ;  and,  in  appearance,  very  analogous  to 
the  vessels  distributed  in  the  tissue  of  organs.  When  a  portion  of 
coagulated  lymph  is  examined,  it  seems  to  consist  of  two  parts : — the 
one  solid,  formed  of  numerous  cells,  which  contains  the  other  or  more 
liquid  part;  and  if  the  former  be  separated,  the  latter  coagulates.  Mr. 
Brande1  collected  the  lymph  from  the  thoracic  duct  of  an  animal,  that 
had  been  kept  without  food  for  twenty-four  hours.  He  found  its  chief 
constituent  to  be  water,  besides  which,  it  contained  chloride  of  sodium 
and  albumen: — the  latter  being  in  such  minute  quantity,  that  it  coagu- 
lated only  by  the  action  of  galvanism.  The  lymph  of  a  dog  yielded 
to  M.  Chevreul,  water,  926-4;  fibrin,  4-2;  albumen,  61*0;  chloride  of 
sodium,  6-1;  carbonate  of  soda,  1-8;  phosphate  of  lime,  phosphate  of 
magnesia,  and  carbonate  of  lime,  0*5.  That  of  the  horse  yielded  to 
M.  Lassaigne,  water,  192-5;  fibrin,  0-33;  albumen,  5*73;  chlorides  of 
sodium  and  potassium,  with  soda  and  phosphate  of  lime,  1-43.  Total, 
100.  MM.  Marchand  and  Colberg2  found  its  constituents  to  be, — 
water,  96-926;  fibrin,  0-520;  albumen,  0-434;  osmazome  (and  loss), 
0'312;  fatty  oil  and  crystalline  fat,  0-264;  chloride  of  sodium,  chloride 
of  potassium,  carbonate  and  lactate  of  an  alkali,  and  sulphate  of  lime, 
phosphate  of  lime,  and  oxide  of  iron,  1'544.  Total,  100-000.  Gmelin 
found,  in  1000  parts  of  human  lymph,  water,  961-0;  solid  constituents, 
30*74;  fibrin,  5*20;  albumen,  4-34;  extractive  matter,  3-12;  fluid  and 
crystalline  fat,  2*64;  chlorides  of  sodium  and  potassium,  alkaline  sul- 
phates and  carbonates,  sulphate  and  phosphate  of  lime,  and  peroxide  of 
iron,  15-44.  M.  L'Heritier3  analyzed  the  lymph  obtained  from  the  thoracic 
duct  of  a  man  who  died  from  softening  of  the  brain,  and  took  nothing 
but  a  little  water  for  thirty  hours  preceding  his  death.  It  contained  in 
1000  parts,— water,  924-36;  solid  constituents,  75-64;  fibrin,  3-20;  fat, 
5-10;  albumen,  60-02;  salts,  8-25.  Lymph,  collected  from  the  absorbent 
vessels  of  the  neck  of  a  horse  was  elaborately  analyzed  by  Nasse,  and 
found  to  contain  in  1000  parts, — water,  950;  solid  residue,  50;  albu- 
men with  fibrin,  39-111;  water  extract,  3*248;  spirit  extract,  0-877; 
alcohol  extract,  0-755;  ethereal  extract,  0-088;  oleate  of  soda,  0-575; 
carbonate  of  soda,  0-560;  phosphate  of  soda,  0-120;  sulphate  of  potassa, 
0-233;  chloride  of  sodium,  4-123;  carbonate  of  lime,  0-104;  phosphate 
of  lime  with  some  iron,  0-095;  carbonate  of  magnesia,  0-044;  silica, 
0-067.  He  compared  the  lymph  with  the  serum  from  the  blood  of  a 
healthy  horse;  and  found  a  remarkable  coincidence  in  the  salts  of  the 
two  fluids. 

1  Turner's  Chemistry,  4th  Amer.  edit.,  p.  567. 

2  Miiller's  Archiv.  Jahrgang,  1838,  s.  129,  cited  in  V.  Bruns,  Lehrbuch  der  Physiologie 
des  Menschen,  s.  135,  Braunschweig,  1841. 

3  Traite  de  Chimie  Pathologique,  p.  18,  Paris,  1842. 


LYMPH. 


671 


Alkaline  chlorides  ... 

Alkaline  carbonates  (oleate  of  soda  included) 
Alkaline  sulphates  ... 

Alkaline  phosphates 


Serum. 

4-055 

1-130 

0-311 

0-115 

5-611 


Lymph. 

4-123 

1-135 

0-233 

0-120 

5-6111 


The  same  observer2  has  given  a  tabular  view  of  six  analyses  of  the 
lymph  of  the  horse  and  ass. 


Water 

Fibrin  -  -  nearly 

Albumen         .... 
Extractive  matter  soluble  only  in  water 
Extractive  matter  soluble  in  alcohol   • 

Fat 

Soluble  salts  )       contained  in 

Salts  of  lime,  magnesia  >  the 

and  silica                      )  extractive  matters 
Oxide  of  iron  ... 
Loss 0-4 


Reuss  and 
Emmert. 

960-0 
3-0 

396 
i 

ters 

Gmelin. 
I. 

961-0 
2-5 
27-5 
2-1 
6-9 

o-o 

Gmelin. 
II. 

967-70 
1-30 
14-85 
2-58 
9-69 
traces 

Lassaigne. 

925-00 
3-30^ 

57-36 
14-34 

Rees. 

965-36 
1-207 
12-005 
13-19 
2-40 
a  trace 

585 
a  trace 

Nasse. 

950-00 
39-11 

3-25 
1-63 

0-09 

5-61 
5    0-31 

3-88 


A  comparative  analysis  of  the  chyle  and  lymph  of  the  ass  has  been 
made  by  Dr.  G.  0.  Rees.3  The  fluids  were  obtained  from  the  chyli- 
ferous  and  lymphatic  vessels  seven  hours  after  a  full  meal,  previous  to 
their  entrance  into  the  thoracic  duct. 


Water          ...... 

Albuminous  matter  -  -  • 

Fibrinous  matter      ..... 

Animal  extractive  matter,  soluble  in  water  and  alcohol 
Animal  extractive  matter,  soluble  in  water  only 
Fatty  matter  ... 

Salts: — alkaline  chloride,  sulphate, and  carbonate,  with 
traces  of  alkaline  phosphate  and  oxide  of  iron 


Chyle. 

90-237 
3-516 
0-370 
0-332 
1-233 
3-601 

0-711 


1 00-000 


Lymph. 

96-536 
1-200 
0-120 
0-240 
1-319 

a  trace. 

0-585 


100-000 


The  chyle — it  will  be  observed — contains  a  larger  proportion  of  de- 
cidedly organizable  matters.  Dr.  Rees4  examined  the  contents  of  the 
thoracic  duct  of  a  human  subject,  procured  an  hour  and  a  quarter  after 
death  by  hanging.  They  amounted  to  six  drachms,  and  yielded  the 
following  results: — 

Water               -  ....  90-48 

Albumen,  with  traces  of  fibrinous  matter         ....  7-QS 

Aqueous  extractive  (zomodine)  .....  Q-56 

Alcoholic  extractive  (osmazome)  .....  0*52 

Alkaline  chloride,  carbonate,  and  sulphate,  with  traces  of  phosphate,  and  )      n  A  . 

oxide  of  iron  5 

Fatty  matters                -             -  -             -             -             -             -  0'92 


100-00 

1  Simon's  Animal  Chemistry,  Sydenham  Soc.  edit.,  p.  353,  Lond.,  1845,  or  Amer.  edit., 
Philad.,  1846. 

2  Wagner's  Handworterbuch  der  Physiologie,  9te  Lieferung,  s.  396,  Braunschweig,  1845. 

3  Lond.  Med.  Gazette,  Jan.,  1841. 

4  Proceedings  of  the  Royal  Society,  Feb.  10,  1842. 


672  k       ABSORPTION. 

Chyle  and  lymph  strikingly  therefore  resemble  each  other;  and  ac- 
cording to  M.  Millon,1  when  taken  from  the  same  animal  at  one  time 
the  analogy  in  composition  is  very  great.  Without  impropriety  they 
may,  indeed,  be  termed  rudimental  blood. 

It  is  impossible  to  estimate  the  quantity  of  lymph  contained  in  the 
body.  It  would  seem,  that  notwithstanding  the  great  capacity  of  the 
lymphatic  vessels,  there  is,  under  ordinary  circumstances,  little  fluid  cir- 
culating in  them.  Frequently,  when  examined,  they  have  appeared  to 
be  empty,  or  pervaded  by  a  mere  thread  of  lymph.  M.  Magendie2  endea- 
voured to  obtain  the  whole  of  the  lymph  from  a  dog  of  large  stature.  He 
could  collect  but  an  ounce  and  a  half;  and  it  appeared  to  him  that  the 
quantity  increased  whenever  the  animal  was  kept  fasting;  but  on  this 
point  he  does  not  seem  to  express  himself  positively. 

3.    PHYSIOLOGY   OF    LYMPHOSIS. 

The  term  lympJiosis  has  been  proposed  by  Chaussier  for  the  action 
of  elaboration  by  which  lymph  is  formed, — as  chylosis  has  been  used 
..3*  for  the  formation  of  chyle,  and  hsematosis  for  that  of  the  blood.  In 
describing  the  organs  concerned,  the  striking  similarity — we  might 
almost  say — identity  in  structure  and  arrangement  between  them  and 
the  chyliferous  organs  will  have  been  apparent.  A  part  of  the  vascu- 
Mr  apparatus  is  common  to  both ;  and  they  manifestly  constitute  one 
and  the  same  system.  This  would  be  sufficient  to  induce  us  to  assign 
them  similar  functions;  and  it  would  require  powerful  and  positive  tes- 
timony to  establish  an  opposite  view.  At  one  period,  lymph  was  con- 
sidered to  be  simply  the  watery  portion  of  the  blood;  and  the  lymphatic 
vessels  were  regarded  as  the  continuation  of  ultimate  arterial  ramifi- 
cations. It  was  affirmed,  that  the  blood,  on  reaching  the  terminal 
branches  of  the  arteries,  separated  into  two  parts ;  the  red  and  thicker 
portion  returning  to  the  heart  by  the  veins ;  and  the  white,  serous  portion 
— liquor  sanguinis — by  the  lymphatics.3  The  reasons  for  this  belief 
were,  the  great  resemblance  between  lymph  and  the  serum  of  the  blood; 
and  the  facility  with  which  an  injection  passes,  in  the  dead  body,  from  the 
arterial  into  the  lymphatic  capillary  vessels.  M.  Magendie  has  revived 
the  ancient  doctrine;  and,  of  consequence,  no  longer  considers  the 
lymphatics  to  form  part  of  the  absorbent  system ;  but  to  belong  to  the 
circulatory  apparatus,  and  to  serve  the  office  of  waste  pipes,  in  case  of 
emergency.  Without  canvassing  this  subject  now,  we  may  assume  it 
for  granted,  that  the  lymph  which  circulates  in  the  lymphatic  vessels 
is  as  identical  in  its  nature,  or  as  little  subject  to  alteration,  as  the 
chyle ;  and  that,  consequently,  whatever  may  be  the  materials  that 
constitute  it,  an  action  of  elaboration  and  selection  must  be  exerted  in 
its  formation. 

It  has  been  conceived,  that  many  of  the  tissues  of  the  body,  the 
serous  membranes,  for  example,  do  not  receive  red  blood;  and  must, 
consequently,  be  nourished  by  white  blood.  The  lymphatics,  in  such 
cases,  have  been  considered  to  be  to  the  white  arteries  what  the  veins 

1  Archives  Generates  de  M«§decine,  Fevr.,  1850,  p.  237. 

2  Op.  citat.,  ii.  192. 

3  Kiikcs  and  Paget,  Manual  of  Physiology,  Amer.  edit.,  p.  256,  Philad.,  1849. 


LYMPHOSIS. 


673 


are  to  the  red.  Such  has  been  presumed  to  be  one  of  their  offices,  but 
it  will  be  seen,  hereafter,  that  all  the  tissues  supplied  with  vessels  receive 
red  blood;  and  hence  it  is  unnecessary  to  suppose,  that  the  lymphatics 
execute  any  venous  function. 

Assuming,  for  the  present,  that  lymph  is  wholly  obtained  from 
materials  already  deposited  in  the  body ;  the  next  inquiry  is, — the  mode 
in  which  its  formation  and  simultaneous  absorption  are  effected.  On 
this  topic,  we  have  no  arguments  to  employ  in  addition  to  those  adduced 
regarding  the  function  of  the  chyliferous  radicles.  In  every  respect, 
they  are  situate  identically,  and  to  the  history  of  the  latter  we  must 
refer  for  an  exposition  of  the  little  we  know  of  this  part  of  lymphosis. 

The  causes  of  the  progression  of  the  lymph  in  the  vessels  are  the 
same  as  those  that 

influence  the    chyle.  Fig.  260. 

In  addition,  however, 
to  those  mentioned 
under  chyliferous  ab- 
sorption, there  is  one 
that  applies  equally 
to  the  chyliferous 
and  lymphatic  ves- 
sels :  this  is  the  mode 
in  which  the  thoracic 
duct  enters  the  sub- 
clavian  vein.  It  has 
been  already  observ- 
ed that  it  occurs  at 
the  point  of  junction 
between  the  jugular 
and  subclavian,  as  at 
D,  Fig.  260,  where  J 
represents  the  jugu- 
lar, and  V  S  the  subclavian,  in  which  the  blood  flows  from  V  towards 
S,  the  cardiac  extremity. 

Now,  it  is  a  physical  fact,  that  when  a  small  tube  is  inserted  per- 
pendicularly into  the  lower  side  of  a  horizontal  conical  pipe,  in  which 
water  is  flowing  from  the  narrower  to  the  wider  portion;  and  if  the 
small  vertical  tube  be  made  to  dip  into  a  vessel  of  water,  not  only  will 
the  water  of  the  larger  pipe  not  descend  into  the  vessel ;  but  it  will 
draw  up  the  water  through  the  small  tube  so  as  to  empty  the  vessel.1 
Instead  of  supposing  the  canals  in  Fig.  260,  to  be  veins  and  the  tho- 
racic duct;  let  us  presume  that  they  are  rigid  mechanical  tubes;  and 
that  the  extremity  of  the  tube  D,  which  represents  the  thoracic  duct, 
dips  into  the  vessel  B.  As  the  fluid,  proceeding  from  J  to  S  and 
V  to  S,  is  passing  from  the  narrower  portions  of  conical  tubes  to  wider, 
it  follows,  that  the  fluid  will  be  drawn  out  of  the  vessel  B,  simply  by 
traction,  or,  by  what  Venturi2  terms  the  lateral  communication  of  fluids. 
This  would  happen  in  whatever  part  of  the  vessel  the  tube  B  D  termi- 

1  Sir  C.  Bell,  in  Animal  Mechanics,  p.  41,  Library  of  Useful  Knowledge,  Lond.,  1829. 

2  Sur  la  Communication  Laterale  duMouvement  dans  les  Fluides,  Paris,  1798. 

VOL.  i. — 43 


Termination  of  Thoracic  Duct. 


674  ABSORPTION. 

nated.  But  its  insertion  at  D  has  another  advantage.  By  the  mode 
in  which  the  current  from  J  towards  S  unites  with  that  from  V  towards 
S,  a  certain  degree  of  diminished  pressure  must  exist  at  D  ;  so  that  the 
atmospheric  pressure,  on  the  surface  of  the  water  in  the  vessel  B,  will 
be  exerted  in  propelling  it  forwards.  In  the  progress,  then,  of  the 
chyle  and  lymph  along  the  thoracic  duct,  not  only  may  the  traction  of 
the  more  forcible  stream  along  the  veins  draw  the  fluid  in  the  thoracic 
duct  along  with  it,  but,  owing  to  the  diminished  pressure  at  the  mouth 
of  the  duct,  atmospheric  pressure  may  have  some — although  probably 
but  little — influence,  in  forcing  the  chyle  and  lymph  from  the  chylife- 
rous  and  lymphatic  radicles  onwards.  The  lymphatic  glands  have  been 
looked  upon  as  small  hearts  for  the  propulsion  of  lymph ;  and  Malpighi 
accounts  for  the  greater  number  in  the  groin  in  this  way; — the  lymph 
having  to  ascend  to  the  thoracic  duct  against  gravity:  and  this  appears 
to  have  been  somewhat  the  opinion  of  Bichat.  There  seems,  however, 
to  be  nothing  in  their  structure  that  ought  to  lead  to  this  belief;  and, 
if  it  be  not  muscular  or  contractile,  it  is  manifest,  that  their  number 
must  have  the  effect  of  retarding  rather  than  accelerating  the  flow. 
The  most  prevalent  sentiment  is,  that  they  are  somehow  concerned  in 
the  admixture  of  the  lymph ;  and  by  many  it  is  conceived,  that  some 
kind  of  elaboration  is  effected  by  them ;  but,  on  this  topic,  we  have 
only  conjectures.  Of  their  true  functions  we  know  nothing  definite. 

On  the  subject  of  the  moving  powers  of  the  lymph,  M.  Adelon1  has 
remarked,  that  if  we  admit  it  to  be  the  serous  portion  of  the  blood; 
and  that  the  lymphatics  are  vessels  of  return,  as  the  veins  are,  the 
heart  might  be  considered  to  have  the  same  influence  over  lymphatic, 
that  it  has  been  presumed  to  have  over  venous,  circulation;  and  whether 
we  admit  this  or  not,  as  the  thoracic  duct  opens  into  the  subclavian 
vein,  .the  influence  of  the  suction  power  of  the  organ  on  the  venous 
blood  may  affect  the  progression  of  the  chyle  also.  It  cannot,  how- 
ever, as  Muller2  remarks,  be  the  primary  cause  of  the  motion  of  the 
chyle,  for  Autenrieth,  Tiedemann,  and  Carus  observed,  when  a  liga- 
ture was  applied  to  the  thoracic  duct,  that  the  part  of  the  duct  below 
the  ligature  became  distended  even  to  bursting.  We  shall  see  here- 
after, that  during  inspiration,  absorption,  it  is  imagined,  may  be  facili- 
tated by  the  dilatation  of  the  chest,  and  the  necessary  diminution  of 
pressure  on  the  heart  and  great  vessels. 

Professor  Miiller3  discovered,  that  the  frog,  and  several  other  am- 
phibious animals,  are  provided  with  large  receptacles  for  lymph,  situate 
immediately  under  the  skin,  and,  like  the  heart,  exhibiting  distinct  and 
regular  pulsations.  The  use  of  these  lymph  hearts  appears  to  be  to 
propel  the  lymph  along  the  lymphatics.  In  the  frog,  four  of  them, 
have  been  found;  two  posterior,  behind  the  joint  of  the  hip;  and  two 
anterior,  on  each  side  of  the  transverse  process  of  the  third  vertebra, 
and  under  the  posterior  extremity  of  the  scapula.  The  pulsations  of 

1  Art.  Absorption,  in  Dict.de  Medecine,  2de  edit.,  i.  239,  Paris,  1832;  and  Physiologic 
de  1'Homrae,  edit,  cit.,  iii.  92. 

2  Handbuch,  u.  s.  w.;  and  Baly's  translation,  p.  284,  Lond.,  1838. 

3  Philos.  Transact,  for  1833;  and  op.  cit.     See,  also,  his  Observations  on  the  Lymphatic 
Hearts  of  Tortoises,  in  Muller's  Archiv.,  Heft  1,  1840. 


LYMPHOSIS. 


675 


r 

Lymph  Heart  of  Python  Bivit- 

tatui  after  Weber.    Heart 
9  lines  long;  4  broad. 

*.  External  areoiar  coat.   5. 


- 
here>  and  tw°  veins,  '2,  2.    e. 

Smooth  lining  membrane  of  the 

cavity.  7.  An  appendix  or  au- 
'  C°m" 


these  lymphatic  hearts  do  not  correspond  with  Fig.  261. 

those  of  the  sanguiferous  heart;  nor  do  those  of 
the  right  and  left  sides  occur  synchronously. 
They  often  alternate  irregularly.  Prof.  E.  H. 
"Weber  has  described  them  in  a  larger  species 
of  serpent — python  bivittatus;1  and  Dr.  Joseph 
J.  Allison,  of  Philadelphia,2  a  young  and  zeal- 
ous observer,  who  was  cut  off  early  in  his  ca- 
reer, saw  them  in  the  tadpole,  the  frog,  the 
sauria,  ophidia,  and  chelonia.  His  researches 
led  him  to  conclude : — First.  That  the  pulsa- 
tions of  the  lymphatic  organs  vary  in  different 
specimens  (frogs  and  tadpoles)  from  60  or  less 
to  200  per  minute.  Secondly.  That  they  vary 
in  the  same  individual  so  as  sometimes  to  be- 
come double  in  frequency.  Thirdly.  That 
the  lymphatic  pulsations  bear  no  fixed  relation 
to  those  of  the  pulmonary  heart  or  to  respira- 
tion, the  lymphatic  hearts  beating — on  an 
average — with  greater  frequency. 

More  recently,  Professor  Stannius3  has  dis- 
covered lymphatic  hearts  in  various  birds. 

Unlike  that  of  the  heart,  the  action  of  these  lymph  hearts  appears 
to  be  dependent  upon  a  certain  limited  portion  of  the  spinal  cord ;  for 
Volkmann4  found,  that  by  dividing  the  anterior  or  motor  roots  of  the 
spinal  nerves  connected  with  them,  the  pulsations  immediately  ceased. 

The  course  of  the  lymph  is  by  no  means  rapid.  If  a  lymphatic  be 
divided  on  a  living  individual,  the  lymph  oozes  slowly,  and  never  with 
a  jet.  M.  Cruikshank  estimated  its  velocity  along  the  vessels  to  be 
four  inches  per  second  or  twenty  feet  per  minute;  but  it  is  probably 
much  less.  M.  Collard  de  Martigny5  obtained  nine  grains  of  lymph 
in  ten  minutes  from  the  thoracic  duct  of  a  rabbit,  which  had  taken  no 
food  for  twenty-four  hours.  Having  pressed  out  the  lymph  from  the 
principal  lymphatic  trunk  of  the  neck,  in  a  dog,  the  vessel  filled  again 
in  seven  minutes :  in  a  second  experiment  it  filled  in  eight  minutes. 
The  data  for  any  correct  evaluation  of  this  matter  are  altogether  in- 
adequate, the  deranging  influence  of  all  such  experiments  being  con- 
siderable. 

In  man  and  living  animals,  the  lymphatics  of  the  limbs,  head,  and 
neck  rarely  contain  lymph;  their  inner  surface  appearing  to  be  merely 
lubricated  by  a  very  thin  fluid.  Occasionally,  however,  the  lymph 
stops  in  different  parts  of  the  vessels;  distends  them;  and  gives  them 
an  appearance  very  like  that  of  varicose  veins,  except  as  to  colour. 
Somrnering  states,  that  he  saw  several  in  this  condition  on  the  top  of 

1  Muller,  op.  citat,  p.  275. 

2  American  Journal  of  the  Medical  Sciences,  for  August,  1838. 

3  Muller's  Archiv.,  1843,  Heft  5. 

4  Ibid.,  419,  Berlin,  1844;  and  Valentin,  Lehrbuch  der  Physiologie  des  Menschen,  ii.  769, 
Braunschweig,  1844. 

5  Journal  de  Physiologie,  torn.  viii. 


676  ABSORPTION. 

the  foot  of  a  female ;  and  M.  Magendie  one  around  the  corona  glandis 
of  a  male.  In  dogs,  cats,  and  other  living  animals,  lymphatics,  filled 
with  lymph,  are  frequently  seen  at  the  surface  of  the  liver,  gall-bladder, 
vena  cava,  vena  portae,  and  at  the  sides  of  the  spine.  Magendie  re- 
marks, that  he  has  never  met  with  the  thoracic  duct  empty,  even  when 
the  lymphatics  of  the  rest  of  the  body  were  entirely  so.1  It  must  be 
recollected,  however,  that  the  thoracic  duct  must  always  contain  the 
product  of  the  digestion  either  of  food  or  of  secretions  from  the  aliment- 
ary tube.  The  stagnation  of  lymph  in  particular  vessels  has  given 
occasion  to  the  belief,  that  it  flows  with  different  degrees  of  velocity  in 
different  parts  of  the  system;  and  this  notion  has  entered  into  the 
pathological  views  of  writers,  who  have  presumed,  that  something  like 
determinations  of  lymph  may  occur,  and  produce  lymphatic  swellings. 
M.  Bordeu,2  indeed,  speaks  of  currents  of  lymph.  All  the  phenomena 
of  the  course  of  the  lymph  negative,  however,  this  presumption ;  and  in- 
duce us  to  believe,  that  its  progress  is  pretty  uniform,  and  always  slow; 
and  when  an  accumulation,  or  engorgement,  or  stagnation  occurs  in 
any  vessel,  it  is  more  probably  owing  to  increased  formation  by  the 
lymphatic  radicles  that  communicate  with  the  vessel  in  question,  or  to 
loss  of  tone  in  the  parietes  of  the  engorged  lymphatics. 

The  lymph,  which  proceeds  by  the  thoracic  duct,  is  emptied,  along 
with  the  chyle,  into  the  subclavian  vein.  At  the  confluence,  a  valve 
is  placed,  which  does  not,  however,  appear  to  be  essential,  as  the  duct 
opens  so  favourably  between  the  two  currents  from  the  jugular  and 
subclavian,  that  there  is  little  or  no  tendency  in  the  blood  to  reflow  into 
it.  It  has  been  suggested,  that  its  use  may  be,  to  moderate  the  instilla- 
tion of  the  fluid  from  the  thoracic  duct  into  the  venous  blood. 

With  regard  to  the  question,  whether  the  lymph  is  the  same  at  the 
radicles  of  the  lymphatics  as  in  the  thoracic  duct,  or  whether  it  does 
not  gradually  become  more  and  more  animalized  in  its  course  towards 
the  venous  system,  and  especially  in  its  progress  through  the  lymphatic 
glands,  the  remarks  made  upon  this  subject,  as  respects  the  chyle,  apply 
with  equal  force  to  the  lymph.  Our  ignorance  is  no  less  profound. 

The  glands  of  the  mesentery,  and  lymphatics  in  general,  seem  to  be 
concerned  in  some  of-  the  most  serious  diseases.  Swelling  of  the 
lymphatic  glands  of  the  groin  may  indicate  the  existence  of  a  venereal 
sore  on  the  penis.  A  wound  on  the  foot  produces  tumefaction  of  the 
inguinal  glands ;  one  on  the  hand  inflames  those  of  the  axilla.  When- 
ever, indeed,  a  lymphatic  gland  is  symptomatically  enlarged,  the  source 
of  irritation  will  be  found  at  a  greater  distance  from  the  vein  into  wh&h 
the  great  lymphatic  trunks  pour  their  fluid  than  the  gland  is.  In 
plague,  one  of  the  essential  phenomena  is  swelling  of  the  lymphatic 
glands  of  the  groin  and  axilla;  hence,  it  has  been  termed  adeno-ady- 
namic  fever  (from  aS^,  a  gland).  In  scrofula,  the  lymphatic  system  is 
generally  deranged;  and,  in  the  doctrine  of  Broussais,  a  very  active 
sympathy  is  affirmed  to  exist  between  the  glands  of  the  mesentery,  and 
the  mucous  surface  of  the  stomach  and  intestines.  This  discovery,  we 
are  told,  belongs  to  the  "physiological  doctrine"  which  has  shown,  that 

1  Precis,  &c.,  ii.  224.  2  (Euvres  completes,  par  Richerand,  Paris,  1818. 


VENOUS.  677 

all  gastro-enterites  are  accompanied  by  tumefaction  of  the  mesenteric 
glands :  although  chyle  may  be  loaded  with  acrid,  irritating,  or  even 
poisonous  matters,  it  traverses  the  glands  with  impunity,  provided  it 
does  not  inflame  the  gastro-enteric  mucous  surface.  "Our  attention," 
Broussais1  adds,  "has  been  for  a  long  time  directed  to  this  question, 
and  we  have  not  observed  any  instance  of  mesenteric  ganglionitis,  which 
had  not  been  preceded  by  well-evidenced  gastro-enteritis."  The  dis- 
covery will  not  immortalize  the  "doctrine."  We  should  as  naturally 
look  for  tumefaction  of  the  mesenteric  glands  or  ganglia,  in  cases  of 
irritation  of  the  intestine,  as  for  enlargement  of  the  glands  of  the  groin 
in  irritation  of  the  foot. 

Lastly;  the  lymph,  from  whatever  source  obtained — united  with  the 
chyle — is  discharged  into  the  venous  system.  Both,  therefore,  go  to 
the  composition  of  the  body.  They  are  entirely  analogous  in  proper- 
ties; but  differ  materially  in  quantity; — the  nutritious  fluid,  formed 
from  materials  obtained  from  without,  being  far  more  copious.  A  due 
supply  of  it  is  required  for  continued  existence ;  yet  the  body  can  live 
for  a  time,  when  the  supply  of  nutriment  is  entirely  cut  off.  Under 
such  circumstances,  the  necessary  proportion  of  nutritive  fluid  must  be 
obtained  from  the  decomposition  of  the  tissues;  but,  from  the  perpetual 
drain,  that  takes  place  through  the  various  excretions,  this  soon  becomes 
insufficient,  and  death  is  the  result.  In  a  note  to  the  recent  editions 
of  his  "Principles  of  Human  Physiology,"2  Dr.  Carpenter  remarks,  that 
at  the  time  of  the  publication  of  the  first  edition  of  his  work  (1842)  he 
was  under  the  impression,  that  the  view  maintained  by  him,  "that  the 
special  function  of  the  lymphatics  like  that  of  the  lacteals  is  nutritive 
absorption,"  was  altogether  novel.  The  author  attaches  little  value  to 
originality  in  such  matters;  but  he  thinks  it  well  to  state,  that  the  doc- 
trine in  the  text  is,  that  adopted  by  him  in  the  first  edition  of  this  work 
(1832),  and  taught  by  him  ever  since  he  has  been  a  teacher;  yet  he  is 
far  from  regarding  it  as  original  with  him. 

We  have  seen,  then,  that  both  chyle  and  lymph  are  poured  into  the 
venous  blood; — itself  a  compound  of  the  residue  of  arterial  blood,  and 
various  heterogeneous  absorptions.  As  an  additional  preliminary  to  the 
investigation  of  the  agents  of  internal  absorption,  let  us  inquire  into  the 
nature  and  course  of  the  fluid  contained  in  the  veins;  but  so  far  only 
as  to  enable  us  to  understand  the  function  of  absorption ;  the  other  con- 
siderations relating  to  the  blood  appertain  to  the  function  of  circulation. 

III.   VENOUS  ABSORPTION. 

The  apparatus  of  venous  absorption  consists  of  myriads  of  vessels 
called  veins,  which  commence  in  the  very  tissues,  by  what  are  called 
capillary  vessels,  and  thence  pass  to  the  great  central  organ  of  the  cir- 
culation— the  heart;  receiving,  in  their  course,  the  products  of  the  va- 
rious absorptions  effected  not  only  by  themselves,  but  by  the  chyliferous 

1  Traite"  de  Physiologie,  &c.,  and  Bell  and  La  Roche's  translation,  3d  Amer.  edit.,  p.  362, 
Philadelphia,  1832. 

2  Fourth  American  edition,  p.  506,  Philad.,  1850.    See  on  this  subject,  Adelon,  Art.  Absorp- 
tion, in  Diet,  de  Medecine,  i.  p.  117,  Paris,  1821;  arid  Moultrie,  American  Journal  of  the 
Medical  Sciences  for  1827,  and  On  the  Organic  Functions  of  Animals,  Charleston,  1844. 


6T8  ABSORPTION. 

and  lymphatic  vessels.     The  anatomy  of  the  venous  system  will  be 
given  under  Circulation. 

1.    PHYSIOLOGY   OF   VENOUS   ABSORPTION. 

Whilst  the  opinion  prevailed  universally,  that  the  lymphatics  are  the 
sole  agents  of  absorption,  the  fluid,  circulating  in  the  veins,  was  con- 
sidered to  consist  entirely  of  the  residue  of  arterial  blood,  after  it  had 
passed  through  the  capillary  system,  and  been  subjected  to  the  different 
nutritive  processes.  We  have  seen,  however,  that  drinks  are  absorbed 
by  the  mesenteric  veins;  and  we  shall  hereafter  find,  that  various  other 
substances  enter  the  venous  system.  It  is  obvious,  therefore,  that  ve- 
nous blood  cannot  be  simply  the  residue  of  arterial  blood;  and  we  can 
thus  account  for  the  greater  capacity  of  the  venous  than  of  the  arterial 
system.  The  facts,  which  were  referred  to,  when  considering  the  ab- 
sorption of  fluids  from  the  intestinal  canal,  may  have  been  sufficient 
to  show,  that  veins  are  capable  of  absorbing;  as  odorous  and  colouring 
properties  of  substances  were  distinctly  found  in  the  mesenteric  veins. 
A  question  arises,  whether  any  vital  elaboration  is  concerned,  as  in  the 
case  of  the  chyle,  or  whether  the  fluid,  when  it  attains  the  interior  of 
the  vessel,  is  the  same  as  without?  M.  Adelon,1 — who,  with  many  of 
the  German  physiologists,  believes  in  both  venous  and  lymphatic  ab- 
sorption, and  venous  and  chyliferous  absorption, — conceives,  that  a  vital 
action  takes  place  at  the  very  extremities  of  the  venous  radicles,  pre- 
cisely similar  to  that  which  is  presumed  to  be  exerted  at  the  extremities 
of  the  lymphatic  and  chyliferous  radicles.  In  his  view,  consequently, 
an  action  of  elaboration  is  exerted  upon  the  fluid,  which  becomes,  in  all 
cases,  converted  into  venous  blood  at  the  very  moment  of  absorption. 
On  the  other  hand,  MM.  Magendie,2  FodeYa,3  and  others  maintain,  that 
the  substance  when  possessed  of  the  necessary  tenuity  soaks  through  the 
vessel ;  and  that  this  act  of  imbibition  is  purely  physical.  In  their  view, 
consequently,  the  fluid  within  the  vessel  must  be  the  same  as  without. 

In  favour  of  the  vital  action  of  the  veins  we  have  none  of  that  evi- 
dence, which  strikes  us  in  the  case  of  the  chyliferous  and  lymphatic 
vessels.  In  the  last  we  invariably  find  fluids,  identical — in  all  essen- 
tial respects — in  physical  characters  ;  and  never  containing  extraneous 
matter, — if  we  make  abstraction  of  certain  salts,  that  have  been  occa- 
sionally met  with  in  the  thoracic  duct.  In  the  veins,  on  the  other  hand, 
the  sensible  properties  of  odorous  and  colouring  substances  have  been 
frequently  apparent.  It  may  be  remarked,  however,  that  the  fluid, 
flowing  in  the  veins,  is  as  identical  in  composition  as  the  chyle  or  the 
lymph.  This  is  true  ;  but  it  must  be  recollected,  that  the  greater  part 
of  it  is  the  residue  of  arterial  blood  ;  and  that  its  hue  and  other  sen- 
sible properties  are  such  as  to  disguise  any  absorbed  fluid,  not  itself 
possessing  strong  characteristics.  The  fact, — now  indisputable, — that 
various  substances,  placed  outside  the  veins,  have  been  detected  in  the 
blood  within,  is  not  only  a  proof  that  the  veins  absorb ;  but  that  no 

1  Art.  Absorption,  in  Diet,  de  Medecine,  2de  edit.,  i.  239,  Paris,  1832 ;  and  Physiologie  de 
1'Homme,  2de  edit,  iii.  113,  Paris,  1829. 

2  Precis,  &c.,  2de  edit.,  ii.  271. 

3  Recherches  Experimentales  sur  1'Exhalation  et  1'Absorption,  Paris,  1823. 


VENOUS.  679 

action  of  elaboration  is  exerted  on  the  absorbed  fluid.  Of  this  we  have 
the  most  convincing  proof  in  certain  experiments  by  M.  Magendie.1  In 
exhibiting  to  his  class  the  mode  in  which  medicines  act  upon  the  sys- 
tem, he  showed,  on  a  living  animal,  the  effects  of  introducing  a  quantity 
of  water,  of  the  temperature  of  104°  Fah.,  into  the  veins.  In  perform- 
ing this  experiment,  it  occurred  to  him  to  notice  what  would  be  the 
effect  produced  by  artificial  plethora  on  the  phenomena  of  absorption. 
Having  injected  nearly  a  quart  of  water  into  the  veins  of  a  dog  of  middle 
size,  he  placed  in  the  cavity  of  the  pleura  a  small  dose  of  a  substance 
with  the  effects  of  which  he  was  familiar,  and  was  struck  with  the  fact, 
that  they  did  not  exhibit  themselves  for  several  minutes  after  the  ordi- 
nary period.  He  immediately  repeated  the  experiment,  and  with  a 
like  result.  In  several  other  experiments,  the  effects  appeared  at  the 
ordinary  time,  but  were  manifestly  feebler  than  they  ought  to  have 
been  from  the  dose  of  the  substance  employed  ;  and  were  kept  up  much 
longer  than  usual. 

In  another  experiment,  having  introduced  as  much  water  as  the  ani- 
mal could  bear  without  perishing, — which  was  about  two  quarts, — the 
effects  did  not  occur  at  all.  After  having  waited  nearly  half  an  hour 
for  their  developement,  which  generally  required  only  about  two  minutes, 
he  inferred,  that  if  the  distension  of  the  bloodvessels  was  the  cause  of 
the  defect  of  absorption,  if  the  distension  were  removed,  absorption 
ought  to  take  place.  He  immediately  bled  the  animal  largely  in  the 
jugular ;  and,  to  his  great  satisfaction,  found  the  effects  manifesting 
themselves  as  the  blood  flowed.  He  next  tried  whether,  if  the  quantity 
of  blood  were  diminished  at  the  commencement  of  the  experiment,  ab- 
sorption would  be  more  rapid ;  and  the  result  was  as  he  anticipated. 
An  animal  was  bled  to  the  extent  of  about  half  a  pound  ;  and  the  effects, 
which  did  not  ordinarily  occur  until  after  the  second  minute,  appeared 
before  the  thirtieth  second.  As  the  results  of  these  experiments  seemed 
to  show,  that  absorption  is  in  an  inverse  ratio  to  the  degree  of  vascular 
distension,  he  inferred,  that  it  is  effected  physically  ;  is  dependent  upon 
capillary  attraction ;  and  ought  to  take  place  as  well  after  death  as 
during  life.  To  prove  this,  he  instituted  the  following  experiments. — He 
took  a  portion  of  the  external  jugular  of  a  dog,  about  an  inch  long  and 
devoid  of  branches.  Removing  carefully  the  surrounding  areolar  tissue, 
he  attached  to  each  extremity  a  glass  tube,  by  means  of  which  he  kept  up 
a  current  of  warm  water  within  it.  He  then  placed  the  vein  in  a  slightly 
acid  liquor,  and  carefully  collected  the  fluid  of  the  current.  During  the 
first  few  minutes,  it  exhibited  no  change ;  but,  in  five  or  six  minutes, 
became  sensibly  acid.  This  experiment  was  repeated  on  veins  taken 
from  the  human  subject  with  like  results;  and  not  only  on  veins  but  on 
arteries. 

Similar  experiments  were  next  made  on  living  animals.  He  took  a 
young  dog,  about  six  weeks  old,  whose  vessels  were  thin,  and,  conse- 
quently, better  adapted  for  the  success  of  the  experiment,  and  exposed 
one  of  its  jugular  veins.  From  this  he  dissected  entirely  the  surround- 
ing matter,  and  especially  the  areolar  tissue,  and  the  minute  vessels 
that  ramified  upon  it ;  and  placed  it  upon  a  card,  in  order  that  there 

1  Op.  citat.,  ii.  273. 


680  ABSORPTION. 

might  be  no  point  of  contact  between  it  and  the  surrounding  parts.  He 
then  let  fall  upon  its  surface  and  opposite  the  middle  of  the  card  a 
thick  watery  solution  of  nux  vomica, — a  substance,  that  exerts  a  power- 
ful action  on  dogs.  He  took  care,  that  no  particle  of  the  poison  touched 
any  thing  but  the  vein  and  cord ;  and  that  the  course  of  the  blood, 
within  the  vessel,  was  free.  Before  the  expiration  of  three  minutes, 
the  effects  he  expected  appeared, — at  first  feebly,  but  afterwards  with 
so  much  activity,  that  to  prevent  fatal  results  he  had  to  inflate  the 
lungs.  The  experiment  was  repeated  on  an  older  animal  with  the  same 
results  ;  except  that,  as  might  have  been  expected,  they  were  longer  in 
exhibiting  themselves,  owing  to  the  greater  thickness  of  the  parietes  of 
the  veins. 

Satisfied,  as  regarded  the  veins,  he  now  directed  his  attention  to  the 
arteries: — the  results  were  the  same.  They  were,  however,  slower  in 
appearing  than  in  the  case  of  the  veins,  owing  to  the  tissue  of  the  arte- 
ries being  less  spongy.  It  required  upwards  of  a  quarter  of  an  hour 
for  imbibition  to  be  accomplished.  In  one  of  the  rabbits,  which  died 
under  the  experiment,  they  had  an  opportunity  of  discovering,  that 
absorption  could  not  have  been  effected  by  any  small  veins,  that  had 
escaped  dissection.  One  of  the  carotids, — the  subject-vessel  of  the 
experiment, — was  taken  from  the  body;  and  the  small  quantity  of  blood, 
adherent  to  its  inner  surface,  was  found  by  M.  Magendie,  and  his  friends 
who  assisted  at  the  experiment,  to  possess  the  extreme  bitterness  that 
characterizes  nux  vomica.  These  experiments  were  sufficient  to  prove 
the  fact  of  imbibition  by  the  large  vessels,  both  in  the  dead  and  in  the 
living  state.  His  attention  was  now  directed  to  the  smaller;  which 
seemed,  a  priori,  favourable  to  the  action,  from  their  delicacy  of  organi- 
zation. He  took  the  heart  of  a  dog,  that  had  died  the  day  before,  and 
injected  water,  of  the  temperature  of  86°  of  Fah.,  into  one  of  the 
coronary  arteries,  which  readily  returned  by  the  coronary  vein  into  the 
right  auricle,  whence  it  was  allowed  to  flow  into  a  vessel.  Half  an 
ounce  of  water,  slightly  acidulated,  was  now  placed  in  the  pericardium. 
At  first,  the  injected  fluid  did  not  exhibit  any  signs  of  acidity;  but,  in 
five  or  six  minutes,  the  evidences  were  unequivocal. 

From  these  facts,  M.  Magendie1  draws  the  too  exclusive  deduction,  that 
"all  bloodvessels,  arterial  and  venous,  dead  or  living,  large  or  small, 
possess  a  physical  property  capable  of  accounting  for  the  principal 
phenomena  of  absorption."  We  shall  endeavour  to  show,  that  it 
explains  only  certain  varieties  of  absorption, — those  in  which  the 
vessel  receives  the  fluid  unmodified, — but  that  it  is  unable  to  account 
for  other  absorption  in  which  an  action  of  selection  and  elaboration  is 
necessary. 

After  these  experiments  were  performed,  others  were  instituted  by 
MM.  S£galas2  and  FodeVa,3  from  which  the  latter  physiologist  attempts 
to  show,  that  exhalation  is  simply  a  transudation  of  substances  from  the 
interior  of  vessels  to  the  exterior ;  and  absorption  an  imbibition  or  pas- 
sage of  fluids  from  the  exterior  to  the  interior.  The  facts  adduced  by 

1  Precis,  &c.,  ii.  283.  2  Magendie's  Journal  de  Physio).,  ii.  217. 

3  Recherches  Experiment,  sur  1' Absorption,  &c.,  Paris,  1824,  and  Magendie's  Journal,  &c., 
iii.  35. 


VENOUS.  681 

M.  FodeVa  in  support  of  his  views  will  be  considered  under  the  head  of 
SECRETION.  They  go  chiefly  to  show  the  facility  with  which  substances 
penetrate  the  parietes  of  vessels  and  other  tissues  of  the  body ;  an  action 
which  he  found  to  be  singularly  accelerated  by  the  galvanic  influence. 
Prussiate  of  potassa  was  injected  into  the  cavity  of  the  pleura;  and  sul- 
phate of  iron  introduced  into  that  of  the  peritoneum  in  a  living  animal. 
Under  ordinary  circumstances,  it  requires  five  or  six  minutes  before  the 
two  substances  meet  by  imbibition  through  the  diaphragm ;  but  the  ad- 
mixture is  instantaneous  if  the  diaphragm  be  subjected  to  a  slight  gal- 
vanic current.  The  same  fact  is  observed,  if  one  of  the  liquids  be  placed 
in  the  urinary  bladder,  and  the  other  in  the  abdomen;  or  the  one  in  the 
lung,  and  the  other  in  the  cavity  of  the  pleura.  It  was  further  found, 
that,  according  to  the  direction  of  the  current,  the  union  took  place  in 
the  one  or  the  other  cavity.  Dr.  Bostock,1  in  commenting  on  these 
cases,  thinks  it  must  be  admitted,  that  they  "go  very  far  to  prove  that 
membranes,  perhaps  even  during  life,  and  certainly  after  death,  before 
their  texture  is  visibly  altered,  have  the  power  of  permitting  the  transu- 
dation  of  certain  fluids."  That  such  imbibition  occurs  during  life,  ap- 
pears to  be  indisputably  proved.  If  the  clear  and  decisive  experiments 
of  Magendie  and  Fod6ra  were  insufficient,  the  additional  testimony, — 
afforded  by  Lawrence,  Coates,  and  Harlan ;  by  Dutrochet,  Faust,  Mit- 
chell, Rogers,  Draper,  and  others, — would  command  it.  By  the  different 
rates  of  penetrativeness  of  different  fluids,  and  of  permeability  of  dif- 
ferent tissues,  we  can  explain  why  imbibition  may  occur  in  one  set  of 
vessels  and  not  in  another;  and  the  constant  current,  established  in  the 
interior  of  the  vessel  is  a  sufficient  reply  to  the  suggestion,  that  there  may 
not  be  the  same  tendency  to  transude  after  the  fluid  has  entered  it. 
M.  Adelon2  is  of  opinion,  that  under  the  view  of  imbibition  we  ought 
to  find  substances  in  the  arteries  and  lymphatics  also ;  but  a  sufficient 
objection  to  this  would  be, — the  comparative  tardiness,  with  which  the 
former  admit  the  action ;  and  the  selection,  and,  consequently,  refusal, 
exerted  by  the  latter;  but  even  here  evidences  of  adventitious  imbibition 
are  occasionally  met  with;  as  in  the  case  of  salts,  which — we  have  seen 
— have  been  detected  in  the  thoracic  duct,  after  having  been  intro- 
duced into  the  cavity  of  the  abdomen. 

The  two  following  experiments  by  Prof.  J.  K.  Mitchell,1  which  are 
analogous  to  numerous  others,  performed  in  the  investigation  of  this 
subject,  well  exhibit  endosmose  in  living  tissues.  A  quantity  of  a  solution 
of  acetate  of  lead  was  thrown  into  the  peritoneal  cavity  of  a  young  cat; 
sulphuretted  hydrogen  being  passed,  at  the  same  time,  into  the  rectum. 
In  four  minutes,  the  poisonous  gas  killed  the  animal.  Instantly  on  its 
death,  the  peritoneal  coat  of  the  intestines,  and  the  parietes  of  the 
cavity  in  contact  with  them,  were  found  lined  with  a  metallic  precipi- 
tate, which  adhered  to  the  surface,  and  was  removable  by  nitric  acid 
moderately  diluted.  It  was  the  characteristic  precipitate  of  sulphuretted 
hydrogen,  when  acting  on  lead.  In  another  experiment  on  a  cat,  a 
solution  of  acetate  of  lead  was  placed  in  the  thorax,  and  sulphuretted 
hydrogen  in  the  abdomen.  Almost  immediately  after  the  entrance  of 

1  Physiology,  edit,  cit.,  p.  629.  2  °P-  cit- 

3  American  Journal  of  the  Medical  Sciences,  vii.  44,  Philada.,  1830. 


682  ABSORPTION. 

the  sulphuretted  hydrogen  into  the  abdominal  cavity,  death  ensued. 
On  inspecting  the  thoracic  side  of  the  diaphragm,  which  was  done  as 
quickly  as  possible,  the  tendinous  part  of  it  exhibited  the  leaden  appear- 
ance of  the  precipitate  thrown  down  by  sulphuretted  hydrogen.  The 
experiment  of  J.  Muller,  referred  to  in  a  preceding  page,  establishes 
the  same  fact. 

It  may  be  concluded,  then,  that  all  living  tissues  imbibe  liquid  mat- 
ters which  come  in  contact  with  them;  and  that  the  same  occurs  to 
solids,  provided  they  are  soluble  in  the  humours,  and  especially  in  the 
serum  of  the  blood.  But  although  imbibition  is  doubtless  effected  by 
living  tissues,  too  great  a  disposition  has  been  manifested  to  refer  all 
the  vital  phenomena  of  absorption  and  exhalation  to  it.  Even  dead 
animal  membrane  has  been  supposed  to  exert  a  positive  agency  in  re- 
spect to  bodies  placed  on  either  side  of  it.  In  the  early  part  of  this 
work1  the  phenomena  of  imbibition  were  investigated,  and  it  was  there 
explained  how  endosmose  and  exosmose  are  effected  through  organic 
membranes.  A  careful  examination  of  those  phenomena  would  lead  to 
the  belief,  that  in  many  cases  the  membrane  exerts  no  agency  except  in 
the  manner  last  suggested  by  M.  Dutrochet.  This  is  signally  manifested 
in  experiments  with  porous,  inorganic  substances ;  and  it  has  been  in- 
geniously and  ably  confirmed  by  Dr.  Draper,2  of  New  York,  who  found, 
that  the  phenomena  were  elicited,  when,  instead  of  an  organic  tissue, 
fissured  glass  was  employed.  Still,  as  has  been  demonstrated,  the 
nature  of  the  septum  or  membrane  has  in  other  cases  a  marked  effect 
on  endosmose. 

Sir  David  Barry,3 — in  different  memoirs  laid  before  the  Academie 
Royale  de  Mgdecine,  the  Academie  Royale  des  Sciences  of  Paris,  and 
the  Medico-  Chirurgical  Society  of  London, — maintained,  that  the  whole 
function  of  external  absorption  is  a  physical  result  of  atmospheric  pres- 
sure; and  "that  the  circulation  in  the  absorbing  vessels  and  in  the 
great  veins  depends  upon  this  same  cause  in  all  animals  possessing 
the  power  of  contracting  and  dilating  a  cavity  around  that  point  to 
which  the  centripetal  current  of  their  circulation  is  directed."  In  other 
words,  it  is  his  opinion,  that,  at  the  time  of  inspiration,  a  tendency 
to  a  vacuum  is  produced  in  the  chest  by  its  expansion;  and  as  the 
atmospheric  pressure  externally  thus  ceases  to  be  counterbalanced,  the 
pressure  without  occasions  the  flow  of  blood  towards  the  heart  along 
the  veins.  The  consideration  of  the  forces  that  propel  the  blood  will 
afford  us  an  opportunity  of  saying  a  few  words  on  this  view ;  at  present, 
we  may  only  observe,  that  Sir  David  ascribes  absorption, — which  he 
explicitly  states  to  be,  in  his  opinion,  extra  vital, — to  the  same  cause. 
In  proof  of  this,  he  instituted  numerous  experiments,  in  which  the 
absorption  of  poisons  from  wounds  appeared  to  take  place,  or  to  be 
suspended,  according  as  the  wounds  were,  as  he  conceived,  exposed  to 
atmospheric  pressure,  or  freed  from  its  influence  by  the  application  of 
a  cupping-glass.  The  same  quantity  of  poison,  which,  under  ordinary 

1  See  p.  65. 

2  Amer.  Journ.  of  the  Med.  Sciences,  for  Aug.,  1836,  p.  276;  Nov.,  1837,  p.  122  ;  May, 
1838,  p.  23,  and  August,  1838— more  especially  the  two  last. 

3  Experimental  Researches  on  the  Influence  of  Atmospheric  Pressure  upon  the  Circulation, 
&c.,Lond.,1826. 


VENOUS.  683 

circumstances,  destroyed  an  animal  in  a  few  seconds,  was  rendered  com- 
pletely innocuous  by  the  exhausted  glass;  and  what  is  singular,  even 
when  the  symptoms  had  commenced,  the  application  of  the  cupping-glass 
had  the  effect  of  speedily  and  completely  removing  them; — a  fact  of  es- 
sential importance  in  its  therapeutical  relations.  In  commenting  on  the 
conclusions  of  Sir  D.  Barry,  Messrs.  Addison  and  Morgan,1 — who  main- 
tain the  doctrine,  that  all  poisonous  agents  produce  their  specific  effects 
upon  the  brain,  and  general  system,  through  the  sentient  extremities  of 
nerves,  and  through  the  sentient  extremities  of  nerves  only;  and  that, 
when  such  agents  are  introduced  into  the  current  of  the  circulation  in  any 
way,  their  effects  result  from  the  impression  made  upon  the  sensible 
structure  of  the  bloodvessels,  and  not  from  their  direct  application  to 
the  brain  itself, — contend,  that  the  soft  parts  of  the  body,  when  covered 
by  an  exhausted  cupping-glass,  must  necessarily,  from  the  pressure  of 
the  edges  of  the  glass,  be  deprived  for  a  time  of  all  connexion,  both 
nervous  and  vascular,  with  the  surrounding  parts; — that  the  nerves 
must  be  partially  or  altogether  paralysed  by  compression  of  their  trunks; 
and  that,  from  the  same  cause,  all  circulation  through  the  veins  and 
arteries  within  the  area  of  the  glass,  must  cease;  that  the  rarefaction 
of  the  air  within  the  glass  being  still  farther  increased  by  means  of 
the  small  pump  attached  to  it,  the  fluids,  in  the  divided  extremities  of 
the  vessels,  are  forced  into  the  vacuum,  and,  with  these  fluids,  either  a 
part  or  the  whole  of  the  poison,  which  had  been  introduced ;  and  that, 
in  such  a  condition  of  parts,  the  compression,  on  the  one  hand,  and  the 
removal  of  the  poison  from  the  wound  on  the  other,  will  sufficiently 
explain  the  result  of  the  experiment,  either  according  to  the  views  of 
those  who  conceive  the  impression  to  be  made  on  the  nerves  of  the 
bloodvessels,  or  of  those  who  think,  that  the  agent  must  be  carried 
along  with  the  fluid  of  the  circulation  to  the  part  to  be  impressed. 

Thus  far  allusion  has  been  made  only  to  the  passage  of  tenuous  fluids 
into  the  veins.  Insoluble  substances  have,  however,  been  detected  by 
Professor  Oesterlen2  in  the  mesenteric  veins.  On  administering  levi- 
gated charcoal  to  animals  for  five  or  six  days  in  succession,  the  blood 
of  these  veins  exhibited  distinctly  particles  of  charcoal  of  different 
sizes,  some  of  them  so  large,  that  it  was  a  matter  of  surprise  how  they 
could  have  made  their  way  into  the  blood  through  the  epithelium,  mu- 
cous membrane  and  the  walls  of  the  bloodvessels.  We  have  no  diffi- 
culty, consequently,  in  comprehending  how  the  mild  chloride  and  other 
insoluble  preparations  of  mercury  may  be  able  to  enter  the  bloodvessels 
in  this  manner. 

Such  would  seem  to  be  the  main  facts  regarding  the  absorbent  action 
of  the  veins,  which  rests  on  as  strong  evidence  as  we  possess  regarding 
any  of  the  functions  of  the  body;  yet,  in  the  treatise  on  Animal  and 
Vegetable  Physiology  by  Dr.  Roget,3  we  find  it  passed  by  without  a 
comment ! 

We  have  still  to  inquire  into  the  agents  of  internal  and  adventitious 
absorption. 

»  An  Essay  on  the  Operation  of  Poisonous  Agents  upon  the  Living  Body,  Lond.,  1829. 

2  Heller's  Archiv.,  Bd.  iv.  Heft  1,  cited  in  Lond.  Med.  Gazette  for  July,  1847. 

3  Bridgewater  Treatise,  Lond.,  1834,  Amer.  edit.,Philad.,  1836. 


684  ABSORPTION. 


IV.   INTERNAL  ABSORPTION. 

On  this  point  but  few  remarks  will  be  necessary,  after  the  exposition 
of  the  different  vascular  actions  concerned  in  absorption.  The  term 
comprehends  interstitial  absorption,  and  the  absorption  of  recrementitial 
fluids.  The  first  comprises  the  agency  by  which  the  different  textures 
of  the  body  are  decomposed  and  conveyed  into  the  mass  of  blood.  It 
will  be  considered  more  at  length  under  the  head  of  NUTRITION;  the 
second,  that  of  the  various  fluids  effused  into  cavities;  and  the  third, 
that  which  is  effected  on  the  excretions  in  their  reservoirs  or  excretory 
ducts.  All  these  must  be  accomplished  by  one  of  the  two  sets  of  vessels 
previously  described;  lymphatics,  or  veins,  or  both.  Now,  we  have 
attempted  to  show,  that  an  action  of  selection  and  elaboration  is  exerted 
by  lymphatics;  whilst  we  have  no  evidence  of  such  action  in  the  case 
of  the  veins.  It  would  follow,  then,  that  all  the  varieties  of  internal 
absorption,  in  which  the  substance,  when  received  into  the  vessel,  pos- 
sesses different  characters  from  those  it  had  when  without,  must  be 
executed  by  lymphatics;  whilst  those,  in  which  no  conversion  occurs, 
take  place  by  the  veins.  In  the  constant  absorption,  and  corresponding 
deposition,  incessantly  going  on  in  the  body,  the  solid  parts  must  be 
reduced  to  their  elements,  and  a  new  compound  be  formed;  inasmuch 
as  we  never  find  bone,  muscle,  cartilage,  membrane,  &c.,  existing  in 
these  states  in  any  of  the  absorbed  fluids;  and  it  is  probable,  therefore, 
that,  at  the  radicles  of  the  lymphatic  vessels,  they  are  converted  into 
the  same  fluid — the  lymph — in  like  manner  as  the  heterogeneous  sub- 
stances in  the  intestinal  canal  afford  to  the  lacteals  the  elements  of  a 
fluid  the  character  of  which  is  always  identical.  On  the  other  hand, 
when  the  recrementitial  fluid  consists  simply  of  the  serum  of  the  Blood, 
more  or  less  diluted,  there  can  be  no  obstacle  to  the  passage  of  its 
aqueous  portion  immediately  through  the  coats  of  the  veins  by  imbi- 
bition, whilst  the  more  solid  part  is  taken  up  by  the  lymphatic  vessels. 
In  the  case  of  excrementitious  fluids,  there  is  reason  to  believe,  that 
absorption  simply  removes  some  of  their  aqueous  portions ;  and  this,  it 
is  obvious,  can  be  effected  directly  by  the  veins,  through  imbibition. 
The  facts,  connected  with  the  absorption  of  substances  from  the  interior 
of  the  intestine,  have  clearly  shown,  that  the  chyliferous  vessels  alone 
absorb  chyle,  and  that  the  drinks  and  adventitious  substances  pass  into 
the  mesenteric  veins.  These  apply,  however,  to  external  absorption 
only;  but  similar  experiments  and  arguments  have  been  brought  forward 
by  the  supporters  of  the  two  opinions,  in  regard  to  substances  placed 
on  the  peritoneal  surface  of  the  intestine,  and  other  parts  of  the  body. 
Whilst  some  affirm,  that  they  have  entered  the  lymphatics ;  others  have 
only  been  able  to  discover  them  in  the  veins.  Mr.  Hunter,  having  in- 
jected water  coloured  with  indigo  into  the  peritoneal  cavity  of  animals, 
saw  the  lymphatics,  a  short  time  afterwards,  filled  with  a  liquid  of  a 
blue  colour.  In  animals,  that  had  died  of  pulmonary  or  abdominal 
hemorrhage,  Mascagni  found  the  lymphatics  of  the  lungs  and  peritoneum 
filled  with  blood;  and  he  asserts,  that,  having  kept  his  feet  for  some 
hours  in  water,  swelling  of  the  inguinal  glands  supervened,  with  trans- 
udation  of  a  fluid  through  the  gland;  coryza,  &c.  M.  Desgenettes 


INTERNAL.  685 

observed  the  lymphatics  of  the  liver  containing  a  bitter,  and  those  of 
the  kidneys  a  urinous,  lymph.  Sommering  detected  bile  in  the  lymph- 
atics of  the  liver;  and  milk  in  those  of  the  axilla.  M.  Dupuytren  relates 
a  case,  which  M.  Magendie  conceives  to  be  much  more  favourable  to  the 
doctrine  of  absorption  by  the  lymphatic  vessels  than  any  of  the  others. 
A  female,  who  had  an  enormous  fluctuating  tumour  at  the  upper  and 
inner  part  of  the  thigh,  died  at  the  H6tel  Dieu,  of  Paris,  in  1810. 
A  few  days  before  her  death,  inflammation  occurred  in  the  subcutaneous 
areolar  tissue  at  the  inner  part  of  the  tumour.  The  day  after  dissolu- 
tion, M.  Dupuytren  opened  the  body.  On  dividing  the  integuments,  he 
noticed  white  points  on  the  lips  of  the  incision.  Surprised  at  the  ap- 
pearance, he  carefully  dissected  away  some  of  the  skin,  and  observed 
the  subcutaneous  areolar  tissue  overrun  by  whitish  lines,  some  of  which 
were  as  large  as  a  crow's  quill.  These  were  evidently  lymphatics  filled 
with  puriform  matter.  The  glands  of  the  groin,  with  which  these 
lymphatics  communicated,  were  injected  with  the  same  matter.  The 
lymphatics  were  full  of  the  fluid,  as  far  as  the  lumbar  glands;  but 
neither  the  glands  nor  the  thoracic  duct  presented  any  trace  of  it.1  On 
the  other  hand,  multiplied  experiments  have  been  instituted,  by  throw- 
ing coloured  and  odorous  substances  into  the  great  cavities  of  the 
body ;  and  these  have  been  found  always  in  the  veins,  and  never  in  the 
lymphatics. 

To  the  experiments  of  Mr.  Hunter,  objections  have  been  urged,  simi- 
lar to  those  brought  against  his  experiments  to  prove  the  absorption  of 
milk  by  the  lacteals ;  and  sources  of  fallacy  have  been  pointed  out.  The 
blue  colour,  which  the  lymphatics  seemed  to  him  to  possess,  and  which 
was  ascribed  to  the  absorption  of  indigo,  was  noticed  in  the  experiments 
of  Messrs.  Harlan,  Lawrence,  and  Coates  ;2  but  they  discovered  that 
this  was  an  optical  illusion.  What  they  saw  was  the  faint  blue,  which 
transparent  substances  assume,  when  placed  over  dark  cavities.  Mr. 
Mayo3  has  also  affirmed  that  the  chyliferous  lymphatics  always  assume 
a  bluish  tint  a  short  time  after  death,  even  when  the  animal  has  not 
taken  indigo.  The  cases  of  purulent  matter,  &c.,  found  in  the  lymph- 
atics, may  be  accounted  for  by  the  morbid  action  having  produced  dis- 
organization of  the  vessel,  so  that  the  fluid  could  enter  the  lymphatics 
directly;  and,  if  once  within,  its  progression  could  be  readily  under- 
stood. 

M.  Magendie4  asserts,  that  M.  Dupuytren  and  he  performed  more 
than  one  hundred  and  fifty  experiments,  in  which  they  submitted  to  the 
absorbent  action  of  serous  membranes  different  fluids,  and  never  found 
any  of  them  within  the  lymphatic  vessels.  These  fluids  produced  their 
effects  more  promptly,  in  proportion  to  the  rapidity  with  which  they 
were  capable  of  being  absorbed.  Opium  exerted  its  narcotic  influence; 
wine  produced  intoxication,  &c.,  and  M.  Magendie  found,  from  nume- 
rous experiments,  that  the  ligature  of  the  thoracic  duct  in  no  respect 
diminished  the  promptitude  with  which  these  effects  supervened.  The 

1  Magendie,  Precis,  &c.,  2de  edit,  ii.  195,  et  seq.;  and  Adelon,  art.  Absorption,  Diet,  de 
Med.,  2de  edit.,  i.239,  and  Physiologie  de  rHomme,  2de  edit.,  iii.  65,  Paris,  1829. 

2  Harlan's  Physical  Researches,  p.  459,  Philad.,  1835. 

3  Outlines  of  Human  Physiology,  3d  edit.,  Lond.,  1833.  4  Op.  cit.,  ii.  211. 


686  ABSORPTION. 

partisans  of  lymphatic  absorption,  however,  affirm  that  even  if  these 
substances  are  met  with  in  the  veins,  it  by  no  means  follows,  that  ab- 
sorption has  been  effected  by  them;  for  the  lymphatics,  they  assert, 
have  frequent  communications  with  the  veins;  and,  consequently,  they 
may  still  absorb  and  convey  their  products  into  the  venous  system.  In 
reply  to  this,  it  may  be  urged,  that  all  the  vessels — arterial,  venous, 
and  lymphatic — appear  to  have  intercommunication;  but  there  is  no 
reason  to  believe,  that  the  distinct  offices,  performed  by  them,  are, 
under  ordinary  circumstances,  interfered  with ;  and,  again,  where  would 
be  the  necessity  for  these  intermediate  lymphatic  vessels,  seeing  that 
imbibition  is  so  readily  effected  by  the  veins  ?  The  axiom — quod  fieri 
potest  per  pauca,  non  debet  fieri  per  multa — is  here  strikingly  appro- 
priate. The  lymphatics,  too,  as  we  have  endeavoured  to  show,  exert 
an  action  of  selection  and  elaboration  on  substances  exposed  to  them ; 
but,  in  the  case  of  venous  absorption,  there  is  not  the  slightest  evidence, 
that  any  such  selection  exists, — odorous  and  coloured  substances  retain- 
ing, within  the  vessel,  the  properties  they  had  without.  Lastly.  Where 
would  be  the  use  of  organs  of  a  distinct  lymphatic  circulation  open- 
ing into  the  thoracic  duct,  seeing  that  the  absorbed  matters  might 
enter  the  various  venous  trunks  directly  through  these  supposititious 
communicating  lymphatics;  and  ought  we  not  occasionally  to  be  able  to 
detect  in  the  lymphatic  trunks  some  evidence  of  those  substances,  which 
their  fellows  are  supposed  to  take  up  and  convey  into  the  veins  ? 
These  carrier  lymphatics  have  obviously  been  devised  to  support  the 
tottering  fabric  of  exclusive  lypphatic  absorption, — undermined,  as  it 
has  been,  by  the  powerful  facts  and  reasonings  that  have  been  adduced 
in  favour  of  absorption  by  veins. 

From  the  whole  of  the  preceding  history  of  absorption,  we  are  of 
opinion,  that  the  chyliferous  and  lymphatic  vessels  form  only  chyle  and 
lymph,  refusing  all  other  substances,  with  the  exception  of  saline  and 
other  matters,  that  enter  probably  by  imbibition, — that  the  veins  admit 
every  liquid,  which  possesses  the  necessary  tenuity;  and  that  whilst  all 
the  absorptions,  which  require  the  substances  acted  upon  to  be  decom- 
posed and  transformed,  are  effected  by  chyliferous  and  lymphatic 
vessels;  they  that  are  sufficiently  thin,  and  demand  no  alteration,  are 
accomplished  directly  through  the  coats  of  the  veins  by  imbibition;  and 
we  shall  see  that  such  is  the  case  with  several  of  the  transudations  or 
exhalations. 

V.    ACCIDENTAL   ABSORPTION. 

The  experiments,  to  which  reference  has  been  made,  have  shown, 
that  many  substances,  adventitiously  introduced  into  various  cavities, 
or  placed  in  contact  with  different  tissues,  have  been  rapidly  absorbed 
into  the  blood,  without  experiencing  any  transformation.  Within  cer- 
tain limits,  the  external  envelope  of  the  body  admits  of  this  function; 
out  by  no  means  to  the  same  extent  as  its  prolongation,  which  lines  the 
different  excretory  ducts.  The  absorption  of  drinks  is  sufficient  evidence 
of  the  activity  of  the  function  as  regards  the  gastro-enteric  mucous 
membrane.  The  same  may  be  said  of  the  pulmonary  mucous  membrane. 
Through  it,  oxygen  and  nitrogen  pass  to  reach  the  blood  in  the  lungs,  as 


CUTANEOUS.  687 

well  as  carbonic  acid  in  its  way  outwards.  Aromatic  substances,  such 
as  spirit  of  turpentine,  breathed  for  a  time,  are  detected  in  the  urine ; 
proving  that  their  aroma  has  been  absorbed;  and  it  is  by  absorption, 
that  contagious  miasmata  probably  produce  their  pestiferous  agency. 
Dr.  Madden,1  however,  thinks  that  the  lungs  do  not  absorb  watery 
vapour  with  the  rapidity,  or  to  the  extent,  that  has  been  imagined ; 
whilst  Dr.  A.  Combe2  hazards  the  hypothesis,  that  owing  apparently 
to  the  extensive  absorption  of  aqueous  vapour  by  the  lungs,  the  inha- 
bitants of  marshy  and  humid  districts,  as  the  Dutch,  are  remarkable 
for  the  predominance  of  the  lymphatic  system. 

Not  only  do  the  tissues,  as  we  have  seen,  suffer  imbibition  by  fluids, 
but  by  gases  also :  the  experiments  of  Chaussier  and  Mitchell  astonish 
us  by  the  rapidity  and  singularity  of  the  passage  of  the  latter  through 
the  various  tissues; — the  rapidity  varying  according  to  the  permeability 
of  the  tissue,  and  the  penetrative  power  of  the  gas. 

a.   Cutaneous  Absorption. 

On  the  subject  of  cutaneous  absorption,  much  difference  of  sentiment 
has  prevailed; — some  asserting  it  to  be  possible  to  such  an  extent,  that 
life  may  be  preserved,  for  a  time,  by  nourishing  baths.  It  has  also  been 
repeatedly  affirmed,  that  rain  has  calmed  the  thirst  of  shipwrecked 
mariners  who  have  been,  for  some  time,  deprived  of  water.  It  is 
obvious,  from  what  we  know  of  absorption,  that,  in  the  first  of  these 
cases,  the  water  only  could  be  absorbed;  and  even  the  possibility  of  this 
has  been  denied  by  many.  Under  ordinary  circumstances,  it  can  hap- 
pen to  a  trifling  extent  only,  if  at  all ;  but,  in  extraordinary  cases,  where 
the  system  has  been  long  devoid  of  its  usual  supplies  of  moisture,  and 
where  we  have  reason  to  believe,  that  the  energy  of  absorption  is 
increased,  such  imbibition  may  be  possible.  Sanctorius,3  Von  Gorter,4 
Keill,5  Mascagni,6  Madden,7  R.  L.  Young,8  Dill,9  and  others  believe, 
that  this  kind  of  absorption  is  not  only  frequent  but  easy.  It  has  been 
affirmed,  that  after  bathing  the  weight  of  the  body  has  been  manifestly 
augmented ;  and  the  last  of  these  individuals  has  adduced  many  facts 
and  arguments  to  support  the  position.  Strong  testimony  has  been 
brought  forward  in  favour  of  extensive  absorption  of  moisture  from  the 
atmosphere.  This  is  probably  effected  rather  through  the  pulmonary 
mucous  surface  than  the  skin.  A  case  of  ovarian  dropsy  is  referred  to 
by  Dr.  Madden,10  in  which  the  patient,  during  eighteen  days,  drank 
692  ounces  of  fluid ;  and  discharged  by  urine  and  paracentesis  1298 
ounces,  being  an  excess  of  606  ounces  of  fluid  egesta  over  the  fluid 
ingesta.  Bishop  Watson,  in  his  Chemical  Essays,  states,  that  a  lad  at 
Newmarket,  having  been  almost  starved,  in  order  that  he  might  be 
reduced  to  the  proper  weight  for  riding  a  match,  was  weighed  at  9, 
and  again  at  10,  A.  M.,  when  he  was  found  to  have  gained  nearly  30 

1  Experimental  Inquiry  into  the  Physiology  of  Cutaneous  Absorption,  p.  64,  Edinb.,  1838. 

2  Principles  of  Physiology  applied  to  the  Preservation  of  Health,  5th  edit.,  p.  72,  Edinb., 
1836. 

3  De  Static.  Medic.,  Lugd.  Bat.*  1711.  4  De  Perspirat.  Insensib.,  Lugd.  Bat,  1736. 
6  Tentatnin.  Medico-Physic.,  Lond.,  1718.  6  Vas.  Lyrnphat.  Hist.,  Senis,  1783. 

'  Op.  cit,  p.  58.  8  De  Cutis  Inhalatione,  Edinb.,  1813. 

»  Edinb.  Medico-Chir.  Transact.,  ii.  350.  10  Op.  cit.,  p.  55. 


688  ABSORPTION. 

ounces  in  weight  in  the  interval,  although  he  had  only  taken  half  a  glass 
of  wine.  Dr.  Carpenter1  gives  a  parallel  case,  which  was  related  to  him 
by  Sir  G.  Hill,  Governor  of  St.  Vincent.  A  jockey  had  been  for  some 
time  in  training  for  a  race  in  which  Sir  G.  Hill  was  much  interested, 
and  had  been  reduced  to  the  proper  weight.  On  the  morning  of  the 
race,  suffering  much  from  thirst,  he  took  one  cup  of  tea,  and  shortly 
afterwards  his  weight  was  found  to  have  increased  six  pounds,  so  that 
he  was  incapacitated  for  riding.  These  cases  certainly  appear  difficult 
of  belief:  yet  the  authority  is  good.  Dr.  Carpenter  presumes,  that 
nearly  the  whole  of  the  increase  in  Bishop  Watson's  case,  and  at  least 
three  fourths  of  it  in  Sir  G.  Hill's  case,  must  be  attributed  to  cutaneous 
absorption,  which  was  probably  stimulated  by  the  wine  that  was  taken 
in  the  one,  and  by  the  tea  in  the  other.  Bichat  was  under  the  im- 
pression, that,  in  this  way  he  imbibed  the  tainted  air  of  the  dissecting 
room,  in  which  he  passed  a  large  portion  of  his  time.  To  avoid  an 
objection,  that  might  be  urged  against  this  idea, — that  the  miasmata 
might  have  been  absorbed  by  the  air  passages,  he  so  contrived  his 
experiment,  as,  by  means  of  a  long  tube,  to  breathe  the  fresh  outer  air; 
when  he  found,  that  the  evidence,  which  consisted  in  the  alvine  evacu- 
ations having  the  smell  of  the  miasmata  of  the  dissecting-room,  con- 
tinued. It  is  obvious,  however,  that  such  an  experiment  would  hardly 
admit  of  satisfactory  execution,  and  it  is  even  doubtful,  whether  there 
was  any  actual  relation  between  the  assigned  effect  and  the  cause. 
The  testimony  of  MM.  Andral,  Boyer,  Dume'ril,  Dupuytren,  Serres, 
Lallemand,  Ribes,  Lawrence,  Parent-Duchatelet,  and  that  afforded  by 
the  author's  own  observation,  are  by  no  means  favourable  to  the  great 
unwholesomeness  of  cadaveric  exhalations.2 

Dr.  J.  Bradner  Stuart3  found,  after  bathing  in  infusions  of  madder, 
rhubarb,  and  turmeric,  that  the  urine  was  tinged  with  these  substances. 
A  garlic  plaster  affected  the  breath,  when  every  care  was  taken,  by 
breathing  through  a  tube  connected  with  the  exterior  of  the  apartment, 
that  the  odour  should  not  be  received  into  the  lungs.  Dr.  Thomas 
Sewall4  found  the  urine  coloured,  after  bathing  the  feet  in  infusion  of 
madder,  and  the  hands  in  infusions  of  madder  and  rhubarb.  Dr. 
Mussey5  proved,  that  if  the  body  be  immersed  in  a  decoction  of  mad- 
der, the  substance  may  be  detected  in  the  urine,  by  using  an  appro- 
priate test.  Dr.  Barton  found,  that  frogs,  confined  in  dry  glass  ves- 
sels, became  enfeebled,  diminished  in  size,  and  unable  to  leap;  but  that, 
on  the  introduction  of  a  small  quantity  of  water,  they  soon  acquired 
their  wonted  vigour,  became  plump,  and  as  lively  as  usual  in  their 
motions.6  M.  W.  F.  Edwards7  of  Paris,  is,  also,  in  favour  of  absorp- 
tion being  carried  on  by  the  skin  to  a  considerable  extent. 

1  Human  Physiology,  §  462,  Lond.,  1842. 

2  Parent-Duchatelet,  Hygiene  Publique,  Paris,  1836;  and  the  remarks  of  the  author  in  his 
Human  Health,  p.  77,  Philad.,  1844. 

a  New  York  Med.  Repos.,  vols.  i.  and  iii.  1810-11. 

4  Med.  and  Physical  Journ.,  xxxi.  80,  Lond.,  1814. 

5  Philad.  Medical  and  Physical  Journal,  i.  288,  Philad.,  1808. 

6  Klapp,  Inaugural  Essay  on  Cuticular  Absorption,  p.  30,  Philad.,  1805. 

7  Sur  I'lnfluence  des  Agens  Physiques;  or  Drs.  Hodgkin  and  Fisher's  translation,  p.  61, 
and  p.  187,  &c.,  Lond.,  1832. 


CUTANEOUS.  689 

To  deny  cutaneous  absorption  altogether  is  impossible.  It  is  a 
channel,  in  fact,  by  which  we  introduce  one  of  our  most  active  reme- 
dial agents  into  the  system ; — and  it  has  not  unfrequently  happened, 
where  due  caution  has  been  omitted,  that  the  noxious  effects  of  different 
mineral  and  other  poisons  have  been  developed  by  their  application  to 
the  surface,  but  it  is  by  no  means  common  or  easy,  when  the  cuticle 
is  sound,  unless  the  substance  employed  possesses  unusually  penetrat- 
ing properties.  M.  Chaussier  found,  that  to  kill  an  animal,  it  is  suffi- 
cient to  make  sulphuretted  hydrogen  gas  act  on  the  surface  of  the  body, 
taking  care  that  none  gets  into  the  air-passages ;  the  researches  of 
Prof.  J.  K.  Mitchell1  have  also  shown  that  this  gas  is  powerfully  pene- 
trant.  Unless,  however,  the  substances,  in  contact  with  the  epidermis, 
are  of  such  a  nature  as  to  attack  its  chemical  composition,  there  is 
usually  no  extensive  absorption. 

It  is  only  of  comparatively  late  years,  that  physiologists  have  ven- 
tured to  deny,  that  the  water  of  a  bath,  or  the  moisture  from  a  damp 
atmosphere,  is  taken  up  under  ordinary  circumstances;  and  if,  in  such 
cases,  the  body  appears  to  have  increased  in  weight,  it  is  affirmed,  and 
with  some  appearance  of  truth,  that  this  may  be  owing  to  diminution 
of  the  cutaneous  transpiration.  It  is,  indeed,  probable,  that  one  great 
use  of  the  epidermis  is  to  prevent  the  inconveniences  to  which  we  should 
necessarily  be  liable,  were  such  absorption  easy.  This  is  confirmed  by 
the  fact,  that  if  the  skin  be  deprived  of  the  epidermis,  and  the  vessels 
that  creep  on  the  outer  surface  of  the  true  skin  be  thus  exposed,  ab- 
sorption occurs  as  rapidly  as  elsewhere.  J.  Muller  affirms,  that  saline 
solutions  applied  to  the  corium  penetrate  the  capillaries  in  a  second  of 
time.  To  insure  this  result  in  inoculation  and  vaccination,  the  matter 
is  always  placed  beneath  the  cuticle;  and,  indeed,  the  small  vessels  are 
generally  slightly  wounded,  so  that  the  virus  gets  immediately  into  the 
venous  blood.  Yet — it  is  proper  to  remark — the  lizard,  whose  skin  is 
scaly,  after  having  lost  weight  by  exposure  to  air,  recovers  its  weight 
and  plumpness  when  placed  in  contact  with  water;  and  if  the  scaly 
skin  of  the  lizard  permits  such  absorption,  M.  Edwards  thinks  it  impos- 
sible not  to  attribute  this  property  to  the  cuticle  of  man.  When  the 
epidermis  is  removed,  and  the  system  is  affected  by  substances  placed 
in  contact  with  the  true  skin,  we  have  the  endermic  method  of  me- 
dication. 

M.  Se'guin2  instituted  a  series  of  experiments  to  demonstrate  the  ab- 
sorbent or  non-absorbent  action  of  the  skin.  His  conclusion  was,  that 
water  is  not  absorbed,  and  that  the  epidermis  is  a  natural  obstacle  to 
the  action.  To  discover,  whether  this  was  the  case  as  regarded  other 
fluids,  he  experimented  on  individuals  labouring  under  venereal  affec- 
tions, who  immersed  their  feet  and  legs  in  a  bath,  composed  of  sixteen 
pints  of  water  and  three  drachms  of  corrosive  chloride  of  mercury,  for 
an  hour  or  two,  twice  a  day.  Thirteen,  subjected  to  the  treatment  for 
twenty-eight  days,  gave  no  signs  of  absorption;  the  fourteenth  was 
manifestly  affected,  but  he  had  itchy  excoriations  on  the  legs ;  and  the 

1  Amer.  Journal  of  the  Med.  Sciences,  via.  44 ;  and  p.  68  of  this  work. 

2  Annales  de  Chimie,  xc.  185. 

VOL.  i.— 44 


690  ABSORPTION. 

same  was  the  case  with  two  others.  As  a  general  rule,  absorption  ex- 
hibited itself  in  those  only  whose  epidermis  was  not  in  a  state  of  integrity. 
At  the  temperature  of  74°  Fahrenheit,  however,  the  sublimate  was  oc- 
casionally absorbed,  but  never  the  water.  From  other  experiments,  it 
appeared  evident,  that  the  most  irritating  substances,  and  those  most 
disposed  to  combine  with  the  epidermis,  were  partly  absorbed,  whilst 
others  were  apparently  not.  Having  weighed  a  drachm  (seventy-two 
grains,  poids  de  marc)  of  calomel,  and  the  same  quantity  of  camboge, 
scammony,  salt  of  alembroth,  and  tartar  emetic,  M.  Se'guin  placed  an 
individual  on  his  back,  washed  the  skin  of  the  abdomen  carefully,  and 
applied  to  it  these  substances  at  some  distance  from  each  other,  covering 
each  with  a  watch-glass,  and  maintaining  the  whole  in  situ  by  a  linen 
roller.  The  heat  of  the  room  was  kept  at  65°.  M.  Se'guin  remained 
with  the  patient,  in  order  that  the  substances  should  not  be  displaced: 
and  he  protracted  the  experiment  for  ten  hours  and  a  quarter.  The 
glasses  were  then  removed,  and  the  substances  carefully  collected  and 
weighed.  The  calomel  was  reduced  to  71J  grains.  The  scammony 
weighed  71| ;  the  camboge,  71;  the  salt  of  alembroth,  62  grains,1  and 
the  tartar  emetic  67  grains.2 

It  requires,  then,  in  order  that  matters  shall  be  absorbed  by  the  skin, 
that  they  shall  be  kept  in  contact  with  it,  so  as  to  penetrate  its 
pores,  or  the  channels  by  which  the  cutaneous  transpiration  exudes; 
or  else  that  they  shall  be  forced  through  the  cuticle  by  friction, — the 
iatraleptic  mode.  In  this  way,  the  substance  comes  in  contact  with  the 
cutaneous  vessels,  and  enters  them  probably  by  imbibition.  Certain  it 
is,  that  mercury  has  been  detected  in  the  venous  blood  by  Colson, 
Christison,  Cantu,  Autenrieth,  Zeller,  Schubarth,  and  others.3 

Not  long  after  the  period  that  M.  Se'guin  was  engaged  in  his  experi- 
ments, Dr.  Rousseau,4  of  Philadelphia,  contested  the  existence  of  ab- 
sorption through  the  epidermis,  and  attempted  to  show,  in  opposition 
to  the  experiments  we  have  detailed,  that  the  pulmonary  organs,  and 
not  the  skin,  are  the  passages  by  which  certain  substances  enter  the 
system.  By  cutting  off  all  communication  with  the  lungs,  which  he 
effected  by  breathing  through  a  tube  communicating  with  the  atmo- 
sphere on  the  outside  of  the  chamber,  he  found,  that  although  the  sur- 
face of  the  body  was  bathed  with  the  juice  of  garlic,  or  the  spirit  of 
turpentine,  none  of  the  qualities  of  these  fluids  could  be  detected,  either 
in  the  urine,  or  the  serum  of  the  blood.  From  subsequent  experiments, 
performed  by  Dr.  Rousseau,  assisted  by  Dr.  Samuel  B.  Smith,5  and 
many  of  which  Professor  Chapman6  witnessed,  the  following  results 
were  deduced.  First,  That  of  all  the  substances  employed,  madder  and 
rhubarb  were  those  only  that  affected  the  urine, — the  latter  of  the  two 
more  readily  entering  the  system ;  and  secondly,  that  the  power  of  ab- 
sorption is  limited  to  a  very  small  portion  of  the  surface  of  the  body. 

1  Several  pimples  were  excited  on  the  part  to  which  it  was  applied. 

2  Magendie's  Precis,  &c.,  ii.  262. 

3  The  author's  General  Therapeutics  and  Materia  Medica,  4th  edit.,  i.  90,  Philad.,  1850. 

4  Experimental  Dissert,  on  Absorption,  Philad.,  1800. 
6  Philad,  Medical  Museum,  i.  34,  Philad.,  1811. 

«  Elements  of  Therapeutics  and  Materia  Medica,  6th  edit.,  i.  65,  Philad.,  1831. 


ACCIDENTAL.  691 

The  only  parts,  indeed,  that  seemed  to  possess  it,  were  the  spaces  be- 
tween the  middle  of  the  thigh  and  hip,  and  between  the  middle  of  the 
arm  and  shoulder.  Topical  bathing,  with  a  decoction  of  rhubarb  or 
madder,  and  poultices  of  these  substances  applied  to  the  back,  abdo- 
men, sides,  or  shoulders,  produced  no  change  in  the  urine ;  nor  did 
immersion  of  the  feet  and  hands  for  several  hours  in  a  bath  of  the 
same  materials  afford  the  slightest  proof  of  absorption. 

From  these  and  other  facts,  sufficiently  discrepant  it  is  true,  we  are 
justified  in  concluding,  that  cuticular  absorption,  under  ordinary  circum- 
stances, is  not  easy ;  but  we  can  readily  conceive,  from  the  facility  with 
which  water  soaks  through  animal  tissues,  that  if  the  animal  body  be 
immersed  sufficiently  long  in  it,  and  especially  if  the  vessels  have  been 
previously  drained,  imbibition  may  take  place  to  a  considerable  extent. 
This,  however,  would  be  a  physical  absorption,  and  might  be  effected 
as  well  in  the  dead  as  in  the  living  body. 

b.   Other  Accidental  Absorptions. 

Amongst  the  adventitious  absorptions  have  been  classed  all  those  that 
are  exerted  upon  substances  retained  in  the  excretory  ducts,  or  situate 
in  parts  not  natural  to  them.  The  bile,  arrested  in  one  of  the  biliary 
ducts,  affords  us,  in  jaundice,  a  familiar  example  of  such  absorption  by 
the  positive  existence  of  bile  in  the  bloodvessels;  although  the  yellow 
colour  has  been  gratuitously  supposed  to  be  caused  by  an  altered  con- 
dition of  the  red  globules,  and  not  by  the  presence  of  bile.  This  con- 
dition of  the  red  globules  would  account  for  some  of  the  symptoms, — 
as  the  yellow  colour  of  the  skin,  and  urine, — but  it  does  not  explain  the 
clayey  appearance,  which  the  evacuations  present,  and  which  has  been 
properly  ascribed  to  the  absence  of  the  biliary  secretion.  We  have, 
moreover,  examples  of  this  kind  of  absorption,  where  blood  is  effused 
into  the  areolar  membrane,  as  in  the  case  of  a  common  sprain,  or  in 
those  accumulations  of  fluid  in  various  cavities,  that  are  found  to  dis- 
appear by  time ; — the  serous  portion  being  taken  up  at  first  with  some 
of  the  colouring  matter,  and,  ultimately,  the  fibrin.  In  the  case  of  ac- 
cumulation of  the  serous  fluid,  that  naturally  lubricates  cavities,  it  is  of 
such  a  character — the  aqueous  portion  at  least — as  to  be  imbibed  with 
facility,  and  probably  passes  into  the  veins,  in  this  manner, — the  func- 
tions of  exhalation  and  absorption  consisting  mainly,  in  such  case,  of 
transudation  and  imbibition. 

But  absorption  is  not  confined  to  these  fluids.  It  must,  of  course,  be 
exerted  on  all  morbid  deposits;  and  it  is  to  excite  the  action  of  the  ab- 
sorbents, that  our  remedial  agents  are  directed.  This  absorption — in 
the  case  of  solids — is  of  the  interstitial  kind ;  and,  as  the  morbid  forma- 
tion has  to  undergo  an  action  of  elaboration,  it  ought  to  be  referred  to 
lymphatic  agency. 

To  conclude  the  function  of  absorption: — All  the  products, — whether 
the  absorption  has  been  chyliferous,  lymphatic,  or  venous,— are  united 
in  the  venous  system,  and  form  part  of  venous  blood.  This  fluid  must, 
consequently,  be  variable  in  its  composition,  in  proportion  to  the  quan- 
tity of  heterogeneous  materials  taken  up  by  the  veins,  and  the  activity 


692  ABSORPTION. 

of  chyliferous  and  lymphatic  absorption.  It  is  also  clear,  that,  between 
the  parts  of  the  venous  system  into  which  the  supra-hepatic  veins, — 
loaded  with  the  products  of  intestinal  absorption  of  fluids, — enter,  and 
the  opening  of  the  thoracic  duct  into  the  subclavian,  the  blood  must 
differ  materially  from  that  which  flows  in  other  parts  of  the  system. 
All,  however,  undergo  admixture  in  their  passage  through  the  heart; 
and  all  are  converted  into  arterial  blood  by  the  function,  that  will  next 
engage  us, — RESPIRATION. 


END   OF  VOL.   I. 


NOVEMBER,  1851. 



CATALOGUE 

OF 

MEDICAL  AND  SURGICAL  WORKS, 

PUBLISHED  BY 

BLANCHARD  &  LEA, 

PHILADELPHIA, 

AND 

FOR  SALE  BY   ALL   BOOKSELLERS. 


TO  THE  MEDICAL  PROFESSION. 

The  Subscribers  subjoin  a  list  of  their  publications  in  medical  and  other  sciences,  to  which  they  would 
invite  the  attention  ofthe  Profession,  with  the  full  confidence  that  they  will  be  found  to  correspond  in  every 
respect  with  the  description.  They  are  to  l>e  had  of  all  the  principal  booksellers  throughout  the  Union,  from 
whom,  or  from  the  publishers  particulars  respecting  price,  &c.,  may  be  had  on  application 

BLANCH  \RD  &  I/FA, 

Philadelphia,  Nov.,  1551.  (Late  LEA  &  BLANCHABD.) 


DICTIONARIES,  JOURNALS,  &e, 

American  Journal  ofthe  Medical  Sciences,  quar- 
terly, at  $5  a  year. 

Cyclopedia  of  Practical  Medicine,  by  Forbes. 
Tweedie,  &c.,  edited  by  Dunglison,  in  4  super 
royal  volumes,  3154  double  columned  pages. 

Dunglison's  Medical  Dictionary,  8th  ed.,  1  vol. 
imp.  Svo. ,  928  large  pages,  (now  ready.) 

Hoblyn's  Dictionary  of  Medical  Terms,  by  Hays, 

1  vol.  large  12mo.,  402  pages,  double  columns. 
Neill  and  Smith's  Compend  of  the  Medical  Sci- 
ences, 1  vol.,  large  12mo.,  900  pp.,  350  cuts. 

Transactions  ofthe  American  Medical  Associa- 
tion, Vols.  I,  II,  and  III,  cloth  or  paper. 
Medical  News  and  Library,  monthly,  at  $  1  a  year. 

ANATOMY, 

Anatomical  Atlas,  by  Smith  and  Horner,  large 
imp.  8vo.,  650  figures.  New  and  cheaper  ed. 

Homer's  Special  Anatomy  and  Histology,  new 
edition,  2  vols.  8vo.,  many  cuts,  (now  ready.) 

Homer's  United  States  Dissector,  1  vol.  large 
royal  12mo.,  many  cuts,  444  pages. 

Maclise's  Surgical  Anatomy,  now  complete  in  1 
large  imp.  4to.  vol.,  strongly  bound,  with  68 
magnificent  colored  plates. 

Sharpey  and  Quain's  Anatomy,  by  Leidy,  2  vols. 
8v<>.,  1300  pages,  511  wood-cuts. 

Wilson's  Human  Anatomy,  by  Goddard,4th  edi- 
tion, 1  vol.  8vo.,  252  wood-cuts,  580  pp. 

Wilson's  Dissector,  by  Goddard.  New  edition, 
with  cuts,  1  vol.  12mo.,458  pages. 

PHYSIOLOGY, 

Carpenter's  Principles  of  Human  Physiology,  1 
vol.  8vo.,  752  pp.,  300  cuts  and  2  plates,  new 
and  improved  edition,  (nearly  ready.) 

Carpenter's  Elements,  or  Manual  of  Physiology, 
new  and  improved  ed.,  1  vol.Svo.,  (now  ready.) 

Carpenter's  General  and  Comparative  Physiolo- 
gy, 1  vol.  8vo.,pp.  1 122,  321  cuts,  (now  ready.) 

Dunglison's  Human  Physiology,  7th  edition,  2 
vols.  8vo.,  1428  pages,  and  472  wood-cuts. 

Harrison  on  the  Nerves,  1  vol.  8vo.,  292  pages. 

Kirkes  and  Paget's  Physiology,  1  vol.  12mo., 
many  cuts,  550  pages. 

Longet's  Physiology.    Translated  by  F.G.  Smith. 

2  vols.  8vo.,  many  cuts,  (preparing.) 
Matteucci  on  the  Physical  Phenomena  of  Living 

Beings,  1  vol.  12tno.,  388  pp.,  cuts. 
Solly  on  the  Brain,  1  vol.Svo.,  496  pp.,  118  cuts. 
Todd  and  Bowman's  Physiological  Anatomy  and 

Physiology  of  Man,  with  numerous  wood-cuts. 

Parts  I. ,11.  and  III.,  1  vol.  8vo.,  156  wood-cuts. 

PATHOLOGY, 

Abercrombie  on  the  Brain,  1  vol.  8vo.,  324  pp. 
Blakiston  on  Diseasesof  the  Chest,  1  vol.,  384  pp. 
Blood    and   Urine  Manuals,  by  Reese,  Griffith, 

Markwick,  Bird,  and  Flick,   2   vols.   12mo., 

many  cuts  and  plates. 
Budd  on  the  Liver,  1  vol.  8vo.,  392  pages,  plates 

and  wood-cuts. 
Burrows  on    Cerebral  Circulation,   1  vol.  8vo., 

216  pages,  with  6  colored  plates. 
Billing's  Principles,  new  and  unproved  edition, 

1  vol.  8vo.,  250  pages,  (just  issued.) 
Bird  on  Urinary  Deposits,  12mo.,  new  and  im- 
proved edition,  (just  issued.) 
Copland  on  Palsy  and  Apoplexy,  1  vol.  12mo., 

236  pp. 

Frick  on  Renal  Affections,  1  vol.  12mo.,  cuts. 
Hasse's  Pathological  Anatomy,  Svo.,  379  pages. 
Hope  on  the  Heart,  new  ed.,  pi's,  1  vol.  Svo. ,572  p. 
Hughes  on  the  Lungs,  &c.,  1  vol.  12mo.,  270  pp. 


Lallemand  on  Spermatorrhoea,  1  vol.Svo.,  320pp. 
Mitchell  on  Fevers,  1  vol.  12mo.,  138  pages. 
Philip  on  Protracted  Indigestion,  8vo.,  240  pp. 
Philips  on  Scrofula,  1  vol.  8vo.,  350  pages. 
Hicord  on  Venereal,  new  ed.,  1  vol.  8vo.,  340  pp. 
Stanley  on  Diseases  of  the   Bones,  1  vol.  8vo., 

286  pages. 
Vb'gel's  Pathological   Anatomy   of   the  Human 

Body,   1   vol.  8vo.,  536  pages,  col.  plates. 
Wilson  on  the  Skin,  1  vol.  8vo.,  new  ed.,  440  pp. 

Same  work,  with  colored  plates. 
Whitehead  on  Sterility  and  Abortion,  1  vol.Svo., 

368  pages. 
Williams'  Principles  of  Medicine,  by  Clymer,  2d 

edition,  440  pages,  1  vol.  Svo. 
Williams  on  the  Respiratory  Organs,  by  Clymer, 

1  vol.  8vo.,  500  pages. 

PRACTICE  OF  MEDICINE, 

Ashwell  on  Females,  2d  ed.,  1  vol.  Svo.,  520  pp. 
Barlow's  Practice  of  Medicine,  (preparing.) 
Bennet  on  the  Uterus,  2d  and  enlarged  edition, 

1  vol.Svo.,  356  pages. 
Bartlett  on  Fevers,  2d  edition,  550  pages. 
Benedict's  Compendium  of  Chapman's  Lectures, 

I  vol.  Svo.,  258  pages. 
Chapman  on  Fevers, Gout,  Dropsy,  &c.  &c.,  1  vol. 

8vo.,  450  pages. 
Colombat  do  L'Isere  on  Females,  by  Meigs,  1  vol. 

Svo.,  720  pages,  cuts.     New  edition. 
Condie  on  the  Diseases  of  Children,  3d  edition, 

1  vol.  Svo. 

Churchill  on  the  Diseases  of  Infancy  and  Child- 
hood, 1  vol.  Svo. 

Churchill  on  the  Diseasesof  Females,  by  Huston, 
5th  ed.,  rev'd  by  the  author,  1  vol.  Svo. ,  632  pp. 

Churchill's  Monographs  of  the  Diseases  of  Fe- 
males, 1  vol.  Svo.,  now  ready,  450  pages. 

Clymer  and  others  on  Fevers,  a  complete  work 
in  1  vol.  Svo. ,600  pages. 

Day  on  Old  Age,  1  vol.  Svo.,  226  pages. 

Dewees  on  Children,  9th  ed.,  1  vol.  Svo.,  548  pp. 

Deweeson  Females, 9th  ed.,  1  vol. Svo. ,532  p.  pis. 

Dunglison's   Practice  of  Medicine,  3d   edition, 

2  vols.  Svo.,  1500  pages. 

Esquirol  on  Insanity,  by  Hunt,  Svo.,  496  pages. 
Meigs'   Letters  on  Diseases  of  Females,  1   vol. 

Svo. ,690  pp.,2d  ed.,  improved,  (lately  issued.) 
Meigs  on  Certain  Diseases  of  Infancy,  1  vol.Svo., 

216  pp.,  (a  new  work.) 
Thomson   on  the  Sick  Room,  &c.,   1  vol.  large 

12mo.,  360  pages,  cuts. 
Watson.'s  Principles  and  Practice  of  Physic,  3d 

edition  by  Condie,  1  vol.  Svo. ,1060  large  pages. 
West's  Lectures  on  the  Diseases  of  Infancy  and 

Childhood.     1  vol.  Svo.,  452  pp. 
Walshe  on  the  Heart  and  Lungs.     A  new  work, 

now  ready,  1  vol.  ro>al  12mo.  ex.  cloth. 

SURGERY, 

Brodie  on  Urinary  Organs,  1  vol.  Svo. ,  214  pages. 

Brodie  on  the  Joints,  1  vol.  Svo.,  216  pages. 

Brodie's  Lectures  on  Surgery,  1  vol.  Svo. ,350  pp. 

Brodie'sSelectSurgical  Works, 780  pp.  I  vol.Svo. 

Chelius'  System  of  Surgery,  by  South  and  Norris, 
in  3  large  Svo.  vols.,  near  2200  pages. 

Cooperon  Dislocationsand  Fractures,  1  vol.Svo., 
500  pages,  many  cuts. 

Cooper  on  Hernia,  1  vol.  imp.  8vo.,  many  plates. 

Cooper  on  the  Testis  and  Thymus  Gland,  1  vol. 
imperial  Svo.,  many  plates. 

Cooper  on  the  Anatomy  and  Diseases  ofthe  Breast, 
Surgical  Papers,  &c  &c.,  1  vol.  imp. Svo.,  pl'te. 

Druitt's  Principles  and  Practice  of  Modern  Sur- 
gery, 1  vol.  Svo.,  576  pages,  193  cuts,  4th  ed. 


BLANCHARD  &  LEA'S  PUBLICATIONS  —(Medical  Works.)  3 

Beale  on  Health  of  Mind  and  Body,  1  vol.  12mo., 
extra  cloth,  (now  ready.) 

Bowman's  Medical  Chemistry,  1  vol.  12mo., 
many  cuts,  just  ready,  288  pages. 

Dunglison  on  Human  Health, 2d  ed.,8vo.,  464  pp. 

Fowne's  Elementary  Chemistry,  3d  ed.,  1  vol. 
12tno.,  much  improved,  many  cuts,  now  ready. 

Graham's  Chemistry,  by  Bridges,  new  and  im- 
proved edition.  P,irt  1,  (in  press.) 

Gardner's  Medical  Chemistry,  1  vol.  12mo.  400pp. 

Griffith's  Chemistry  of  the  Four  Seasons,  1  vol. 
royal  12mo.,  451  pages,  many  cuts. 

Knapp's  Chemical  Technology,  by  Johnson,  2 
vols.  8vo.,  936  pp.,  460  large  cuts. 

Simon's  Chemistry  of  Man,  8vo.,  730  pp.,  plates. 

MEDICAL  JURISPRUDENCE,  EDUCATION,  &c, 

Bartlett's  Philosophy  of  Medicine,  1  vol.8vo., 

312  pages. 
Bartlett  on  Certainty  in  Medicine,  1  vol.  small 

8vo.,  84  pages. 

Dunglison's  Medical  Student,  2ded.l2mo., 312  pp. 
Taylor's  Medical  Jurisprudence,  by  Griffith,    1 

vol.  8vo.,  new  edition,  1850,  670  pp. 
Taylor  on  Poisons,  by  Griffith,  1  vo! .  Svo.,  688  pp. 

NATURAL  SCIENCE,  to, 

Arnott's  Physics,  1  vol    8vo.,  484  pp., many  cute. 
Ansted's  Ancient  World,  Popular  Geology,  in  1 

I2mo.  volume,  with  numerous  cuts,  382  pages. 
Bird's   Natural   Philosophy,  1  vol.  royal   12mo., 

402  pages  and  372  wood-cuts. 
Brewster'sOptics,!  vol.  12mo.  423  pp.  many  cute. 
Broderip's  Zoological  Recreations,  1  vol.  12mo., 

3"76  pp. 

Coleridge's  Idea  of  Life,  12mo.,  94  pages. 
Carpenter'sGeneral  and  Comparative  Physiology, 

1  large  Svo.  vol.,  many  wood-cuts,  (now  ready.) 
Dana  on  Zoophytes,  being  vol.  8  of  Ex.  Expedi- 
tion, royal  4to.,  extra  cloth. 

Atlas  to  "Dana  on  Zoophytes,"  im.  fol.,  col.  pi's. 
Gregory  on  Animal   Magnetism,   1   vol.,   royal 

12mo.,  (now  ready.) 
De  la  Beche's  Geological  Observer,  1  large  8vo. 

vol.,  many  wood-cuts,  (just  ready.) 
Hale's  Ethnography  and  Philology  of  the  U.  S. 

Exploring  Expedition,  in  1  large  imp.  4to.  vol. 
Herschel's  Treatise  on  Astronomy,  1  vol.  12mo., 

417  pages,  numerous  plates  and  cuts. 
Herschel's  Outlines  of  Astronomy,  1  vol.  small 

Svo. ,  plates  and  cuts.    (A  new  work.)    620pp. 
Humboldt's  Aspects  of'Nature,  1  vol.  12mo.,  new 

edition. 
Johnston's  Physical  Atlas,  1  vol.  imp.  4to.,  half 

bound,  25  colored  maps. 
Kirby  and  Spence's  Entomology,  1  vol.  Svo. ,600 

large  pages;  plates  plain  or  colored. 
Knox  on  Races  of  Men,  1  vol.  12mo. 
Lardner's  Handbooks  of  Natural  Philosophy,  2 

vols.  royal  12mo.,  with  800  cuts,  (in  press.) 
Miiller's  Physics  and  Meteorology,  1  vol.  bvo., 

636  pp.,  with  540  wood-cuts  and2col'd  plates. 
Small  Books  on  Great  Subjects,  12  parts,  done  up 

in  3  handsome  12mo.  volumes,  extra  cloth. 
Somerville's  Physical  Geography,  1  vol.  12mo., 

cloth,  540  pages,  enlarged  edition,  now  ready. 
Weisbach's  Mechanics  applied  to  Machinery  and 

Engineering,  Vol.I.8vo.,48Gp.550  wood-cuts. 

Vol.  II.,  8vo.,  400  pp.,  340  cuts. 


Dufton  on  Deafness  and  Diseases  of  the  Ear,  1  vol. 

12mo.,  120  pages. 

Durlacher  on  Corns,  Bunions,  &c.,  12mo.,134  pp 
Ear,  Diseases  of,  a  new  work,  (preparing.) 
Fergusson's  Practical   Surgery,   1    vol.  8vo.,  3d 

edition,  630  pages,  274  cuts. 
Guthrie  on  the  Bladder,  Svo. ,  150  pages. 
Gross  on  Injuries  and  Diseases  of  Urinary  Organs, 

1  Irg.  vol.  Svo. ,726  pp.  many  cuts,  (now  ready.) 
Jones'  Ophthalmic   Medicine   and  Surgery,    by 

Hays,  1  vol.  12mo.,  529  pp.,  cuts  and  plates. 
Liston's  Lectures  on  Surgery,  by  Mutter,  1  vol. 

8vo.,  566  pages,  many  cuts. 
Lawrence  on  the  Eye,  by  Hays,  new  ed.  much 

improved,  863  pp.,  many  cuts  and  plates. 
Lawrence  on  Ruptures,  1  vol.  8vo.,  480  pages. 
Miller's  Principles  of  Surgery, 2d  edition,  1  vol. 

8vo.,538pp.,  1848. 

Miller's  Practice  of  Surgery,  1  vol.  Svo.,  496  pp. 
Malgaigne's  Operative  Surgery,  by  Brittan,  with 

cuts.     Now  complete  in  one  Svo.  vol.,  of  about 

600  pages. 
Maury's  Dental  Surgery,  1  vol.  8vo.,  286  pages, 

many  plates  and  cuts. 

Skey's  Operative  Surgery,  1  vol.  large  Svo.,  ma- 
ny cuts,  662  pages,  a  new  work,  (just  issued.) 
Sargent's  Minor  Surgery,  1  vol.  royal  I2mo.,  380 

pages,  128  cuts. 
Smith  on  Fractures,  1  vol.  8vo.,  200  cuts,  314pp. 

MATERIA  MEDICA  AND  THERAPEUTICS, 

Bird's  (Golding)  Therapeutics,  (preparing.) 

Christison's  and  Griffith's  Dispensatory,  1  large 
vol.  Svo.,  216  cuts,  over  1000  pages. 

Carpenter  on  Alcoholic  Liquors  in  Health  and 
Disease,  I1  vol.  12mo. 

Carson's  Synopsis  of  Lectures  onMateria  Medica 
and  Pharmacy  in  the  University  of  Pennsyl- 
vania, 1  vol.  Svo.,  208  pages,  (now  ready.) 

Dunglison's  Materia  Medica  and  Therapeutics, 
now  ready,  4th  ed.,  much  improved,  182  cuts, 

2  vols.  Svo. ,1850. 

Dunglison  on  New  Remedies,  6th  ed.,  much  im- 
proved, 1  vol.  Svo.,  750  pages. 

De  Jongh  on  Cod-Liver  Oil,  12mo. 

Ellis'  Medical  Formulary,  9th  ed.,  much  improv- 
ed, 1  vol.  Svo.,  268  pages. 

Griffith's  Universal  Formulary,  1  large  vol.  8vo., 
560  pages. 

Griffith's  Medical  Botany,  a  new  work,  1  large 
vol.  Svo.,  704  pp.,  with  over  350  illustrations. 

Mayne's Dispensatory,  1  vol.  12mo.,  330  pages. 

Mohr,  Redwood,  and  Procter's  Pharmacy,  1  vol. 
8vo.,  550  pages,  506  cuts. 

Pereira's  Materia  Medica,  by  Carson,  3d  ed.,  2 
vols.  8vo.,  much  improved  and  enlarged,  with 
400  wood  cuts,  (nearly  ready.) 

Royle's  Materia  Medica  and  Therapeutics,  by 
Carson,  1  vol.  Svo.,  689  pages,  many  cuts. 

OBSTETRICS, 

Churchill's  Theory  and  Practice  of  Midwifery,  a 

new  and  improved  ed.,  by  Condie,  1  vol.  8vo., 

510  pp.,  many  cuts,  (just  issued.) 
Dewees' Midwifery,  llth  ed.,  1  vol.  Svo. ,660  pp., 

plates. 

Lee's  Clinical  Midwifery,  12mo.,  238  pages. 
Meigs'  Obstetrics;  the  Science  and  the  Art;  1 

vol.  Svo.,  686  pages,  121  cuts. 
Ramsbotham  on  Parturition,  with  many  plates,  1 

large  vol.,  imperial  8vo.,  520  pp.     6th  edition, 

(now  ready,) 
Rigby's   Midwifery,  new  edition,   1   vol.   Svo., 

(just  issued,)  422  pages. 
Smith  (Tyler)  on  Parturition,  1  vol.  12mo.,400  pp. 

CHEMISTRY  AND  BYGIENE, 

Bowman's    Practical, Chemistry,   1    vol.    12mo., 

97  cuts,  350  pages. 

Brigham  on  Excitement, &c.,  1  vol.!2mo.,  204  pp. 
Other  new  and  important 


VETERINARY  MEDICINE, 

Claterand  Skinner's  Farrier,  I  vol.  12mo.,220  pp. 

Youatt's  Great  Work  on  the  Horse,  by  Skinner, 
1  vol.  8vo.,  448  pages,  many  cuts. 

Youatt  and  Clater's  Cattle  Doctor,  1  vol.  12mo., 
282  pages,  cuts. 

Youatt  on  the  Dog,  by  Lewis,  1  vol.  demy  8vo., 
403  pages,  beautiful  plates. 

Youatt  on  the  Pig,  a  new  work,  with  beautiful  il- 
lustrations of  all  the  different  varieties,  12mo. 
works  are  in  preparation. 


TWO    MEDICAL    PERIODICALS    FOR  FIVE    DOLLARS. 

THE  AMERICAN7  JOURNAL  OF 
THE    MEDICAL    SCIENCES, 

EDITED  BY  ISAAC  HAYS,  M:  D., 

IS  PUBLISHED  QUARTERLY,  ON  THE  FIRST  OF  JANUARY,  APRIL,  JULY,  AND  OCTOBER, 
By  &Z,MJYCIIJIJR1*  #  LEM,  Philadelphia. 

Each  Number  contains  about  Two  Hundred  and  Eighty  Large  Octavo  Pages, 
Appropriately  Illustrated  with  Engravings  on  Copper,  Wood,  Stone,  &c. 

THE  MEDICAL  NEWS  AND  LIBRARY 

Is  Published  Monthly,  and  consists  of 
THIRTY-TWO    VERY    LARGE    OCTAVO    PAGES, 

Containing  the  Medical  Information  of  the  day,  as  well  as  a  Treatise  of  high  character  on  some 

prominent  department  of  Medicine. 

In  this  manner  its  subscribers  have  been  supplied  with 

WATSON'S  LECTURES  ON  THE  PRACTICE  OF  MEDICINE, 

BRODIE'S    CLINICAL    LECTURES    ON    SURGERY, 

TODD    &    BOWMAN'S   PHYSIOLOGY, 

AND  WEST  ON  THE  DISEASES  OF  INFANCY  AND    CHILDHOOD. 
And  the  work  at  present  appearing  in  its  columns  is 

P&£CtAIft]fE?g    OPERATIVE    SURGERY, 

TRANSLATED  AND  EDITED  BY  BRITTAN, 

With  Engravings  on  Wood. 
Which  will  be  completed  in  the  present  year,  and  be  succeeded,  in  1852,  by  a  work  of  equal  value. 

TERMS. 

THE  SUBSCRIPTION  TO  THE 

AMERICAN  JOURNAL  OF  THE  MEDICAL  SCIENCES 

/»  FIfVE  i*0i£.f J£S  PER  AJWilJU. 

When  this  amount  is  paid  in  advance,  the  subscriber  thereby  becomes  entitled  to  the 

MEDICAL  NEWS  AND  LIBRARY  FOR  ONE  YEAR,  GRATIS, 

When  ordered  separately,  the  price  of  the  "  News"  is  ONE  DOLLAR  per  annum,  invariably  in 

advance. 


For  the  small  sum,  therefore,  of  FIVE  DOLLARS,  the  subscriber  can  obtain  a  Quarterly  and 
a  Monthly  Journal  of  the  highest  character,  presenting  about 

Fifteen  hundred  large  octavo  pages,  with  numerous  Illustrations, 

Rendering  these  among 

The  Cheapest  of  American  Medical  Periodicals, 

Those  who  are  desirous  of  subscribing  are  recommended  to  forward  their  names  without  loss  of 
time,  as  the  increase  of  the  subscription  list  has  almost  exhausted  the  whole  edition  printed  for  the 
present  year,  and  the  publishers  cannot  pledge  themselves  to  supply  copies  unless  ordered  early. 

REDUCTION     OF     POSTAGE. 

Under  the  new  postage  law,  subscribers  to  the  American  Journal  of  the  Medical  Sciences  are 
entitled  to  the  benefit  of  the  half  rates  of  postage  for  advance  payment,  which  is  thus  defined  in 
the  Post  Master  General's  circular  of  June  llth,  1851  : — 

"  When  a  periodical  is  published  only  quarterly,  the  actual  and  bona  fide  subscriber  to  such 
periodical  may  pay  in  advance,  and  have  the  benefit  of  such  advance  payment,  provided  he  pays 
to  the  postmaster  at  the  office  where  he  is  to  receive  the  periodical,  before  its  delivery." 

It  will  therefore  be  seen  that  the  subscriber  has  only  to  pay  for  each  number  before  taking  it 
out  of  the  office,  in  order  to  secure  the  benefit  of  the  half  postage,  which  is  as  follows: — 
For  any  distance  under  500  miles,          -         -         -     £  cent  per  ounce, 
"  "         between  500  and  1500  miles,       -     1     "         " 

"  "  "         1500  and  2500     "         -     H  "         " 

When  the  postage  is  not  thus  paid  in  advance,  it  will  be  at  double  these  rates. 
The  Medical  News  and  Library  pays  postage  as  a  newspaper.     Each  number  weighs  between 
one  and  two  ounces.     Subscribers  will   therefore,  under  the  new  postage  law,  pay  in  advance  for 
each  quarter  as  follows  : — 

For  any  distance  under  50  miles,         -         -         -     1£  cents  per  quarter. 
"  «         between  50  and  300  miles,        -     2j     "          " 

«  "  "        300  and  1000  miles,     -     3f  «"          " 

«  "  "        1000  and  2000  miles,       5      "          " 


BLANCHARD  &  LEA'S  PUBLICATIONS. 


NEILL    &    SMITH'S    COMPENDIUM. 
NEW  EDITION,  Nearly  Ready. 

AN  ANALYTICAL  COMPENDIUM 

OF  THE  VARIOUS  BRANCHES  OF  MEDICAL  SCIENCE, 

FOR  THE  USE  AND  EXAMINATION  OF  STUDENTS. 
BY  JOHN  NEILL,  M.  D., 

Demonstrator  of  Anatomy  in  the  University  of  Pennsylvania,  Lecturer  on  Anatomy  in  the  Medical  Institute 

of  Philadelphia,  &c., 
AND 

FRANCIS  GURNEY  SMITH,  M.D., 

Lecturer  on  Physiology  in  the  Philadelphia  Association  for  Medical  Instruction,  &c.&c. 
Second  Edition,  Revised  and  Improved. 

In  one  very  large  and  handsomely  printed  volume,  royal  12mo.,  of  over  900  large  pages,  with  about 
350  illustrations,  strongly  bound  in  leather,  with  raised  bands. 

The  rapid  exhaustion  of  a  large  edition  of  this  work  is  sufficient  evidence  that  it  has  fulfilled  the 
object  for  which  it  was  designed  by  the  authors,  not  only  as  a  manual  for  the  use  and  examination 
of  students,  enabling  them  to  recall  the  facts  presented  in  the  lecture  room  or  in  the  larger  text- 
books, but  also  as  an  aid  to  the  practitioner  who  may  be  desirous  of  refreshing  his  knowledge  by 
a  volume  furnishing  a  rapid,  but  exact,  outline  of  all  the  various  branches  of  medical  science.  In 
the  preparation  of  the  new  edition  every  effort  has  been  made  to  keep  it  on  a  level  with  the  ad- 
vance of  investigation  and  discovery  in  all  its  different  departments,  and  the  experience  which  its 
use  has  afforded,  has  been  employed  to  adapt  it  still  further  to  the  wants  of  the  student.  To 
accomplish  this  it  has  been  thoroughly  revised,  and  in  many  parts  remodelled  and  rewritten,  while 
additional  illustrations  have  been  introduced,  where  necessary.  An  improvement  will  also  be 
found  in  its  mechanical  execution,  while  the  very  large  size  of  the  pages,  and  the  abundance  of 
illustrative  engravings  render  it  one  of  the  cheapest  works  offered  to  the  notice  of  the  profession. 

The  arrangement  adopted  will  be  found  at  once  concise  and  clear ;  while  its  mechanical  execution,  its  co- 
pious pictorial  illustrations  in  the  branches  of  anatomy,  physiology,  surgery,  obstetrics,  materia  medica  and 
chemistry,  together  with  its  neat,  cheap,  and  convenient  form,  will  recommend  it  to  all  such  students  and 
practitioners  who  may  desire  to  avail  themselves  of  what  cannot  fail  to  prove,  if  kept  within  its  proper  sphere, 
a  convenient  and  useful  remembrancer. — American  Journal  of  the  Medical  Sciences. 

We  do  not  share  in  the  opinion  entertained  by  some,  that  compendiums  of  science  are  not  desirable,  or 
with  the  still  smaller  number,  who  esteem  them  useless.  On  the  contrary,  when  well  executed,  they  are  of 
essential  service  to  the  student.  Taking  the  work  before  us,  we  can  certainly  say  that  no  one  who  has  not 
occupied  himself  with  the  different  scientific  treatises  and  essays  that  have  appeared  recently,  and  has 
withal  a  rare  memory,  could  pretend  to  possess  the  knowledge  contained  in  it;  and  hence  we  can  recom- 
mend it  to  such — as  well  as  to  students  especially— for  its  general  accuracy  and  adequacy  for  their  pur- 
poses; and  to  the  well-informed  practitioner  to  aid  him  in  recalling  what  may  easily  have  passed  from  his 
remembrance.  We  repeat  our  favorable  impression  as  to  the  value  of  this  book,  or  series  of  books;  and 
recommend  it  as  decidedly  useful  to  those  especially  who  are  commencing  the  study  of  their  profession. — 
The  Medical  Examiner. 

We  have  no  hesitation  in  recommending  it  to  students.— Southern  Medical  and  Surgical  Journal. 

Books  of  this  description  are  most  erroneously  denounced,  from  the  supposition  that  they  are  intended  to 
take  the  place  of  elaborate  treatises  ;  but  their  object  is  rather  to  assist  the  student  in  mastering  the  elements 
of  medicine,  and  to  aid  the  practitioner  by  refreshing  his  recollection  of  former  studies.  We  have  looked 
through  this  compendium,  and  we  find  that  the  authors  have  really  succeeded  in  compressing  a  large  amount 
of  valuable  information  into  a  very  small  compass.  We  recommend  this  work  especially  to  the  notice  of 
our  junior  readers.  To  those  who  are  about  to  commence  their  studies  in  a  medical  school  it  will  be  found 
a  serviceable  guide. — London  Medical  Gazette. 


PROFESSOR   DICKSON'S   ESSAYS-Nearly   Ready, 

ESSAYS  ON  LIFE,  SLEEP,  PAIN,  INTELLECTION,  HYGIENE,  AND  DEATH, 
BY  SAMUEL  HENRY  DICKSON,  M.D., 

Professor  of  the  Institutes  and  Practice  of  Medicine  in  the  Charleston  Medical  College. 
In  one  very  handsome  volume,  royal  12mo. 

MALGAIGNE'S    SURGERY.— Now  Ready. 


OPERATIVE    SURGERY, 

BASED    ON    NORMAL   AND   PATHOLOGICAL   ANATOMY. 

BY  J.  F.  MALGAIGNE. 

TRANSLATED    FROM    THE    FRENCH, 

BY  FREDERICK  BRITTAN,  A.  B.,  M.D.,  M.R.C.S.L. 

WITH   NUMEROUS   ILLUSTRATIONS    ON   WOOD. 
In  one  handsome  octavo  volume  of  nearly  600  pages. 

This  work  has,  during  its  passage  through  the  columns  of  the  "Medical  News  and  Library" 
in  1850  and  1851,  received  the  unanimous  approbation  of  the  profession,  and  in  presenting  it  in 
a  complete  form  the  publishers  confidently  anticipate  for  it  an  extended  circulation. 

Certainly  one  of  the  best  books  published  on  operative  surgery. — Edinburgh  Med.  Journal. 

We  can  strongly  recommend  it  both  to  practitioners  and  students,  not  only  as  a  safe  guide  in  the  dissect- 
ing-room or  operating-theatre,  but  also  as  a  concise  work  of  reference  for  all  that  relates  to  operative  sur- 
gery.—  Forbes'1  Review. 

Dr.  Brutan  has  performed  his  task  of  translator  and  editor  with  much  judgment.  The  descriptions  are 
perfectly  clear  and  explicit;  and  the  author's  occasional  omissions  of  important  operations  proposed  by 
British  surgeons  are  judiciously  supplied  in  brief  notes. — Medical  Gazette. 


6  BLANCHARD  &  LEA'S  PUBLICATIONS.— (Surgery.) 

GROSS  ON  URINARY  ORGANS— (Just  Issued.) 
A  PRACTICAL  TREATISE  ON  THE 

DISEASES  AND  INJURIES  OF  THE  URINARY  ORGANS, 

BY  S.  D.  GROSS,  M.  D.,  &c., 

Professor  of  Surgery  in  the  New  York  University. 

In  one  large  and  beautifully  printed  octavo  volume,  of  over  seven  hundred  pages. 
With  numerous  Illustrations. 

The  author  of  this  work  has  devoted  several  years  to  its  preparation,  and  has  endeavored  to 
render  it  complete  and  thorough  on  all  points  connected  with  the  important  subject  to  which  it  is 
devoted.  It  contains  a  large  number  of  original  illustrations,  presenting  the  natural  and  patholo- 
gical anatomy  of  the  parts  under  consideration,  instruments,  modes  of  operation,  &c.  &c.,  and  in 
mechanical  execution  it  is  one  of  the  handsomest  volumes  yet  issued  from  the  American  press. 

A  very  condensed  summary  of  the  contents  is  subjoined. 

INTRODUCTION.— CHAPTER  I.  Anatomy  of  the  Perinaeum.— CHAP.  II,  Anatomy  of  the  Urinary  Bladder.— 
CHAP.  III.  Anatomy  of  the  Prostate.— CHAP.  IV,  Anatomy  of  the  Urethra.— CHAP.  V,  Urine. 

PART.  I.  DISEASES  AND  INJURIES  OF  THE  BLADDER. 

CHAP.  I,  Malformations  and  Imperfections.— CHAP.  II,  Injuries  of  the  Bladder.— CHAP.  Ill,  Inflammation 
of  the  Bladder.— CHAP.  IV,  Chronic  Lesionsof  the  Bladder.— CHAP.  V,  Nervous  Affeclionsof  the  Bladder. 
— CHAP.  Vf.  Heterologous  Formations  of  the  Bladder.-  CHAP.  VII,  Polypous,  Fungous,  Erectile,  and 
other  Morbid  Growths  of  the  Bladder.— CHAP.  VIII  Worms  in  the  Bladder.— CHAP.  IX,  Serous  Cvsts 
and  Hydalids.— CHAP.  X,  Foetal  Remain?  in  the  Bladder.— CHAP.  XI,  Hair  in  the  Bladder —CHAP.  XII, 
Air  in  the  Bladder.— CHAP.  XIII.  Hemorrhage  of  the  Bladder.— CHAP.  XIV,  Retention  of  Urine.— CHAP. 
XV,  Incontinence  of  Urine.— CHAP.  XVI,  Hernia  of  the  Bladder.—  CHAP.  XVII,  Urinary  Deposits. — 
CHAP.  XVI il.  Stone  in  the  Bladder.— CHAP.  XIX.  Foreign  Bodies  in  the  Bladder. 

PART  II.  DISEASES  AND  INJURIES  OF  THE  PROSTATE  GLAND. 

CHAP.  I,  Wounds  of  the  Prostate.— CHAP.  II,  Acute  Prostatis.— CHAP.  Ill,  Hypertrophy  of  the  Prostate. — 
CHAP.  IV,  Atrophy  of  the  Prostate.— CHAP.  V,  Heterologous  Formations  of  the  Prostate.— CHAP  VI,  Cys- 
tic Disease  of  the  Prostate. — CHAP.  VII,  Fibrous  Tumors  of  the  Prostate — CHAP.  V11I,  Hemorrhage  of 
the  Prostate.— CHAP.  IX.  Calculi  of  the  Prostate.— CHAP.  X,  Phlebitis  of  the  Prostate. 

PART  III,  DISEASES  AND  INJURIES  OF  THE  URETHRA. 

CHAP.  I,  Malformations  and  Imperfections  of  the  Urethra.— CHAP.  II,  Laceration  of  the  Urethra.—  CHAP. 
Ill,  Stricture  of  the  Urethra.— CHAP.  IV,  Polypoid  and  Vascular  Tumors  of  the  Urethra.— CHAP.  V,  Neu- 
ralgia of  the  Urethra  —CHAP.  VI,  Hemorrhage  of  the  Urethra.— CHAP.  VII,  Foreign  Bodies  in  the  Urethra. 
— CHAP.  VIII,  Infiltration  of  Urine. — CHAP  IX.  Urinary  Abscess.— CHAP.  X,  Fistula  of  the  Urethra. — 
CHAP.  XI,  False  Passages.— CHAP.  XII,  Lesions  of  the  Gallinaginous  Crest.— CHAP.  XIII,  Inflammation 
and  Abscess  of  Cowper's  Glands. 


COOPER  ON  DISLOCATIONS — New  Edition— (Just  Issued.) 
A  TREATISE  ON 

ISLOOATIONS  AND  FRACTURES  OF  THE  JOINTS, 

BY  SIR  ASTLEY  P.  COOPER,  BART.,  R  R.  S.,  &c. 

EDITED  BY  BRANSBY  B.  COOPER,  F.  R.  S.,  &c. 

WITH  ADDITIONAL  OBSERVATIONS  BY  PROF.  J.  C.  WARREN. 

A    NEW     AMERICAN     EDITION, 

In  one  handsome  octavo  volume,  with  numerous  illustrations  on  wood. 

After  the  fiat  of  the  profession,  it  would  be  absurd  in  us  to  eulogize  Sir  Astley  Cooper's  work  on  Disloca- 
tions.   It  is  a  national  one,  and  will  probably  subsist  as  long  as  English  Surgery. — Medico- Chirurg.  Review. 


WORKS    BY    THE    SAME    AUTHOR. 
COOPER  (SIR  ASTLEY)  ON  THE  ANATOMY  AND  TREATMENT  OF  ABDOMINAL  HERNIA. 

1  large  vol.,  imp.  8vo.,  with  over  130  lithographic  figures. 
COOPER  ON  THE  STRUCTURE  AND  DISEASES  OF  THE  TESTIS,  AND  ON  THE  THYMUS 

GLAND.  1  vol.,  imp.  8vo.,  with  177  figures  on  29  plates. 
COOPER  ON  THE  ANATOMY  AND  DISEASES  OF  THE  BREAST,  WITH  TWENTY-FIVE 

MISCELLANEOUS  AND  SURGICAL  PAPERS.    1  large  vol.,  imp.  8vo.,  with  252  figures  on  36  plates. 

These  three  volumes  complete  the  surgical  writings  of  Sir  Astley  Cooper.  They  are  very  handsomely 
printed,  with  a  large  number  of  lithographic  plates,  executed  in  the  best  style,  and  are  presented  at  exceed- 
ingly low  prices. 

LISTON  &  MUTTER'S  SITHGERY. 

LECTURES  ON  THE  OPERATIONS  OF  SURGERY, 

AND  ON  DISEASES  AND  ACCIDENTS  REQUIRING  OPERATIONS. 

BY  ROBERT   LISTON,  ESQ.,   F.R.S.,&c. 

EDITED,  WITH  NUMEROUS  ADDITIONS  AND  ALTERATIONS, 

BY  T.  D.  MUTTER,  M.  D., 

Professor  of  Surgery  in  the  Jefferson  Medical  College  of  Philadelphia. 
In  one  large  and  handsome  octavo  volume  of  566  pages,  with  216  wood-cuts. 


BLANCHARD  &  LEA'S  PUBLICATIONS.— 


LIBRARY    OF    SURGICAL    KNOWLEDGE. 

A  SYSTEM  OF  SURGERY. 

BY   J.    M.   CHELIUS. 

TRANSLATED  FROM  THE  GERMAN, 
AND  ACCOMPANIED  WITH  ADDITIONAL  NOTES  AND  REFERENCES 

BY  JOHN  F.  SOUTH. 

Complete  in  three  very  large  octavo  volumes  of  nearly  2200  pages,  strongly  bound,  with  raised 
bands  and  double  titles:  or  in  seventeen  numbers,  at  fifty  cents  each. 

We  do  not  hesitate  to  pronounce  it  the  best  and  most  comprehensive  system  of  modern  surgery  with 
which  we  are  acquainted. —  Mtdico-Chirurgical  Review. 

The  fullest  and  ablest  digest  extant  of  all  that  relates  to  the  present  advanced  state  of  Surgical  Pathology.  - 
American  Medical  Journal. 

If  we  were  confined  to  a  single  work  on  Surgery,  that  work  should  be  Chelius's.—  St.  Lows  Med.  Journal. 

As  complete  as  any  system  of' Surgery  can  well  be.— Southern  Medical  and  Surgical  Journal. 

The  most  finished  system  of  Surgery  in  the  English  language.  —  Western  Lancet. 

The  mo>-t  learned  and  complete  systematic  treatise  now  extant. — Edinburgh  Medical  Journal. 

No  work  in  the  English  language  comprises  so  large  an  amount  of  information  relative  to  operative  medi- 
cine and  surgical  pathology. — Medical  Gazette. 

A  complete  encyclopedia  of  surgical  science— a  very  complete  surgical  library— by  far  the  most  complete 
and  scientific  system  of  surgery  in  the  English  language.— TV.  Y.  Journal  of  Medicine. 

One  of  the  most  complete  treatises  on  Surgery  in  the  English  language  — Monthly  Journal  of  Med.  Science. 

The  most  extensive  and  comprehensive  accountof  the  art  and  science  of  Surgery  in  our  language. — Lancet. 


A  TREATISE  ON  THE  DISEASES  OF  THE  EYE. 

BY  W.  LAWRENCE,  F.R.S. 

A  new  Edition.     With  many  Modifications  and  Additions,  and  the  introduction  of  nearly  200  Illustration*, 

BY  ISAAC  HAYS,  M.D. 
In  one  very  large  8vo.  vol.  of  S60  pages,  with  plates  and  wood-cuts  through  the  text. 


JONES  OST  THE  EYE. 

THE  PRINCIPLES  AND  PRACTICE 

OF  OPHTHALMIC  MEDICINE  AND  SURGERY, 

BY  T.  WHARTON  JONES,  F.  R.  S.,  &c.  &c. 

EDITED  BY  ISAAC  HAYS,  M.  D.,  &c. 

la  one  very  neat  volume,  large  royal  12mo.  of  529  pages,  with  four  plates,  plain  or  colored,  and 
ninety-eight  well  executed  wood-cuts. 


MILLER'S  PRINCIPLES  AND  PRACTICE  OF  SURGERY. 

THE    PRINCIPLES   OF   SURGERY. 

Second  edition,  one  vol.  8vo. 

THE  PRACTICE  OP  SURGERY. 

Second  edition,  one  vol.  8vo. 

BY  JAMES  MILLER,  F.  R.  S.  E., 

Professor  of  Surgery  in  the  University  of  Edinburgh,  &c. 


STANLEY  ON  THE  BONES.— A  Treatise  on  Diseases  of  the  Bones.    In  one  vol.  8vo..  extra  cloth.  288pp. 
BRODIK'r-  SURGICAL  LF.C  I' URES.— -Clinical  Lectures  on  Surgery.    1  vol.  8vo.,  cloih.    330pp. 
BRODIK  ON  THE  JOINTS. — Pathological  and  Surgical  Observations  ort  the  Diseases  of  the  Joints.    1  vol. 

8vo    cloth.    210  pp. 
BRODIK  ON  URINARY  ORGANS.— Lectures  on  the  Diseases  of  the  Urinary  Organs.    1  vol.  8vo.,  clotfc. 

214  pp. 

*,*  These  three  works  may  be  had  neatly  bound  together,  forming  a  large  volume  of  "Brodie'a 

Snnrical  Works."    730  pp. 
RICORD  ON  VENEREAL.— A  Practical  Treatise  on  Venereal  Diseases.  With  a  Therapeutical  Summary 

and  Special  Formulary     Translated  by  Sidney  Doane,  M  D.     Fourth  edition.     lvol.8vo.    340  pp 
DURLACilKR  ON  CORNS.  BUNIONS.  £c.— A  Treaiise  on  Corns,  Bunions,  the  Diseases  of  Nails,  and 

the  General  Management  of  i1)e  Feet.    In  one  12mo.  volume,  cloth.    134  pp 
GUTHRIK  ON  THE  BLADDER,  &c.— The  Anatomy  of  the  Bladder  and  Urethra,  and  the  Treatment  of  the 

Ol>«trm:iion<  10  which  ihoso  Passages  are  liable.    In  one  vol.  8vo.     150  pp. 
LAWRENt  E  ON  RUPTURES.— A  Treatise  on  Ruptures,  from  the  fifth  London  Edition.    In  one  8vo.  rol. 

M  A  URY'S  DENTAL  SURGERY.— A  Treatise  on  the  Dental  Art.  founded  on  Actual  Experience.  Ilfu«- 
trau-d  l.ytMl  lithographic  figures  and  54  wood-cuts.  Translated  by  J.  B.  Savier.  In  I  Hvo.  vol., sheep.  2!-6pp. 

DUFTON  ON  THE  EAR.—  The  Nature  andTreatmeiuof  Deafness  arid  Diseasei-of  the  Ear;  and  ihe  Treat- 
ment of  the  Deaf  and  Dumb.  One  small  12mo.  volume.  120pp. 

SMITH  ON  FRACTURES  —  A  Treatise  on  Fractures  iu  the  vicinity  of  Joints,  and  on  Dislocations,  On« 
vol.  bvo.,  wiiu  200  beautiful  wood-cuts. 


BLANCHARD    &  LEA'S   PUBLICATIONS.— (Surgery.} 


NEW  AND  IMPORTANT  WORK  ON  PRACTICAL  SURGERY,-(JUST  ISSUED,) 

OPERATIVE    SURGERY. 

BY  FREDERICK  C.  SKBY,  F.  R.  S.,  &c. 

In  one  very  handsome  octavo  volume  of  over  650  pages,  with  about  one  hundred  wood-cuts. 
The  object  of  the  author,  in  the  preparation  of  this  work,  has  been  not  merely  to  furnish  the 
student  with  a  guide  to  the  actual  processes  of  operation,  embracing  the  practical  rules  required 
to  justify  an  appeal  to  the  knife,  but  also  to  present  a  manual  embodying  such  principles  as  might 
render  it  a  permanent  work  of  reference  to  the  practitioner  of  operative  surgery,  who  seeks  to 
uphold  the  character  of  his  profession  as  a  science  as  well  as  an  art.  In  its  composition  he  has 
relied  mainly  on  his  own  experience,  acquired  during  many  years'  service  at  one  of  the  largest  of 
the  London  hospitals,  and  has  rarely  appealed  to  other  authorities,  except  so  far  as  personal  inter- 
course and  a  general  acquaintance  with  the  most  eminent  members  of  the  surgical  profession 
have  induced  him  to  quote  their  opinions. 

From  Professor  C.  B.  Gibson,  Richmond,  Virginia. 

I  have  examined  the  work  with  some  care,  and  am  delighted  with  it.  The  style  is  admirable,  ihe  matter 
excellent,  and  much  of  it  original  and  deeply  interesting,  whilst  the  illustrations  are  numerous  and  belter 
executed  than  those  of  any  similar  work  I  possess. 

In  conclusion  we  must  express  our  unqualified  praise  of  the  work  as  a  whole.  The  high  moral  tone,  the 
liberal  views,  and  the  sound  information  which  pervades  it  throughout,  reflect  the  highest  credit  upon  the 
talented  author.  We  know  of  no  one  who  has  succeeded,  whilst  supporting  operative  surgery  in  its  proper 
rank,  in  promulgating  at  the  same  time  sounder  and  more  enlightened  views  upon  that  most  important  of 
all  subjects,  the  principle  that  should  guide  us  in  having  recourse  to  the  knife. — Medical  Times. 

The  treatise  is,  indeed,  one  on  operative  surgery,  but  it  is  one  in  which  the  author  throughout  shows  that 
he  is  most  anxious  to  place  operative  surgery  in  iis  just  position.  He  has  acted  as  a  judicious,  but  not 
partial  friend;  and  while  he  shows  throughout  that  he  is  able  and  ready  to  perform  any  operation  which  the 
exigencies  and  casualties  of  the  human  frame  may  require,  he  is  most  cautious  in  specifying  the  circum- 
stances which  in  each  case  indicate  and  contraindicate  operation.  It  is  indeed  gratifying  to  perceive  the 
sound  and  correct  views  which  Mr.  Skey  entertains  on  the  subject  of  operations  in  general,  and  the  gentle- 
manly tone  in  which  he  impresses  on  readers  the  lessons  which  he  is  desirous  to  inculcate.  His  work  is  a 
perfect  model  for  the  operating  surgeon,  who  will  learn  from  it  not  only  when  and  how  to  operate,  but  some 
more  noble  and  exalted  lessons  which  cannot  fail  to  improve  him  as  a  moral  and  social  agent.— Edinburgh 
Medical  and  Surgical  Journal. 

THE    STUDEN-PS    TEXT-BOOK. 

THE  PRINCIPLES  AND  PRACTICE  OF  MODERN  SURGERY, 

BY  ROBERT  DRUITT,  Fellow  of  the  Royal  College  of  Surgeons. 
A  New  American,  from  the  last  and  improved  London  Edition, 

EDITED  BY  F.  W.  SARGENT,  M.D.,  Author  of  "Minor  Surgery,"  &c. 

ILLUSTRATED  WITH  ONE  HUNDRED  AND  NINETY-THREE  WOOD  ENGRAVINGS. 

In  one  very  handsomely  printed  octavo  volume  of  576  large  pages. 

From  Professor  Brainard,  of  Chicago,  Illinois. 
I  think  it  the  best  work  of  its  size,  on  that  subject,  in  the  language. 

From  Professor  Rivers,  of  Providence,  Rhode  Island. 

I  have  been  acquainted  with  it  since  its  first  republication  in  this  country,  and  the  universal  praise  it  has 
received  I  think  well  merited. 

From  Professor  May,  of  Washington,  D.  C. 

Permit  me  to  express  my  satisfaction  at  the  republication  in  so  improved  a  form  of  this  most  valuable  work. 
I  believe  it  to  be  one  of  the  very  best  text-books  ever  issued. 

From  Professor  Me  Cook,  of  Baltimore. 

I  cannot  withhold  my  approval  of  its  merits,  or  the  expression  that  no  work  is  better  suited  to  the  wants 
of  the  student.  I  shall  commend  it  to  my  class,  and  make  it  my  chief  text-book. 


FERGUSSON'S  OPERATIVE  SURGERY.    NEW  EDITION. 

A  SYSTEM   OF   PRACTICAL  SURGERY, 

BY  WILLIAM  FERGUSSON,  F.  R.  S.  E., 

4|tttB(  Professor  of  Surgery  in  King's  College,  London,  &c.  &c. 

lov  ,  THIRD  AMERICAN,  FROM  THE  LAST  ENGLISH  EDITION. 

With  274  Illustrations. 

In  one  large  and  beautifully  printed  octavo  volume  of  six  hundred  and  thirty  pages. 
..Itis  with  unfeigned  satisfaction  that  we  call  the  attention  of  the  profession  in  this  country  to  this  excellent 
work.    It  richly  deserves  the  reputation  conceded  to  it,  of  being  the  best  practical  Surgery  extant,  at  least  in 
the  English  language. — Medical  Examiner. 

A    NEW     MINOR    SURGERY. 

ON  BANDAGING  AND  OTHER  POINTS  OF  MINOR  SURGERY. 

BY  F.  W.  SARGENT,  M.  D. 

In  one  handsome  royal  12mo.  volume  of  nearly  400  pages,  with  128  wood-cuts. 

From  Professor  Gilbert,  Philadelphia. 

Embracing  the  smaller  details  of  surgery,  which  are  illustrated  by  very  accurate  engravings,  the  work 
becomes  one  of  very  great  importance  to  the  practitioner  in  the  performance  of  his  daily  duties,  since  such 
information  is  rarely  found  in  the  general  works  on  surgery  now  in  use. 


BLANCHARD  &  LEA'S  PUBLICATIONS.— (Surgery.)  0 

THE    GREAT    ATLAS    OF    SURGICAL    ANATOMY. 

(NOW    COMPLETE.) 

SURGIOAI.~A]Sr  ATOMY, 

BY  JOSEPH  MACLISE,  SURGEON. 

IN  ONE  VOLUME,  IN  VERY  LARGE  IMPERIAL  QUARTO, 

With  Sixty-eight  large  and  splendid  Plates,  drawn  in  the  toest  style,  and 

beautifully  colored, 

Containing  one  hundred  and  ninety  Figures,  many  of  them  the  size  of  life, 

TOGETHER   WITH   COPIOUS   EXPLANATORY   LETTER-PRESS. 

Strongly  and  handsomely  bound,  being  one  of  the  best  executed  and  cheapest  surgical  works  ever 

presented  in  this  country. 

This  great  work  being  now  complete,  the  publishers  confidently  present  it  to  the  attention  of  the 
profession  as  worthy  in  every  respect  of  their  approbation  and  patronage.  No  complete  work 
of  the  kind  has  yet  been  published  in  the  English  language,  and  it  therefore  will  supply  a  want 
long  felt  in  this  country  of  an  accurate  and  comprehensive  Atlas  of  Surgical  Anatomy  to  which 
the  student  and  practitioner  can  at  all  times  refer,  to  ascertain  the  exact  relative  position  of 
the  various  portions  of  the  human  frame  towards  each  other  and  to  the  surface,  as  well  as  their 
abnormal  deviations.  The  importance  of  such  a  work  to  the  student  in  the  absence  of  anato- 
mical material,  and  to  the  practitioner  when  about  attempting  an  operation,  is  evident,  while  the 
price  of  the  book,  notwithstanding  the  large  size,  beauty,  and  finish  of  the  very  numerous  illustra- 
tions is  so  low  as  to  place  it  within  the  reach  of  every  member  of  the  profession.  The  publishers 
therefore  confidently  anticipate  a  very  extended  circulation  for  this  magnificent  work. 

To  present  some  idea  of  the  scope  of  the  volume,  and  of  the  manner  in  which  its  plan  has  been 
carried  out,  the  publishers  subjoin  a  very  brief  summary  of  the  plates. 

Plates  1  and  2. — Form  of  the  Thoracic  Cavity  and  Position  of  the  Lungs,  Heart,  and  larger  Blood- 
vessels. 

Plates  3  and  4. — Surgical  Form  of  the  Superficial  Cervical  and  Facial  Regions,  and  the  Relative 
Positions  of  the  principal  Blood-vessels,  Nerves,  &c. 

Plates  5  and  6. — Surgical  Form  of  the  Deep  Cervical  and  Facial  Regions,  and  Relative  Positiona 
of  the  principal  Blood-vessels,  Nerves,  &c. 

Plates  7  and  8. — Surgical  Dissection  of  the  Subclavian  and  Carotid  Regions,  and  Relative  Anatomy 
of  their  Contents. 

Plates  9  and  10. — Surgical  Dissection  of  the  Sterno-Clavicular  or  Tracheal  Region,  and  Relative 
Position  of  its  main  Blood-vessels,  Nerves,  &c. 

Plates  11  and  12. — Surgical  Dissection  of  the  Axillary  and  Brachial  Regions,  displaying  the  Relative 
Order  of  their  contained  parts. 

Plates  13   and!4. — Surgical  Form  of  the  Male  and  Female  Axillae  compared. 

Plates  15  and  16. — Surgical  Dissection  of  the  Bend  of  the  Elbow  and  the  Forearm,  showing  the 
Relative  Position  of  the  Arteries,  Veins,  Nerves,  &c. 

Plates  17,  18  and  19. — Surgical  Dissections  of  the  Wrist  and  Hand. 

Plates  20  and  21. — Relative  Position  of  the  Cranial,  Nasal,  Oral,  and  Pharyngeal  Cavities,  &c. 

Plate  22. — Relative  Position  of  the  Superficial  Organs  of  the  Thorax  and  Abdomen. 

Plate  23. — Relative  Position  of  the  Deeper  Organs  of  the  Thorax  and  those  of  the  Abdomen. 

Plate  24. — Relations  of  the  Principal  Blood-vessels  to  the  Viscera  of  the  Thoracico-Abdominal 
Cavity. 

Plate  25. — Relations  of  the  Principal  Blood-vessels  of  the  Thorax  and  Abdomen  to  the  Osseous 
Skeleton,  &c. 

Plate  26. — Relation  of  the  Internal  Parts  to  the  External  Surface  of  the  Body. 

Plate  27. — Surgical  Dissection  of  the  Principal  Blood-vessels,  &c.,  of  the  Inguino-Femoral  Region. 

Plates  28  and  29.— Surgical  Dissection  of  the  First,  Second,  Third,  and  Fourth  Layers  of  the 
Inguinal  Region,  in  connection  with  those  of  the  Thigh. 

Plates  30  and  31. — The  Surgical  Dissection  of  the  Fifth,  Sixth,  Seventh  and  Eighth  Layers  of  the 
Inguinal  Region,  and  their  connection  with  those  of  the  Thigh. 

Plates  32,  33  and  34.— The  Dissection  of  the  Oblique  or  External  and  the  Direct  or  Internal  Ingui- 
nal Hernia. 

Plates  35,  36,  37  and  38. — The  Distinctive  Diagnosis  between  External  and  Internal  Inguinal  Hernia, 
the  Taxis,  the  Seat  of  Stricture,  and  the  Operation. 

Plates  39  and  40. — Demonstrations  of  the  Nature  of  Congenital  and  Infantile  Inguinal  Hernia,  and 
of  Hydrocele. 

Plates  41  and  42. — Demonstrations  of  the  Origin  and  Progress  of  Inguinal  Hernia  in  general. 

Plates  43  and  44. — The  Dissection  of  Femoral  Hernia,  and  the  Seat  of  Stricture. 

Plates  45  and  46. — Demonstrations  of  the  Origin  and  Progress  of  Femoral  Hernia,  its  Diagnosis,  the 
Taxis,  and  the  Operation. 

Plate  47.— The  Surgical  Dissection  of  the  principal  Blood-vessels  and  Nerves  of  the  Iliac  and  Fe- 
moral Regions. 

Plates  48  and  49.— The  Relative  Anatomy  of  the  Male  Pelvic  Organs. 

Plates  50  and  61. — The  Surgical  Dissection  of  the  Superficial  Structures  of  the  Male  Perineum. 

Plates  52  and  53.— The  Surgical  Dissection  of  the  Deep  Structures  of  the  Male  Perineum.— The 
Lateral  Operation  of  Lithotomy. 


10  BLANCHARD  &  LEA'S  PUBLICATIONS.— (Surgery.'} 

MACLISE'S  SURGICAL  ANATOMY— (Continued.) 

Plates  54,  55  and  56.— The  Surgical  Dissection  of  the  Male  Bladder  and  Urethra.— Lateral  and 
Bilateral  Lithotomy  compared. 

Plates  57  and  58. — Congenital  and  Pathological  Deformities  of  the  Prepuce  and  Urethra. — Struc- 
ture and  Mechanical  Obstructions  of  the  Urethra. 

Plates  59  and  60. — The  various  forms  and  positions  of  Strictures  and  other  Obstructions  of  the 
Urethra. — False  Passages. — Enlargements  and  Deformities  of  the  Prostate. 

Plates  61  and  62. — Deformities  of  the  Prostate. — Deformities  and  Obstructions  of  the  Prostatic 
Urethra. 

Plates  63  and  64.— Deformities  of  the  Urinary  Bladder.— The  Operations  of  Sounding  for  Stone,  of 
Catheterism,  and  of  Puncturing  the  Bladder  above  the  Pubes. 

Plates  65  and  66. — The  Surgical  Dissection  of  the  Popliteal  Space,  and  the  Posterior  Crural  Region. 

Plates  67  and  68. — The  Surgical  Dissection  of  the  Anterior  Crural  Region,  the  Ankles, and  the  Foot. 

Notwithstanding  the  short  time  in  which  this  work  has  been  before  the  profes- 
sion, it  has  received  the  unanimous  approbation  of  all  who  have  examined  it.  From 
among  a  very  large  number  of  commendatory  notices  with  which  they  have  been 
favored,  the  publishers  select  the  following : — 

From  Prof.  Kimball,  Pittsfteld,  Mass. 

I  have  examined  these  numbers  with  the  greatest  satisfaction,  and  feel  bound  to  say  that  they  are  alto- 
gether, the  most  perfect  and  satisfactory  plates  of  the  kind  that  I  have  ever  seen. 

From  Prof.  Brainard,  Chicago,  III. 

The  work  is  extremely  well  adapted  to  Ihe  use  both  of  students  and  practitioner?,  being  sufficiently  exten- 
sive for  practical  purposes,  without  being  so  expensive  as  to  place  it  beyond  their  reach.  Such  a  work  was 
a  desideratum  in  this  country,  and  I  shall  not  fail  to  recommend  ii  to  those  within  the  sphere  of  rny  acquaint- 
ance. 

From  Prof.  P.  F.  Eve,  Augusta,  Ga. 

I  consider  this  work  a  great  acquisition  to  my  library,  and  shall  take  pleasure  in  recommending  it  on  all 
suilable  occasions. 

From  Prof.  Peaslee,  Brunswick,  Me. 

The  second  part  more  than  fulfils  the  promise  held  out  by  the  first,  so  far  as  the  beauty  of  the  illustrations 
is  concerned  ;  and,  perfecting  my  opinion  of  the  value  of  the  work,  so  far  as  it  has  advanced,  I  need  add 
nothing  to  what  I  have  previously  expressed  to  you. 

From  Prof.  Gunn,  Ann  Arbor,  Mich. 

The  plates  in  your  edition  of  Macli.<e  answer,  in  an  eminent  degree,  the  purpose  for  which  they  are 
intended.  I  shall  take  pleasure  in  exhibiting  it  and  recommending  it  to  my  class. 

From  Prof.  Rivers,  Providence,  R.  I. 
The  plates  illustrative  of  Hernia  are  the  most  satisfactory  I  have  ever  met  with. 

From  Professor  S.  D.  Gross,  Louisville,  Ky. 

The  work,  as  far  as  it  has  progressed,  is  most  admirable,  and  cannot  fail,  when  completed,  to  form  a  most 
valuable  contribution  to  the  literature  of  our  profession.  It  will  afford  me  great  pleasure  to  recommend  it  to 
the  pupils  of  the  University  of  Louisville. 

From  Professor  R.  L.  Howard,  Columbus,  Ohio. 

In  all  respects,  the  first  number  is  the  beginning  of  a  most  excellent  work,  filling  completely  what  might 
be  considered  hitherto  a  vacuum  in  surgical  literature.  For  myself,  in  behalf  of  the  medical  profession,  I 
wish  to  express  to  you  my  thanks  for  this  truly  elegant  and  meritorious  work.  I  am  confident  that  it  will 
meet  with  a  ready  and  extensive  sale.  I  have  spoken  of  it  in  the  highest  terms  to  my  class  and  my  profes- 
sional brethren. 

From  Prof.  C.  B.  Gibson,  Richmond,  Va. 

I  consider  Maclise  very  far  superior,  as  to  the  drawings,  to  any  work  on  Surgical  Anatomy  with  which  I 
am  familiar,  and  I  am  particularly  struck  with  the  exceedingly  low  price  at  which  it  is  sold.  I  cannot  doubt 
that  it  will  be  extensively  purchased  by  the  profession. 

From  Prof.  Granville  S.  Pattison,  New  York. 

The  profession,  in  my  opinion,  owe  you  many  thanks  for  the  publication  of  this  beautiful  work — a  work 
which,  in  the  correctness  of  its  exhibitions  of  Surgical  Anatomy,  is  not  surpassed  by  any  work  with  which 
I  am  acquainted;  and  the  admirable  manner  in  which  the  lithographic  plates  have  been  executed  and 
colored  is  alike  honorable  to  your  house  and  to  the  arts  in  the  United  States. 

From  Prof.  J.  F.  May,  Washington,  D.  C. 

Having  examined  the  work,  I  am  pleased  to  add  my  testimony  to  its  correctness,  and  to  its  value  as  a 
work  of  reference  by  the  surgeon. 

From  Prof.  Alden  Marsh,  Albany,  N.  Y. 

From  what  I  have  seen  of  it,  I  think  the  design  and  execution  of  the  work  admirable,  and,  at  the  proper 
time  in  my  course  of  lectures,  I  shall  exhibit  it  to  the  class,  and  give  it  a  recommendation  worthy  of  its  great 
merit. 

From  H.  H.  Smith,  M.  D.,  Philadelphia. 

Permit  me  to  express  my  gratification  at  the  execution  of  Maclise's  Surgical  Anatomy.  The  plates  are,  in 
ray  opinion,  the  best  lithographs  that  I  have  seen  of  a  medical  character,  and  the  coloring  of  this  number 
cannot,  I  think,  be  improved.  Estimating  highly  the  contents  of  this  work,  I  shall  continue  to  recommend  it 
to  my  class  as  I  have  heretofore  done. 

From  Prof.  D.  Gilbert,  Philadelphia. 

Allow  me  to  say,  gentlemen,  that  the  thanks  of  the  profession  at  large,  in  this  country,  are  due  to  you  for 
the  republication  of  this  admirable  work  of  Maclise.  The  precise  relationship  of  the  organs  in  the  regions 
displayed  is  so  perfect,  that  even  those  who  have  daily  access  to  the  dissecting-room  may,  by  consulting 
this  work,  enliven  and  confirm  their  anatomical  knowledge  prior  to  an  operation.  But  it  is  to  the  thousands 
of  practitioners  of  our  country  who  cannot  enjoy  these  advantages  that  the  perusal  of  those  plates,  with 
their  concise  and  accurate  descriptions,  will  prove  of  infinite  value.  These  have  supplied  a  desideratum, 
which  will  enable  them  to  refresh  their  knowledge  of  the  important  structures  involved  in  their  surgical 
oases,  thus  establishing  their  self-confidence,  and  enabling  them  to  undertake  operative  procedures  with 
every  assurance  of  success.  And  as  all  the  practical  departments  in  medicine  rest  upon  the  same  basis,  and 
are  enriched  from  the  same  sources,  I  need  hardly  add  that  this  work  should  be  found  in  the  library  of  every 
practitioner  in  the  Jand. 


BLANCHARD  &  LEA'S   PUBLICATIONS.— (Surgery.)  ]1 

MACLISE'S   SURGICAL  ANATOMY— (Continued.) 

From  Professor  J.  M.  Bush,  Lexington,  Ky. 

1  am  delighted  with  both  the  plan  and  execution  of  the  work,  and  shall  take  all  occasions  to  recommend  it 
to  my  private  pupils  and  public  classes. 

The  most  accurately  engraved  and  beautifully  colored  plates  we  have  ever  seen  in  an  American  book — 
one  of  the  best  and  cheapest  surgical  works  ever  published.—  Buffalo  Medical  Journal. 

It  is  very  rare  that  so  elegantly  printed,  so  well  illustrated,  and  so  useful  a  work,  is  offered  at  so  moderate 
a  price. —  Charleston  Medical  Journal. 

A  work  which  cannot  but  please  the  most  fastidious  lover  of  surgical  science,  and  we  hesitate  not  to  say 
that  if  the  remaining  three  numbers  of  this  work  are  in  keeping  with  the  present,  ii  cannot  fail  to  give  uni- 
versal satisfaction.  In  it,  by  a  succession  of  plates,  are  brought  to  view  the  relative  anatomy  of  the  parts 
included  in  the  important  surgical  divisions  of  the  human  body,  with  that  fidelity  and  neatness  of  touch  which 
is  scarcely  excelled  by  nature  herself.  The  part  before  us  differs  in  many  respects  from  anything  of  the  kind 
which  we  have  ever  seen  before.  While  we  believe  that  nothing  but  an  extensive  circulation  can  compen- 
sate the  publishers  for  the  outlay  in  the  production  of  this  edition  of  the  work— furnished  as  it  is  at  a  very 
moderate  price,  within  the  reach  of  all— we  desire  to  see  it  have  that  circulation  which  the  zeal  and  peculiar 
skill  of  the  author  (he  being  his  own  draughtsman),  the  utility  of  the  work,  and  the  neat  style  with  which  it 
is  executed,  should  demand  for  it  in  a  liberal  profession. — N.  Y.  Journal  of  Medicine. 

This  is  an  admirable  reprint  of  a  deservedly  popular  London  publication.  Its  English  prototype,  although 
not  yet  completed,  has  already  won  its  way,  amongst  our  British  brethren,  to  a  remarkable  success.  Its 
plates  can  boast  a  superiority  that  places  them  almost  beyond  the  reach  of  competition.  And  we  feel  too 
thankful  to  the  Philadelphia  publishers  for  their  very  handsome  reproduction  of  the  whole  work,  and  at  a 
rate  within  everybody's  reach,  not  to  urge  all  our  medical  friends  to  give  it.  for  their  own  sakes,  the  cordial 
welcome  it  deserves. in  a  speedy  and  extensive  circulation. —  The  Medical  Examiner. 

The  plates  are  accompanied  by  references  and  explanations,  and  when  the  whole  has  been  published  it 
will  be  a  complete  and  beautiful  system  of  Surgical  Anatomy,  haying  an  advantage  which  is  important,  and 
not  possessed  by  colored  plates  generally,  viz.,  its  cheapness,  which  places  it  within  the  reach  of  every  one 
who  may  feel  disposed  to  possess  the  work.  Every  practitioner,  we  think,  should  have  a  work  of  this  kind 
within  reach,  as  there  are  many  operations  requiring  immediale  performance  in  which  a  book  of  reference 
will  prove  most  valuable. — Southern  Medical  and  Surg.  Journal. 

The  work  of  Maclise  on  Surgical  Anatomy  is  of  the  highest  value.  In  some  respects  it  is  the  best  pub- 
lication of  its  kind  we  have  seen,  and  is  worthy  of  a  place  in  the  library  of  any  medical  man,  while  the  stu- 
dent could  scarcely  make  a  better  investment  than  this. —  The  Western  Journal  of  Medicine  and  Surgery. 

No  such  lithographic  illustrations  of  surgical  regions  have  hitherto,  we  think,  been  given.  While  the  ope- 
rator is  shown  every  vessel  and  nerve  where  an  operation  is  contemplated,  the  exact  anatomist  is  refreshed 
by  those  clear  and  distinct  dissections  which  every  one  must  appreciate  who  has  a  particle  of  enthusiasm. 
The  English  medical  press  has  quite  exhausted  the  words  of  praise  in  recommending  this  admirable  treatise. 
Those  who  have  any  curiosity  to  gratify  in  reference  to  the  perfectibility  of  the  lithographic  art  in  delinea- 
ting the  complex  mechanism  of  the  human  body,  are  invited  to  examine  our  specimen  copy.  If  anything 
will  induce  surgeons  and  students  to  patronize  a  book  of  such  rare  value  and  every-day  importance  to  them, 
it  will  be  a  survey  of  the  artistical  skill  exhibited  in  these  fac-similes  of  nature. — Boston  Medical  and  Surg. 
Journal. 

The  fidelity  and  accuracy  of  the  plates  reflect  the  highest  credit  upon  the  anatomical  knowledge  of  Mr. 
Maclise.  We  strongly  recommend  the  descriptive  commentaries  to  the  perusal  of  the  student  both  of  sur- 
gery and  medicine.  These  plates  will  form  a  valuable  acquisition  to  practitioners  settled  in  the  country, 
whether  engaged  in  surgical,  medical,  or  general  practice.— Edinburgh  Medical  and  Surgical  Journal. 

We  are  well  assured  that  there  are  none  of  the  cheaper,  and  but  few  of  the  more  expensive  works  on 
anatomy,  which  will  form  so  complete  a  guide  to  the  student  or  practitioner  as  these  plates.  To  practitioners, 
in  particular,  we  recommend  this  work  as  far  better,  and  not  at  all  more  expensive,  than  the  heterogeneous 
compilations  most  commonly  in  use,  and  which,  whatever  their  value  to  the  student  preparing  for  examina- 
tion, are  as  likely  to  mislead  as  to  guide  the  physician  in  physical  examination,  or  the  surgeon  in  the  per- 
formance of  an  operation. — Monthly  Journal  of  Medical  Sciences. 

The  dissections  from  which  these  various  illustrations  are  taken  appear  to  have  been  made  with  remark- 
able success ;  and  they  are  most  beautifully  represented.  The  surgical  commentary  is  pointed  and  practical. 
We  know  of  no  work  on  surgical  anatomy  which  can  compete  with  it. — Lancet. 

This  is  by  far  the  ablest  work  on  Surgical  Anatomy  that  has  come  under  our  observation.  We  know  of 
no  other  work  that  would  justify  a  student,  in  any  degree,  for  neglect  of  actual  dissection.  A  careful  study 
of  these  plates,  and  of  the  commentaries  on  them,  would  almost  make  an  anatomistof  a  diligent  student.  And 
to  one  who  has  studied  anatomy  by  dissection,  this  work  is  invaluable  as  a  perpetual  remembrancer,  in  mat- 
ters of  knowledge  that  may  slip  from  the  memory.  The  practitioner  can  scarcely  consider  himself  equipped 
for  the  duties  of  his  profession  without  such  a  work  as  this,  and  this  has  no  rival,  in  his  library.  In  those 
sudden  emergencies  that  so  often  arise,  and  which  require  the  instantaneous  command  of  minute  anatomical 
knowledge,  a  work  of  this  kind  keeps  the  details  of  the  dissecting-room  perpetually  fresh  in  the  memory. 
We  appeal  to  our  readers,  whether  any  one  can  justifiably  undertake  the  practice  of  medicine  who  is  not 
prepared  to  give  all  needful  assistance,  in  all  matters  demanding  immediate  relief. 

We  repeal  that  no  medical  library,  however  large,  can  be  complete  without  Maclise's  Surgical  Anatomy. 
The  American  edition  is  well  entitled  to  the  confidence  of  the  profession,  and  should  command,  among  them, 
an  extensive  sale.  The  investment  of  the  amount  of  the  cost  of  this  work  will  prove  to  be  a  very  profitable 
one,  and  if  practitioners  would  qualify  themselves  thoroughly  with  such  important  knowledge  as  is  contained 
in  works  of  this  kind,  there  would  be  fewer  of  them  sighing  for  employment.  The  medical  profession  should 
spring  towards  such  an  opportunity  as  is  presented  in  this  republication,  to  encourage  frequent  repetitions  of 
American  enterprise  of  this  kind.—  The  Western  Journal  cf  Medicine  and  Surgery. 

It  is  a  wonderful  triumph,  showing  what  ingenuity,  skill,  and  enterprise  can  effect  if  supported  by  a  suffi- 
cient number  of  purchasers.  No  catchpenny  sketches  on  flimsy  material  and  with  bad  print,  but  substantial 
lithographs  on  fine  paper  and  with  a  bold  and  legible  type.  The  drawings  are  of  the  first  class,  and  the  light 
and  shade  so  liberally  provided  for,  that  the  most  ample  expression,  with  great  clearness  and  sharpness  of 
outline,  is  secured.—  Dublin  Medical  Press. 

Our  hearty  good  wishes  attend  this  work,  which  promises  to  supply,  when  complete,  a  far  better  series  of 
delineations  of  surgical  regions  than  has  been  yet  given,  and  at  a  price  as  low  as  that  of  the  most  ordinary 
series  of  illustrations. —  The  British  and  Foreign  Medico- Chirurgical  Review. 

The  plates  continue  to  be  of  the  same  excellent  character  that  we  have  before  ascribed  to  them,  and  their 
description  all  that  might  naturally  be  expected  from  so  good  an  anatomist  as  Mr.  Machsfe.  The  work  ought 
to  be  in  the  possession  of  every  one,  for  it  really  forms  a  valuable  addition  to  a  surgical  library.—  TheMedi 
cal  Times. 

It  is,  and  it  must  be  unique,  for  the  practical  knowledge  of  the  surgeon,  the  patience  and  skill  of  the  dissec- 
tor, in  combination  with  the  genius  of  the  artist,  as  here  displayed,  have  never  before  been,  and  perhaps, 
never  will  be  again  associated  to  a  similar  extent  in  the  same  individual.— Lancet. 

The  plates  are  accurate  and  truthful  j  and  there  is  but  one  word  in  the  English  language  descriptive  ot 
the  letter- press — faultless. 

For  the  quality,  it  is  the  cheapest  work  that  we  have  seen,  and  will  constitute  a  valuable  contribution  to 
the  surgeon's  library.— The  N.  W.  Medical  and  Surgical  Journal. 


12  BLANCHARD  &  LEA'S  PUBLICATIONS.— (Anatomy.) 

SHARPEY  AND  QUAIN'S  ANATOMY.— Lately  Issued. 

HUMAN   A~N  ATOMY. 

BY    JONES    QUAIN,   M.D. 

FROM     THE    FIFTH     LONDON     EDITION. 

EDITED  BY 

RICHARD  QUAIN,  F.R.S., 

AND 

WILLIAM  SHARPEY,  M.D.,  F.R.S., 

Professors  of  Anatomy  and  Physiology  in  University  College,  London. 
REVISED,   WITH    NOTES   Atfl>   ADDITIONS, 

BY  JOSEPH  LEIDY,  M.  D. 

Complete  in  Two  large  Octavo  Volumes,  of  about  Thirteen  Hundred  Pages. 

BEAUTIFULLY  ILLUSTRATED 
With  over  Five  Hundred  Engravings  on  "Wood. 

We  have  here  one  of  the  best  expositions  of  the  present  state  of  anatomical  science  extant.  There  is  not 
probably  a  work  to  be  found  in  the  English  language  which  contains  so  complete  an  account  of  the  progress 
and  present  state  of  general  and  special  anatomy  as  this.  By  the  anatomist  this  work  must  be  eagerly 
sought  for,  and  no  student's  library  can  be  complete  without  it.—  The  N.  Y.  Journal  of  Medicine. 

We  know  of  no  work  which  we  would  sooner  see  in  the  hands  of  every  student  of  this  branch  of  medical 
science  than  Sharpey  and  Quain's  Anatomy. —  The  Western  Journal  of  Medicine  and  Surgery. 

It  may  now  be  regarded  as  the  most  complete  and  best  posted  up  work  on  anatomy  in  the  language.  It 
will  be  found  particularly  rich  in  general  anatomy. —  The  Charleston  Medical  Journal. 

We  believe  we  express  the  opinion  of  all  who  have  examined  these  volumes,  that  there  is  no  work  supe- 
rior to  them  on  the  subject  which  they  so  ably  describe.—  Southern  Medical  and  Surgical  Journal. 

It  is  one  of  the  most  comprehensive  and  best  works  upon  anatomy  in  the  English  language.  It  is  equally 
valuable  to  the  teacher,  practitioner,  and  student  in  medicine,  and  to  the  surgeon  in  particular.— The  Ohio 
Medical  and  Surgical  Journal. 

To  those  who  wish  an  extensive  treatise  on  Anatomy,  we  recommend  these  handsome  volumes  as  the  best 
that  have  ever  issued  from  the  English  or  American  Press.— The  N.  W.  Medical  and  Surgical  Journal. 

We  believe  that  any  country  might  safely  be  challenged  to  produce  a  treatise  on  anatomy  so  readable,  so 
clear,  and  so  full  upon  all  important  topics. — British  and  Foreign  Medico- Chirurgical  Review. 

It  is  indeed  a  work  calculated  to  make  an  era  in  anatomical  study,  by  placing  before  the  student  every  de- 
partment of  his  science,  with  a  view  to  the  relative  importance  of  each ;  and  so  skillfully  have  the  different 
parts  been  interwoven,  that  no  one  who  makes  this  work  the  basis  of  his  studies  will  hereafter  have  any  ex- 
cuse for  neglecting  or  undervaluing  any  important  particulars  connected  with  the  structure  of  the  human 
frame ;  and  whether  the  bias  of  his  mind  lead  him  in  a  more  especial  manner  to  surgery,  physic,  or  physiolo- 
gy, he  will  find  here  a  work  at  once  so  comprehensive  and  practical  as  to  defend  him  from  exclusiveness  on 
tlie  one  hand,  and  pedantry  on  the  other. — Monthly  Journal  and  Retrospect  of  the  Medical  Sciences 

We  have  no  hesitation  in  recommending  this  treatise  on  anatomy  as  the  most  complete  on  that  subject  in 
the  English  language  ;  and  the  only  one,  perhaps,  in  any  language,  which  brings  the  state  of  knowledge  for- 
ward to  the  most  recent  discoveries. —  The  Edinburgh  Medical  and  Surgical  Journal. 

Admirably  calculated  to  fulfil  the  object  for  which  it  is  intended.— Provincial  Medical  Journal. 

The  most  complete  Treatise  on  Anatomy  in  the  English  language. — Edinburgh  Medical  Journal. 

There  is  no  work  in  the  English  language  to  be  preferred  to  Dr.  Quain's  Elements  of  Anatomy.— London 
Journal  of  Medicine. 


THE  STUDENT'S  TEXT-BOOK  OF  ANATOMY. 
NEW   AND   IMPROV'ED   EDITION-JUST   ISSUED. 

A  SYSTEM  OF  HUMAN   ANATOMY, 

GENERAL    AND    SPECIAL. 

BY  ERASMUS  WILSON,  M.  D. 

FOURTH   AMERICAN    FROM  THE  LAST  ENGLISH   EDITION. 
EDITED  BY  PAUL  B.  GODDARD,  A.  M.,  M.  D. 

WITH    TWO  HUNDRED   AND   FIFTY    ILLUSTRATIONS. 

Beautifully  printed,  in  one  large  octavo  volume  of  nearly  six  hundred  pages. 

In  many,  if  not  all  the  Colleges  of  the  Union,  it  has  become  a  standard  text-book.  This,  of  itself,  is  sufficiently 
expressive  of  its  value.  A  work  very  desirable  to  ihe  student ;  one,  the  possession  of  which  will  greatly 
facilitate  his  progress  in  the  study  of  Practical  Anaiomy. — New  York  Journal  of  Medicine. 

Its  author  ranks  with  the  highest  on  Anatomy.—  South ern  Medical  and  Surgical  Journal. 

It  offers  to  the  student  all  the  assistance  that  can  be  expected  from  such  a  work. — Medical  Examiner. 

The  most  complete  and  convenient  manual  for  the  student  we  possess.—  American  Journal  of  Med.  Science. 

In  every  respect  this  work,  as  an  anatomical  guide  for  the  student  and  practitioner,  merits  our  warmest 
and  most  decided  praise. — London  Medical  Gazette, 


BLANCHARD  &,  LEA'S  PUBLIC  ATI  ONS.—Unafomy.)  13 

HORNER'S    ANATOMY. 

JHUCH  IMPROVED  AJ\*D  ENLARGED  EDITION.— (Just  Issued.) 

SPECIAL  ANATOMY  AND  HISTOLOGY. 

BY  WILLIAM  E.  HOKNEB,  M.  D.7 

Professor  of  Anatomy  in  the  University  of  Pennsylvania,  &c. 

EIGHTH   EDITION. 
EXTENSIVELY  REVISED  AND  MODIFIED    TO    1851. 

In  two  large  octavo  volumes,  handsomely  printed,  wi'th  several  hundred  illustrations. 

This  work  has  enjoyed  a  thorough  and  laborious  revision  on  the  part  of  the  author,  with  the 
view  of  bringing  it  fully  up  to  the  existing  state  of  knowledge  on  the  subject  of  general  and  special 
anatomy.  To  adapt  it  more  perfectly  to  the  wants  of  the  student,  he  has  introduced  a  large  number 
of  additional  wood  engravings,  illustrative  of  the  objects  described,  while  the  publishers  have  en- 
deavored to  render  the  mechanical  execution  of  the  work  worthy  of  the  extended  reputation  which 
it  has  acquired.  The  demand  which  has  carried  it  to  an  EIGHTH  EDITION  is  a  sufficient  evidence 
of  the  value  of  the  work,  and  of  its  adaptation  to  the  wants  of  the  student  and  professional  reader. 


NEW  AND  CHEAPER  EDITION  OF 
SMITH  Sf  UOXUTEiVS   JiJr^T 

AN   ANATOMICAL  ATLAS, 

ILLUSTRATIVE  OF  THE  STRUCTURE  OF  THE  HUMAN  BODY. 
BY  HENRY   H.  SMITH,  M.  D.,  &c. 

UNDER   THE  SUPERVISION    OF 

WILLIAM  E.    HORNER,    M.D., 

Professor  of  Anatomy  in  the  University  of  Pennsylvania. 
In  one  volume,  large  imperial  octavo,  with  about  six  hundred  and  fifty  beautiful  figures. 

With  the  view  of  extending  the  sale  of  this  beautifully  executed  and  complete  "Anatomical  Atlas,"  the 
publishers  have  prepared  a  new  edition,  printed  on  both  sides  of  the  page,  thus  materially  reducing  its  cost, 
and  enabling  them  to  present  it  at  a  price  about  forty  per  cent,  lower  than  former  editions,  while,  at  the  same 
time,  the  execution  of  each  plate  is  in  no  respect  deteriorated,  and  not  a  single  figure  is  omitted. 

These  figures  are  well  selected,  and  present  a  complete  and  accurate  representation  of  that  wonderful 
fabric,  the  human  body.  The  plan  of  this  Atlas,  which  renders  it  so  peculiarly  convenient  for  the  student,  and 
its  superb  artistical  execution,  have  been  already  pointed  out.  We  must  congratulate  the  student  upon  the 
completion  of  this  Atlas,  as  it  is  the  most  convenient  work  of  the  kind  that  has  yet  appeared  ;  and  we  must 
add,  the  very  beautiful  manner  in  which  it  is  "got  up"  is  so  creditable  to  the  country  as  to  be  flattering 
to  our  national  pride. — American  Medical  Journal. 


HOHNER'S  DISSECTOR. 

THE   UNITED   STATES    DISSECTOR; 

Being  a  new  edition,  with  extensive  modifications,  and  almost  re-written,  of 

"HORNER'S  PRACTICAL   ANATOMY." 
In  one  very  neat  volume,  royal  12mo.,  of  440  pages,  with  many  illustrations  on  wood. 

•WILSON'S  DISSECTOR,  New  Edition— (Just  Issued.) 

THE  DISSECTOR; 

OR,  PRACTICAL   A!¥D  SURCJICA1L  ANATOUIY.  . 
BY  ERASMUS  WILSON. 

MODIFIED    AND    RE-ARRANGED    BY 
PAUL  BECK  GODDARD,  M.  D. 

A  NEW  EDITION,  WITH  REVISIONS  AND  ADDITIONS. 

In  one  large  and  handsome  volume,  royal  12mo.,  with  one  hundred  and  fifteen  illustrations. 

In  passing  this  work  again  through  the  press,  the  editor  has  made  such  additions  and  improve- 
ments as  the  advance  of  anatomical  knowledge  has  rendered  necessary  to  maintain  the  work  in  the 
high  reputation  which  it  has  acquired  in  the  schools  ol  the  United  States  as  a  complete  and  ITuth 
guide  to  the  student  of  practical  anatomy.  A  number  of  new  illustrations  have  been  added,  espe- 
cially in  the  portion  relating  to  the  complicated  anatomy  of  Hernia.  In  mechanical  execution  the 
work  will  be  found  superior  to  former  editions. 


14  BLANC  EIARD  &  LEA'S  PUBLICATIONS.— (Physiology.) 


WORKS  BY  W,  B,  CARPENTER,  M  D, 

COMPARATIVE    PHYSIOLOGY—  (JYow  Heady.) 

PHINOIPLBS  OP  PHYSIOLOGY, 

GENERAL    AND    COMPARATIVE. 

THIRD   EDITION,  GREATLY  ENLARGED. 
In  one  very  handsome  octavo  volume,  of  over  1100  pages,  with  321  beautiful  wood-cuts. 

This  great  work  will  supply  a  want  long  felt  by  the  scientific  public  of  this  country,  who  have  had  no  ac- 
cessible treatise  to  r(  iVr  to,  presenting,  in,' an  intelligible  form,  a  complete  and  thorough  outline  of  this  im- 
portant subject.  The  high  reputation  of  the  author,  on  both  sides  of  the  Atlantic,  is  u  sufficient  guarantee  fur 
the  completeness  and  accuracy  of  any  work  to  which  his  name  is  prefixed;  but  this  volume  cornts  with  the 
additional  recommendation  that  it  is  the  one  on  which  the  author  has  bestowed  the  greatest  care,  and  on 
which  he  is  desirous  ;o  rest  his  reputation.  Two  years  have  been  devoted  to  the  preparation  of  this  edition, 
which  has  been  thoroughly  remoulded  and  rewritten,  so  as,  in  fact,  to  constitute  a  new  work.  The  amount 
of  alterations  and  addition*  may  be  understood  from  the  fact  that  of  the  ten  hundred  and  eighty  pages  of  the 
text,  but  one  hundred  and  tiny  belong  to  the  previous  edition.  Containing,  as  it  does,  the  results  of  years 
devoted  to  study  ai.d  observation,  il  may  be  regarded  as  a  complete  exposition  of  the  most  advanced  slate  of 
knowledge  in  this  rapidly-'progresgive  branch  of  science,  and  as  a  storehouse  of  facts  and  principles  in  all 
departments  of  Physiology,  such  as  perhaps  no  man  but  its  author  could  have  accumulated  and  classified. 

In  every  point  of  mechanical  execution,  and  profuseness  and  beauty  of  illustration,  the  Publishers  risk  no- 
thing in  saying  that  it  will  be  found  all  that  the  most  fastidious  taste  could  desire. 

A  truly  magnificent  work.    In  itself  a  perfect  physiological  s'udy.—  Ranking's  Abstract,  July  21,  1851. 

This  work  stands  without  its  fellow.  It  is  one  few  men  in  Europe  could  have  undertaken ;  it  is  one  no 
man.  we  believe,  could  have  brought  to  so  successful  an  issue  as  Dr.  Carpente-.  It  required  for  its  produc- 
tion a  physiologist  fit  once  deeply  read  in  the  labours  of  others,  capable  of  taking. a  general,  critical,  and  un- 
prejudiced view  of  those  labours,  and  of  combining  the  varied,  heterogeneous  materials  at  his  disposal,  so  as 
to  form  an  harmonious  whole.  We  feel  that  this  abstract  can  give  the  reader  a  very  imperfect  idea  of  the 
fulness  of  this  wotk.  and  no  idea  of  its  unity,  of  the  admirable  manner  in  which  material  has  been  brought, 
from  the  most  various  sources,  to  conduce  10  its  completeness,  of  the  lucidity  of  the  reasoning  it  contains,  or 
of  <he  clearness  of  language  in  which  the  whole  is  clothed.  Not  the  profession  only,  but  the  scientific  world 
ul  lar»*»,  must  feel  deeply  indebted  to  Dr.  Carpenter  for  this  great  work.  It  must,  indeed,  add  largely  even 
to  his  high  reputation.—  Medical  Times. 

CARPENTER'S  ELEMENTS  OF  PHYSIOLOGY,  New  and  Improved  Edition— (Now  Ready,) 

ELEMENTS  OF~PHYSIOLOGY; 

INCLUDING    PHYSIOLOGICAL    ANATOMY. 

WITH    NEARLY   TWO   HUNDRED   ILLUSTRATIONS. 
Second   American,    from    the    Second   London   Edition* 

In  one  handsome  octavo  volume,  of  about  six  hundred  pages. 

This  work  has  been  subjected  to  a  thorough  revision  by  the  author,  who,  without  materially  in- 
creasing its  size,  has  brought  it  up  completely  with  the  most  recent  researches  and  investigations. 
It  may,  therefore,  be  regarded  as  the  latest  exponent  of  the  views  of  the  author,  with  respect  to 
all  the  modern  doctrines  of  physiology.  Numerous  wood-cuts  have  been  added,  the  work  has  been 
carefully  read  during  its  passage  through  the  press,  and  in  every  point  of  mechanical  execution  it 
will  be  found  equal,  if  not  superior,  to  the  former  edition. 

To  say  that  it  is  the  h/st  manual  of  Physiology  now  before  the  public,  would  not  do  sufficient  justice  to  the 
author  —Buffalo  Med.  Journal. 

In  his  former  works  it  would  seem  that  he  had  exhausted  the  subject  of  Physiology.  In  the  present,  he 
"•jves  the  essence,  as  it  were,  of  the  whole. —  N.  Y.  Journal  of  Medidne. 

The  best  and  most  complete  expose"  of  modern  physiology,  in  one  volume,  extant  in  the  English  language. 
—  St.  Louis  Med.  Journal. 

Those  who  have  occasion  for  an  elementary  treatise  on  physiology,  cannot  do  better  than  to  possess  them- 
selves of  the  manual  of  Dr.  Carpenter.— Medical  Examiner. 


CARPENTER'S  HUMAN  PHYSIOLOGY-(New  Edition,  Preparing.) 

PRINCIPLES  OF  HUMAN  PHYSIOLOGY, 

WITH  THEIR  CHIEF  APPLICATIONS  TO 

PATHOLOGY,  HYGIENE,  AND  FORENSIC  MEDICINE. 

A  NEW  EDITION,  WITH  EXTENSIVE  ADDITIONS  AND  IMPROVEMENTS  BY  THE  AUTHOR. 

With  Two  Lithographic  Plates,  and  over  ^00  Wood-cuts, 

In  one  large  and  handsomely  printed  octavo  volume  of  over  seven  hundred  and  fifty  pages. 

In  preparing  a  new  edition  of  this  very  popular  text-book,  it  has  been  thoroughly*  revised  by  the  author, 
who,  without  materially  increasingly  bulk,  has  embodied  in  it  all  the  recent  investigations  and  discove- 
ries in  physiological  science,  and  has  rendered  it  in  every  respect  on  a  level  with  the  improvements  o!  the  day. 
Although  the  number  of  ihe  wood-engravings  has  been  but  little  increased,  a  considerable  change  will  be 
found.  °In  passing  the  volume  through  the  press  in  this  country,  the  services  of  a  professional  gentleman 
have  been  secured,  in  order  to  insuie  the  accuracy  so  necessary  to  a  scientific  work. 

In  recommending  this  work  to  their  classes.  Professors  of  Physiology  can  rely  on  their  being  always  able 
to  procure  editions  brought  thoroughly  up  with  the  advance  of  science. 


BLANCHARD  &  LEA'S  PUBLICATIONS.— (Physiology.)  15 

DUNGLISON'S     PHYSIOLOGY. 
New  and  much  Improved  Edition.— (Just  Issued.) 

HUMAN    PHYSIOLOGY. 

BY  ROBLEY  DUNGLISON,  M.  D., 

Professor  of  the  Institutes  of  Medicine  in  ihe  Jefferson  Medical  College,  Philadelphia,  etc.  etc. 

SEVENTH  EDITION. 

Thoroughly  revised  and  extensively  modified  and  enlarged, 
With  nearly  Fire  Hundred  Illustrations. 

In  two  large  and  handsomely  printed  octavo  volumes,  containing  nearly  1450  pages. 

On  no  previous  revision  of  this  work  has  the  author  bestowed  more  care  than  on  the  present,  it 
having  been  subjected  to  an  entire  scrutiny,  not  only  as  regards  the  important  matters  of  which  it 
treats,  but  also  the  language  in  which  they  are  conveyed  ;  and  on  no  former  occasion  has  he  felt 
as  satisfied  with  his  endeavors  to  have  the  work  on  a  level  with  the  existing  state  of  the  science. 
Perhaps  at  no  time  in  the  history  of  physiology  have  observers  been  more  numerous,  energetic, 
and  discriminating  than  within  the  last  few  years.  Many  modifications  of  fact  and  inference  have 
consequently  taken  place,  which  it  has  been  necessary  for  the  author  to  record,  and  to  express  hia 
views  in  relation  thereto.  On  the  whole  subject  of  physiology  proper,  as  it  applies  to  the  functions 
executed  by  the  different  organs,  the  present  edition,  the  author  flatters  himself,  will  therefore  be 
found  to  contain  the  views  of  the  most  distinguished  physiologists  of  all  periods. 

The  amount  of  additional  matter  contained  in  this  edition  may  be  estimated  from  the  fact  that 
the  mere  list  of  authors  referred  to  in  its  preparation  alone  extendsover  nine  large  and  closely  printed 
pages.  The  number  of  illustrations  has  been  largely  increased,  the  present  edition  containing  four 
hundred  and  seventy-four,  while  the  last  had  but  three  hundred  and  sixty-eight;  while,  in  addition 
to  this,  many  new  and  superior  wood-cuts  have  been  substituted  for  those  which  were  not  deemed 
sufficiently  accurate  or  satisfactory.  The  mechanical  execution  of  the  work  has  also  been  im- 
proved in  every  respect,  and  the  whole  is  confidently  presented  as  worthy  the  great  and  continued 
favor  which  it  has  so  long  received  from  the  profession. 

It  has  long  since  taken  rank  as  one  of  the  medical  classics  of  our  language.  To  say  that  it  is  by  far  the  best 
text-book  of  physiology  ever  published  in  this  country,  is  butechoing  the  general  testimony  of  the  profession. 
— N.  Y.  Journal  of  Medicine. 

The  most  full  and  complete  system  of  Physiology  in  our  language. —  Western  Lancet. 

The  most  complete  and  satisfactory  system  of  1'hysiology  in  the  English  language. — Amer.  Med.  Journal. 

The  best  work  of  the  kind  in  the  English  language.— -Sitliman's  Journal. 

"We  have,  on  two  former  occasions,  drought  this  excellent  work  under  the  notice  of  our  readers,  and  we 
have  now  only  to  say  that,  instead  of  failing  behind  in  the  rapid  march  of  physiological  science,  each  edition 
brings  it  nearer  to  the  van. — British  and  Foreign  Medical  Review. 

A  review  of  such  a  well-known  work  would  be  out  of  place  at  the  present  time.  We  have  looked  over  it, 
and  find,  what  we  knew  would  be  the  case,  that  Dr.  Dunglisnn  has  kept  pace  with  the  science  to  which  he 
has  devoted  so  much  study,  and  of  which  he  is  one  of  the  living  ornaments.  We  recommend  the  work  to  the 
medical  student  as  a  valuable  text-book,  and  to  all  inquirers  into  Natural  Science,  as  one  which  will  well 
and  delightfully  repay  perusal. —  The  New  Orleans  Medical  and  Surgical  Journal. 


KIRKES    AND   PAGET'S  PHYSIOLOGY. -(Lately  Issued.) 

A  MANUAL  OF  PHYSIOLOGY, 

FOR    THE    USE   OF    STUDENTS. 
BY   WILLIAM  SENHOUSE   KIRKES,  M.  I)., 

ASSISTED  BY  JAMES  PAGET, 

Lecturer  on  General  Anatomy  and  Physiology  in  St.  Bartholomew's  Hospital. 
In  one  handsome  volume,  royal  12mo.,  of  550  pages,  with  118  wood-cuts. 

An  excellent  work,  and  for  students  one  of  the  best  within  reach.— -Boston  Medical  and  Surgical  Journal. 
One  of  the  best  little  books  on  Physiology  which  we  possess.—  BraithwaWs  Retrospect. 
Particularly  adapted  to  those  who  desire  to  possess  a  concise  digest  of  the  facts  of  Human  Physiology. — 
British  and  Foreign  Med.-Chirurg.  Review. 

One  of  the  best  treatises  which  can  be  put  into  the  hands  of  the  student.— London  Medical  Gazette. 
We  conscientiously  recommend  it  as  an  admirable  "  Handbook  of  Physiology." — London  Jour,  of  Medicine. 

SOLLY  ON   THE    BRAIN. 

THE  HUMAN  BRAIN;  ITS  STRUCTURE,  POSIOLOGY,  AND  DISEASES, 

"WITH    A   DESCRIPTION   OF  THE  TYPICAL  FORM   OF   THE   BRAIN  IN   THE   ANIMAL  KINGDOM. 

BY  SAMUEL  SOLLY,  F.  R.  S.,  &c  , 

Senior  Assistant  Surgeon  to  the  St.  Thomas'  Hospital,  &c. 

From  the  Second  and  much  Enlarged  London  Edition.    In  one  octavo  volume,  with  120  Wood-cuts. 

HARRISON  ON  THE  NERVES.— An  Essay  towards  a  correct  theory  of  the  Nervous  System.    In  one 

ociavo  volume,  292  pagts. 
MATFEUCCI  ON  LIVING  BEINGS.- Lectures  on  the  Physical  Phenomena  of  Living  Beings.    Edited 

hy  Pereira.     In  one  neat  royal  1'2mo.  volume,  extra  cloih.  with  cuts — 38S  pages. 
ROHET'S  PHYSIOLOGY.-  A  Treatise  on  Animal  and  Vegetable  Physiology,  with  over  400  illustrations  on 

wood.    In  two  oetavo  volumes,  cloth. 

ROGF/T'S  OUTLINES  -Outlines  of  Physiology  and  Phrenolog-y.    In  one  octavo  volume,  cloth— 516  pages. 
ON  THE   CONNECTION   BKTWEEN   PHYSIOLOGY    AND   INTELLECTUAL   SCIENCE.    In  one 

l'2mo.  volume,  paper,  price  25  cents. 
TODD  &  BOWMAN'S  PHYSIOLOGY —Physiological  Anatomy  and  Physiology  of  Man.  With  numerous 

handsome  wood-cuts.    Parts  I,  II,  and  III,  in  one  8vo.  volume.  552  pp.    Part  IV  will  complete  the  wor*. 


16  BLANCHARD    &   LEA'S  PUBLICATIONS.— (Pathology.) 

W11IL.IJ1M&  PniJVCIPLES—JVew  and  Enlarged  Edition. 

PRINCIPLES  OF  MEDICINE: 

Comprising  General  Pathology  and  Therapeutics, 

AND  A  BRIEF  GENERAL  VIEW  OF 

ETIOLOGY,  NOSOLOGY,   SEMEIOLOGY,  DIAGNOSIS,   PROGNOSIS,   AND   HYGIENICS, 
BY  CHARLES  J.  B.  WILLIAMS,  M.  D.,  F.  R.  S., 

Fellow  of  the  Royal  College  of  Physicians,  &c. 

EDITED,  WITH  ADDITIONS,  BY  MEREDITH  CLYMER,  M.  D., 

Consulting  Physician  to  the  Philadelphia  Hospital,  &c.  &e. 
THIRD    AMERICAN,   FROM   THE    SECOND   AND   ENLARGED    LONDON    EDITION. 

In  one  octavo  volume,  of  440  pages. 
BILLIXG'S  PRINCIPLES,  NEtY  EDITIOX— (Just  Issued.) 

THE  PRINCIPLES  OF  MEDICINE. 

BY  ARCHIBALD  BILLING,  M.  D.,  &c. 
Second  American  from  the  Fifth  and  Improved  London  Edition. 

In  one  handsome  octavo  volume,  extra  cloth,  250  pages. 

We  can  strongly  recommend  Dr.  Billing's  "Principles"  as  a  code  of  instruction  which  should  be  con- 
stantly present  to  the  mind  of  every  well-informed  and  philosophical  practitioner  of  medicine.— Lancet. 

MANUALS  ON  THE  BLOOD  AND  URINE. 

In  one  handsome  volume  royal  12mo.,  extra  cloth,  of  460  large  pages,  with  numerous  illustrations. 

CONTAINING 

I.  A  Practical  Manual  on  the  Blood  and  Secretions  of  the  Human  Body.    BY  JOHN  WILLIAM 
GRIFFITH,  M.  D.,  &c. 

II.  On  the  Analysis  of  the  Blood  and  Urine  in  health  and  disease,  and  on  the  treatment  of  Urinary 
diseases.     BY  G.  OWEN  REESE,  M.  D.,  F.  R.  S.,   &c.  &c. 

III.  A  Guide  to  the  Examination  of  the  Urine  in  health  and  disease.  BY  ALFRED  MARKWICK. 
The  importance  now  attached  to  the  Diagnosis  of  the  Blood  and  Urine,  and  the  rapid  increase  of  our  know- 
ledge respecting  the  pathological  conditions  of  the  fluids  of  the  human  body,  have  induced  the  publishers  to 
present  these  manuals  in  a  cheap  and  convenient  form,  embracing  the  results  of  the  most  recent  observers  in 
a  practical  point  of  view.    On  the  subject  of  the  chemical  and  microscopical  examinations  of  these  fluids, 
they  would  also  call  the  attention  of  the  student  to  BOWMAN'S  MEDICAL  CHEMISTEY,  and  SIMON'S  ANIMAL 
CHEMISTRY.    See  p.  30. 

NEW  EDITION— (Jusx  ISSUED.) 

URINARY  "DEPOSITS; 

THEIR  DIAGNOSIS,  PATHOLOGY,  AND  THERAPEUTICAL  INDICATIONS. 

BY  GOLDING  BIRD,  A.  M.,  M.  D.,  &c. 

A    NEW   AMERICAN,    FROM   THE   THIRD   AND   IMPROVED   LONDON    EDITION. 

In  one  very  neat  volume,  royal  12mo.,  with  over  sixty  illustrations. 

Though  the  present  edition  of  this  well-known  work  is  but  little  increased  in  size,  it  will  be  found  essen- 
tially modified  throughout,  and  fully  up  10  the  present  state  of  knowledge  on  its  subject.  The  unanimous  tes- 
timony of  the  medical  press  warrants  the  publishers  in  presenting  it  as  a  complete  and  reliable  manual  for 
the  student  of  this  interesting  and  important,  branch  of  medical  science. 

THE  PATHOLOGICAL  ANATOMY^F  THE  HUMAN  BODY, 

BY  JULIUS  VOGEL,  M.  D.,  &c. 

Translated  from  the  German,  with  Additions, 

BY  GEORGE  E.  DAY,  M.  D.,  &c. 

ILLUSTRATED    BY  UPWARDS   OF  ONE   HUNDRED    FIGURES,   PLAIN    AND    COLORED. 

In  one  neat  octavo  volume. 


ABERCROMBIE  ON  THE  BRAIN.— Pathological  and  Practical  Researches  on  Diseases  of  the  Brain  and 

Spinal  Cord.     A  new  edition,  in  one  small  Svo.  volume,  pp.  324. 
BURROWS  ON  CEREBRAL  CIRCULATION.— On  Disorders  of  the  Cerebral  Circulation,  and  on  the 

Connection  between  Affections  of  the  Brain  and  Diseases  of  the  Heart.  In  one  Svo.  vol.,  with  colored  plates, 

£p.  216. 
AKISTON  ON  THE  CHEST.— Practical  Observations  on  certain  Diseases  of  the  Chest,  and  on  the 

Principles  of  Auscultation.    In  one  volume,  Svo.,  pp.  384. 
HASSE'S  PATHOLOGICAL  AN  ATOMY.— An  Anatomical  Description  of  the  Diseasesof  Respiration  and 

Circulation.    Translated  and  Edited  by  Swaine.    In  one  volume,  Svo.,  pp.  379. 
HUGHES  ON  THE  LUNGS  AND  HEART.— Clinical  Introduction  to  the  Practice  of  Auscultation,  and 

other  modes  of  Phv«io«l  Diagnosis.     In  one  12mo.  volume,  with  a  plate,  pp.  270. 
FRICK  ON  THE  URINE.— Renal  Aflections,  their  Diagnosis  and  Pathology.    In  one  handsome  volume, 

royal  12mo..  with  illustrations. 
COPLAND  ON  PALSY.— Of  the  Causes,  Nature,  and  Treatment  of  Palsy  and  Apoplexy.    In  one  volume, 

royal  12mo.    (Just  Issued.) 


BLANCHARD  &  LEA'S    PUBLIC ATlONS.-(Practice  of  Medicine.}        17 

DUNGLISON'S  PRACTICE  OF  MEDICINE. 

ENLARGED  AND  IMPROVED  EDITION. 

THE    PRACTICE~OF    MEDICINE. 

A  TREATISE   ON 

SPECIAL  PATHOLOGY  AND  THERAPEUTICS. 

THIRD  EDITION. 

BY  ROBLEY  DUNGLISON,  M.  D., 

Professor  of  the  Institutes  of  Medicine  in  the  Jefferson  Medical  College  ;  Lecturer  on  Clinical  Medicine,  &c. 
In  two  large  octavo  volumes,  of  fifteen  hundred  pages. 

The  student  of  medicine  will  find,  in  these  two  elegant  volumes,  a  mine  of  facts,  a  gathering 
of  precepts  and  advice  from  the  world  of  experience,  that  will  nerve  him  with  courage,  and  faith- 
fully direct  him  in  his  efforts  to  relieve  the  physical  sufferings  of  the  race. — Boston  Medical  and 
Surgical  Journal. 

Upon  every  topic  embraced  in  the  work  the  latest  information  will  be  found  carefully  posted  up. 
Medical  Examiner. 

It  is  certainly  the  most  complete  treatise  of  which  we  have  any  knowledge.  There  is  scarcely  a 
disease  which  the  student  will  not  find  noticed. — Western  Journal  of  Medicine  and  Surgery. 

One  of  the  most  elaborate  treatises  of  the  kind  we  have. — Southern  Medical  and  Surg.  Journal. 


A  New  Work.    Now  Ready. 

DISEASES  OF  THE  HEARTTIUNGS,  AND  APPENDAGES; 

THEIR   SYMPTOMS  AND  TREATMENT. 
BY  W.  H.  WALSHE,  M.D., 

Professor  of  the  Principles  and  Practice  of  Medicine  in  University  College,  London,  8fC. 

In  one  handsome  volume,  large  royal  12mo. 

The  author's  design  in  this  work  has  been  to  include  within  the  compass  of  a  moderate  volume,  all  really 
essential  facts  bearing  upon  the  symptoms,  physical  signs,  and  treatment  of  pulmonary  and  cardiac  diseases. 
To  accomplish  this,  the  first  part  of  the  work  is  devoted  to  the  description  of  the  various  modes  of  physical 
diagnosis,  auscultation,  percussion,  mensuration,  &c.,  which  are  fully  and  clearly,  but  succinctly  entered 
into,  both  as  respects  their  theory  and  clinical  phenomena.  In  the  second  part,  the  various  diseases  of  the 
heart,  lungs,  and  great  vessels  are  considered  in  regard  to  symptoms,  physical  signs  and  treatment,  with 
numerous  references  to  cases.  The  eminence  of  the  author  is  a  guarantee  to  the  practitioner  and  student 
that  the  work  is  one  of  practical  utility  in  facilitating  the  diagnosis  and  treatment  of  a  large,  obscure  and 
important  class  of  diseases. 

r/\  

THE    GREAT    MEDICAL    LIBRARY. 

THE  CYCLOPEDIA  OF  "PRACTICAL  MEDICINE; 

COMPRISING 

Treatises  on  the  Nature  and  Treatment  of  Diseases,  Materia  Medica,  and  Thera- 
peutics, Diseases  of  Women  and  Children,  Medical  Jurisprudence,  &c.  &c. 

EDITED    BY 

JOHN  FORBES,  M.  D.,  F.  R.  S.,  ALEXANDER  TWEEDIE,  M.  D.,  F.  R.  S. 

AND  JOHN  CONNOLLY,  M.  D. 

Revised,  with  Additions, 

BY  ROBLEY  DUNGLISON,  M.  D. 

THIS  WORK  IS  NOW  COMPLETE,  AND   FORMS  FOUR  LARGE  SUPER- ROYAL  OCTAVO  VOLUMES, 

Containing  Thirty-two  Hundred  and  Fifty-four  unusually  large  Pages  in  Double  Columns,  Printed 
on  Good  Paper,  with  a  new  /ind  clear  type. 

THE   WHOLE  WELL   AND   STRONGLY   BOUND   WITH   RAISED   BANDS   AND   DOUBLE    TITLES. 

This  work  contains  no  less  than  FOUR  HUNDRED  AND  EIGHTEEN  DISTINCT  TREATISES, 
By  Sixty-eight  distinguished  Physicians. 

The  most  complete  work  on  Practical  Medicine  extant;  or,  at  least,  incur  language. — Buffalo  Medical 
and  Surgical  Journal. 

For  reference,  it  is  above  all  price  to  every  practitioner. —  Western  Lancet. 

One  of  the  most  valuable  medical  publications  of  the  day— as  a  work  of  reference  it  is  invaluable.— 
Western  Journal  of  Medicine  and  Surgery. 

It  has  been  1o  us,  both  as  learner  and  teacher,  a  work  for  ready  and  frequent  reference,  one  in  which 
modem  English  medicine  is  exhibited  in  the  most  advantageous  light.— Me/lical  Examiner. 

We  rejoice  that  this  work  is  to  be  placed  within  the  reach  of  the  profession  in  this  country,  it  being  unques- 
tionably one  of  very  great  value  to  the  practitioner.  This  estimate  of  it  has  not  been  formed  from  a  batty  ex- 
amination, but  after  an  intimate  acquaintance  derived  from  frequent  consultation  of  it  during  the  past  nine  or 
ten  years.  The  editors  are  practitioners  of  established  reputation,  and  the  list  of  coulributors  embraces  many 
of  the  most  emineul  professors  and  teachers  of  London,  Edinburgh.  Dublin,  and  Glasgow.  It  is,  indeed,  the 
great  merit  of  this  work  that  the  principal  articles  have  been  furnished  by  practitioners  who  have  not  only 
devoted  especial  attention  to  the  diseases  about  which  they  have  written,  but  have  also  enjoyed  opportunities 
for  an  extensive  practical  acquaintance  with  them, — and  whose  reputation  carries  the  assurance  of  their 
competency  justly  to  appreciate  the  opinions  of  others,  while  it  stamps  their  own  doctrines  with  high  and  just 
authority. — American  Medical  Journal. 


18  BLANCHARD  &   LEA'S    PUBLICATIONS.— (Practice  of  Medicine.) 

WATSON'S  PRACTICE  OF  MEDICINE— New  Edition. 

LECTURED  ON  THE 

PRINCIPLES  AND  PRACTICE  OF  PHYSIC, 

BY  THOMAS  WATSON,  M.  D.,  &c.  &c. 

Third  American,  from  the  last  London  Edition. 

REVISED,  WITH  ADDITIONS,  BY  D.  FRANCIS  CONDIE,  M.  D., 

Author  of  "  A  Treatise  on  the  Diseases  of  Children,"  &c. 

IN    ONE    OCTAVO    VOLUME, 
Of  nearly  ELEVEN  HUNDRED  LARGE  PAGES,  strongly  bound  with  raised  bands. 

To  say  that  it  is  the  very  best  work  on  the  subject  now  extant,  is  but  to  echo  the  sentiment  of  the  medrcal 
press  throughout  the  country. —  N.  O.  Medical  Journal. 

Of  the  textbooks  recently  republished  Watson  is  very  justly  the  principal  favorite.— Holmes'1  Report  to 
Nat.  Med.  Assoc. 

By  universal  consent  the  work  ranks  among  the  very  best  text-books  in  our  language.—  III.  and  Ind.  Med. 
Journal. 

Regarded  on  all  hands  as  one  of  the  very  best,  if  not  the  very  best,  systematic  treatise  on  practical  medi- 
cine extant  —  St.  Louis  Med.  Journal. 

Confessedly  one  of  the  very  best  works  on  the  principles  and  practice  of  physic  in  the  English  or  any  other 
language. — Med,  Examiner. 

As  a  text-book  it  has  no  equal;  as  a  compendium  of  pathology  and  practice  no  superior. —  IV.  Y.  Annalist. 

We  know  of  no  work  belter  calculated  for  being  placed  in  the  hands  of  the  student,  and  for  a  text  book, 
on  every  important  point  the  author  seems  to  have  posted  up  his  knowledge  to  the  day.— Amur.  Med.  Journal. 

One  of  the  most  practically  useful  books  that  ever  was  presented  to  the  student. — N.  Y.  Med.  Journal. 


WILSON   ON   THE    SKIN. 

ON     DISEASE  S~~0  F    THE    SKIN. 

BY  ERASMUS  WILSON,  F.  R.S., 

Author  of"  Human  Anatomy,"  &c. 
SECOND    AMERICAN    FROM   THE   SECOND    LONDON   EDITION. 

In  one  neat  octavo  volume,  extra  cloth,  440  pages. 

Also,  to  TJC  liad  with  eight  beautifully  colored  steel  plates. 
Also,  the  plates  sold  separate,  in  boards. 


Much  Enlarged  Edition  of  BARTI^ETT  ON  FEVERS. 

THE  HISTORY,  DIAGNOSIS,  AND  TREATMENT  OF  THE 

FEVERS  OF  THE  UNITED  STATES, 

BY   ELISHA  BARTLETT,  M.D., 

In  one  octavo  volume  of  550  pages,  beautifully  printed  and  strongly  bound. 


CLYMER  AND  OTHERS  ON  FEVERS. 

FEVERS;   THEIR  DIAGNOSIS,  PATHOLOGY,   AND  TREATMENT, 

PREPARED    AND    EDITED,    WITH    LARGE    ADDITIONS, 
FROM  THE  ESSAYS  ON  FEVER  IN  TWEEDIE'S  LIBRARY  OF  PRACTICAL  MEDICINE, 

BY    MEREDITH    CLYMER,    M.  D. 

In  one  octavo  volume  of  six  hundred  pages. 


BENEDICT'S  CHAPMAN.— Compendium  of  Chapman's  Lectures  on  the  Practice  of  Medicine.    One  neat 

volume,  8vo.,  pp.  256. 
BUDD  ON  THE  LIVER.— On  Diseases  of  the  Liver.    In  one  very  neat  8vo.  vol.,  with  colored  plates  and 

wood-cuts,  pp.  392 
CHAPMAN'S  LECTURES. — Lectures  on  Fevers,  Dropsy,  Gout,  Rheumatism,  &c.  &c.    In  one  neatSvo. 

volume,  pp.  450. 
ESQU1ROL  ON  INSANITY.— Mental  Maladies,  considered  in  relation  to  Medicine,  Hygiene,  and  Medical 

Jurisprudence.    Translated  by  K  K.  Hunt,  M.  D ,  &c.     In  one  Svo.  volume,  pp.  496. 
THOMSON  ON  THE  SICK  ROOM. — Domestic  managementof  the  siclc  Room,  necessary  in  aid  of  Medical 

Treatment  for  the  cure  of  Diseases.    Edited  by  R.  E.  Griffith,  M.  D.    In  one  large  royal  12rno.  volume,  with 

HOPE  ON  THE  HEART. — A  Treatise  on  the  Diseases  of  the  Heart  and  Great  Vessels.  Edited  by  Pen- 
nock.  In  one  volume,  8vo  ,  with  plates,  pp.  572. 

LALLEMAND  ON  SPERMATORRHOEA..— The  Causes,  Symptoms,  and  Treatment  of  Spermatorrhoea. 
Translated  and  Edited  by  Henry  J.  McDongal.  In  one  volume,  8vo.,  pp.  320. 

PHILIPS  ON  SCROFULA.— Scrofula:  its  Nature,  its  Prevalence,  its  Causes,  and  the  Principles  of  its 
Treatment  In  one  volume,  Svo.,  with  a  plate,  pp.  350. 

WHITEHEAD  ON  ABORTION,  &c.— The  Causes  and  Treatment  of  Abortion  and  Sterility;  being  the 
Result  of  an  Extended  Practical  Inquiry  into  the  Physiological  and  Morbid  Conditions  of  the  Uterus.  In 
one  volume,  Rvo..  pp  3fiS. 

WILLIAMS  ON  RESPIRATORY  ORGANS.— A  Practical  Treatise  on  Diseases  of  the  Respiratory  Or- 
gans; including  Diseases  of  the  Larynx,  Trachea,  Lungs,  and  Pleurae.  With  numerous  Additions  and 
Notes  by  M.  Ciymer.  M.D.  With  wood-cuts,  [n  one  octavo  volume,  pp  508 

DAY  ON  OLD  AGE.— A  Practical  Treatise  on  the  Domestic  Management  arid  more  important  Diseases  of 
Advanced  Life.  With  an  Appendix  on  a  new  and  successful  mode  of  treating  Lumbago  and  other  forms 
of  Chronic  Rheumatism.  1  vol.  8vo.,  pp.  226. 


BLANCHARD    &   LEA'S  PUBLIC  ATIONS.—  (Dw«a«.,  of  Females.)  19 

BIEIGS  ON  FEMALES,  New  andjmproved  Edition—  (Lately  Issued,) 

WOMAN;  HER  DISEASES"  ANO  THEIR  REMEDIES; 

A    SERIES    OF    LETTERS    TO    HIS    CLASS. 

BY  C.  B.  MEIGS,  M.  B., 

Professor  of  Midwifery  and  Diseases  of  Women  and  Children  in  the  Jefferson  Medical  College  of 

Philadelphia,  &c.  &c. 

In  one  large  and  beautifully  printed  octavo  volume,  of  nearly  seven  hundred  large  pages. 
"  I  am  happy  to  offer  to  my  Class   an   enlarged  and  amended  edition  of  my  Letters  on  the  Pis- 
eases  of  Women  ;  and  I  avail  myself  of  this  occasion  to  return  my  heartfelt  thanks  to  them,  and 
to  our  brethren   generally,  for  the  flattering  manner  in  which  they  have  accepted  this  fruit  of  my 
labor"-- 


The  value  attached  to  this  work  by  the  profession  is  sufficiently  proved  by  the  rapid  ex- 
haustion of  the  first  edition,  and  consequent  demand  for  a  second.  In  preparing  this  the 
author  has  availed  himself  of  the  opportunity  thoroughly  to  revise  and  greatly  to  improve 
it.  The  work  will  therefore  be  found  completely  brought  up  to  the  day,  and  in  every  way 
worthy  of  the  reputation  which  it  has  so  immediately  obtained. 

Professor  Meigs  has  enlarged  and  amended  this  great  work,  for  such  it  unquestionably  is.  having  passed 
the  ordeal  of  criticism  at  home  and  abroad,  but  been  improved  thereby  ;  for  in  Ihis  new  ed.tion  the  author 
has  introduced  real  improvements,  and  increased  the  value  and  utiliiy  of  the  book  immeasurably.  It  presents 
so  many  novel;  bright  and  sparkling  thoughts;  such  an  exuberance  of  new  ideas  on  almost  every  pa^e, 
that  we  confess  ourselves  to  have  become  enamored  with  the  book  and  its  author;  end  cannot  withhold 
our  congratulations  from  our  Philadelphia  confreres,  that  such  a  teacher  is  in  their  service.  We  regret  that 
our  limits  will  not  allow  of  a  more  extended  notice  of  this  work,  but  mu>t  content  our.-elves  with  thus  corn- 
mending  it  as  worthy  of  diligent  perusal  by  physicians  as  well  as  students,  who  are  seekingto  be  thoroughly 
instructed  in  the  important  practical  subjects  of  which  it  treats—  N.  Y.  Med.  Gazette. 

It  contains  a  vast  amount  of  practical  knowledge,  by  one  who  has  accurately  observed  and  retained  the 
experience  of  many  years,  and  who  tells  the  result  in.  a  free,  familiar,  and  pleasant  manner.—  Dublin  Quar- 
terly Journal. 

There  is  an  off-hand  fervor,  a  glow  and  a  warm-heartedness  infecting  the  effort  of  Dr.  Meigs,  which  is  en- 
tirely captivating,  and  which  absolutely  hurries  the  reader  through  from  beginning  to  end.  Besides,  the 
book  teems  with  solid  instruction,  and  it  shows  the  very  highest  evidence  of  ability,  viz.,  the  clearness  with 
which  the  information  is  presented.  We  know  of  no  better  test  of  one's  understanding  a  subject,  than  the 
evidence  of  the  power  of  lucidly  explaining  it.  The  most  elementary,  as  well  as  the  obscurest  subjects,  un- 
der the  pencil  of  Prof.  Meigs,  are  isolated  and  made  to  stand  out  in  such  bold  relief,  as  to  produce  distinct 
impressions  upon  the  mind  and  memory  of  the  reader.—  The  Charleston  Medical  Journal. 

The  merits  of  the  first  edition  of  this  work  were  so  generally  appreciated,  and  with  such  a  high  degree  of 
favor  by  the  medical  profession  throughout  the  Union,  that  we  aa*  not  surprised  in  seeing  a  second  edition 
of  it  It  is  a  standard  work  on  the  diseases  of  females,  and  in  many  respects  is  one  of  the  very  best  of  ita 
kind  in  the  English  language.  Upon  the  appearance  of  the  first  edition,  we  gave  the  work  a  cordial  recep- 
tion. and  spoke  of  it  in  the  warmest  terras  of  commendation.  Time  has  not  changed  the  favorable  estimate 
we  placed  upon  it,  but  has  rather  increased  our  convictions,  of  its  superlative  merits.  But  we  do  not  now 
deem  it  necessary  to  say  more  than  to  commend  this  work,  on  the  diseases  of  women,  and  the  remedies 
for  them,  to  the  attention  of  those  practitioners  who  have  not  supplied  themselves  with  it.  The  most  select 
library  would  be  imperfect  without  it.  —  The  Western  Journal  of  Medicine  and  Surgery. 

He  is  a  bold  thinker,  and  possesses  more  originality  of  thought  and  style  than  almost  any  American  writer 
on  medical  subjects.  If  he  is  not  an  elegant  writer,  there  is  at  least  a  freshness—  a  raciness  in  his  mode  of 
expressing  himself—  that  cannot  fail  to  draw  the  reader  after  him,  even  to  the  close  of  his  work  :  you  cannot 
nod  over  his  pages;  he  stimulates  rather  than  narcotises  your  senses,  and  the  reader  cannot  lay  aside  these 
letters  when  once  he  enters  into  their  merits.  This,  the  second  edition,  is  much  amended  and  enlarged,  and 
affords  abundant  evidence  of  the  author's  talents  and  industry.—  A^  O.  Medical  and  Surgical  Journal. 

The  practical  writings  of  Dr.  Meigs  are  second  to  none.—  The  N.  Y.  Journal  of  Medicine. 

The  excellent  practical  directions  contained  in  this  volume  give  it  great  utility,  which  we  trust  will  not  be 
lost  upon  our  older  colleagues  ;  with  some  condensation,  indeed,  we  should  think  it  well  adapted  for  trans- 
lation into  German.—  Zeitschrift  fur  die  Gesammte  Medecin. 

NEW  AND  IMPROVED  EDITION—  (Lately  Issued.) 

A  TREATISE  ON  THE  DISEASES  OF  FEMALES, 

AND  ON  THE  SPECIAL  HYGIENE  OF  THEIR  SEX, 
BY   COLOMBAT  DE    L'lSERE,  M.  B. 

TRANSLATED,  WITH  MANY  NOTES    AND  ADDITIONS,  BY  C.  D.  MEIGS,  M.  D. 

SECOND   EDITION,    REVISED    AND    IMPROVED. 

In  one  large  volume,  octavo,  of  seven  hundred  and  twenty  pages,  with  numerous  wood-cuts. 
We  are  satisfied  it  is  destined  to  take  the  front  rank  in  this  department  of  medical  science.     It  is  in  fact  a 
complete  exposiiion  of  the  opinions  and  practical  methods  of  all  the  celebrated  practitioners  of  ancient  and 
modern  times.  —  New  York  Journ.  of  Medicine. 

ASHWELI.    OKT    THE    DISEASES    OP   FEMALES. 

A  PRACTICAL  TREATISE  ON  THOISEASES  PECULIAR  TO  WOMEN. 

ILLUSTRATED    BY    CASES    DERIVED    FROM    HOSPITAL   AND    PRIVATfc  PRACTICE. 

BY  SAMUEL  ASHWELL,  M.  D.    WITH  ADDITIONS  BY  PAUL  BECK  GODDARD,  AI.  D. 

Second  American  edition.     In  one  octavo  volume,  of  520  pages. 
One  of  the  very  best  works  ever  issued  from  the  press  on  the  Diseases  of  Females.  —  Western  Lancet. 

ON  THE  CAUSES  AND  TREATMENT  OF  ABORTION   AND   STERILITY.    By  James  Whitehead, 
M.  D.j  &c.    In  one  volume  octavo,  of  about  three  hundred  and  seventy-five  pages. 


20  BLANCHARD  &  LEA'S  PUBLICATIONS.-CPiseases  of  Female*.) 

NEW  AND  IMPROVED  EDITION-(Lately  Issued.) 

THE  DISEASES~OF  FEMALES, 
INCLUDING  THOSE  OF  PREGNANCY  AND  CHILDBED. 

BY  FLEETWOOD  CHURCHILL,  M.  D.,  M.  R.  I.  A., 

Author  of  "Theory  and  Practice  of  Midwifery,"  "Diseases  of  Females,"  &c. 
A  New  American  Edition  (The  Fifth),   Revised  by  the  Author. 

WITH  THE  NOTES  OF  ROBERT  M.  HUSTON,  M.  D. 
In  one  large  and  handsome  octavo  volume  of  632  pages,  with  wood-cuts. 

To  indulge  in  panegyric,  when  announcing  the  fifth  edition  of  any  acknowledged  medical  authority,  were 
to  attempt  lo"  gild  refined  gold."  The  work  announced  above,  has  too  long  been  honored  with  the  terra 
"  classical"  to  leave  any  doubt  as  to  its  true  worih,  and  we  content  ourselves  with  remarking,  that  the  author 
has  carefully  retained  the  notes  of  Dr.  Huston,  who  edited  the  former  American  edition,  thus  really  enhanc- 
ing the  value  of  the  work,  and  paying  a  well  merited  compliment.  All  who  wish  to  be  "posted  up"  on  all 
that  relates  to  the  diseases  peculiar  to  the  wife,  the  mother,  or  the  maid,  will  hasten  to  secure  a  copy  of  this 
most  admirable  treatise. — The  Ohio  Medical  and  Surgical  Journal. 

We  know  of  no  author  who  deserves  that  approbation,  on  "•  the  diseases  of  females,"  to  the  same  extent 
that  Dr.  Churchill  does.  His,  indeed,  is  the  only  thorough  treatise  we  know  of  on  the  subject,  and  it  may  be 
commended  to  practitioners  and  students  as  a  masterpiece  in  its  particular  department.  The  former  editions 
of  this  work  have  been  commended  strongly  in  this  journal,  and  they  have  won  their  way  to  an  extended, 
and  a  well  deserved  popularity.  This  fifth  edition,  before  us,  is  well  calculated  to  maintain  Dr.  Churchill's 
high  reputation.  It  was  revised  and  enlarged  by  the  author,  for  his  American  publishers,  and  it  seems  to  us, 
that  there  is  scarcely  any  species  of  desirable  information  on  its  subjects,  that  may  not  be  found  in  this  work. 
—  The  Western  Journal  of  Medicine  and  Surgery. 

We  are  gratified  to  announce  a  new  and  revised  edition  of  Dr.  Churchill's  valuable  work  on  the  diseases 
of  females.  We  have  ever  regarded  it  as  one  of  the  very  best  works  on  the  subjects  embraced  within  its 
scope,  in  the  English  language;  and  the  present  edition,  enlarged  and  revised  by  the  author,  renders  it  stilj 
more  entitled  to  the  confidence  of  the  profession.  The  valuable  notes  of  Prof.  Huston  have  been  retained, 
and  contribute,  in  no  small  degree,  to  enhance  the  value  of  the  work.  It  is  a  source  of  congratulation  that 
the  publishers  have  permitted  the  author  to  be,  in  this  instance,  his  own  editor,  thus  securing  all  the  revision 
which  an  author  alone  is  capable  of  making. — The  Western  Lancet. 

As  a  comprehensive  manual  for  students,  or  a  work  of  reference  for  practitioners,  we  only  speak  with 
common  justice  when  we  say  that  it  surpasses  any  other  that  has  ever  issued  on  the  same  subject  from  the 
British  press.—  The  Dublin  Quarterly  Journal. 


Churchill's  Monographs  on  Females —(Lately  Issued.) 

ESSATS  ON  THE  PUERPERAL  FEVER,  AND  OTHER  DISEASES 

PECULIAR    TO    WOMEN. 

SELECTED  FROM  THE  WRITINGS  OF  BRITISH  AUTHORS  PREVIOUS  TO  THE  CLOSE  OF 
THE  EIGHTEENTH  CENTURY. 

Edited  by  FLEETWOOD  CHURCHILL,  M.  D.,  M.  R.  I.  A., 

Author  of  "Treatise  on  the  Diseases  of  Females,"  &c. 
In  one  neat  octavo  volume,  of  about  four  hundred  and  fifty  pages. 

To  these  papers  Dr.  Churchill  has  appended  notes,  embodying  whatever  information  ha«  been  laid  before 
the  profession  since  their  authors'  time.  He  has  also  prefixed  to  the  essays  on  puerperal  fever,  which  occu- 
py the  larger  portion  of  the  volume,  an  interesting  historical  sketch  of  the  principal  epidemics  of  that  disease. 
The  whole  forms  a  very  valuable  collection  of  papers  by  professional  writers  of  eminence,  on  some  of  the 
most  important  accidents  to  which  the  puerperal  female  is  liable. — American  Journal  of  Medical  Sciences. 


MUCH  ElVLAR&ED  AJVD  IMPROVED  EDITION— (Lately  Issued.) 
A    PRACTICAL    TREATISE    ON 

INFLAMMATION  OF  THE  UTERUS  AND  ITS  APPENDAGES, 

AND  ON  ULCERATION  AND  INDURATION  OF  THE  NECK  OF  THE  UTERUS, 
BY  HENRY  BENNETT,  M.  D., 

Obstetric  Physician  to  the  Western  Dispensary. 
Second  JEditton,  much  enlarged. 

In  one  neat  octavo  volume  of  350  pages,  with  wood-cuts. 

This  edition  is  so  enlarged  as  to  constitute  a  new  work.  It  embraces  the  study  of  inflammation 
in  all  the  uterine  organs,  and  its  influence  in  the  production  of  displacements  and  of  the  reputed 
functional  diseases  of  the  uterus. 

Few  works  issue  from  the  medical  press  which  are  at  once  original  and  sound  in  doctrine  ;  but  such,  we 
feel  assured,  is  the  admirable  treatise  now  before  us.  The  important  practical  precepts  which  the  author 
inculcates  are  all  rigidly  deduced  from  facts.  .  .  .  Every  page  of  the  book  is  good,  and  eminently  practical. 
So  far  as  we  know  and  believe,  it  is  the  best  work  on  the  subject  on  which  it  treats.— Monthly  Journal  of 
Medical  Science. 

A  TREATISE  ON  THE  DISEASES  OF  FEMALES. 
BY  W.  P.  DEWEES,  M.  D. 

NINTH  EDITION. 
In  one  volume,  octavo.    532  pages,  with  plates. 


BLANCHARD  &  LEA'S  PUBLICATIONS.— (Diseases  of  Children.)  21 

MEIGS   ON  CHILDREN— Just  Issued, 

OBSERVATIONS   ON 

CERTAIN  OF  THE  DISEASES  OF  YOUNG  CHILDREN, 

BY  CHARLES  D.  MEIGS,  M.  D., 

Professor  of  Midwifery  and  of  the  Diseases  of  Women  and  Children  in  the  Jefferson 
Medical  College  of  Philadelphia,  &c.  &c. 

In  one  handsome  octavo  volume  of  214  pages. 

While  this  work  is  not  presented  to  the  profession  as  a  systematic  and  complete  treatise  on  In- 
fantile disorders,  the  importance  of  the  subjects  treated  of,  and  the  interest  attaching  to  the  views 
and  opinions  of  the  distinguished  author  must  command  for  it  the  attention  of  all  who  are  called 
upon  to  treat  this  interesting  class  of  diseases. 

It  puts  forth  no  claims  as  a  systematic  work,  but  contains  an  amount  of  valuable  and  useful  matter, 
scarcely  to  be  found  in  the  same  space  in  our  home  literature.  It  can  not  but  prove  au  acceptable  offering 
to  the  profession  at  large. — N.  Y.  Journal  of  Medicine. 

The  work  before  us  is  undoubtedly  a  valuable  addition  to  the  fund  of  information  which  has  already  been 
treasured  up  on  the  subjects  in  question.  It  is  practical,  and  therefore  eminently  adapted  to  the  general 
practitioner.  Dr.  Meigs'  works  have  the  same  fascination  which  belongs  to  himself.— Medical  Examiner. 

This  is  a  most  excellent  work  on  the  obscure  diseases  of  childhood,  and  will  afford  the  practitioner  and 
student  of  medicine  much  aid  in  their  diagnosis  and  treatment.— The  Boston  Medical  and  Surgical  Journal. 

We  take  much  pleasure  in  recommending  this  excellent  little  work  to  the  attention  of  medical  practition- 
ers. It  deserves  their  attention,  and  after  they  commence  its  perusal,  they  will  not  willingly  abandon  it, 
until  they  have  mastered  its  contents.  We  read  the  work  while  suffering  from  a  carbuncle,  and  its  fasci- 
nating pages  often  beguiled  us  into  forgetfulness  of  agonizing  pain.  May  it  teach  others  to  relieve  the  afflic- 
tions of  the  young. —  The  Western  Journal  of  Medicine  and  Surgery. 

All  of  which  topics  are  treated  with  Dr.  Meigs'  acknowledged  ability  and  original  diction.  The  work  is 
neither  a  systematic  nor  a  complete  treatise  upon  the  diseases  of  children,  but  a  fragment  which  may  be  con- 
sulted with  much  advantage.— Southern  Medical  and  Surgical  Journal. 


NEW  WORK  BY  DR.  CHURCHILL. 
ON    THE 

DISEASES  OF  INFANTS  AND  CHILDREN. 

BY  FLEETWOOD  CHURCHILL,  M.  D.,  M.  R.  I.  A.,      . 

Author  of  "Theory  and  Practice  of  Midwifery,"  "Diseases  of  Females,"  &c. 
In  one  large  and  handsome  octavo  volume  of  over  600  pages. 

From  Dr.  Churchill's  known  ability  and  industry,  we  were  led  to  form  high  expectations  of  this  work ;  nor 
were  we  deceived.  Its  learned  author  seems  to  have  set  no  bounds  to  his  researches  in  collecting  informa- 
tion which,  with  his  usual  systematic  address,  he  has  disposed  of  in  the  most  clear  and  concise  manner,  so 
as  to  lay  before  the  reader  every  opinion  of  importance  bearing  upon  the  subject  under  consideration. 

We  regard  this  volume  as  possessing  more  claims  to  completeness  than  any  other  of  the  kind  with  which 
we  are  acquainted.  Most  cordially  and  earnestly,  therefore,  do  we  commend  it  to  our  professional  brethren, 
and  we  feel  assured  that  the  stamp  of  their  approbation  will  in  due  time  be  impressed  upon  it. 

After  an  attentive  perusal  of  its  contents,  we  hesitate  not  to  say,  that  it  is  one  of  the  most  comprehensive 
ever  written  uj>on  the  diseases  of  children,  and  that,  for  copiousness  of  reference,  extent  of  research,  and  per- 
spicuity of  detail,  it  is  scarcely  to  be  equalled,  and  not  to  be  excelled  in  any  language. — Dublin  Quarterly 
Journal. 

The  present  volume  will  sustain  the  reputation  acquired  by  the  author  from  his  previous  works.  The 
reader  will  find  in  it  full  and  judicious  directions  for  the  management  of  infants  at  birth,  and  a  compendious, 
but  clear,  account  of  the  diseases  to  which  children  are  liable,  and  the  most  successful  mode  of  treating  them. 
We  must  not  close  this  notice  without  calling  attention  to  the  author's  style,  which  is  perspicuous  and 
polished  to  a  degree,  we  regret  to  say,  not  generally  characteristic  of  medical  works.  We  recommend  the 
work  of  Dr.  Churchill  most  cordially,  both  to  students  and  practitioners,  as  a  valuable  and  reliable  guide  in 
the  treatment  of  the  diseases  of  children. — Am.  Journ.  of  the  Med.  Sciences. 

After  this  meagre,  and  we  know,  very  imperfect  notice,  of  Dr.  Churchill's  work,  we  shall  conclude  by 
saying,  that  it  is  one  that  cannot  fail  from  its  copiousness,  extensive  research,  and  general  accuracy,  to  exalt 
still  higher  the  reputation  of  the  author  in  this  country.  The  American  reader  will  be  particularly  pleased 
to  find  that  Dr.  Churchill  has  done  full  justice  throughout  his  work,  to  the  various  American  authors  on  this 
subject.  The  names  of  Dewees,  Eberle,  Condie,  and  Stewart,  occur  on  nearly  every  page,  and  these  authors 
are  constantly  referred  to  by  the  author  in  terms  of  the  highest  praise,  and  with  the  most  liberal  courtesy.— 
The  Medical  Examiner. 

We  know  of  no  work  on  this  department  of  Practical  Medicine  which  presents  so  candid  and  unpreju- 
diced a  statement  or  posting  up  of  our  actual  knowledge  as  this.— N.  Y.  Journal  of  Medicine. 

Its  claims  to  merit,  both  as  a  scientific  and  practical  work,  are  of  the  highest  order.  Whilst  we  would 
not  elevate  it  above  every  other  treatise  on  the  same  subject,  we  certainly  believe  that  very  few  are  equal 
to  it,  and  none  superior.— Sou  them  Med.  and  Surg.  Journal. 


22  BLANCHARD  &  LEA'S  PUBLICATIONS.— (Diseases  of  Children.") 

New  and  Improved  Edition. 
A  PRACTICAL  TREATISE  ON  THE 

DISEASES    OF    CHILDREN. 

BY  D.  FRANCIS  CONDIE,  M.  D., 

Fellow  of  the  College  of  Physicians,  &c.  &c. 
Third  edition,  revised  and  augmented.    In  one  large  volume,  Svo.,  of  over  700  pages. 

In  the  preparation  of  a  third  edition  of  the  present  treatise,  every  portion  of  it  has  been  subjected 
to  a  careful  revision.  A  new  chapter  has  been  added  on  Epidemic  Meningitis,  a  disease  which, 
although  not  confined  to  children,  occurs  far  more  frequently  in  them,  than  in  adults.  In  the  other 
chapters  of  the  work,  all  the  more  important  facts  that  have  been  developed  since  the  appearance 
of  the  last  edition,  in  reference  to  the  nature,  diagnosis,  and  treatment  of  the  several  diseases  of 
which  they  treat,  have  been  incorporated.  The  great  object  of  the  author  has  been  to  present,  in 
each  succeeding  edition,  as  full  and  connected  a  view  as  possible  of  the  actual  state  of  the  pa- 
thology and  therapeutics  of  those  affections  which  most  usually  occur  between  birth  and  puberty. 

To  the  present  edition  there  is  appended  a  list  of  the  several  works  and  essays  quoted  or  referred 
to  in  the  body  of  the  work,  or  which  have  been  consulted  in  its  preparation  or  revision. 

Every  important  fact  that  has  been  verified  or  developed  since  the  publication  of  the  previous  edition, 
either  in  relation  to  the  nature,  diagnosis,  or  treatment  of  the  diseases  of  children,  have  been  arranged  and 
incorporated  into  the  body  of  the  work  ;  thus  posting  up  to  date,  to  use  a  counting-house  phrase,  all  the 
valuable  facts  and  useful  information  on  the  subject.  To  the  American  practitioner.  Dr.  Condie's  remarks 
on  the  diseases  of  children  will  be  invaluable,  and  we  accordingly  advise  those  who  have  failed  to  read  this 
work  to  procure  a  copy,  and  make  themselves  lamiliar  with  its  sound  principles. — The  New  Orleans  Medical 
and  Surgical  Journal. 

We  feel  persuaded  that  the  American  Medical  profession  will  soon  regard  it,  not  only  as  a  very  good,  but 
as  the  VERY  BEST  u  Practical  Treatise  on  the  Diseases  of  Children." — American  Medical  Journal. 

We  pronounced  the  first  edition  to  be  the  best  work  on  the  Diseases  of  Children  in  the  English  language, 
and.  notwithstanding  all  that  has  been  published,  we  still  regard  it  in  that  light. — Medical  Examiner. 
From  Professor  Wm.  P.  Johnston,  Washington,  D.  C. 

I  make  use  of  it  as  a  text-book,  and  place  it  invariably  in  the  hands  of  my  private  pupils. 
From  Professor  D.  Humphreys  Storer,  of  Boston. 

I  consider  it  to  he  the  best  work  on  the  Diseases  of  Children  we  have  access  to,  and  as  such  recommend  it 
to  all  who  ever  refer  to  the  subject. 

From  Professor  M.  M.  Fallen,  of  St.  Louis. 

I  consider  it  the  best  treatise  on  the  Diseases  of  Children  that  we  possess,  and  as  such  have  been  in  the 
habit  of  recommending  it  to  my  classes. 

Dr.  Condie's  scholarship,  acumen,  industry,  and  practical  sense  are  manifested  in  this,  as  in  all  his  nu- 
merous contributions  10  science.— -Dr.  Hulmes^s  Report  to  the  American  Medical  Association. 

Taken  as  a  whole,  in  our  judgment.  Dr.  Condie's  Treatise  is  the  one  from  the  perusal  of  which  the  practi- 
tioner in  this  country  will  rise  with  the  greatest  satisfaction.—  Western  Journal  of  Medicine  and  Surgery. 

One  of  the  best  works  upon  the  Diseases  of  Children  in  the  English  language. —  Western  Lancet . 

We  feel  assured  from  actual  experience  that  no  physician's  library  can  be  complete  without  a  copy  of  this 
work.—  N.  Y.  Journal  of  Medicine 

Perhaps  the  most  full  and  complete  work  now  before  the  profession  of  the  United  States;  indeed,  we  may 
say  in  the  English  language.  It  is  vastlv  superior  to  most  of  its  predecessors. — Transylvania  Med  Journal. 

A  veritable  psediatric  encyclopaedia,  and  an  honor  to  American  medical  literature.—  Ohio  Medical  and  Sur- 
gical Journal. 

WEST  OJF  DISEASES  OF  CHILDREJV. 

LECTURES  ON  THE 

DISEASES  OF  INFANCY  AND  CHILDHOOD. 

BY  CHARLES  WEST,  M.  D., 

Senior  Physician  to  the  Royal  Infirmary  for  Children,  &c.  &c.  . 

In  one  volume,  octavo. 

Every  portion  of  these  lectures  is  marked  by  a  general  accuracy  of  description,  and  by  the  soundness  of 
the  views  set  forth  in  relation  to  the  pathology  and  therapeutics  of  the  several  maladies  treated  of.  The  lec- 
tures on  the  diseases  of  the  respiratory  apparatus,  about  one-third  of  the  whole  number,  are  particularly 
excellent,  forming  one  of  the  fullest  and  most  able  accounts  of  these  affections,  as  they  present  themselves 
during  infancy  and  childhood,  in  the  English  language.  The  history  of  the  several  forms  of  phthisis  during 
these  periods  of  existence,  with  their  management,  will  be  read  by  all  with  deep  interest.— The  American 
Journal  of  the  Medical  Sciences. 

The  Lectures  of  Dr.  West,  originally  published  in  the  London  Medical  Gazette,  form  a  most  valuable 
addition  to  this  branch  of  practical  medicine.  For  many  years  physician  to  the  Children's  Infirmary,  his 
opportunities  for  observing  their  diseases  have  been  most  extensive,  no  less  than  14,000  children  having  been 
brought  under  his  notice  during  the  past  nine  years.  These  have  evidently  been  studied  with  great  care, 
and  the  result  has  been  the  production  of  the  very  best  work  in  our  language,  so  far  as  it  goes,  on  the  dis- 
eases of  this  class  of  our  patients.  The  symptomatology  and  pathology  of  their  diseases  are  especially 
exhibited  most  clearly;  and  we  are  convinced  that  no  one  can  read  with  care  these  lectures  without  deriv- 
ing from  them  instruction  of  the  most  important  kind.—  Charleston  Med.  Journal. 


A    TREATISE 
ON  THE  PHYSICAL  AND  MEDICAL  TREATMENT  OP  CHILDREN. 

BY  W.  P.  DEWEES,  M.  D. 
Ninth  edition.    In  one  volume,  octavo.    548  pages. 


BLANCHARD   &  LEA'S  PUBLICATIONS.— (Obstetrics.)  23 

Jl   J\'E\V  WORK— (Lately  Issued.) 

OBSTETRICS: 

THE    SCIENCE    AND    THE    ART. 

BY  CHARLES  LX  MEIGS,  M.D., 

Professor  of  Midwifery  and  the  Diseases  of  Women  and  Children  in  the  Jefferson  Medical  College, 

Philadelphia,  &c.&c. 

With  One  Hundred  and  Twenty  Illustrations. 
In  one  beautifully  printed  octavo  volume,  of  six  hundred  and  eighty  large  pages. 

As  an  elementary  treatise — concise,  but,  withal,  clear  and  comprphensive— we  know  of  no  one  better 
adapted  for  the  use  of  the  student;  while  the  young  practitioner  will  find  in  it  a  body  of  sound  doctrine, 
and  a  series  of  excellent  practical  directions,  adapted  to  all  the  conditions  of  the  various  forms  of  labor 
and  their  results,  which  he  will  be  induced,  we  are  persuaded,  again  and  again  to  consult,  and  always  with 
profit. 

It  has  seldom  been  our  lot  to  peruse  a  work  upon  the  subject,  from  which  we  have  received  greater  satis- 
faction, and  which  we  believe  to  be  better  calculated  to  communicate  to  the  student  correct  and  definite 
views  upon  the  several  topics  embraced  within  the  scope  of  its  teachings. — American  Journal  of  the  Medical 
Sciences. 

We  are  acquainted  with  no  work  on  midwifery  of  greater  practical  value. — Boston  Medical  and  Surgical 
Journal. 

Worthy  the  reputation  of  its  distinguished  author. — Medical  Examiner. 

We  most  sincerely  recommend  it,  both  to  the  student  and  practitioner,  as  a  more  complete  and  valuable 
work  on  the  Science  and  Art  of  Midwifery,  than  any  of  the  numerous  reprints  and  American  editions  of 
European  works  on  the  same  subject. — N.  Y.  Annalist. 

We  have,  therefore,  great  satisfaction  in  bringing  under  our  reader's  notice  the  matured  views  of  the 
highest  American  authority  in  the  department  to  which  he  has  devoted  his  life  and  talents. — London  Medical 
Gazette. 

An  author  of  established  merit,  a  professor  of  Midwifery,  and  a  practitioner  of  high  reputation  and  immense 
experience— we  may  assuredly  regard  his  work  now  before  us  as  representing  the  most  advanced  state  of 
obstetric  science  in  America  up  to  the  time  at  which  he  writes.  We  consider  Dr.  Meigs'  book  as  a  valuable 
acquisition  to  obstetric  literature,  and  one  that  will  very  much  assist  the  practitioner  under  many  circum- 
stances of  doubt  and  perplexity. —  The  Dublin  Quarterly  Journal. 

These  various  heads  are  subdivided  so  well,  so  lucidly  explained,  that  a  good  memory  is  all  that  is  neces- 
sary in  order  to  put  the  reader  in  possession  of  a  thorough  knowledge  of  this  important  subject.  Dr.  Meigs 
has  conferred  a  great  benefit  on  the  profession  in  publishing  this  excellent  work.— St.  Louis  Medical  and 
Surgical  Journal. 

No  reader  will  lay  the  volume  down  without  admiration  for  the  learning  and  talents  of  the  author.  An  abler 
volume,  on  the  whole,  we  do  hot  hope  soon  to  see. —  Western  Journal  of  Medicine  and  Surgery. 

A  safe  and  efficient  guide  to  the  delicate  and  ofttimes  difficult  duties  which  devolve  upon  the  obstetrician.— 
Ohio  Medical  and  Surgical  Journal. 

One  of  the  very  best  treatises  on  this  subject,  and  worthy  of  being  placed  in  the  library  of  every  American 
physician. — Northwestern  Medical  and  Surgical  Journal. 

He  has  an  earnest  way  with  him  when  speaking  of  the  most  elementary  subjects  which  fixes  the  attention 
and  adds  much  value  to  the  work  as  a  text-book  for  students.— British  and  Foreign  Medico- Chirurgical 
Review. 

TYLER   SMITH   ON   PARTURITION. 

ON    PARTURITION, 

AND  THE  PRINCIPLES  AND  PRACTICE  OF  DDSTETRICS. 

BY  W.  TYLEK,  SMITH,  M.  D., 

Lecturer  on  Obstetrics  in  the  Hunterian  School  of  Medicine,  &c.  &c. 
In  one  large  duodecimo  volume,  o-f  400  pages. 

The  work  will  recommend  itself  by  its  intrinsic  merit  to  every  member  of  the  profession.—  Lancet. 

We  can  imagine  the  pleasure  with  which  William  Hunter  or  Denman  would  have  welcomed  the  present 
work;  certainly  the  most  valuable  contribution  to  obstetrics  that  has  been  made  since  their  own  day.  For 
ourselves,  we  consider  its  appearance  as  the  dawn  of  a  new  era  in  this  department  of  medicine.  We  do 
most  cordially  recommend  the  work  as  one  absolutely  necessary  to  be  studied  by  every  accoucheur.  It  will, 
we  may  add.  prove  equally  interesting  and  instructive  to  the  student,  the  general  practitioner,  and  pure  ob- 
stetrician. It  was  a  bold  undertaking  to  reclaim  parturition  for  Reflex  Physiology,  and  it  has  been  well  per- 
formed.— London  Journal  of  Medicine. 

LEE'S   CLINICAL   MIDWIFERY. 

CLINICAL    MIDWIFERY, 

COMPRISING   THE    HISTORIES    OF  FIVE   HUNDRED  AND   FORTY-FIVE   CASES   OF  DIFFI- 
CULT, PRETERNATURAL.  AND  COMPLICATED  LABOR,  WITH  COMMENTARIES. 

BY  ROBERT  LEE,  M.  D.,  F.  R.  S.,  &c. 
From  the  2d  London  Edition. 

In  one  royal  12rno.  volume,  extra  cloth,  of  238  pages. 

More  instructive  to  the  juvenile  practitioner  than  a  score  of  systematic  works. — Lancet. 

An  invaluable  record  for  the  practitioner — N.  Y.  Annalist.  . 

A  storehouse  of  valuable  facts  and  precedents.— American  Journal  of  the  Medical  Sciences. 


24  BLANCHARD  &  LEA'S  PUBLICATIONS.— (Obstetrics.) 

CHURCHILL'S  MIDWIFERY,  BY  CONDIE,  NEW  AND  IMPROVED  EDITION-(Just  Issued.) 

ON~THE 

THEORY  AND  PRACTICE  OF  MIDWIFERY. 

BY  FLEETWOOD  CHURCHILL,  M.  D.,  &c. 

A  NEW  AMERICAN  FROM  THE  LAST  AND  IMPROVED  ENGLISH  EDITION, 

EDITED,  WITH  NOTES  AND  ADDITIONS, 

BY  D.  FKANCIS  CONDIE,  M.  D., 

Author  of  a  "  Practical  Treatise  on  the  Diseases  of  Children,"  &c. 
l**ITH  OJTJE  HUNDRED  ^JTD    THIRTJP-JYIJYJE   IJLLUSTRJLTIOJVS. 

In  one  very  handsome  octavo  volume. 

In  the  preparation  of  the  last  English  edition,  from  which  this  is  printed,  the  author  has  spared 
no  pains,  with  the  desire  of  bringing  it  thoroughly  up  to  the  present  state  of  obstetric  science. 
The  labors  of  the  editor  have  thus  been  light,  but  he  has  endeavored  to  supply  whatever  he  has 
thought  necessary  to  the  work,  either  as  respects  obstetrical  practice  in  this  country,  or  its 
progress  in  Europe  since  the  appearance  of  Dr.  Churchill's  last  edition.  Most  of  the  notes  of  the 
former  editor,  Dr.  Huston,  have  been  retained  by  him,  where  they  have  not  been  embodied  by  the 
author  in  his  text.  The  present  edition  of  the  favorite  text-book  is  therefore  presented  to  the  pro- 
fession in  the  full  confidence  of  its  meriting  a  continuance  of  the  great  reputation  which  it  has 
acquired  as  a  work  equally  well  fitted  for  the  student  and  practitioner. 

To  bestow  praise  on  a  hook  that  has  received  such  marked  approbation  would  be  superfluous.  We  need 
only  say,  therefore,  that  if  the  first  edition  was  thought  worthy  of  a  favorable  reception  by  the  medical  pub- 
lic, we  can  confidently  affirm  that  this  will  be  found  much  more  so.  The  lecturer,  the  practitioner,  and  the 
student,  may  all  have  recourse  to  its  pages,  and  derive  from  their  perusal  much  interest  and  instruction  in 
everything  relating  to  theoretical  and  practical  midwifery. — Dublin  Quarterly  Journal  of  Medical  Science. 

A  work  of  very  great  merit,  and  such  as  we  can  confidently  recommend  to  the  study  of  every  obstetric 
practitioner. — London  Medical  Gazette. 

This  is  certainly  the  most  perfect  system  extant.  It  is  the  be?t  adapted  for  the  purposes  of  a  text-book,  and 
that  which  he  whose  necessities  confine  him  to  one  book,  should  select  in  preference  to  all  others. — Southern 
Medical  and  Surgical  Journal. 

The  most  popular  work  on  Midwifery  ever  issued  from  the  American  press  — Charleston  Medical  Journal. 

Certainly,  in  our  opinion,  the  very  best  work  on  the  subject  which  exists. — 2V.  Y.  Annalist. 

Were  we  reduced  to  the  necessity  of  havingbut  one  work  on  Midwifery,  and  permitted  to  choose,  we  would 
unhesitatingly  take  Churchill. —  Western  Medical  and  Surgical  Journal. 

It  is  impossible  to  conceive  a  more  useful  and  elegant  Manual  than  Dr.  Churchill's  Practice  of  Midwifery. 
—  Provincial  Medical  Journal. 

No  work  holds  a  higher  position,  or  is  more  deserving  of  being  placed  in  the  handsof  the  tyro,  the  advanced 
student,  or  the  practitioner. — Medical  Examiner. 


JEDITIOJV  OF  RAJflSBOTHJIJtl  OJV  PARTURITIOJY-(JVou)  Ready,  1851.) 

THE  PRINCIPLES~AND  PRACTICE  OP 

OBSTETRIC  MEDICINE  AND  SURGERY, 

In  reference  to  the  Process  of  Parturition, 
BY   FRANCIS    H.    KAMSBOTHAM,    M.  D., 

Physician  to  the  Royal  Maternity  Charity,  &c.  &c. 
SIXTH  AMERICAN  FROM  THE  LAST  LONDON  EDITION. 

Illustrated  with  One  Hundred  and  Forty-eight  Figures  on  Fifty-five  Lithographic  Plates. 
In  one  large  and  handsomely  printed  volume,  imperial  octavo,  with  520  pages. 

In  this  edition  the  plates  have  all  been  redrawn,  and  the  text  carefully  read  and  corrected.  It 
is  therefore  presented  as  in  every  way  worthy  the  favor  with  which  it  has  so  long  been  received. 

From  Professor  Hodge,  of  the  University  of  Pennsylvania. 

To  the  American  public,  it  is  most  valuable,  from  its  intrinsic  undoubted  excellence,  and  as  being  the  best 
authorized  exponent  of  British  Midwifery.  Its  circulation  will,  I  trust,  be  extensive  throughout  our  country. 

We  recommend  the  student,  who  desires  to  master  this  difficult  subject  with  the  least  possible  trouble,  to 
possess  himself  at  once  of  a  copy  of  this  work. — American  Journal  of  the  Medical  Sciences. 

It  stands  at  the  head  of  the  long  list  of  excellent  obstetric  works  published  in  the  last  few  years  in  Great 
Britain,  Ireland,  and  the  Continent  of  Europe.  We  consider  this  book  indispensable  to  the  library  of  every 
physician  engaged  in  the  practice  of  Midwifery. — Southern  Medical  and  Surgical  Journal. 

When  the  whole  profession  is  thus  unanimous  in  placing  such  a  work  in  the  very  first  rank  as  regards  the 
extent  and  correctness  of  all  the  details  of  the  theory  and  practice  of  so  important  a  branch  of  learning,  our 
commendation  or  condemnation  would  be  of  little  consequence;  but,  regard  ing  it  as  the  most  useful  of  all  works 
of  the  kind,  we  think  it  but  an  act  of  justice  to  urge  its  claims  upon  the  profession.— JY.  O.  Med.  Journal. 


DEWEES'S    MIDWIFERY. 

A  COMPREHENSIVE  SYSTEM  OF  MIDWIFERY, 

ILLUSTRATED  BY  OCCASIONAL  CASES  AND  MANY  ENGRAVINGS. 

BY  WILLIAM  P.  DEWEES,  M.  D. 
Tenth  Edition,  with  the  Author's  last  Improvements  and  Corrections.    In  one  octavo  volume,  of  600  pages. 


BLANCHARD  &  LEA'S  PUBLICATIONS.—  (Materia  Medica  and  Therapeutics.)    25 


/*ol.  I.t  (JVow  Heady.) 
NEW  EDITION,  GREATXY  IMPROVED  AND  ENLARGED,  to  Nov.  1851. 


THE 

OF  MATERIA  MEBICA  AND  THERAPEUTICS. 

COMPREHENDING  THE  NATURAL   HISTORY,  PREPARATION,  PROPERTIES,  COMPOSITION, 

EFFECTS,  AND  USES  OF  MEDICINES, 

BY  JONATHAN  PEREIRA,  M.  D.,  F.  R.  S.  AND  L.  S. 

Third  American  from  the  Third  and  Enlarged  London  Edition. 

WITH   ADDITIONAL    NOTES    AND    OBSERVATIONS    BY   THE   AUTHOR. 

EDITED  BY  JOSEPH  CARSON,  M.  D., 

Professor  of  Materia  Medica  and  Pharmacy  in  the  University  of  Pennsylvania. 
In  two  very  large  volumes,  on  small  type,  with  about  four  hundred  illustrations. 

The  demand  for  this  new  edition  of"  PEREIRA'S  MATERIA  MEDICA"  has  induced  the  publishers 
to  issue  the  First  Volume  separately.  The  Second  Volume,  now  at  press  and  receiving  important 
corrections  and  revisions  from  both  author  and  editor,  may  be  expected  for  publication  in  July  or 
August,  1852. 

The  third  London  edition  of  this  great  work  has  been  thoroughly  revised  and  greatly  enlarged 
by  the  author,  who  has  spared  no  pains  to  render  it  complete  in  every  part,  by  the  addition  of  a 
very  large  amount  of  matter  and  the  introduction  of  many  new  illustrations.  The  present  American 
edition,  however,  in  addition  to  this,  will  not  only  enjoy  the  advantages  of  a  careful  and  accurate 
superintendence  by  the  editor,  but  will  also  embody  the  additions  suggested  by  a  further  revision 
by  the  author,  expressly  for  this  country,  embracing  the  most  recent  discoveries,  and  the  results 
of  several  pharmacopoeias  which  have  appeared  since  the  publication  of  part  of  the  London  edi- 
tion. The  notes  of  the  American  editor  will  be  prepared  with  reference  to  the  new  edition  of  the 
United  States  Pharmacopoeia,  and  will  contain  such  matter  generally  as  may  be  required  to  adapt  it 
fully  to  the  wants  of  the  American  student  and  practitioner,  as  well  as  such  recent  investigations 
and  discoveries  as  may  have  escaped  the  attention  of  the  author.  The  profession  may  therefore 
rely  on  being  able  to  procure  a  work  which  will  not  only  maintain  but  increase  its  right  to  the  ap- 
pellation of 

AN  ENCYCLOPEDIA  OF  MATERIA  MEDICA  AND  THERAPEUTICS. 

We  shall  only  remark  that  every  article  bears  witness  to  the  industry  and  indefatigable  research  of  the 
author.  Instead  of  being  merely  the  elements  of  materia  medica,  it  constitutes  a  complete  encyclopaedia  of 
this  important  subject.  The  student  of  physiology,  pathology,  chemistry,  botany,  and  nalural  history,  will 
find  herein  the  most  recent  facts  and  discoveries  in  his  favorite  branch  of  study,  and  the  medical  practitioner 
will  have  in  this  work  a  safe  guide  for  the  administration  and  employment  of  medicines.—  London  Mtdical 
Gazette. 

The  present  edition  (the  third)  is  very  much  enlarged  and  improved,  and  includes  the  latest  discoveries 
and  views  respecting  medicines  and  their  properties.  We  believe  that  this  work  has  no  equal  in  value  as 
a  book  of  reference,  or  of  general  information  on  materia  medica.—  The  Lancet, 


ROYLE'S  MATERIA  MEDICA. 

MATERIA  MEDICA  AND  THERAPEUTICS; 

INCLUDING   THE 

Preparations  of  the  Pharmacopoeias  of  London,  Edinburgh,  Dublin,  and  of  the  United  States, 

WITH  MANY  NEW  MEDICINES. 

BY  J.  FORBES  ROYLE,  M.  D.,  F.  R,  S., 

Professor  of  Materia  Medica  and  Therapeutics,  King's  College,  London,  &c.  &c. 

EDITED  BY  JOSEPH  CARSON,  M.  D., 
Professor  of  Materia  Medica  and  Pharmacy  in  the  University  of  Pennsylvania. 

WITH  NINETY-EIGHT  ILLUSTRATIONS. 
In  one  large  octavo  volume,  of  about  seven  hundred  pages. 

Being  one  of  the  most  beautiful  Medical  works  published  in  this  country. 
This  work  is,  indeed,  a  most  valuable  one.  and  will  fill  up  an  important  vacancy  that  existed  between  Dr. 
Pereira'smost  learned  and  complete  system'of  Materia  Medica,  and  the  class  of  productions  on  the  other  ex- 
treme, which  are  necessarily  imperfect  from  their  small  extent.— British  and  Foreign  Medical  Review. 


POCKET    DISPENSATORY    AND    FORMULAR    . 

A  DISPENSATORY  AND  THERAPEUTICAL  REMEMBRANCER.  Comprising  the  entire  lists 
of  Materia  Medica,  with  every  Practical  Formula  contained  in  the  three  British  Pharmacopeias. 
With  relative  Tables  subjoined,  illustrating  by  upwards  of  six  hundred  and  sixty  examples,  the 
Extemporaneous  Forms  and  Combinations  suitable  for  the  different  Medicines.  By  JOHN 
MA.YNE,  M.  D.,  L.  R.  C.  S.,  EDIN.,  &c.  &c.  Edited,  with  the  addition  of  the  formulae  of  the 
United  States  Pharmacopoeia,  by  R.  EGLESFELD  GRIFFITH,  M.  D.  In  one  12mo.  volume, 
of  over  three  hundred  large  pages. 
The  neat  typography,  convenient  size,  and  low  price  of  this  volume,  recommend  it  especially  to 

physicians,  apothecaries,  and  students  in  want  of  a  pocket  manual. 


26 


BLANCHARD  &  LEA'S  PUBLICATIONS.— (Materia  Medica, 


NEW  UNIVERSAL  FORMULARY. — (Lately  Issued.) 

A  UNIVERSAL"  FORMULARY, 

CONTAINING   THE 

METHODS  OF   PREPARING   AND  ADMINISTERING 

OFFICINAL  AND  OTHER  MEDICINES, 

THE  WHOLE  ADAPTED  TO  PHYSICIANS  AND  PHARMACEUTISTS, 
BY  R.  EGLESPELD  GRIFFITH,  M.  D., 

Author  of  "American  Medical  Botany,"  &c. 
In  one  large  octavo  volume  of568  pages,  double  columns. 

In  this  work  will  be  found  not  only  a  very  complete  collection  of  formulae  and  pharmaceutic 
processes,  collected  with  great  care  from  the  best  modern  authorities  of  all  countries,  but  also  a 
vast  amount  of  important  information  on  all  collateral  subjects.  To  insure  the  accuracy  so  neces- 
sary to  a  work  of  this  nature,  the  sheets  have  been  carefully  revised  by  Dr.  Robert  Bridges,  while 
Mr.  William  Procter,  Jr.,  has  contributed  numerous  valuable  formulae,  and  useful  suggestions. 

The  want  of  a  work  like  the  present  has  long  been  felt  in  this  country,  where  the  physician  and 
apothecary  have  hitherto  had  access  to  no  complete  collection  of  formulas,  gathered  from  the 
pharmacopoeias  and  therapeutists  of  all  nations.  Not  only  has  this  desideratum  been  thoroughly 
accomplished  in  this  volume,  but  it  will  also  be  found  to  contain  a  very  large  number  of  recipes  for 
empirical  preparations,  valuable  to  the  apothecary  and  manufacturing  chemist,  the  greater  part  of 
which  have  hitherto  not  been  accessible  in  this  country.  It  is  farther  enriched  with  accurate  ta- 
bles of  the  weights  and  measures  of  Europe;  a  vocabulary  of  the  abbreviations  and  Latin  terms 
used  in  Pharmacy;  rules  for  the  administration  of  medicines  ;  directions  for  officinal  preparations; 
remarks  on  poisons  and  their  antidotes ;  with  various  tables  of  much  practical  utility.  To  facili- 
tate reference  to  the  whole,  extended  indices  have  been  added,  giving  to  the  work  the  advantages 
of  both  alphabetical  and  systematic  arrangement. 

To  show  the  variety  and  importance  of  the  subjects  treated  of,  the  publishers  subjoin  a  very 
condensed 

SUMMARY  OF  THE  CONTENTS,  IN  ADDITION  TO  THE  FORMULARY  PROPER, 
WHICH  EXTENDS  TO  BETWEEN  THREE  AND  FOUR  HUNDRED  LARGE  DOUBLE- 
COLUMNED  PAGES. 


PREFACE. 
INTRODUCTION. 

WEIGHTS  AND  MEASURES. 

Weights  of  the  United  States  and  GreatBritain. — 
Foreign  Weights.— Measures. 

SPECIFIC  GRAVITY. 

TEMPERATURES  FOR  CERTAIN  PHARMACEUTICAL  OPE- 
RATIONS. 

HYDROMETKICAL  EQUIVALENTS. 

SPECIFIC  G RAVI IIES  OF  SOME  OF  THE  PREPARATIONS 
OF  THE  PHARMACOPOEIAS. 

RELATION   BETWEEN  DIFFERENT   THERMOMETRICAL 
SCALES. 

EXPLANATION  OF  PRINCIPAL  ABBREVIATIONS  USED  IN 
FORMULA. 

VOCABULARY  OF  WORDS  EMPLOYED  IN  PRESCRIPTIONS. 
OBSERVATIONS  ON  THE  M  ANAGEMENT  OF  THE  SICK  ROOM. 
Ventilation  of  the  Sick  room. — Temperature  of 
the  Sick  room  —  Cleanliness  in  the  Sick  room.— 
Quiet  in  the  Sick  room.— Examination  and  Pre- 
servation of  the  Excretion?. —  Administration  of 
Medicine.— Furniture  of  a  Sick  room.— Proper 
use  of  Utensils  for  Evacuations. 

DOSF.S  OF  MEDICINRS. 

Age  —  Sex.  —  Temperament.  —  Idiosyncrasy  — 
Ihiiiit.—  Stale  of  the  System. — Time  of  day.— In- 
tervals between  Doses. 

RULES  FOR  ADMINISTRATION  OF  MEDICINES. 

Acids  —  Antacids  —  \milithics  and  Litliontriptics 
Antispasiiiodics  —  Anthelminiics  —  Cathartics. - 
Enemata. — Suppositories. —  Demulcents  or  Einol 
lienis  — Diaphoretics. — Diluents  —  Diuretics  — 
Emetics  —  Emmenatjo-'ues  —  Epispa*tics.—  Er- 
rhu.es.  —  Escnaroltcs.  —  Expectorants  —  Narco 
lies  —  Refrigerants  —  Sedatives.— Sialagogues.— 
Stimulants.—  Tonics. 

MANAGEMENT  OF  CONVALESCENCE  AND  RELAPSES. 


DIETETIC    PREPARATIONS    NOT   INCLUDED 
AMONG  THE  PREVIOUS  PRESCRIPTIONS. 
LIST  OF  1NCOMPATIBLES. 
POSOLOGICAL    TABLES    OF   THE  MOST    IM- 

POR  TAN  r  MEDICINES. 

TABLE     OF     PHARMACEUTICAL     NAMES 
WHICH     DIFFER    IN    THE    U.    STATES 
AND  BRITISH  Pri ARMACOPCEIAS. 
OFFICINAL     PREPARATIONS     AND    DIREC- 
TIONS. 

INTERNAL  REMEDIES. 

Powders.— Pills  and  Boluses.— Extracts.— Con- 
fections. Conserves,  Electuarie* — Pulps. —  Sy- 
rups.—Melliies  or  Honeys  -  Infu>ions  —  Decoc- 
tions —  Tinctures  —Wines.— Vinegars  -Mixtures. 
Medicated  Waters  —Distilled,  Essential,  or  Vola- 
tile Oil-.— Fixed  Oils  and  Fats.— Alkaloids.— 
Spirits. — Troches  or  Lozenges. — Inhalations. 
EXTERNAL  REMEDIES. 

Baths  -Cold  Bath  —Cool  Bath.— Temperate  Bath. 
—  Tepid  Bath  —  Warm  Bath.—  Hot  Baih.— Shower 
Bath.— Local  Bath> —Vapor  Bath.—  Warm  Air 
Bath.— Douches.— Medicated  Baths  — Affusion. — 
Sponging —  Fomentations.— Cataplasms,  or  Poul- 
tices.— Lotions,  Luiunents,  Embrocation.-  —  Ve.-i- 
catories,  or  Blisters.—  Issues.—  Setons.  —  Oint- 
ments.— Cerates. — Plasters. — Fumigations. 
BLOOD-LETTING. 

General    Blood-Letting-. — Venesection.     Arterio- 
torny. —  Topical  Blood-Letting  — Cupping.-Leecb- 
ing  —Scarifications. 
POISONS 

INDEX  OF  DISEASES  AND  THEIR  REMEDIES. 
INDEX  OF  PHARMACEUTICAL  AND  BOTANI- 
CAL NAMES 
GENERAL  INDEX. 


From  the  condensed  summary  of  the  contents  thus  given  it  will  be  seen  that  the  completeness 
of  this  work  renders  it  of  much  practical  value  to  all  concerned  in  the  prescribing  or  dispensing 
of  medicines. 


BLANCIIARD  &  LEA'S  PUBLICATIONS.—  (Materia  Medica,  <fc.)  27 

GRIFFITH'S  MEDICAL  FORMULARY—  (Continued.) 

From  a  vast  number  of  commendatory  notices,  the  publishers  select  a  few. 

A  valuable  acquisition  to  the  medical  practitioner,  and  a  useful  book  of  reference  to  the  apothecary  on 
numerous?  occasions  —  American  Journal  of  Pharmacy. 

Dr.  Griffith's  Formulary  is  worthy  of  recommendation,  not  only  on  account  of  the  care  which  has  been 
bestowed  on  it  by  its  estimable  author,  but  for  its  general  accuracy,  and  the  richness  of  its  details.  —  Medical 
Examiner. 

Most  cordially  we  recommend  this  Universal  Formulary,  not  forgetting  its  adaptation  to  druggists  and 
apothecaries,  who  would  find  themselves  vastly  improved  by  a  familiar  acquaintance  with  tnis  every-day 
book  of  medicine.  —  The  Boston  Medical  and  Surgical  Journal. 

Pre-eminent  among  the  best  and  most  useful  compilations  of  the  present  day  will  be  found  the  work  before 
us,  which  can  have  been  produced  only  at  a  very  great  cost  of  thoughi  and  labor.  A  short  description  will 
suffice  toshow  that  we  do  not  puttoo  high  an  estimate  on  this  work.  We  are  not  cognizant  of  the  existence 
of  a  parallel  work.  Its  value  will  be  apparent  to  our  readers  from  the  sketch  of  its  contents  above  given. 

We  strongly  recommend  it  to  all  who  are  engaged  either  in  practical  medicine,  or  more  exclusively  with 
its  literature.  —  London  Medical  Gazette. 

A  very  useful  work,  and  a  most  complete  compendium  on  the  subject  of  materia  medica.  We  know  of  no 
work  in  our  language,  or  any  other,  so  comprehensive  in  all  its  details  —  London  Lancet. 

The  vast  collection  of  formula}  which  is  offered  by  the  compiler  of  this  volume,  contains  a  large  number 
which  will  be  new  to  English  practitioners,  some  of  them  from  the  novelty  of  their  ingredients,  and  others 
from  the  unaccustomed  mode  in  which  they  are  combined  ;  and  we  doubt  not  that  several  of  these  might  be 
advantageously  brought  into  use.  The  authority  for  every  formula  is  given,  and  the  list  includes  a  very  nu- 
merous assemblage  of  Continental,  as  well  as  of  British  and  American  writers  of  repute.  It  is,  therefore. 
a  work  to  which  every  practitioner  may  advantageously  resort  for  hints  to  increase  his  stock  of  remedies 
and  of  forms  of  prescription. 

The  other  indices  facilitate  reference  to  every  article  in  the  "Formulary;"  and  they  appear  to  have  been 
drawn  up  with  the  same  care  as  that  which  the  author  has  evidently  bestowed  on  every  part  of  the  work.  — 
The  British  and  Foreign  Medico-  Chirurgical  Revieiv. 

The  work  before  us  is  all  that  it  professes  to  be.  viz.:  "  a  compendious  collection  of  formula  and  pharma- 
ceutic  processes."  It  is  such  a  work  as  was  much  needed,  and  should  be  in  the  hands  of  every  practitioner 
who  is  in  the  habit  of  compounding  medicines  —  Transylvania  Medical  Journal. 

This  seems  to  be  a  very  comprehensive  work,  so  far  as  the  range  of  its  articles  and  combinations  is  con- 
cerned, with  a  commendable  degree  of  brevity  and  condensation  in  their  explanation. 

It  cannot  fail  to  be  a  useful  and  convenient  book  of  reference  to  the  two  classes  of  persons  to  whom  it 
particularly  commends  itself  in  the  title-page.  —  The  N.  W.  Medical  and  Surgical  Journal 

It  contains  so  much  information  that  we  very  cheerfully  recommend  it  to  the  profession.—  Charleston  Med. 
Journal. 

Well  adapted  to  supply  the  actual  wants  of  a  numerous  and  varied  class  of  persons.  —  N.  Y.  Journal  of 
Medicine. 

CHRISTISON  &  GRIFFITH'S  DISPENSATORY.-(A  New  Work,) 

A  DISPENSATORY, 

OR,  COMMENTARY  ON  THE  PHARMACOPOEIAS  OF  GREAT   BRITAIN  AND  THE  UNITED 

STATES:  COMPRISING  THE  NATURAL  HISTORY,  DESCRIPTION,  CHEMISTRY, 

PHARMACY,  ACTIONS,  USES.  AND  DOSHS  OF  THE  ARTICLES  OF 

THE  MATERIA  MEDICA. 

BY  ROBERT  CHRISTISON,  M.  D.,  Y.  P.  R.  S.  E., 

President  of  the  Royal  College  of  Physicians  of  Edinburgh  ;  Professor  of  Materia  Medica  in  the  University 

of  Edinburgh,  etc. 

Second  Edition,  Revised  and  Improved, 
WITH  A  SUPPLEMENT  CONTAINING  THE  MOST  IMPORTANT  NEW  REMEDIES. 

WITH    COPIOUS    ADDITIONS, 

AND  TWO  HUNDRED  AND  THIRTEEN  LARGE  WOOD  ENGRAVINGS. 
BY  R.  EGLESFELD  GRIFFITH,  M.  D., 

Author  of  "A  Med:cai  Botany,"  etc. 

In  one  very  large  and  handsome  octavo  volume,  of  over  one  thousand  closely  printed  pages,  with 
numerons  wood-cuts,  beautifully  printed  on  fine  white  paper,  presenting  an  immense 

quantity  of  matter  at  an  unusually  low  price. 

It  is  enough  to  say  that  it  appears  to  us  as  perfect  as  a  Dispensatory,  in  the  present  state  of  pharmaceuti- 
cal science,  could  be  made.  —  The  Western  Journal  of  Medicine  and  Surgery. 


SYJ\~OI*SIS-(JVotc  Beady.) 

SYNOPSilToF    THE 

COURSE  OF  LECTURES  ON  MATERIA  MEBICA  AND  PHARMACY, 

Delivered  in  the  University  of  Pennsyi\  ania. 
BY  JOSEPH  CARSON,  M.  D.. 

Professor  of  Materia  Medica  and  Pharmacy  in  the  University  of  Pennsylvania. 

In  one  very  neat  octavo  volume  of'208  pages. 

This  work,  containing  a  rapid  but  thorough  outline  of  the  very  extensive  subjects  under  consideration,  will 
be  found  useful,  not  only  for  ihe  matriculants  and  graduates  of  the  institution  lor  whom  it  is  more  particu- 
larly intended,  but  also  for  those  of  the  profession  who  may  desire  to  recall  their  former  studies. 

THE    THREE    KINDS    OF    COD-LIVER   OIL, 

Comparatively  considered,  with  their  Chemical  and  Therapeutic  Properties,  by  L.  J.  DE  JONGH, 
M.  D.  Translated,  with  an  Appendix  and  Cases,  by  EDWARD  CAREY,  M.  D.  To  which  is 
added  an  article  on  the  subject  from  "  Dunglison  on  New  Remedies."  In  one  small  12mo. 
volume,  extra  cloth. 


28     BLANCHARD  &  LEA'S  PUBLICATIONS.— (Mater ia  Medica  and  Therapeutics.} 

DUNGLISON'S    THERAPEUTICS. 
]\TEW  ATCO  IMPROVED  EDITION.- (Irately  Issued.) 

GENERAL  THERAPEUTICS  AND  MATERIA  MEDICA; 

ADAPTED  FOR  A  MEDICAL  TEXT-BOOK, 

BY   EOBLEY   DUNGrLISON,   M.D., 

Professor  of  Institutes  of  Medicine,  &c.,  in  Jefferson  Medical  College;  Late  Professor  of  Materia  Medica,  &c. 
in  the  Universities  of  Maryland  and  Virginia,  and  in  Jefferson  Medical  College. 

FOURTH   EDITION,   MUCH  IMPROVED. 

With  One  Hundred  and  Eighty-two  Illustrations. 

la  two  large  and  handsomely  printed  octavo  volumes. 

The  present  edition  of  this  standard  work  has  been  subjected  to  a  thorough  revision  both  as  re- 
gards style  and  matter,  and  has  thus  been  rendered  a  more  complete  exponent  than  heretofore  of 
the  existing  state  of  knowledge  on  the  important  subjects  of  which  it  treats.  The  favor  with  which 
the  former  editions  have  everywhere  been  received  seemed  to  demand  that  the  present  should  be 
rendered  still  more  worthy  of  the  patronage  of  the  profession,  and  of  the  medical  student  in  particu- 
lar, for  whose  use  more  especially  it  is  proposed;  while  the  number  of  impressions  through  which 
it  has  passed  has  enabled  the  author  so  to  improve  it  as  to  enable  him  to  present  it  with  some  de- 
gree of  confidence  as  well  adapted  to  the  purposes  for  which  it  is  intended.  In  the  present  edition, 
the  remedial  agents  of  recent  introduction  have  been  inserted  in  their  appropriate  places ;  the 
number  of  illustrations  has  been  greatly  increased,  and  a  copious  index  of  diseases  and  remedies 
has  been  appended,  improvements  which  can  scarcely  fail  to  add  to  the  value  of  the  work  to  the 
therapeutical  inquirer. 

The  publishers,  therefore,  confidently  present  the  work  as  it  now  stands  to  the  notice  of  the 
practitioner  as  a  trustworthy  book  of  reference,  and  to  the  student,  for  whom  it  was  more  especially 
prepared,  as  a  full  and  reliable  text-book  on  General  Therapeutics  and  Materia  Medica. 

Notwithstanding  the  increase  in  size  and  number  of  illustrations,  and  the  improvements  in  the 
mechanical  execution  of  the  work,  its  price  has  not  been  increased. 

In  this  work  of  Dr.  Dunglison,  we  recognize  the  same  untiring  industry  in  the  collection  and  embodying  of 
facts  on  the  several  subjects  of  which  he  treats,  that  has  heretofore  distinguished  him,  and  we  cheerfully 
point  to  these  volumes,  as  two  of  the  most  interesting  that  we  know  of.  In  noticing  the  additions  to  this,  the 
fourth  edition,  there  is  very  little  in  the  periodical  or  annual  literature  of  the  profession,  published  in  the  in- 
terval which  has  elapsed  since  the  issue  of  the  first,  that  has  escaped  the  careful  search  of  the  author.  As 
a  book  for  reference,  it  is  invaluable.—  Charleston  Med.  Journal  and  Review. 

It  may  be  said  to  be  the  work  now  upon  the  subjects  upon  which  it  treats. —  Western  Lancet. 

As  a  text  book  for  students,  for  whom  it  is  particularly  designed,  we  know  of  none  superior  to  it.— St. 
Louis  Medical  and  Surgical  Journal. 

It  purports  to  be  a  new  edition,  but  it  is  rather  a  new  book,  so  greatly  has  it  been  improved  both  in  the 
amount  and  quality  of  the  matter  which  it  contains. — N.  O.  Medical  and  Surgical  Journal. 

We  bespeak  for  this  edition  from  the  profession  an  increase  of  patronage  over  any  of  its  former  ones,  on 
account  of  its  increased  merit. — N.  Y.  Journal  of  Medicine. 

We  consider  this  work  unequalled.— Boston  Mcd.  and  Surg.  Journal, 


NEW  AND  MUCH  IMPROVED  EDITION— Brought  up  to  1851.— (Just  Issued.) 

NEW    REMEDIES, 

WITH   FORMUL/E   FOR    THEIR    ADMINISTRATION. 
BY  ROBLEY  DUNGLISON,  M.  D., 

PROFESSOR  OF  THE  INSTITUTES  OF  MEDICINE,  ETC.  IN  THE  JEFFERSON  MEDICAL  COLLEGE  OF  PHILADELPHIA. 

Sixth  Edition,  with  extensive  Additions. 
In  one  very  large  octavo  volume,  of  over  seven  hundred  and  fifty  pages. 

The  fact  that  this  work  has  rapidly  passed  to  a  SIXTH  EDITION  is  sufficient  proof  that  it  has  supplied  a 
desideratum  to  the  profession  in  presenting'  them  with  a  clear  and  succinct  account  of  all  new  and  impor- 
tant additions  to  the  materia  medica,  and  novel  applications  of  old  remedial  agents.  In  the  preparation  of 
the  present  edition,  the  author  has  shrunk  from  no  labor  to  render  the  volume  worthy  of  a  continuance  of  the 
favor  with  which  it  has  been  received,  as  is  sufficiently  shown  by  the  increase  of  about  one  hundred  pages 
in  the  size  of  the  work.  The  necessity  of  such  large  additions  arises  from  the  fact  that  the  last  few  years 
have  been  rich  in  valuable  gifts  to  Therapeutics;  and  amongst  these,  ether,  chloroform,  and  other  so  called 
anaesthetics,  are  worthy  of  special  attention.  They  have  been  introduced  since  the  appearance  of  the  last 
edition  of  the  "  NEW  RISMEDIKS."  Other  articles  have  been  proposed  for  the  first  time,  and  the  experience  of 
observers  has  added  numerous  interesting  facts  to  our  knowledge  of  the  virtues  of  remedial  agents  pre- 
viously employed. 

The  therapeutical  agents  now  first  admitted  into  this  work,  some  of  which  have  been  newly  introduced 
into  pharmacology,  and  the  old  agents  brought  prominently  forward  with  novel  applications,  and  which  may 
consequently  be  regarded  as  New  Remedies,  are  the  following  :— Adansonia  digitata,  Benzoate  of  Ammonia, 
Valerianate  of  Bismuth,  Sulphate  of  Cadmium,  Chloroform,  Collodion,  Canthandal  Collodion,  Cotyledon  Um- 
bilicus, Sulphuric  Ether,  Strong  Chloric  Ether,  Compound  Ether,  Hura  Braziliensis,  Iberis  Amara,  lodic 
Acid,  Iodide  of  Chloride  of  Mercury,  Powdered  Iron,  Citrate  of  Magnetic  Oxide  of  Iron,  Citrate  of  Iron  and 
Magnesia,  Sulphate  of  Iron  and  Alumina,  Tannate  of  Iron,  Valerianate  of  Iron,  Nitrate  of  Lead,  Lemon 
Juice,  Citrate  of  Magnesia,  Salts  of  Manganese,  Oleum  Cadinum,  Arsenite  of  Q;iinia,  Hydriodate  of  Iron  and 
Quinia,  Sanicula  Manlandica,  and  Sumbul. 


BLANCHARD   &  LEA'S  PUBLICATIONS.— (Maieria  Medica,  £c.)  29 

MOHR,    REDWOOO,    AND    PROCTERS    PHARMACY.- Lately  Issued. 

PEACTICAL"PHAEMACY. 

COMPRISING    THE   ARRANGEMENTS,  APPARATUS,  AND  MANIPULATIONS  OF  THE 
PHARMACEUTICAL    SHOP    AND    LABORATORY. 

BY  FRANCIS  MOHR,  PH.  D., 
Assessor  Pharmaeiee  of  the  Royal  Prussian  College  of  Medicine,  Coblentz; 

AND  THEOPHILUS  REDWOOD, 
Professor  of  Pharmacy  in  the  Pharmaceutical  Society  of  Great  Britain. 

EDITED,   WITH   EXTENSIVE    ADDITIONS,    BY   PROFESSOR   WILLIAM   PROCTER, 

Of  the  Philadelphia  College  of  Pharmacy. 
In  one  handsomely  printed  octavo  volume,  of  570  pages,  with  over  500  engravings  on  wood. 

To  physicians  in  the  country,  and  those  at  a  distance  from  competent  pharmaceutists,  as  well  as 
to  apothecaries,  this  work  will  be  found  of  great  value,  as  embodying  much  important  information 
which  is  to  be  met  with  in  no  other  American  publication. 

After  a  pretty  thorough  examination,  we  can  recommend  it  as  a  highly  useful  hook,  which  should 
be  in  the  hands  of  every  apothecary.  Although  no  instruction  of  this  kind  will  enable  the  beginner  to 
acquire  that  practical  skill  and  readiness  which  experience  only  can  confer,  we  believe  that  this  work  will 
much  facilitate  their  acquisition,  by  indicating  means  for  the  removal  of  difficulties  as  they  occur,  and  sug- 
gesting methods  of  operation  in  conducting  pharmaceutic  processes  which  the  experimenter  would  only 
hit  upon  after  many  unsuccessful  trials;  while  there  are  few  pharmaceutists,  of  however  extensive  expe- 
rience, who  will  not  find  in  it  valuable  hints  that  they  can  turn  to  use  in  conducting  the  affairs  of  the  shop 
and  laboratory.  The  mechanical  execution  of  the  work  is  in  a  style  of  unusual  excellence.  It  contains 
about  five  hundred  and  seventy  large  octavo  pages,  handsomely  printed  on  good  paper,  and  illustrated  by 
over  five  hundred  remarkably  well  executed  wood-cuts  of  chemical  and  pharmaceutical  apparatus.  It 
comprises  the  whole  of  Mohr  and  Redwood's  book,  as  published  in  London,  rearranged  and  classified  by 
the  American  editor,  who  has  added  much  valuable  new  matter,  which  has  increased  the  size  of  the  book 
more  than  one- fourth,  including  about  one  hundred  additional  wood-cuts.—  The  American  Journ.  of  Pharmacy. 

It  is  a  book,  however,  which  will  be  in  the  hands  of  almost  every  one  who  is  much  interested  in  pharma- 
ceutical operations,  as  we  know  of  no  other  publication  so  well  calculated  to  fill  a  void  long  felt.—  The  Medi- 
cal Examiner. 

The  country  practitioner  who  is  obliged  to  dispense  his  own  medicines,  will  find  it  a  most  valuable  assist- 
ant.— Monthly  Journal  and  Retrospect. 

The  book  is  strictly  practical,  and  describes  only  manipulations  or  methods  of  performing  the  numerous 
processes  the  pharmaceutist  has  to  go  through,  in  the  preparation  and  manufacture  of  medicines,  together 
with  all  the  apparatus  and  fixtures  necessary  thereto.  On  these  matters,  this  work  is  very  full  and  com- 
plete, and  details,  in  a  style  uncommonly  clear  and  lucid,  not  only  the  more  complicated  and  difficult  pro- 
cesses, but  those  not  less  important  ones,  the  most  simple  and  common.  The  volume  is  an  octavo  of  five 
hundred  and  seventy-six  pages.  It  is  elegantly  illustrated  with  a  multitude  of  neat  wood  engravings,  and 
is  unexceptionable  in  its  whole  typographical  appearance  and  execution.  We  take  great  satisfaction  in 
commending  this  so  much  needed  treatise,  not  only  to  those  for  whom  it  is  more  specially  designed,  but  to 
the  medical  profession  generally — to  every  one,  who,  in  his  practice,  has  occasion  to  prepare,  as  well  as  ad- 
minister medical  agents. — Buffalo  MedicalJournal. 


JVJE  W    Jjm     COJtt.PL.ETE   JttEDICJLJj 

MEDIC  ALT  BOTANY; 

OR,  A  DESCRIPTION  OF  ALL  THE  MORE  IMPORTANT  PLANTS  USED  IN  MEDICINE,  AND 
OF  THEIR  PROPERTIES,  USES,  AND  MODES  OF  ADMINISTRATION, 

BY  R.  EGLESFELD  GRIFFITH,  M.  D.,  &c.  &c. 
In  one  large  Svo.  vol.  of  704  pages,  handsomely  printed,  with  nearly  350  illustrations  on  wood. 

One  of  the  greatest  acquisitions  to  American  medical  literature.  It  should  by  all  means  be  introduced  at 
the  very  earliest  period,  into  our  medical  schools,  and  occupy  a  place  in  the  library  of  every  physician  in  the 
land.—  Southwestern  Medical  Advocate. 

Admirably  calculated  for  the  physician  and  student — we  have  seen  no  work  which  promises  greater  ad- 
vantages to  the  profession. — N.  O.  Medical  and  Surgical  Journal. 

One  of  the  few  books  which  supply  a  positive  deficiency  in  our  medical  literature.—  Western  Lancet. 

We  hope  the  day  is  not  distant  when  this  work  will  not  only  be  a  text-book  in  every  medical  school  and 
college  in  the  Union,  but  find  a  place  in  the  library  of  every  private  practitioner,— N.  Y.  Journ.  of  Medicine. 


ELLIS' S  MEDICAL  FORMULARY.— Improved  Edition. 

THE  MEDiCAlTFORMULARY: 

BEING  A   COLLECTION  OF  PBESCRIPTIONS,  DERIVED   FROM  THE  WRITINGS  AND  PRACTICE  OF  MANY   OF  THE  MOST 
EMINENT   PHYSICIANS   OF   AMERICA   AND   EUROPE. 

To  which  is  added  an  Appendix,  containing  the  usual  Dietetic  Preparations  and  Antidotes  for  Poisons. 

THE   WHOLE  ACCOMPANIED   WITH  A   FEW   BRIEF   PHARMACEUTIC   AND   MEDICAL    OBSERVATIONS. 

BY    BENJAMIN    ELLIS,    M .  D. 

NINTH  EDITION,  CORRECTED  AND   EXTENDED,   BY  SAMUEL  GEORGE  MORTON,   M.  D. 

In  one  neat  octavo  volume  of  268  pages. 


CARPENTER  ON  ALCOHOLIC  LIQUORS.— (A  New  Work.) 

A  Prize  Essay  on  the  Use  of  Alcoholic  Liquora  in  Health  and  Disease.     By  William  B.  Carpenter, 
M.  D.,  author  of  "  Principles  of  Human  Physiology,"  &c.     In  one  12mo.  volume. 


30  BLANCHARD  &  LEA'S  PUBLICATIONS.— (Chemistry.) 

KEW    AND   IMPROVED    EDITION— (lately  Issued.) 

ELEMENTARY  CHEMISTRY, 

THEORETICAL    AND    PRACTICAL. 

BY  GEORGE  FOWNES,  PH.  D., 

Chemical  Lecturer  in  the  Middlesex  Hospital  Medical  School,  &c.  &c. 

WITH   NUMEROUS   ILLUSTRATIONS. 
THIRD    AMERICAN,    FROM    A   LATE    LONDON    EDITION.      EDITED,   WITH   ADDITIONS, 

BY  EGBERT  BRIDGES,  M.  D., 

Professor  of  General  and  Pharmaceutical  Chemistry  in  the  Philadelphia  College  of  Pharmacy,  &c.  &c. 
In  one  large  royal  12mo.  vol.,  of  over  500  pages,  with  about  180  wood-cuts,  sheep  or  extra  cloth. 

At  the  time  of  his  death,  Professor  Fownes  had  just  completed  the  revision  of  this  work  for  his 
third  edition,  and,  at  his  request,  Dr.  H.  Bence  Jones  undertook  the  office  of  seeing  it  through  the 
press,  and  making  such  additions  in  the  department  of  Animal  Chemistry  as  were  rendered  neces- 
sary by  the  numerous  discoveries  daily  making  in  that  branch  of  the  science.  The  task  of  the 
American  editor,  therefore,  has  merely  been  to  add  such  new  matter  as  may  since  have  appeared, 
and  to  adapt  the  whole  to  the  wants  of  the  American  student,  by  appending  in  the  form  of  notes 
such  points  of  interest  as  would  be  calculated  to  retain  the  position  which  the  original  has  so  justly 
obtained,  and  to  maintain  it  on.;an  equality  with  the  rapid  advance  of  chemical  science.  It  will, 
therefore,  be  found  considerably  enlarged  and  greatly  improved.  Notwithstanding  its  increase  in 
size,  it  has  been  kept  at  its  former  extremely  low  price,  a*d  may  now  be  considered  as  one  of  the 

CHEAPEST  TEXT-BOOKS  ON  CHEMISTRY  NOW  EXTANT, 

The  work  of  Dr.  Fownes  has  long  been  before  the  public,  and  its  merits  have  been  fully  appreciated  as 
the  ht-st  text-book  on  Chemistry  now  in  existence.  We  do  not,  of  course,  place  it  in  a  rank  superior  to  the 
works  of  Erande,  Graham.  Turner,  Gregory,  or  Gmelin,  but  we  say  that,  as  a  work  for  students,  it  is  prefer- 
able lo  any  of  them.—  London  Jmirnal  of  Medicine. 

The  rapid  sale  of  this  Manual  evinces  us  adaptation  to  the  wants  of  the  student  of  chemistry,  whilst  the 
well  known  merits  of  its  lamented  author  have  constituted  a  guarantee  for  its  value,  as  a  faithful  exposition 
of  the  general  principles  and  most  important  facts  of  the  science  to  which  it  professes  to  be  aa  introduction. 

We  have  only  to  add,  that  Dr.  Bunce  Jones  appears  to  have  performed  his  editorial  ta>-k  most  thoroughly, 
the  want  of  the  author's  final  supervision  being  nowhere  discoverable.—  The  British  and  Foreign  Medico- 
Chirurti'ical  Review. 

A  work  well  adapted  to  the  wants  of  the  student.  It  is  an  excellent  exposition  of  the  chief  doctrines  and 
facts  of  modern  chemistry,  originally  intended  as  a  guide  to  the  lectures  of  the  author,  corrected  by  his  own 
hand  shortly  before  his  death  in  Ifc49  and  recently  revised  by  Dr.  Bence  Jones,  who  has  made  some  additions 
to  the  chapter  on  animal  chemistry.  Although  not  intended  to  supersede  the  more  extended  treatises  on 
chemistry,  Professor  Fownes'  Manual  may,  we  think,  be  often  used  as  a  work  of  reference,  even  by  those 
advanced  in  the  study,  who  may  be  desirous  of  refreshing  their  memory  on  some  forgotten  point.  The  size 
of  the  work,  and  still  more  the  condensed  yet  perspicuous  style  in  which  it  is  written,  absolve  it  from  the 
charges  very  properly  urged  against  most  manuals  termed  popular,  viz.,  of  omitting  details  of  indispensable 
importance,  of  avoiding  technical  difficulties,  instead  of  explaining  them,  and  of  treating  subjects  of  high  sci- 
entific interest  in  an  unscientific  way. — Edinburgh  Monthly  Journal  of  Medical  Science. 

BOWMAN'S  MEDICAL  CHEMISTRY- (Lately  Issued.) 

PRACTICAL  HANDBOOK  OF  MEDICAL  CHEMISTRY. 

BY  JOHN  E.  BOWMAN,  M.  D. 

In  one  neat  volume,  royal  12mo.,  with  numerous  illustrations. 

We  cannot  too  highly  commend  the  very  elaborate,  yet  clear  and  distinct  manner,  in  which  the  appear- 
ances of  these  fluids,  and  their  variations  111  disease,  are  described.  To  the  practitioner,  the  book  is  specially 
recommended,  as  giving  a  very  clear  account  of  many  chemical  matters,  which  must  be  ever  coming  before 
him  in  his  daily  practice.  Every  practitioner,  and  every  student  of  clinical  medicine,  should  endeavor  to 
enrich  his  collection  of  books  with  Mr.  Bowman's  little  volume. — London  Journal  of  Mtdicine. 

Mr.  Bowman  has  succeeded  in  supplying  a  desideratum  in  medical  literature.  In  the  little  volume  before 
us,  he  has  given  a  concise  but  comprehensive  account  of  all  matters  in  chemistry  which  the  man  in  practice 
may  desire  to  know. — Lancet. 

BY  TSHE  SAME  AUTHOR— (L,ately  Issued.) 
INTRODUCTION  TO  PRACTICAL  CHEKEISTRY,  Including  Analysis, 

With  Numerous  Illustrations.    In  one  neat  volume,  royal  12mo. 


GARDNER'S  MEDICAL  CHEMISTRY. 

MEDICAL    C~HEMISTRY, 

FOR    THE    USE    OF    STUDENTS    AND    THE    PROFESSION; 

BEING   A   MANUAL    OF  THE   SCIENCE.   WITH   ITS  APPLICATIONS   TO  TOXICOLOGY, 
PHYSIOLOGY,  THERAPEUTICS,  HYGIENE,  &c. 

BY  D.  PERELRA  GARDNER,  M.  D 

In  one  handsome  royal  12mo.  volume,  with  illustrations. 

t\Tew  Edition,  Preparing,— TEE  ELEMENTS  OP  CHEMISTRY. 

INCLUDING  THE   APPLICATION   Of   THK  SCIENCE   TO   THE   ARTS.      WITH  NUMEROUS   ILLUSTRATIONS. 

BY    THOMAS    GRAHAM,  F.   K.  S.,  L.   E.  &.  D. 

WITH  NOTES  AND  ADDITIONS   BY  ROBERT  BRIDGES,  M.  D.,  &c.  &c. 

SIMON'S  ANIMAL  CHEMISTRY,  with  Reference  to  the  Physiology  and  Pathology 
of  Man.    ByG.E.DAT.    One  vol.  8ve.,  700  pages 


BLANCHARD  &  LEA'S  PUBLICATIONS.  31 


MEDICAL   JURIS  JPJR  UDEJTCE. 

MEDICAL     JURISPRUDENCE. 

BY  ALFRED  S.  TAYLOR, 

SECOND   AMERICAN,   FROM  THE   THIRD   AND    ENLARGED    LONDON    EDITION. 
With  numerous  Notes  and  Additions,  and  References  to  American  Practice  and  Law. 

BY  R.  E.  GRIFFITH,  M.  D. 

In  one  large  octavo  volume. 

This  work  has  been  much  enlarged  by  the  author,  and  may  now  be  considered  as  the  standard 
authority  on  the  subject,  both  in   England   and   this  country.     It  has  been  thoroughly  revised,  in 


this  edition,  and  completely  brought  up  to  the  day  with  reference  to  the  most  recent  investigations 

further  evidence  of  its  popularity  is 
short,  time  that  has  elapsed  since  it  originally  appeared,  passed  to  three  editions  in  England,  and 


and  decisions.     No  further  evidence  of  its  popularity  is  needed  than  the  fact  of  its  having,  in  the 


two  in  the  United  States. 

We  recommend  M  r.  Tay  lor's  work  as  the  ablest,  most  comprehensive,  and,  above  all,  the  most  practically 
useful  book  which  exists  on  the  subject  of  legal  medicine.  Any  man  of  sound  judgment,  who  ha?  mastered 
the  contems  of  Taylor's  "Medical  Jurisprudence,"  may  go  inlo  a  court  of  law  wan  the  most  perfect  confi- 
dence of  being  able  to  acquit  himself  creditably.—  Medico-  Chirurgical  Review. 

The  most  elaborate  and  complete  work  that  has  yet  appeared.  It  contains  an  immense  quantity  of  cases 
lately  tried,  which  entitle  it  to  be  considered  what  Beck  was  in  its  day.  —  Dublin  Medical  Journal. 

TAYLOR    ON    POISONS. 

ON    POl  S  O  MTS, 

IN  RELATION  TO  MEDICAL  JURISPRUDENCE  AND  MEDICINE, 

BY  ALFRED  S.  TAYLOR,  F.  R.  S.,  &c. 

EDITED,  WITH  NOTES  AND  ADDITIONS,  BY  R.  E.  GRIFFITH,  M.  D. 

In  one  large  octavo  volume,  of  688  pages. 

The  most  elaborate  work  on  the  subject  that  our  literature  possesses.—  Brit,  and  For.Medico-Chirur  Review. 
One  of  the  most  practical  and  trustworthy  works  on  Poisons  in  our  language.  —  Western  Journal  of  Med. 
It  coniains  a  vast  body  of  facts,  which  embrace  ail  that  is  important  in  lexicology,  all  that  is  necessary  to 
tie  guidance  of  the  medical  jurist,  and  all  that  can  be  desired  by  the  lawyer.  —  Medico-  Chirurgical  Review. 

It  is,  so  far  as  our  knowledge  extends,  incomparably  the  be^t  upon  the  subject  ;  in  the  highesi  decree  credit- 
able to  the  author,  entirely  trustworthy,  and  indispensable  to  the  student  and  practitioner.—  N.  Y.  Annalist. 


BEAI.S   ON    HEALTH-NQW 

THS  LAWS  OF  HEALTH  IN  RELATION  TO  MIND  AID  BODY. 

A    SERIES    OF    LETTERS    FROM    AN    OLD    PRACTITIONER    TO    A    PATIENT. 

BY  LIONEL  JOHN  BEALE,   M.  R.  C.  S..,  &c. 

In  one  handsome  volume,  royal  I2mo.,  extra  cloth. 

The  "Laws  of  Health,"  in  relation  to  mind  and  body,  is  a  book  which  will  convey  much  instruction  to 
non-pro'es?i  nal  readers;  they  may,  from  these  letters,  glean  the  principles  upon  which  young  persons 
should  be  educated  and  derive  much  useful  information,  which  will  apply  to  the  preservation  of  health  at 
all  ages.—  Med.  Times. 

GREGORY  ON  ANIMAL  MAGNETISM  -(Now  Ready.) 

LETTERS    TO    A   CANDID    ENQUIRER 

ON    ANIMAL    MAGNETISE, 

DESCRIPTION  AND  ANALYSIS  OF  THE  PHENOMENA,    DETAILS  OF  FACTS  AND  CASES, 
BY  WILLIAM  GREGORY,  M.  D.,  F.  R.  S.  E., 

Professor  of  Chemistry  in  the  University  of  Edinburgh,  &c. 
In  one  neat  volume,  royal  12mo.,  extra  cloth. 


TRANSACTIONS    OF    THE 

AMERICAN   MEDICAL   ASSOCIATION, 

VOLUME  I.  FOR  1848,  VOL.  II.  FOR  1849,  VOL.  IIL  FOR  1850. 

Large  octavo,  extra  cloth,  or  paper  covers  for  mailing. 
Any  volume  sold  separate,  or  the  whole  in  sets  at  a  reduced  price* 

$5"  Orders  Cor  the  supply  of  Medical  Societies  should  be  sent  direct  to  the  Treasurer  of  the  As- 
sociation, Isaac  Hays,  M.  D.,  care  of  Blanchard  &  Lea,  with  the  amount  enclosed. 

DUNGLISON  ON  HUMAN  HEALTH —HUMAN  HE  ALTH.orthe  Influence  of  Atmosphere  and  Locality, 
Change  of  Air  mid  Climate,  Seasons.  Food,  Clothing,  Bathing,  Exercise.  Sleep,  &c.  &c.  &.C..  on  healthy 
man;  ooiigmutmg  Elements  of  Hygiene.  Second  edition,  with  many  modifications  and  additions.  By 
Rooky  DungiUon.  M.  D  .  &c.  Sec..  In  one  ociuvo  volume  of  464  pages. 

DUNGUSON'S  MEDICAL  *TU  DEN  I'.— The  Medical  Student.,  or  Aids  to  the  Study  of  Medicine.  Revised 
and  Modified  Edition  1  vol.  roval  l'2mo  .  extra  cloth  312  pp. 

BARTLKTT»!»  PrIILOSOPHV  OF  MEDICINE— An  Essay  on  the  Philosophy  of  Medical  Science.  In 
one  handsome  8vo  volume  312  pp. 

BARlLErl'  ON  CERTAINTY  IN  MEDICINE— An  Inquiry  into  the  Degree  of  Certainty  in  Medicine, 
and  into  the  Nature  and  Exienl  of  its  Power  over  Disease.  In  one  vol.  royal  12rao.  84  pp. 


32  BLANCHARD  &  LEA'S  PUBLICATIONS. 

THE  GREAT  AMERICAN    MEDICAL    DICTIONARY. 

New  aiid  Enlarged  Edition,  brought  up  to  October,  1851. 

NOW    READY. 

MEDICAL  "LEXICON ; 

A    DICTIONARY    OF    MEDICAL    SCIENCE, 

Containing  a  Concise  Explanation  of  the  various  Subjects  and  Terms  of 

PHYSIOLOGY,   PATHOLOGY,   HYGIENE,  THERAPEUTICS,   PHARMACOLOGY,  OB- 
STETRICS, MEDICAL  JURISPRUDENCE,  &c. 

WITSI  THE  FRENCH  AtfD  OTHER  SYWOJVYMES. 

NOTICES    OF   CLIMATE    AND    OP    CELEBRATED    MINERAL   WATERS; 
Formulae  for  various  Officinal,  Empirical,  and  Dietetic  Preparations,  &c. 

BY  ROBLEY  DUNGLISON,  M.  D., 

Professor  of  Institutes  of  Medicine,  &c.,  in  Jefferson  Medical  College,  Philadelphia,  &c. 

EIGHTH  EDITION, 

REVISED  AND  GREATLY  ENLARGED. 

In  one  very  thick  8vo.  vol.,  of  927  large  double-columned  pages,  strongly  bound,  with  raised  bands. 

Every  successive  edition  of  this  work  bears  the  marks  of  the  industry  of  the  author,  and  of  his  determina-^ 
lion  to  keep  it  fully  on  a  level  with  the  most  advanced  state  of  medical  science.  Thus  the  last  two  editions 
contained  about  NINE  THOUSAND  SUBJECS  AND  TERMS  not  comprised  in  the  one  immediately  preceding,  and  the 
present  has  not  less  than  roua  THOUSAND  not  in  any  former  edition.  As  a  complete  Medical  Dictionary; 
therefore,  embracing  over  FIFTY  THOUSAND  definitions^  in  all  the  branches  of  the  science,  it  is  presented  as 
meriting  a  continuance  of  the  great  favor  and  popularity  which  have  carried  it,  within  no  very  long  space  of 
time,  to  an  eighth  edition. 

Every  precaution  has  been  taken  in  the  preparation  of  the  present  volume,  to  render  its  mechanical  exe- 
cution and  typographical  accuracy  worthy  of  its  extended  reputation  and  universal  use.  The  very  exten- 
sive additions  have  been  accommodated,  without  materially  increasing  the  bulk  of  the  volume,  by  the  employ- 
ment of  a  small  but  exceedingly  clear  type,  cast  for  this  purpose.  The  press  has  been  watched  with  great 
care,  and  every  effort  used  to  insure  the  verbal  accuracy  so  necessary  to  a  work  of  this  nature.  The  whole 
is  printed  on  fine  white  paper;  and  while  thus  exhibiting  in  every  respect  so  great  an  improvement  over 
former  issues,  it  is  presented  at  the  original  exceedingly  low  price. 

A  few  notices  of  former  editions  are  subjoined. 

Dr.  Dunglison's  Lexicon  has  the  rare  merit  that  it  certainly  has  no  rival  in  the  English  language  for  ac- 
curacy and  extent  of  references.  The  terms  generally  include  short  physiological  and  pathological  des- 
criptions, so  that,  as  the  author  justly  observes,  the  reader  does  not  possess  in  this  work  a  mere  dictionary, 
but  a  book,  which,  while  it  instructs  him  in  medical  etymology,  furnishes  him  with  a  large  amount  of  useful 
information.  That  we  are  not  over-estimating  the  merits  of  this  publication,  is  proved  by  the  fact  that  we 
have  now  before  us  the  seventh  edition.  This,  at  any  rate,  shows  that  the  author's  labors  have  been  pro- 
perly appreciated  by  his  own  countrymen  ;  and  we  can  only  confirm  their  judgment,  by  recommending  this 
most  useful  volume  to  the  notice  of  our  cisatlantic  readers.  No  medical  library  will  be  complete  without  it. 
—  The  London  Med.  Gazette. 

It  is  certainly  more  complete  and  comprehensive  than  any  with  which  we  are  acquainted  in  the  English 
language.  Few,  in  fact,  could  be  found  better  qualified  than  Dr.  Dunglison  for  the  production  of  such  a  work. 
Learned,  industrious,  persevering,  and  accurate,  he  brings  to  the  task  all  the  peculiar  talents  necessary  for 
its  successful  performance  :  while,  at  the  same  time,  his  familiarity  with  the  writings  of  the  ancient  and 
modern  "  masters  of  our  art,"  renders  him  skilful  to  note  the  exact  usage  of  the  several  terms  of  science,  and 
the  various  modifications  which  medical  terminology  has  undergone  with  the  change  of  theories  or  the  pro- 
gress of  improvement. — American  Journal  of  the  Medical  Sciences. 

One  of  the  most  complete  and  copious  known  to  the  cultivators  of  medical  science. — Boston  Med.  Journal. 

This  most  complete  Medical  Lexicon—certainly  one  of  the  best  works  of  the  kind  in  the  language.— 
Charleston  Medical  Journal. 

The  most  complete  Medical  Dictionary  in  the  English  language.—  Western  Lancet. 

Dr.  Dunglison's  Dictionary  has  not  its  superior,  if  indeed  its  equal,  in  the  English  language.— St.  Louis 
Med.  and  Siirg.  Journal. 

Familiar  with  nearly  all  the  medical  dictionaries  now  in  print,  we  consider  the  one  before  us  the  most 
complete,  and  an  indispensable  adjunct  to  every  medical  library. — British  American  Medical  Journal. 

Admitted  by  all  good  judges,  both  in  this  country  and  in  Europe,  to  be  equal,  and  in  many  respects  superior 
to  any  other  work  of  the  kind  yet  published. — Northwestern  Medical  and  Surgical  Journal. 

We  repeat  our  former  declaration  that  this  is  the  best  Medical  Dictionary  in  the  English  language.— 
Western  Lancet. 

We  have  no  hesitation  to  pronounce  it  the  very  best  Medical  Dictionary  now  extant. — Southern  Medical 
and  Surgical  Journal. 

The  most  comprehensive  and  best  English  Dictionary  of  medical  terms  extant. — Buffalo  Med.  Journal. 

Whence  the  terms  have  all  been  derived  we  find  it  rather  difficult  to  imagine.  We  can  only  say  that, 
after  looking  for  every  new  and  strange  word  we  could  think  of,  we  have  not  been  disappointed  in  regard  to 
more  than  a  few  of  most  recent  introduction,  such  as  the  designations  given  by  Professor  Owen  to  the  com- 
ponent, part?  of  a  Vertebra. — British  and  Foreign  Medico- Chirurgical  Review. 

Dr.  Dunglisou's  masterpiece  of  literary  labor.— N.  Y.  Journal  of  Medicine. 

>  ~C6 

HOBLYN'S   MEDICAL   DICTIONARY. 

A  DICTIONARY  OF  THE  TERMS  USED  IN  MEDICINE 

AND    THE   COLLATERAL    SCIENCES. 
BY  RICHARD   D.    HOBLYN,  A.  M.,  OXON. 

REVISED,  WITH  NUMEROUS  ADDITIONS,  FROM  THE  SECOND  LONDON  EDITION, 
BY  ISAAC  HAYS,  M.  D.,  &c.    In  one  large  royal  12mo.  volume  of  402  pages,  double  columns. 
We  cannot  too  strongly  recommend  this  small  and  cheap  volume  to  the  library  of  every  student  and  prac- 
titioner.— Medico- Chirurgical  Review. 


DATE   DUE   SLIP 

UNIVERSITY  OF  CALIFORNIA  MEDICAL  SCHOOL  LIBRARY 

THIS  BOOK   IS   DUE    ON   THE  LAST  DATE 
STAMPED  BELOW 


ljw-4,'29 


• 


i-8,'29 


1348S 


